Patent Publication Number: US-2012041378-A1

Title: Catheter anchoring system

Description:
RELATED CASES  
     This is a continuation of copending application Ser. No. 11/837,442 filed Aug. 10, 2007, which is a continuation of application Ser. No. 10/996,870 filed Nov. 23, 2004, now U.S. Pat. No. 7,887,515 issued on Feb. 15, 2011, which is a divisional of application Ser. No. 10/096,088 filed Mar. 11, 2002, now U.S. Pat. No. 6,827,705 issued on Dec. 7, 2004, which is a continuation of application Ser. No. 09/165,367 filed Oct. 2, 1998, now U.S. Pat. No. 6,837,875 issued on Jan. 4, 2005, which is a continuation-in-part of application Ser. No. 09/069,029 filed Apr. 27, 1998, now U.S. Pat. No. 6,290,676 issued on Sep. 18, 2001, all of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to a percutaneous catheterization system, and, in particular, to a catheter anchoring system which securely interconnects an indwelling catheter with a tubing and securely anchors such interconnection to a patient&#39;s skin. 
     2. Description of Related Art 
     Medical treatment of patients commonly involves the use of percutaneously inserted catheters to direct fluids directly into the bloodstream, a specific organ or an internal location of the patient, or to monitor vital functions of the patient. For instance, intra-arteriosus catheters are commonly used to direct fluids and/or medication directly into the bloodstream of the patient. Epidural catheters are commonly used to direct anesthesia into an epidural space to anesthetize a specific location of the patient. Intervascular catheters are commonly used to monitor arterial blood pressure. 
     The fluid (e.g., parenteral liquid, medication or anesthesia) typically drains from a container positioned above the patient. The fluid flows through tubing and into an indwelling catheter. The catheter and fluid tubing are commonly removably attached by a conventional lure-type connector, such as the type described in U.S. Pat. No. 4,224,937. 
     In common practice, a health care provider, such as, for example, a nurse or doctor (for ease of description, as used herein the term “nurse” will refer to health care providers generally and will not be restrictive in meaning), uses adhesive or surgical tape to maintain the catheter in place on the skin of the patient. The connection between the tubing and the catheter is likewise maintained by use of tape. 
     The nurse may also form a safety loop in the tubing so that any tension applied to the tubing does not directly pass to the catheter cannula, but rather is absorbed by the slack of the safety loop. The nurse typically loosely tapes the loop to the skin of the patient. 
     This entire taping procedure takes several minutes of the valuable time of the health care provider. Furthermore, nurses commonly remove their gloves when taping because most nurse find such taping procedures difficult and cumbersome when wearing gloves. 
     The catheterization process often requires frequent disconnection between the catheter and the fluid supply tube. For instance, intravenous catheterization is frequently maintained for several days, depending upon the condition of the patient. The catheter tubing is generally replaced every 24 to 48 hours in order to maintain the sterility of the fluid and the free-flow of the fluid through the tubing. A nurse must thus frequently change the tubing and retape the connection. Moreover, the tape, which secures the catheter to the skin of the patient, often covers the cannula insertion point. The nurse must remove the tape to inspect the insertion point for inflammation or infection, and must then repeat the above-described taping procedure. 
     A great deal of valuable time is thus used in applying significant amounts of surgical tape to indwelling catheters. The frequent application and removal of surgical tape also commonly results in the excoriation of the skin of the patient in the area of the insertion. 
     A number of catheterization systems have recently been developed which improve the stabilization of the catheter system and obviate the need for frequent application and removal of surgical tape. One such system is disclosed by U.S. Pat. No. 5,192,273 issued to the present Applicant, which is hereby incorporated by reference. 
     The &#39;273 patent discloses an adaptor which interconnects the catheter with a fluid supply tubing. The adaptor snaps into a base attached to the patient&#39;s skin by an adhesive pad. Specifically, a nurse presses the adaptor between upstanding legs of the base. Detents on the adaptor legs slide into corresponding annular grooves in the adaptor body to hold the adaptor to the base. 
     Although the base holds the adaptor securely in place, a nurse may have difficulty positioning and aligning the annular grooves of the adaptor with the detents on the base. Exigent circumstances may further exacerbate the difficulties associated with properly positioning the adaptor onto the base. Some nurses and other health care providers may also have trouble determining how to engage the catheter adaptor with the base. 
     SUMMARY OF THE INVENTION 
     The catheter anchoring system of the present invention provides an adaptor retainer which is not position or technique sensitive. That is, the nurse simply locates the catheter adaptor generally above the retainer, and presses the adaptor into the retainer. Engagement requires only coarse alignment of the adaptor with the retainer. 
     In accordance with one aspect of the present invention, an anchoring system is provided for use with a catheter having an adaptor with at least one recess. A retainer is provided to receive the adaptor. The retainer includes a channel that extends through the retainer about a longitudinal axis. The channel is configured to receive at least a portion of the adaptor in a snap-fit manner. At least one projection on the retainer extends into the channel in a direction generally normal to the longitudinal axis. The projection has a longitudinal length so dimensioned to substantially equal the longitudinal length of the recess of the adaptor. The cooperation between the projection of the retainer and the recess of the adaptor inhibit longitudinal movement of the adaptor relative to the retainer. 
     In accordance with another aspect of the present invention, an anchoring system is provided for use with a catheter having an adaptor with a recess. The retainer includes a channel that extends through the retainer about a longitudinal axis. The channel is configured to receive at least a portion of the adaptor in a snap-fit manner. At least one projection on the retainer extends into the channel in a direction generally normal to the longitudinal axis. The projection has a longitudinal length so dimensioned to substantially equal the longitudinal length of the recess of the adaptor. The cooperation between the projection of the retainer and the recess of the adaptor inhibit longitudinal movement of the adaptor relative to the retainer. 
     In accordance with yet another aspect of the present invention, an anchoring system is provided for use with a catheter having an adaptor with a radially extending member that projects from the fitting. The anchoring system comprises a retainer that includes first and second channel portions. The channel portions extend about a longitudinal axis, and each is configured to receive a corresponding portion of the catheter fitting. A plurality of lateral slots are positioned between the channel portions. Each lateral slot is dimensioned so as to receive the radially extending member of the catheter fitting to prevent the catheter from moving in a longitudinal direction. The lateral slots are also arranged next to each other along the longitudinal axis so as to provide multiple positions in the longitudinal direction in which to insert the radially extending member of the catheter fitting when positioning the catheter fitting within the retainer. 
     Another aspect of the present invention involves a catheterization system includes a catheter and a retainer to secure the catheter to a patient. The catheter includes a fitting with a radially extending member that projects from the fitting. The retainer includes first and second channel portions that extend about a longitudinal axis. Each channel portion generally has a truncated cross-sectional shape with an opening along the longitudinal axis. Each channel is also sized to surround at least a portion of the fitting through an arc of greater than 180° about the longitudinal axis. At least one lateral slot of the retainer extends generally perpendicular to the longitudinal axis and lies between the first and second channel portions. The slot has a longitudinal length so dimensioned to substantially equal the thickness of the radially extending member of catheter fitting and to be generally less than the combined longitudinal lengths of the first and second channel portions. This dimensional relationship between the channel portions and the slot provides lateral stability of the catheter fitting when the radially extending member is positioned within the lateral slot of the retainer. 
     In accordance with a further aspect of the present invention, a catheter anchoring system comprises a catheter adaptor, a retainer and a base pad which adheres to the skin of a patient and supports the retainer. The catheter adaptor comprises a tubular body connected to a radially extending support arm. The support arm in turn connects to a clip which pivots relative to the tubular body. 
     The retainer comprises a pair of opposing longitudinal walls. Each wall defines a series of slots. Each slot is sized such that a portion of the support arm of the catheter adaptor extends through the slot. The slot prevents the support arm from moving in a direction generally parallel to a longitudinal direction of the retainer. 
     The retainer further comprises a central channel which extends through the retainer about an axis which is generally parallel to the longitudinal axis. The channel is interposed between the opposing longitudinal walls and has a truncated circular cross-sectional shape. The central channel, in cross-section, is sized to encompass the tubular body through an angle greater than about 180N. 
     The anchoring system may additionally comprise a tube clip configured to receive a portion of the tube. The anchoring system may also comprise an S-clip having a plurality of retainers to secure a microbore tubing connected to the tube by the adaptor. 
     An additional aspect of the present invention provides a catheter anchoring system for securing an indwelling catheter within a body lumen of a patient and for securely interconnecting the indwelling catheter with a tube. The catheter anchoring system comprises a catheter adapter having a generally tubular body defined between distal and proximal ends. The distal end is configured to engage the catheter proximal end and the proximal end is configured to couple to a distal end of the supply tube. The catheter adapter additionally comprises a radially extending member which projects from an exterior surface of the tubular body in a radial direction. 
     A retainer of the catheter anchoring system comprises a longitudinal channel configured to receive the tubular body of the adapter in a snap fit manner. The retainer additionally comprises a plurality of lateral slots or projections which are sized to receive and to capture the radially extending member of the adapter with the adapter positioned within the channel The slots can be formed in a variety of ways, such as by laterally arranging a plurality of gaps next to each other and through the opposing longitudinal walls of the retainer. The projections can similarly be formed in a variety of ways, such as by laterally arranging a plurality of projections next to each other from the opposing longitudinal walls of the retainer and projecting the projections into the channel. 
     The retainer prevents the adapter from sliding in a longitudinal direction when one of the slots. 
     In a preferred embodiment, the radially extending member comprises a support arm which connects a clip to the tubular body. In an alternative preferred embodiment, the radially extending member comprises an annular collar which circumscribes the tubular body. 
     In accordance with a preferred method of anchoring an indwelling catheter/tube interconnection to a patient, an adapter is provided having a generally tubular body with a recess. An anchor pad is also provided with an adhesive back. The anchor pad supports a retainer configured to receive the adapter and has a series of lateral projections. The anchor pad is attached to the patient&#39;s skin proximate to an indwelling catheter. The recess of the adapter is positioned above the series of projections. The retainer is deflected so as to open the channel to a size sufficient to receive the adapter, and the adapter is inserted into the channel. The recess is inserted around at least a portion of one of the projections. The retainer is then permitted to spring back to an undeflected position such that the tubular body is captured within the retainer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of the invention will now be described with reference to the drawings of preferred embodiments which are intended to illustrate and not to limit the invention, and in which: 
         FIG. 1  is a perspective view of a catheter anchoring system in accordance with a preferred embodiment of the present invention, mounted on the back of a patient&#39;s hand; 
         FIG. 2  is a top plan view of the catheter anchoring system of  FIG. 1 ; 
         FIG. 3  is a top plan view of a retainer of the catheter anchoring system of  FIG. 2 ; 
         FIG. 4   a  is a front elevational view of the retainer of  FIG. 3 ; 
         FIG. 4   b  is a rear elevational view of the retainer of  FIG. 3 ; 
         FIG. 5  is a side elevational view of the retainer of  FIG. 3 ; 
         FIG. 6  is a top plan view of a catheter anchoring system in accordance with another preferred embodiment of the present invention; 
         FIG. 7   a  is a front elevational view of a retainer and rail assembly of the catheter anchoring system of  FIG. 6 ; 
         FIG. 7   b  is a side elevational view of the retainer and rail assembly of  FIG. 6 ; 
         FIG. 8  is a cross-sectional view of the retainer and rail assembly taken along line  8 - 8  of  FIG. 7   a;    
         FIG. 9  is a top plan view of a catheter anchoring system in accordance with an additional preferred embodiment of the present invention; 
         FIG. 10  is a side elevational view of an S-clip of the catheter anchoring system of  FIG. 9  taken along line  10 - 10 ; 
         FIG. 11  is a top perspective view of a catheter anchoring system in accordance with an additional preferred embodiment of the present invention; 
         FIG. 12  is a top plan view of the catheter anchoring system of  FIG. 11  illustrating an adaptor held by a retainer; 
         FIG. 13   a  is a side elevational view of the retainer of  FIG. 12 ; 
         FIG. 13   b  is a top plan view of the retainer of  FIG. 12 ; 
         FIG. 14  is a partially sectioned perspective view of an alternative embodiment of a catheter adaptor which may be used with the anchoring system of  FIG. 11 ; 
         FIG. 15   a  is side elevational view of a catheterization system in accordance with another preferred embodiment of the present invention with a retainer of the catheterization system shown in cross-section; 
         FIG. 15   b  is a top plan view of the retainer of  FIG. 15   a  as viewed in the direction of arrows  15   b - 15   b;    
         FIG. 15   c  is a front end elevational view of the retainer of  FIG. 15   a  as viewed in the direction of arrows  15   c - 15   c;  and 
         FIG. 16  is a perspective view of a catheterization system configured in accordance with another embodiment of the present invention, and illustrates a catheter in a position separate from a retainer of the catheterization system; 
         FIG. 17  is a perspective view of a catheterization system configured in accordance with another embodiment of the present invention, and illustrates the a catheter adaptor having a plurality of radial recesses and a retainer having a plurality of projections that cooperate with the recesses when the retainer receives the catheter adaptor; and 
         FIG. 18  is a perspective view of the catheterization system configured in accordance with an additional embodiment of the present invention, and illustrates the catheter adaptor having a plurality of radial recesses and a retainer having a plurality of projections that extend into a channel having a tapered diameter. 
     
    
    
     DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS  
       FIG. 1  illustrates in perspective view a catheter anchoring system  10  in accordance with the present invention. The anchoring system  10  securely connects a tube  12  (e.g., a fluid supply tube) to an indwelling catheter  14  and maintains the catheter  14  in the desired indwelling position. The anchoring system  10  is designed for rapid attachment to the catheter  14  and to the patient, without requiring precise alignment or positioning of the components of the anchoring system  10 . 
     Moreover, sturdy anchoring of the catheterization system is achieved without the use of surgical tape. For most catheterization, the anchoring system is attached to the patient only once. Although the fluid supply tubing  12  may be replaced every 24 to 48 hours for intravenous catheterization, the components of the anchoring system  10  attached to the patient remains in place. Thus, surgical tape need not be applied and removed from the patient&#39;s skin on multiple occasions. 
     The catheter anchoring system  10  principally comprises a flexible pad  16  having an adhesive bottom side  18  which attaches to the skin of a patient when used. The pad  16  supports a retainer  20 . The retainer  20  is configured to receive and secure in place a catheter adaptor  22  which interconnects the hub  30  of an indwelling catheter  14  and the fluid supply tube  12  connected to a fluid supply container (not shown). The container maintains the fluid to be dispensed to the patient which is fed either by gravity or by pressure. A clamp (not shown) may be used to regulate the fluid flow through the tubing  12 . The pad  16  may also support a tubing clip  24  which is used to retain a portion of tubing  12 . 
     Although  FIG. 1  illustrates the catheter anchoring system located on the back of a patient&#39;s hand (illustrated in phantom lines), it is contemplated that the present invention may be used for catheterization in other locations on the patient&#39;s body. For instance, the anchoring system may be used on the medial side of the wrist in connection with a radial artery. The anchoring system  10  may also be used for epidural catheterization, as discussed in detail below, and thus located on the anterior or posterior of the patient&#39;s torso. 
       FIG. 1  illustrates a longitudinal axis, a transverse axis and a lateral axis in relation to the catheter anchoring system  10  to facilitate the following description. Additionally, as used herein, “the longitudinal direction” refers to a direction substantially parallel to the longitudinal axis. “The lateral direction” and “the transverse direction” are in reference to the lateral axis and transverse axis, respectively. Also, “proximal” and “distal” are in reference to the proximity of the fluid supply container attached to the tube  12  (see  FIG. 1 ). The individual components of the catheter anchoring system  10  will now be described in detail. 
     Catheter Adaptor 
       FIG. 1  illustrates the catheter adaptor  22  interconnected with a catheter  14 .  FIG. 2  illustrates the catheter adaptor  22  disconnected from catheter  14 . Although these figures illustrate the adaptor  22  as the type disclosed in U.S. Pat. No. 5,193,273, it is contemplated that other types of adaptors can be used as well with the present catheter anchoring system  10 . For instance, the catheter adaptor  22  could be a lure-type adaptor, such as the type illustrated by  FIG. 11  and described below, or a lure-lock type catheter adaptor  22 , such as the type illustrated by  FIG. 14  and described below. It is contemplated that those skilled in the art could readily select the type of catheter adaptor  22  to be used with the present catheter anchoring system  10  depending on the particular application (e.g., venous, arterial, epidural, peripheral, etc.) of the anchoring system  10 . 
     As best seen in  FIG. 2 , the adaptor  22  comprises a tubular body  25  defined between a distal end  26  and a proximal end  28 . The proximal end  28  is adapted to receive a distal end of the tube  12 . In an exemplary embodiment, at least a portion the fluid supply tube is permanently attached to the body proximal end  28 . As shown in  FIG. 2 , the proximal end of the tubing may then include a standard lure-type connector  29  to connect into a fluid supply line  12 . 
     The distal end  26  is configured to engage the proximal hub  30  of the catheter  14  (see  FIG. 1 ) or any lure-type connector. Although  FIG. 2  illustrates the distal end of the adaptor  22  as having a frusto-conical shape configured to engage a standard lure-type catheter hub  30 , it is contemplated that the distal end  26  could be configured as well to engage other types of catheter connectors, such as, for example, a Toughy-Bourst adaptor. 
     A support arm  32  extends outwardly from the tubular body  25  in cantilever fashion. The support arm  32  supports, on a radially outer end of the arm  32 , a clip support element (not shown) that extends generally parallel to and is spaced from a longitudinal axis of the tubular body  25 . 
       FIG. 2  further illustrates a clip  34  of the catheter adaptor. The clip  34  attaches to and slides over the clip support element in the longitudinal direction. The clip  34  includes a distal latch  36  which has a generally forked shape to engage a outer surface of the catheter hub  30  distal of a hub collar  38  (see  FIG. 1 ) to securely attach the adaptor  22  to the catheter hub  30 . 
     Interengaging structure (not shown) between the clip support element and the clip  34  permits the clip  34  to slide in the proximal direction, but prevents the clip  34  from sliding in the distal direction. The interengaging element desirably comprises a series of ratchet teeth (not shown) disposed up on upper surface of the clip support element and a pawl (not shown) connected to the clip  34 . The pawl extends from the clip  34  in a cantilever fashion and engages the ratchet teeth to prevent distal movement of the clip, as discussed in detail in U.S. Pat. No. 5,193,273, which has been incorporated by reference. 
     The tubular body  25 , the support arm  32  and the clip support element are preferably integrally formed of molded plastic, such as, for example, a clear polycarbonate, so as to be generally stiff, but somewhat flexible. The support arm  32  desirably has enough elasticity to bend. Depressing the proximal end of the clip  34  towards the tubular body  25  moves the latch  36  of the clip  34  away from the tubular body  25 . In this manner, the clip  34  pivots about the tubular body  25 . 
     With reference again to  FIG. 2 , the clip support element desirably comprises a protuberance  40  positioned on an inner surface  42  of the clip support element, proximate to the proximal end of the clip  34 . The protuberance is spaced from the support arm by a distance L. The protuberance  40  prevents the clip  34  from pivoting when secured by the retainer  20 , as discussed below in detail. The protuberance  40  also limits the degree of deflection of the support arm  32  to reduce fatigue, as fully explained in U.S. Pat. No. 5,193,273, which has been incorporated by reference. 
     Retainer for Catheter Adaptor 
       FIGS. 3 through 5  illustrate the retainer  20 . The retainer  20  has a generally parallelepiped shape defining a central channel  44  interposed between a pair of opposing longitudinal walls  46 . The central channel  44  extends through the retainer  20  along an axis which is generally parallel to the longitudinal axis of the retainer. 
     As best seen in  FIG. 4 , the central channel  44  has a generally circular cross-sectional shape which is truncated at a upper end to form a generally U-shaped channel having an upper opening  47 . The central channel  44  has a diameter sized to receive the tubular body  25  of the catheter adaptor  22 . In a preferred embodiment, the diameter of the central channel  44  generally matches that of the tubular body  25  or is slightly larger. 
     In cross-section, the central channel  44  extends through an arc greater than 180N about the channel axis such that the transverse length of the opening  47  is less than the diameter of the central channel  44 . In an exemplary embodiment, the central channel  44  extends through an arc of about 200N about the channel axis. 
       FIG. 5  illustrates the channel axis which is desirably skewed relative to a base surface  48  of the retainer  20 . An incident angle e formed between the base surface  48  and the channel axis is less than 45N. The incident angle e desirably ranges between 0N and 30N. In an exemplary embodiment for intravenous use, the angle e preferably equals approximately 7N. In another exemplary embodiment for arterial use, the incident angle θ preferably equals about 22N. In a further exemplary embodiment, for peripherally inserted central catheters (PICC), the incident angle θ preferably equals 0N. 
     The longitudinal walls  46  are substantially identical. Each wall  46  has a thickness measured in the lateral direction less than the length of the support arm  32 . The wall  46  is thus interposed between the tubular body  25  and the clip  34  when the tubular body  25  is inserted into the central channel  44 . The length of each wall  46 , measured in the longitudinal direction, is preferably coextensive with the length of the retainer  20 . 
     Each wall  46  comprises a uniform series of slots  50 . The series comprises at least two (2) slots  50 , and not more than twenty (20) slots  50 . More preferably, the series comprises less than seven (7) slots  50 . In an exemplary embodiment, as illustrated in the figures of the application, the series comprises four (4) slots  50 . 
     Each slot  50  is sized to receive the support arm  32  of the catheter adaptor  22  to prevent longitudinal displacement of the adaptor  22 , as discussed in detail below. Each slot  50  desirably has a rectangular shape. As seen in  FIG. 3 , the slots  50  extend from an exterior surface  52  through the wall  44 , and open into the central channel  44 . The width of each slot  50  (measured longitudinally) is desirably slightly greater than the width of the support arm  32 , measured in the longitudinal direction to receive the support arm  32 , as discussed below. 
     As illustrated by  FIG. 5 , each slot  50  has a height as measured in the transverse direction between an upper edge  54  of the longitudinal wall  46  and the bottom  56  of the central channel  44 . The height of the slot  50  desirably equals approximately the width of the support arm  32  such that the support arm  32  does not protrude from the retainer  20  in the transverse direction. 
     The spacing S between the slots  50 , on center, desirably equals about half the distance L (see  FIG. 2 ) between the support arm  32  and the protuberance  40  of the catheter adaptor  22 . 
     As  FIG. 3  illustrates, a distance X between the most distal slot  50  and the distal end of the retainer  20  is less than the longitudinal distance Y (see  FIG. 2 ) between the support arm  32  and the latch  36  positioned in its most proximal position. This spacing enables the support arm  32  to rest in the most distal slot  50  with the latch  36  retaining a catheter hub  30  distal of the retainer distal end. 
       FIG. 5  illustrates the upper edge  50  of the longitudinal wall  46  which comprises a series of chamfers  58 , each of which slopes into a slot  50 . That is, the portion of upper edge  50  of the longitudinal wall  46  which surrounds a slot  50  includes a pair of chamfers  58 , with one chamfer  58  located on either side of the slot  50 . The chamfers  58  slope downward toward the slot  50  to facilitate the insertion of the support arm  32  of the catheter adaptor  22  into the slot  50 , as discussed below. 
     As shown by  FIGS. 3 and 5 , each longitudinal wall  46  further comprises a relief  60  disposed on the proximal end of the retainer  20 . The relief  60  is sized to receive the protuberance  40  of the adaptor  22 . The depth of the relief  60  measured in the lateral direction desirably is slightly greater than the height of the protuberance  40  (i.e., the distance by which the protuberance protrudes from the inner surface  42 ). 
     The relief  60  is spaced in the longitudinal direction from the most proximal slot  50  by a distance approximately equal to the spacing S between the slots  50 . Thus, the protuberance  40  rests in the relief  60  with the support arm  32  positioned in either of the two most proximal slots  50 , as discussed in detail below. 
       FIGS. 3 and 4  illustrate a key-way groove  62  of the retainer  20 . The key-way groove  62  facilitates the removal of the catheter adaptor  22  from the retainer  20 , as discussed below in detail. The key-way groove  62  lies at the proximal end of the retainer  20 . The key-way groove  62  extends into the retainer  20 , and toward the retainer base surface  48  from the bottom surface  56  of the central channel  44 . The key-way groove  62  has a transverse width less than the diameter of the central channel  44 , and more preferably has a width approximately equal to two-thirds the diameter of the central channel  44 . The longitudinal length of the key-way groove  62  desirably equals approximately the longitudinal length of the recesses  60  in the longitudinal walls  46 . 
     The retainer  20  is made of relatively stiff plastic material (e.g., polycarbonate), but is somewhat flexible such that the adaptor  22  forces the upper edges  54  of the longitudinal walls  46  outwardly when a nurse presses the adaptor  24  into the central channel  44  of the retainer  20 . When the adaptor  22  sits in the central channel  44 , the upper edges  54  of the walls  46  snap inwardly to their original position to securely hold the adaptor  22  within the retainer  20 . 
     An adhesive attaches the retainer  20  to base pad  16 . Alternatively, the retainer  20  may be attached to the base pad  16  by like means (e.g., embedding or otherwise weaving the retainer  20  into the base pad  16 ) as well. 
     Base Pad 
     As illustrated by  FIG. 1 , the flexible base pad  16  comprises a laminate structure comprising an upper paper or other woven or non-woven cloth layer  64 , an inner cellulose foam layer  66 , and the bottom adhesive layer  18 . Alternative, the flexible base pad  16  may comprise an adhesive bottom layer and an upper cellulose foam layer. An upper surface of the foam layer is roughened by corona treating the foam with a low electric charge, as known in the art. The roughened or porous upper surface of the base pad  16  improves cyano-acrylate (or other types of adhesive) adhesion when attaching the retainer  20  to the pad  16 . 
     A removable paper or plastic backing (not shown) desirably covers the bottom adhesive layer  18  before use. The backing preferably resists tearing and is divided into a plurality of pieces to ease attachment of the pad  16  to the patient&#39;s skin, as explained below. Desirably, the backing is split along the center line of the flexible base pad  16  in order to expose only half of the adhesive bottom surface  18  at one time. The backing also advantageously extends beyond at least one edge of the base pad  16  to ease removal of the backing from the adhesive layer  18 . 
     As seen in  FIG. 2 , one or more tabs  67  may be attached to a portion of the backing which extends beyond the flexible base pad  16 . In an exemplary embodiment, the tabs  67  have the same laminate structure as the flexible base pad  16 . The tabs  67  also can be formed by the paper backing extending beyond the edge of the base pad  16 . The tab  67  may also include indicia  69  in the form of dots, words, figures or the like to indicate the placement of fingers when removing the backing from the base pad  16 . 
     A nurse grips the tab  67 , preferably at the location of the indicia  69 , and peels the backing off one half of the bottom adhesive layer  18 . The nurse then places the bottom layer  18  against the patient&#39;s skin to adhere the base pad  16  to the patient. Light pressure over the upper layer  64  assures good adhesion between the base pad  16  and the patient&#39;s skin. The base pad  16 , due to its flexibility, conforms to the contours of the topical surface to which the base pad  16  adheres. The nurse then repeats this procedure for the other half of the pad  16 . Alternatively, the nurse may completely remove the backing from the pad  16  before attaching the pad  16  to the patient&#39;s skin. 
     The base pad  16  desirably comprises a notch  68  positioned distal of the location of the retainer  20  on the pad  16  and adjacent to the point of insertion of the catheter cannula. The notch  68  is sized to permit visual inspection of the catheterized site, 
     As seen in  FIG. 2 , the base pad  16  desirably may comprise indicia  70  in the form of an arrow which indicates the proper orientation of the base pad  16  in reference to catheterized site. Although the figures illustrate the indicia in the form of an arrow, it is contemplated that other forms of indicia, such as, for example, words or other graphics, could be used as well. In proper use, as illustrated in  FIG. 1 , the indicia  70  should point in the proximal direction, towards the indwelling catheter  14 , or otherwise indicate the proper locate of the pad  16  in reference to the indwelling catheter  14 . 
     In an exemplary embodiment, the laminate structure of the base pad is preferably formed by rolling a paper tape, such as a micro-porous rayon tape, available commercially as MICRO-PORE tape from 3M (Item No. 1530), over a medical grade polyvinyl chloride foam tape, such as that available commercially from 3M (Item No. 9777L). The foam tape preferably includes the bottom liner or backing. The base pad  16  and the tabs  67  are then stamped out of the laminated sheet of foam and paper. The backing between the tabs and the base pad, however, is desirably not severed such that the tabs  67  remain attached to the backing covering the adhesive section  18  of the base pad  16 . The backing is then cut into two pieces along the center line of the pad  16  and between the tabs  67 . 
     Tube Clip 
       FIGS. 1 and 2  illustrate the tube clip  24 . The clip  24  secures the fluid supply tube  12  to form a safety loop, as known in the art. 
     The tube clip has a plate-like base  72  adhered to or embedded in the base pad  16 . The tube clip  24  may be located on the base pad  16  on either side of the retainer  20  to accommodate left hand or right hand mounting. As illustrated in  FIG. 6 , the anchoring system  10  may further include a second tube clip  24  located on the other side of the retainer  20  from the first tube clip  24 . 
     The clip  24  defines a channel  74  having a generally circular cross-sectional configuration truncated to form an upper orifice  76 . The diameter of the channel  74  is desirably slightly less than that of the fluid supply tube  12  so as to ensure a secure interconnection. The channel  74  receives a portion of the fluid supply tube  12  through the orifice  76  upon application of gentle pressure or by pulling the tubing  12  across and through the orifice  76  of the tube clip  24 , as explained below. The clip  24  surrounds a substantial portion of the tubing  12  with the tubing  12  positioned within the channel  74 . 
     As seen in  FIG. 2 , the upper edge of the channel includes tapered ends  77  at the proximal and distal ends of the clip  24 . Each tapered end  77  forms a smooth transition between the side edge of the channel  74  and the upper edge, and tapers in lateral width from the side edge toward the center of the tube clip  24 . The tapered ends  77  help guide the fluid supply tube  12  into the channel  74  when a nurse pulls the tube across the clip  24 . Thus, the nurse does not have to pinch the tube  12  to insert it into the clip  24 . Also, the nurse&#39;s gloves do not get stuck in the clip  24  when inserting the tube  12 , as is typically the case where the nurse is required to pinch the tube  12  to insert it into the clip  24 . 
     Slide Clamp 
     As illustrated in  FIGS. 1 and 2 , the catheter anchoring system  10  desirably additionally includes a slide clamp  78  to regulating fluid flow through the tubing, as known in the art. The clamp  78 , at one end, includes an aperture  80  which receives the fluid supply tube  12 , and, at the opposite end, includes a tab  82 . The clamp  78  has a generally forked shape formed by a pair of prongs  84  which defines the aperture  80 . The tube  12  snaps between the prongs  84  and into the aperture  80 , which has a diameter slightly larger that the fluid supply tube  12 . 
     The prongs  84  converge together in the direction towards the tab  82  to form a tapering slot  86  which opens into the aperture  80 . The prongs  84  pinch the tube  12  closed with the tube  12  positioned in the slot  86  so as to block fluid flow therethrough. The clamp  78 , however, slides over the tube  12  with the tube  12  positioned through the aperture  80 . 
     The tab  82  desirably has a rectangular shape which generally corresponds the to shape of the key-way groove  62  of the retainer  20 . The tab  82  preferably has a thickness greater than that of the distal end of key-way groove  62 , measured in the transverse direction, so as to pry the adaptor  22  from the retainer  20 . As explained in detail below, the tab  82  may be used to remove the catheter adaptor  22  from the retainer  20 . 
     Retainer Location Adjustment Mechanism 
       FIG. 6 through 8  illustrate a catheter anchoring system  10   a  in accordance with another preferred embodiment of the present invention. Where appropriate, like numbers with an “a” suffix have been used to indicate like parts of the two embodiments for ease of understanding. 
     The catheter anchoring system  10   a  is substantially identical to the above-described anchoring system  10 , with the addition of a retainer location adjustment mechanism  90 . 
     As best seen in  FIG. 8 , the location adjustment mechanism  90  comprises a base  92  and interlocking mechanism  94  which interconnects the base  92  and the retainer  20   a.  The retainer  20   a  slides over the base  92  and the interlocking mechanism  94  secures the retainer  20   a  to the base  92  at various longitudinal positions. The adjustment mechanism thus allows for precise positioning of the retainer  20  relative to the catheter  14  after the pad  16  is attached to the patient&#39;s skin. 
     The base  92  has a generally parallelepiped shape and comprises a rail  96 .  FIG. 7   a  best illustrates that the rail  96  desirably has a “dove-tail” configuration in cross section. That is, the rail  96  has a cross-sectional shape with a flat upper edge  98  and a pair of opposing side edges  100 , each edge  100  being angled inward from the upper edge  98  toward the middle of the rail  96 . The rail  96  extends along the longitudinal length of the base  92  from the distal end  102  of the base  92  to a point just short of the base proximal end  104 . The base  92  includes a pair of stops  106  at the proximal end  104  which close off the proximal end of the rail  96 . 
     An adhesive attaches the base  92  to base pad  16   a.  Alternatively, the base  92  may be attached to the base pad  16   a  by like means (e.g., embedding or otherwise weaving the base  92  into the base pad  16   a ) as well. 
     The retainer  20   a,  configured in accordance with the above-description, additionally comprises a groove  108  having a cross-sectional shape corresponding to that of the rail  96 . The retainer groove  108  receives the base rail  96  in a manner permitting the retainer  20   a  to slide over the base  92 , but preventing the retainer  20   a  from moving in the transverse direction away from the base  92 . The base stops  106  also limit the retainer&#39;s longitudinal travel in a proximal direction. 
     The interlocking mechanism  94  comprises a plurality of teeth  110  disposed on an upper surface  112  of the base  92 , and a pawl  114  connected to the retainer  20   a.  The teeth  110  desirably have generally rectangular cross-sectional shapes, and lie in seriatim along the longitudinal axis of the base  92 . The upper edge of each tooth  110  includes a chamfer  112  to facilitate the engagement of the pawl  114  with a hollow  116  formed between adjacent teeth  110 , as discussed below. The longitudinal length of each tooth  110  desirably extends generally normal to the longitudinal axis of the base  92 . 
     The pawl  114  has a shape configured to insert into and engage with the hollow  116  defined between the teeth  110 . The pawl  114  preferably has a width, measured in the longitudinal direction, slightly less than that of the hollow  116 . 
     The retainer  20   a  comprises an aperture  118  extending between the retainer base surface  48   a  and the channel bottom surface  56   a.  A flexible finger  120  extends from the retainer  20   a  in a cantilever fashion and into the retainer aperture  118 . The flexible finger  120  supports the pawl  114  at its distal end. Although  FIG. 8  illustrates the finger  120  as extending in the distal direction, it is contemplated that the finger  120  can alternatively extend in the proximal direction as well. 
     The flexible finger  120  preferably comprises a protuberance  122  which extends upwardly beyond the channel bottom surface  56   a  and into the central channel  44   a  with the finger  120  in an undeflected state. The cantilever nature of the finger  120  enables the finger  120  to deflect downward so that the protuberance  122  lies below the retainer bottom surface  56   a.  With the finger  120  so deflected, the pawl  114  engages the series of teeth  110 . That is, the pawl  114  inserts into a hollow  116  defined between the teeth  110 . The interengagement between pawl  114  and the teeth  110  prevents the retainer  20   a  from sliding over the base  92 . 
     S-Clip 
       FIGS. 9 and 10  illustrate a catheter anchoring system  10   b  in accordance with a further embodiment of the present invention. Where appropriate, like numbers with an “b” suffix have been used to indicate like parts of the embodiments for ease of understanding. 
     The catheter anchoring system  10   b  is substantially identical to the anchoring system  10  first described above, with the addition of an S-clip  124  to retain a microbore or small bore tubing  126 . The microbore tubing is commonly used, for example, with epidural catheterization procedures, as discussed in detail below. 
     The S-clip  124  comprises a generally U-shaped channel  128  defined by a pair of arcuate, upstanding walls  130  extending from a base plate  132 . As best seen in  FIG. 10 , the S-clip  124  further comprises a plurality of retainers  134 , each retainer  134  having a spherical head  136  support by a cylindrical stem  138 . The stems  138  extend from the base plate  132 . The retainer stems  138  are positioned from one another and from the upstanding walls  130  by a distance slightly greater than the diameter of the microbore tubing  126 . The retainers  134  are also positioned such that the spherical heads  136  of the retainers  134  are positioned from one another and from the upstanding walls  130  by a distance slightly less than the microbore tubing  126 . As best seen in  FIG. 10 , the retainer heads  136  prevent the microbore tubing  126  from disengaging from the S-clip  124  in the transverse direction once the microbore tubing  126  is snaked between the retainers  134  and the upstanding walls  130 . 
     An adhesive attaches the base plate  132  of the S-clip  124  to base pad  16   b.  Alternatively, the base plate  132  may be attached to the base pad  16   b  by like means (e.g., embedding or otherwise weaving the base plate  132  into the base pad  16   b ) as well. 
     The components of the anchoring system  10 , save the base pad  16  (i.e., the retainer  20 , tube clip  24 , adaptor  22 , slide clamp  78 , base  92  and S-clip  124 ), may be constructed in any of a variety of ways which will be well known to one of skill in the art. For instance, each individual component may be integrally molded such as by injection molding or by thermoplasty. The components preferably comprise a durably, flexible material, and more preferably comprise a generally inert, non-toxic material. In a preferred embodiment, the components are molded of plastic, such as, for example, polycarbonate, polyvinylchloride, polypropylene, polyurethane, tetrafluoroethylene (e.g., TEFLON7), polytetrafluoroethylene (a.k.a., PTEF), acetal resin (e.g., DELRIN7), chlorotrifluoroethylene (e.g., KEL-F7), nylon or like polymers. 
     Method of Use 
     The following discussion of the method of use will be with reference to  FIGS. 1 and 2 , and initially will be in the context of intravenous catheterization. As the following discussion will illustrate, however, it is understood that the anchoring system  10  can be used in other catheterization procedures as well. The discussion of the method of use is intended to augment the above description of the invention, and, thus, should be read together. 
     A nurse typically begins the catheterization process by positioning the catheter  14  at a desired location above a vein. The nurse introduces a needle or other stylus through a cannula portion of the catheter  14  and into the skin of the patient at a desired angle of incident. For intravenous use, the catheter  14  commonly has an incident angle of approximately 7N. The nurse then inserts the cannula of the catheter  14  into the patient and withdraws the needle or stylus. The catheter hub  30  remains exposed above the skin. 
     The nurse inserts the distal end of the adaptor  26  into the catheter hub  30 . The clip  34  has been slidably mounted in a most distal position so that it does not interfere with the insertion of the adaptor distal end  26  into the catheter hub  30 . 
     The nurse then slides the clip  34  in a proximal direction to engage the catheter hub  30 . In this manually selected position, the clip  34  securely attaches the adaptor  22  to the catheter  14 . The rachet teeth of the adaptor  22  cooperate with the pawl to resist distal movement of the clip  34  and to hold the clip  34  in the manually selected position. 
     The nurse removes the paper backing which initially covers the adhesive bottom surface  18  of the base pad  16 , and attaches the pad  16  to the patient&#39;s skin proximate to the indwelling catheter  14 . Specifically, the nurse grips the backing tab  67  proximate to the retainer  20 . The indicia  69  on the tab  67  indicates the locate at which the nurse should grip the tab  67 . The nurse then pulls on the tab  67  and peels the backing off one half of the bottom adhesive layer  18 . The nurse positions the slot  68  of the pad  16  around the catheter cannula  14  with the instructing indicia  70  (e.g., indicating arrow) pointing in the direction of the catheter  14 . The nurse then places the bottom layer  18  against the patient&#39;s skin to adhere the base pad  16  to the patient. Light pressure over the upper layer  64  assures good adhesion between the base pad  16  and the patient&#39;s skin. The base pad  16 , due to its flexibility, conforms to the contours of the topical surface to which the base pad  16  adheres. 
     The nurse then repeats this procedure for the other half of the pad  16 . Alternatively, the nurse may completely remove the backing from the pad  16  before attaching the pad  16  to the patient&#39;s skin. 
     The nurse orients the adaptor  22  with the clip  34  positioned to the side of the tubular body  25  (i.e., with the support arm  32  extending in the lateral direction) and locates the adaptor support arm  32  above the series of retainer slots  50  with the latch  36  positioned distal of the retainer distal end. 
     The nurse then snaps the adaptor  22  into the retainer  20  located proximal of the pad notch  68 . In doing so, the adaptor  22  is pressed between the longitudinal walls  46  of the retainer  20  with the support arm  32  extending in a lateral direction. As the nurse presses the adaptor  22  into the retainer  20 , the chamfered edges  58  around the slots  50  of the longitudinal wall  46  guide the support arm  32  into one of the slots  50 . 
     As mentioned above, the opening  47  of the channel  46  has a smaller width measured in the lateral direction than the diameter of the tubular body  25 . The lateral walls  46  thus deflect outwardly in a lateral direction. Once the tubular body  25  of the adaptor  22  rests within the central channel  44  of the retainer  20 , the lateral walls  46  spring back to snap the adaptor  22  in place. The walls  46  of the retainer  20  thus prevent unintentional transverse and lateral movement of the adaptor  22 . 
     In this position, the protuberance  40  of the adaptor  22  either rests either in a slot  50  or in the relief  60 , proximal of the slot  50  through which the support arm  32  passes. The protuberance  40  engages a portion of the longitudinal wall  46 , which forms either the relief  60  or the slot  50 , to prevent the clip  34  from pivoting relative to the tubular body  25 . The protuberance  40  thus ensures that the latch  36  maintains engagement with the catheter hub  30 . 
     The slot  50  through which the support arm  32  passes prevents the adaptor  22  from sliding in the longitudinal direction. That is, the slot  50  prevents longitudinal displacement of the adaptor  22  when secured within the central channel  44 . 
     The ergonomic design of the retainer  20  provides for a variety of positions of the adaptor  22  in the retainer  20  so that the retainer  22  is not technique or position sensitive. That is, a nurse can simply press the adaptor  22  into the retainer  20 , irrespective of the side on which the support arm  32  is located, and irrespective of the position of the support arm  32  relative to a particular slot  50 . So long as the support arm  32  is positioned above the series of slots  50 , the chamfered edges  58  of the wall  46  will guide the support arm  32  into a slot  50 . The protuberance  40  of the adaptor  22  also fits within an adjacent slot  50  or the relief  60 . 
     With the support arm  32  extending through a slot  50  of the retainer  20 , the adaptor  22  lies in a “low profile” position. That is, the support arm  32  of the adaptor  22  extends in the lateral direction to reduce the overall height of the anchoring system  10 , as measured in the transverse direction. This position of the adaptor  22  reduces the risk of the system  10  interfering with surrounding action. The retainer  20 , however, allows the adaptor  22  to rotate either to a position in which the support arm  32  extends in the transverse direction, or to a position 180N for the original position to locate the adaptor clip  34  on the opposite side of the retainer  20 . 
     Once in the low profile position, the adaptor  22  will normally remain in this position until the adaptor  22  and its associated tubing  12  are removed and replaced by another. 
     As  FIG. 1  illustrates, the nurse may also form a safety loop in the fluid supply tubing  12 , as known in the art, and secure the safety loop to the patient by inserting a portion of the tubing  12  into the tube clip  24 . The safety loop absorbs any tension applied to the fluid supply tube to prevent the adaptor  22  and/or catheter  14  from being pulled. 
     A nurse may use the slide clamp  78  to remove the adaptor body  25  from the retainer  20 . The nurse inserts the tab  82  of the slide clamp  78  into the key-way groove  62  on the proximal end of the retainer  20 . Because the tab  82  has a larger width than the depth of the key-way groove  62 , measured in the transverse direction, the tab  62  pries the tubular body  25  from the central channel  44  as the nurse inserts the tab  82  into the key-way groove  62  in the distal direction. The nurse may further use the slide clamp  78  to leverage the proximal end of the tubular body  25  out the upper opening  47  of the retainer  20 . Having displaced the proximal end of the adaptor  22  from the retainer  20 , the nurse may easily remove the adaptor distal end from of the retainer  20 . Alternatively, the nurse may also remove the tubular body  25  by lifting up on the tubing  12  while holding down the pad  16  or the retainer  20  with the other hand. 
       FIGS. 6 through 8  illustrate the catheter anchoring system  10   a  particularly suited for arterial catheterization. Because of the criticality of the incident angle (i.e., the angle at which the catheter  14   a  projects into the patient) at which the catheter  14   a  must be maintained, it is advantageous to precisely position the retainer  20   a  so that the retainer  20   a  holds the catheter  14   a  at the desired incident angle. The desired range of incident angle commonly is about 5N-30N for arterial catheterization. The incident angle preferably ranges between about 15N and about 25N, and more preferably equals about 22N. 
     A nurse inserts the catheter cannula  14   a  into an artery in a similar manner to that described above in connection with intravenous catheterization. The nurse subsequently connects the adaptor  22   a  to the indwelling catheter  14   a  as previously described. The nurse also attaches the flexible pad  16   a  to the patient in a like manner to that described above. If desired, the nurse can remove one of the wings  140  of the pad  16   a  before attaching the pad  16   a  to the patient, by tearing the pad  16   a  along the perforation line  142 . 
     The nurse orients the adaptor  22   a  with the clip  34   a  positioned to the side of the tubular body  25   a  (i.e., with the support arm  32   a  extending in the lateral direction) and locates the adaptor support arm  32   a  above the series of retainer slots  50   a  with the latch  36   a  positioned distal of the retainer distal end. If the nurse positions pad  16   a  too close to or too far from the indwelling catheter  14   a,  the nurse can slide the retainer  20   a  in the desired direction to locate the retainer slots  50   a  beneath the adaptor support arm  32   a.    
     The nurse then snaps the adaptor  22   a  into the retainer  20   a  located proximal of the pad notch  68   a.  In doing so, the chamfered edges  58   a  around the slots  50   a  of the longitudinal wall  46   a  guide the support arm  32   a  into one of the slots  50   a.  The retainer  20   a  automatically slides longitudinally to precisely position a corresponding slot  50   a  beneath the support arm  32   a.  The adaptor  22   a  thus snaps into the retainer  20   a  without causing the catheter  14   a  to move substantially. 
     The tubular body  25   a  contacts the protuberance  122  of the finger  120  and causes the finger  120  to deflect downward as the adaptor tubular body  25   a  snaps into the central channel  44   a.  In turn, the pawl  114  engages the series of teeth  110  which prevents longitudinal movement of the retainer  20   a  while holding the adaptor  20   a.  If the nurse removes the adaptor  22   a —preferably by using the slide clamp tab  82   a —the finger  120  springs back to its undeflected state and the retainer  20   a  freely slides over the rail  96 . The pawl  114  normally does not engage the series of teeth  110 . 
     The ability to precisely position the retainer  20   a  beneath the catheter adaptor  22   a  connected to the catheter  14   a,  enables the nurse to hold the catheter  14   a  in a stable position and ensures that the retainer  20   a  will hold the adaptor  22   a,  and thus the catheter  14   a,  at the precise incident angle. Without the ability to adjust the longitudinal position of the retainer  20   a,  the nurse may perform a series of position iterations before properly locating base pad  16   a,  and thus the retainer  20   a,  relative to the indwelling catheter  14   a.    
     For epidural catheterization, an anesthesiologist, for example, inserts the distal end of microbore tubing  126  into the epidural space. The proximal end of the microbore tubing  126  conventionally includes a Toughy-Bourst adaptor  144  or other adaptor device to couple with the fluid supply tube  12   b  transporting the anesthesia. It is imperative that the connection between the microbore tubing  126  and the fluid supply tubing  144  remain intact, and that the distal end of the microbore tubing  126  remains in place. For if the epidural space is exposed to air-borne microbes, meningitis may develop. Thus, a secure interconnection between the microbore tubing  126  and the fluid supply  12   b  should exist, and the microbore tubing  126  should be isolated from any tension placed on either the fluid supply tube  12   b,  as well as the adaptor  22   b.    
       FIGS. 9 and 10  illustrate the catheter anchoring system  10   b  particularly suited for epidural catheterization. A doctor uses the present anchoring system  10   b  in a manner similar to that described above in connection with intravenous catheterization, with the exceptions that doctor connects the adaptor  22   b  to microbore tubing  126  and adheres the base pad  16   b  to the patient&#39;s torso. 
     The doctor subsequently snakes the microbore tubing  126  through the S-clip  124  by first pressing the tubing  126  between a retainer  134  and the wall  130 , and then wrapping the tubing  126  between the first and second retainers  134 . Light pressure forces the tube  126  between the retainers  134 . The doctor then wraps the tube  126  back between the second retainer  134  and the second wall  130 , and presses the tube  126  therebetween. The S-clip  124  secures the microbore tube  126  in place and isolates the microbore tube  126  from tension placed on the adaptor  22   b  and/or the fluid supply tube  12   b  with the microbore tube  126  inserted accordingly. 
     Additional Embodiments 
     As mentioned above, it is contemplated that other types of adaptors in addition to the one disclosed above can be used as well with the present catheter anchoring system.  FIGS. 11 and 12  illustrate a catheter anchoring system  10   c  in accordance with a further embodiment of the present invention which includes a different catheter adaptor style. Where appropriate, like numbers with a “c” suffix have been used to indicate like parts of the embodiments for ease of understanding. 
     Like the catheter anchoring systems described above, the present catheter anchoring system  10   c  principally comprises a flexible anchor pad  16   c  having an adhesive bottom side  18   c,  which attaches to the skin of the patient. The pad  16   c  supports a retainer  20   c.  The retainer  20   c  is configured to receive and secure in place a catheter adaptor  22   c  which connects to an indwelling catheter  14   c.  The pad  16   a  may also support a tube clip  24   c  which is used to retain a portion of the tubing  12   c.    
       FIG. 11  illustrates the adaptor  22   c  as comprising a generally tubular body  25   c  defined between a distal end  26   c  and a proximal end  28   c.  The proximal end  28   c  is adapted to receive a distal end of the tube  12   c.  In an exemplary embodiment, at least a portion of the fluid supply tube  12   c  is permanently attached to the body proximal end  28   c.    
     The distal end  26   c  is configured to engage a proximal end of the indwelling catheter  14   c  (not shown). Although  FIGS. 11 and 12  illustrate the distal end  26   c  of the adaptor  22   c  as having a frusto-conical shape configured to engage a standard lure-type catheter hub  30   c  (not shown), it is contemplated that the distal end  26   c  could be configured as well to engage other types of connectors. 
       FIG. 14  illustrates an alternative configuration of the distal end  26   d  of the catheter adaptor  22   d.  Again, for consistency, like numbers with a “d” suffix have been used to indicate like parts of the catheter adaptor of  FIG. 11  and the catheter adaptor of  FIG. 14 . 
     The catheter adaptor  22   d  includes a standard lure-lock type fitting  220  attached to the body  25   d  of the catheter adaptor  22   d  so as to circumscribe the distal end  26   d  of the catheter adaptor  22   d.  The lure-lock fitting  220  preferably is attached in a manner which permits the fitting  220  to be rotated about the catheter adaptor body  25   d.  It is contemplated, however, that the distal end of the adaptor could comprise a female lure-lock type connector (i.e., a hub including nubs or threads on its external surface) as well if required by a particular application. 
     In the illustrated embodiment, the fitting  220  has a generally tubular shape with a closed proximal end  222 . The closed end  222  includes an aperture  224  of a sufficient size to receive a portion of the adaptor body  25   d,  as described below. The fitting  220  includes conventional internal threads  226  in order to engage corresponding threads of a conventional female lure-lock fitting (not shown). 
     The adaptor body  25   d  desirably includes an annular groove  228  which receives a portion of the closed end  222  of the fitting  220  to interconnect the fitting  220  and the adaptor body  25   d.  This interconnection also permits the fitting  220  to be rotated about the adaptor body  25   d.    
     To assemble the catheter adaptor  22   d,  the conical shaped distal end  26   d  of the body  25   d  is inserted into the aperture  224  of fitting closed end  222 . The body  25   d  is then forced into the fitting  220  to slightly deflect the closed end  222  until the closed end  222  snaps into the annular groove  228  of the body  25   d.  In this position, the body  25   d  captures a portion of the fitting  220  to couple these elements together. 
     With reference to  FIG. 11 , the adaptor  22   c  includes at least one annular collar  200  interposed between the proximal and distal ends  28   c,    26   c  of the tubular body  25   c.  The adaptor  22   d  of  FIG. 14  also includes a like annular collar  200   d.  It is contemplated that the collar  200  of the adaptor  22   c  of  FIG. 11  and the collar  200   d  of the adaptor  22   d  of  FIG. 14  will be substantially identical, and, thus, the description herein will be understood as applying equally to both embodiments. 
     The annular collar  200  flares radially outwardly and circumscribes the tubular body  25   c.  The annular collar  200  has a thickness measured in a longitudinal direction which is slightly less than a width of a slot  50   c  in a retainer wall  46   c  so that the collar  200  fits within the slot  50   c  of a retainer wall  46   c,  as discussed in detail below. 
     The adaptor  22   c  is preferably formed of a durable, biocompatible plastic material. The adaptor  22   c  more preferably is formed of clear plastic so a nurse can see bubbles or backflow through the adaptor  22   c.  In an exemplary embodiment, the adaptor is formed of polycarbonate by injection molded; however, those skilled in the art will readily appreciate that the adaptor can be formed by other construction methods known in the art. 
       FIGS. 11 and 12  also illustrate the retainer  20   c  which is substantially identical to the retainer  20  described above. The retainer  20   c  comprises a central channel  44   c  interposed between a pair of opposing longitudinal walls  46   c.  The central channel  44   c  extends through the retainer  20   c  along an axis which is generally parallel to a longitudinal axis of the retainer  20   c.    
     The central channel axis  44   c  has a generally circular cross-sectional shape which is truncated at an upper end to form an opening  47   c.  The central body  44   c  has a diameter sized to receive the tubular body  25   c  of the catheter adaptor  22   c.  In a preferred embodiment, the diameter of the central channel  44   c  generally matches that of the tubular body  25   c.    
     In cross section, the central channel  44   c  extends through an arc greater than 180N about the channel axis such that the lateral length of the opening  47   c  is less than the diameter of the central channel  44   c.  In an exemplary embodiment, the cross-sectional shape of the central channel  44   c  extends through an arc of about 200N about the channel axis. 
     As best seen in  FIG. 13   a , the channel axis is desirably skewed relative to a base surface  48   c  of the retainer  20   c.  An incident angle θ formed between the base surface  48   c  and the channel axis is less than 45N. The incident angle θ desirably ranges between 5N and 30N. In an exemplary embodiment for intravenous use, the angle e preferably approximately equals 7N. 
     The longitudinal walls  46   c  are substantially identical. Each wall  46   c  has a thickness measured in the lateral direction less than the length of the support arm  32  of the adaptor  22 , as it is desirable for the present retainer  20   c  to accept both the above-described adaptor  22  which comprises a support arm  32  connected to a clip  34 , as well as the present adaptor  22   c  which comprises an annular collar  200 . Preferably, the thickness of the wall  46   c  measured in the lateral direction is greater than the distance measured radially by which the collar  200  extends beyond the exterior surface of the tubular body  25   c  (i.e., a radial height). The length of each wall  46   c,  as measured in the longitudinal direction, is preferably coextensive with the length of the retainer  20   c.    
     Each wall  46   c  comprises a uniform series of slot  50   c.  The series comprises at least two (2) slots  50   c  and not more than twenty (20) slots  50   c.  More preferably, the series comprises less than seven (7) slots  50   c.  In an exemplary embodiment, as illustrated in the figures, the series comprises four (4) slots  50   c.    
     As discussed above, each slot  50   c  is sized to receive the collar  200  of the adaptor  22   c,  as well as the support arm  32  of the catheter adaptor  22 , to prevent longitudinal displacement of the respective adaptor  22 ,  22   c.  Each slot  50   c  desirably has a rectangular shape. As seen in  FIG. 12 , the slots  50   c  extend from an exterior surface  52   c,  through the wall  46   c,  and open into the central channel  44   c.  The width of the slot  50   c,  as measured in the longitudinal direction, is desirably slightly greater than the width of the support arm  32  and the width of the collar  200 . 
     As illustrated by  FIG. 13   a , each slot  50   c  extends in the transverse direction from an upper edge  54   c  of the longitudinal wall  46   c  to a point below the bottom  56   c  of the central channel  44   c,  The height of the slot  50   c,  as measured in the transverse direction, is thus greater than the distance between the upper edge  54   c  and the channel bottom  56   c  of the retainer  20   c.  As seen in  FIG. 13   b , the retainer  20   c  further includes a series of lateral grooves  202  which extend between opposing slots  50   c  and extend into the retainer  20   c  from the channel bottom surface  56   c.  The opposing slots  50   c  and groove  202  thus form a lateral channel which extends through the retainer  20   c  in the lateral direction and cuts into the retainer  20   c  from the upper edge  54   c  to a point below the channel bottom surface  56   c.  The groove  202  desirably is sized to receive a portion of the collar  200  such that with the tubular body  25   c  positioned within the central channel  44   c,  the collar  200  extends between opposing slots  50   c  and into the groove  202 . Thus, the groove  202  has a depth, measured between the lower surface  56   c  of the central channel  44   c  and the bottom of the groove in transverse direction, which is greater than the radial height of the annular collar  200 . 
       FIG. 13   b  illustrates that the spacing S between the slots  50   c,  on center, desirably equals about half the distal L (see  FIG. 2 ) between the support arm  32  and the protuberance  40  of the catheter adaptor  22 . The position of the slots in relation to the proximal and distal ends  26   c,    28   c  of the retainer  20   c  is desirably configured in accordance with the spacing and positioning discussed above in connection with the above-described retainer  22 , such that the present retainer  22   c  can be used with the above-described adaptor  22 , including a clip  34 . 
       FIGS. 11 and 13   a  illustrate the upper edge of each longitudinal wall  46   c  which comprises a series of chamfers  58   c  formed and positioned as disclosed above in connection with the retainer  20 . As discussed above, the chamfers  58   c  slope downwardly towards the slot  50   c  to facilitate the insertion of either the support arm  32  of the above-described catheter adaptor  22  or the annular collar  200  of the present catheter adaptor  22   c  into the slot  50   c.    
     As  FIGS. 11-13   b  illustrate, each longitudinal wall  46   c  may further comprise a relief  60   c  disposed on the proximal end of the retainer  20   c.  The configuration and position of the relief  60   c  desirably is in accordance with the above description of the retainer  20 .  FIG. 11  further illustrates that the retainer  20   c  may additionally comprise a key-way groove  62   c  to facilitate removal of the catheter adaptor  22   c  from the retainer  20   c,  as discussed above. The key-way groove  62   c  desirably is also positioned and configured in accordance with the above disclosure in connection with the retainer  20 . 
     The retainer  20   c  is made of relatively stiff plastic material, but is somewhat flexible such that the adaptor  22   c  forces the upper edges  54   c  of the longitudinal walls  46   c  outwardly when a nurse presses the adaptor  22   c  into the central channel  44   c  of the retainer  20   c.  The retainer  20   c  is desirably formed of polycarbonate by injection molding. When the adaptor  22   c  sits within the central channel  44   c,  the upper edges  54   c  of the walls  46   c  snap inwardly to their original position to securely hold the adaptor  22   c  within the retainer  20   c.    
     An adhesive preferably attaches the retainer  20   c  to the anchor pad  16   c.  Alternatively, the retainer  20   c  may be attached to the anchor pad  16   c  by like means as well, e.g., embedding or otherwise weaving the retainer into the anchor pad  16   c.    
       FIG. 11  illustrates the anchor pad  16   c  as comprising a flexible, laminate structure comprising an upper paper or other woven or non-woven cloth layer  64   c  and a bottom adhesive layer  18   c,  with an inner cellulose foam layer  66   c  interposed therebetween. Alternatively, the flexible base pad  16  may comprise an adhesive bottom layer  18  and an upper cellulose foam layer. An upper surface of the foam layer is roughened by corona treating with a low electric charge, as known in the art. The foam layer  66   c  forms a cushion between the patient&#39;s skin and the rigid, plastic retainer  20   c  and tube clamp  24   c.  The adhesive layer  18   c  may comprise a coating of diaphoretic or nondiaphoretic material, depending upon the patient&#39;s skin condition. A medical grade foam tape with a diaphoretic or a nondiaphoretic adhesive is available commercially from NDM Manufacturers. 
     The removable paper or plastic backing (not shown) desirably covers the bottom adhesive layer  18  before use. As discussed above and illustrated in  FIG. 12 , the backing is preferably divided into a plurality of piece and includes tabs  67   c  to ease removal of the backing from the pad  16 . The tabs  67   c  may include indicia  69   c  (e.g., dots, text, arrows, etc.) to indicate the location at which to grip the corresponding tab  67   c  when peeling the removable backing off the pad  16   c.    
     As best seen in  FIG. 12 , the anchor pad  16  desirably has a generally trapezoidal shape with rounded corners. A distal edge  206  of the anchor pad  16   c  desirably has a width, as measured in the lateral direction, wider than that of a proximal edge  204 . The longer distal edge  206  provides a longer adhesive surface over a rough contact surface, such as, for example, over knuckles, vertebrae, or the like. The generally trapezoidal shape, however, minimizes the overall size of the anchor pad  16   c  attached to the patient. The trapezoidal shape also provides the same surface area as a square pad with a appearance of a smaller pad. The longitudinal sides  208  of the anchor pad  16   c  preferably taper from the proximal edge  206  to the distal edge  204 , and more desirably have concave shapes. 
     The anchor pad includes a notch  68   c  positioned along the proximal edge  204  of the anchor pad  16   c  and adjacent to the point of insertion of the catheter cannula. Preferably, the notch  68   c  is symmetrically positioned about the channel axis  44   c  of the retainer  20   c  attached to the anchor pad  16   c.  The notch  68   c  is sized to permit visual inspection of the catheterized site and is large enough to allow for variable placement of the pad  16   c  with respect to the insertion site. That is, the notch  68   c  is large enough that a nurse is not required to precisely position the pad on the patient&#39;s skin with respect to the indwelling catheter  14   c  (not shown). 
     As seen in  FIGS. 11 and 12 , the anchor pad  16   c  desirably may comprise indicia  70   c  sometimes in the form of an arrow which indicates the proper orientation of the anchor pad  16  in reference to the catheterized site. When properly used, the indicia  70   c  points toward the indwelling catheter  14   c  (not shown). 
     The anchor pad  16   c  preferably supports a clip  24   c  which secures the fluid supply tube  12   c  to the anchor pad  16   c.  As seen in  FIG. 12 , the fluid supply tube  12   c  is preferably looped back around in a proximal direction and inserted into the clip  24   c  to form a safety loop, as known in the art. The tube clip  24   c  is desirably configured in accordance with the above description. The clip  24   c  may be made in a variety of sizes to accommodate various calibers of fluid flow tubing  12   c.    
     In use, a nurse typically uses the catheter anchoring system  10   c  in connection with an indwelling catheter  14   c  (not shown). The catheter  14   c  is inserted into a body lumen, such as a vein, in accordance with the above description. The nurse then inserts the distal end  26   c  of the adaptor  22   c  into a catheter hub  30   c  (not shown) to connect the adaptor  22   c  to the catheter  14   c  The nurse may then secure the adapter  22   c  to the catheter  14   c  by means of the ratchet clip, or the lure-lock fitting. 
     The nurse removes the paper backing which initially covers the adhesive bottom surface  18   c  of the anchor pad  16   c,  as described above, and attaches the anchor pad  16   c  to the patient&#39;s skin proximate to the indwelling catheter  14   c.  The nurse specifically positions the notch  68   c  of the pad  16   c  around the catheter cannula  14   c  with the indicating arrow  70   c  pointing in the direction of the catheter  14   c.  The nurse generally aligns the proximal edge  204  of the anchor pad  16   c  with the insertion site. 
     The nurse positions the adaptor  22   c  above the series of retainer slots  50   c,  and snaps the adaptor  22   c  into the retainer  20   c.  In doing so, the adaptor  22   c  is pressed between the longitudinal walls  46   c  of the retainer  20   c  with the annular collar  200  extending into opposing slots  50   c  and into the corresponding groove  202  of the retainer  20   c.  As the nurse presses the adaptor into the retainer  20   c,  the chamfered edges  58   c  around the slots  50   c  of the longitudinal walls  46   c  guide the annular collar  200  into the slots  50   c.  The retainer  20   c  secures the adaptor  20   c  as described above. 
     With the annular collar  200  positioned in the opposing slots  50   c  the adaptor  22   c  is prevented from sliding in a longitudinal direction. 
     Like the above-described embodiments of the retainer, the ergonomic design of the retainer  20   c  provides for various positions of the adaptor  22   c  in the retainer  20   c  so that the retainer  22   c  is not technique- or position-sensitive. That is, a nurse can simply press the adaptor  22   c  into the retainer  20   c,  irrespective of the position of the annular collar  20  relative to a particular slot  50   c  of the retainer  20   c.  So long as the annular collar  200  is positioned above the series of slots  50   c,  the chamfered edges  58   c  of the wall  46   c  will guide the annular collar  200  into the slot  50   c.    
     The present embodiment of the retainer  20   c,  as mentioned above, may also be used with the above-described adaptor  22  having the clip  34 . A nurse uses the present retainer with the above-described adaptor  22  in the same manner as described above in connection with the above-described retainer  20 . 
     If the catheter hub  30  (see  FIG. 1 ) is a standard female lure-lock fitting, the lure-lock fitting  220  ( FIG. 14 ) of the adaptor body  22   d  is rotated with the distal end  26   d  inserted into the catheter hub  30  to interlock the corresponding fittings  222 ,  30  in the known manner. The catheter adaptor  22   d  is then used with the anchoring system in a like manner to that described above. 
     The above embodiments illustrate the adaptor with the radially extending member being affixed to an end of a tube set or other fluid line. The radially extending member can also be arranged on the adaptor or fitting that is affixed to the proximal end of the catheter body.  FIGS. 15   a  through  15   c  illustrate this arrangement. 
       FIGS. 15   a  through  15   c  illustrate a catheterization system configured in accordance with another embodiment of the present invention. The catheterization system includes a catheter and an anchoring system that includes a retainer and an anchoring pad. Although the anchoring pad has been omitted from  FIGS. 15   a  through  15   c  to simplify the drawings, the anchor pad desirably is constructed in accordance with the above description and is shaped in the form shown in  FIG. 16 . Again, for consistency, like numbers with an “e” suffix have been used to indicate like parts of the anchoring system of  FIGS. 11  and of  15   a - 15   c.  The above description of like components thus should be understood as applying equally to the present embodiment, unless stated otherwise. 
     The catheter desirably includes an elongated tubular body with a tubular adaptor or fitting attached to the body. At least one lumen of the adaptor communicates with a corresponding lumen of the catheter. In the illustrated embodiment, the adaptor  22   e  is permanently attached to a proximal end of the fitting and is configured to cooperate with a corresponding adaptor formed on a distal end of a fluid line. The adaptor  22   e,  however, can be releasably attached to the catheter body. 
     In the illustrated embodiment, the tubular adaptor  22   e  is configured as a female-component of the coupling between the catheter body and the fluid line. The adaptor  22   e  of course can be configured as the male component of the coupling. In either case, both the male and female adaptors of the coupling have corresponding generally frusto-conical shapes which mate together in a generally fluid tight engagement. The coupling adaptors also include interengaging elements that lock together the adaptors. The tubular adaptor  22   e  of the illustrated embodiment includes a threaded coupler  306  formed by an external thread that runs about a proximal end  300  of a tubular body of the adaptor  22   e.  The external thread of the threaded coupler is configured to corresponding to an internal thread of a spin nut disposed on the end of the corresponding adaptor (such as the type illustrated in  FIG. 14 ). 
     In the illustrated embodiment, the tubular body of the adaptor  22   e  includes a frusto-conical shaped section  304  on the distal side  302  of the threaded coupler  306 . The corresponding form of the adaptor  22   e  generally corresponds to a conventional catheter hub, such as the type illustrated in  FIG. 1 . 
     Unlike a conventional catheter hub, however, the adaptor  22   e  includes a radially extending member that projects from the tubular body. In the illustrated embodiment, the radially extending member comprises an annular collar  200   e  that circumscribes a portion of the frusto-conical shaped section  304  of the tubular body. The collar  200   e  is generally positioned about midway between the proximal and distal ends  300 ,  302  of the tubular body; however, it need not be as illustrated in embodiment of  FIG. 16 . 
     As understood from  FIGS. 15   a  through  15   c,  the retainer  20   e  defines a central channel  44   e  that has a generally conical shape corresponding to the shape of the adaptor tubular body. The channel  44   e  is interposed between a pair of opposing converging longitudinal walls  46   e.    
     The walls  46   e  are spaced apart such that there is a variable lateral distance therebetween. The walls  46   e  have a proximal end  300  and a distal end  302 , with the proximal end width being desirably wider than the distal end width. 
     The central channel  44   e  extends through the retainer  20   e  along the longitudinal axis and between the converging walls  46   e.  The channel  44   e  is similarly of variable lateral dimension as taken at points along the longitudinal axis direction. 
     The central channel  44   e  has a truncated upper section which gives the channel a generally U-shape having an upper opening  47   e.  The bottom and side surfaces of the channel  44   e  are arcuate and substantially match the shape of the catheter adaptor  22   e,  which can be received therein. The variable diameter of the channel  44   e  is sized to receive the longitudinal length of the catheter adaptor  22   e.  Each section of the channel  44   e  has arcuate shape of a radius of curvature that generally matches a corresponding section of the catheter adaptor  22   e.  In the illustrated embodiment, the radii of curvature vary along the longitudinal length of the channel  44   e;  however, the channel  44   e  can have generally uniform radii of curvature, as illustrated by the above embodiments. 
     In cross section, as best understood from  FIG. 15   c , the channel  44   e  extends through an arc of greater than 180° about the longitudinal axis such that the lateral length of the upper opening  47   e  is less than the diameter of the channel  44   e  at a given point in the longitudinal direction. In the illustrated embodiment, the channel  44   e  desirably extends through an arc of about 200° about the channel axis. 
     The retainer also includes at least one slot  50   e  that lies generally perpendicular to the longitudinal axis and extends across the channel  44   e  to section the channel  44   e  into a proximal channel portion and a distal channel portion. In the illustrated embodiment, the proximal and distal channel portions have generally equal longitudinal lengths; however, they need not have the same length. The length of the channel portions though desirably provides stability to the catheter adaptor  22   e  when inserted into the retainer  20   e  to prevent the catheter adaptor  22   e  from yawing (i.e. pivoting relative to the retainer within a plane parallel to the anchor pad). Each channel section of the retainer  20   e  is also sized to receive a corresponding section of the catheter adaptor  22   e.  Each slot  50   e  is sized to receive the collar  200   e  of the catheter adaptor  22   e.    
     The slot  50   e  has a thickness that substantially matches the thickness of the adaptor collar  200   e.  The thickness of slot  50   e,  however, is less than the combined longitudinal lengths of the proximal and distal channel portions. This dimensional relationship provides further stability to the retained catheter adaptor  22   e  when inserted into the retainer  20   e.    
     In the illustrated embodiment, the retainer  20   e  includes at least two lateral slots  50   e  arranged in series (i.e., next to each other) between the proximal and distal channel portions. The series of slots desirably includes between two (2) and twenty (20) slots. More preferably, the series comprises less than seven (7) slots. The illustrated embodiment shows two (2) slots. 
     As described above, each slot  50   e  is sized to receive a portion of the adaptor annular collar  200   e  to prevent longitudinal displacement of the catheter, as discussed in detail above. Each slot  50   e  desirably has a rectangular shape and extends from an exterior surfaces  52   e  through the walls  46   e,  and across the central channel  46   e.  The width of each slot  50   e  (measured longitudinally) is desirably slightly greater than the width of the fitting  304 , measured in the longitudinal direction to receive the fitting  304 , as discussed above 
     The retainer  20   e  also desirably includes a relief  308  formed on the bottom of the channel  44   e.  The relief  308  is sized to receive a portion of the collar  200   e  when placed within one of the slots  50   e.    
     Finger platforms  310  extend from the side walls  46   e  of the retainer  20   e.  The finger platforms  310  are sized and configured to enable allow a health care provider to press the retainer  20   e  against the skin of the patient while pulling up on the catheter adaptor  22   e  or on the adaptor to which it is connected, when disengaging the catheter adaptor  22   e  from the retainer  20   e.    
     So configured, in addition to the interengagement between the slots  50   e  and annular collar  200   e,  longitudinal movement of the catheter in the proximal-to-distal direction is further inhibited by cooperation between the conical-shaped channel  44   e  and frusto-conical shaped fitting  304 . That is, when an applied force directs the fitting  304  in the distal direction, the fitting  304  advances until contact with a section of the walls  46   e  (which are of uniformly narrower diameter as measured toward the proximal end of the walls  46   e ). When contact is made, the fitting  304 , and catheter which is attached thereto, is restricted from further distal movement. 
       FIG. 16  illustrates another embodiment of the catheterization system similar to that described above in connection with  FIGS. 15   a - 15   c.  Accordingly, like reference numerals with a “f” suffix have been used to indicate similar components between these embodiments. The above description of like components thus applies equally to the present embodiment, unless stated otherwise. 
     In the illustrated embodiment, the conical shaped section of the catheter hub  304  has an irregular step in diameter between the side proximal  300   f  of the collar  200   f  and the side distal  302   f  of the collar  200   f  That is a minimum diameter of the conical section on the side proximal  300   f  the collar  200   f  is larger than a maximum diameter of the conical section on the side distal  302   f  of the collar  200   f.    
     The retainer  20   f  has a shape corresponding to that of the conical section of the catheter adaptor  22   f  The proximal  300   f  channel portion has a radius of curvature generally matching that of the proximal  300   f  side of the adaptor conical section. And the distal  302   f  channel portion has a radius of curvature generally matching that of the distal  302   f  side of the adaptor conical section. As such, a minimum diameter of the proximal  300   f  channel section is larger than a maximum diameter of the distal  302   f  channel section. 
     The retainer  20   f  is mounted atop an anchor pad  16   f  with its upper opening  47 f being exposed and facing away from the anchor pad  16   f  The construction of the anchor pad  16   f  and the retainer  20   f,  as well as the attachment of the retainer  20   f  to the anchor pad  16   f,  are in accordance with the above description. The anchor pad  16   f  also supports a tube clip  24   f,  as illustrated in  FIG. 16 . 
     As similar to the above embodiment, the present catheterization system is used by first connecting the catheter to a fluid line (be it supply or drainage). The catheter is inserted into a body lumen, such as a vein, in accordance with the above description. The nurse then inserts a distal end of one of the coupling adaptor  22   c  into a catheter adaptor to connect together the adaptors. The nurse may then interconnect the adapters by means of the above-described ratchet clip, or the lure-lock fitting formed between the threaded coupler on the proximal end of the catheter adaptor and the spin nut on the end of the adaptor attached to the fluid tube. 
     The nurse removes the paper backing which initially covers an adhesive bottom surface of the anchor pad  16   f,  as described above, and attaches the anchor pad  16   f  to the patient&#39;s skin proximate to the indwelling catheter. The nurse specifically positions a notch of the pad  16   f  around the catheter body or cannula. The nurse generally aligns the proximal edge of the anchor pad  16   f  with the insertion site. 
     The nurse positions the adaptor  22   f  above the series of retainer slots  50   f,  and snaps the adaptor  22   f  into the retainer  20   f.  In doing so, the adaptor  20   f  is pressed between the longitudinal walls  46   f  of the retainer  20   f  with the annular collar  200   f  extending into one of the slots  50   f  of the retainer  20   f.  As the nurse presses the adaptor  22   f  into the retainer  20   f,  chamfered edges  312  around the slots  50   f  (see  FIG. 15   a ) of the longitudinal walls  46   f  guide the annular collar  200   f  into the slots  50   f.  With the annular collar  200   f  positioned in one of the slots  50   f,  the adaptor  22   f  is prevented from sliding in a longitudinal direction. 
     Like the above-described embodiments of the retainer  20   f,  the ergonomic design of the retainer  20   f  provides for various positions of the adaptor  22   f  in the retainer  20   f  so that the retainer  20   f  is not technique- or position-sensitive That is, a nurse can simply press the adaptor  22   f  into the retainer  20   f,  irrespective of the position of the annular collar  200   f  relative to a particular slot  50   f  of the retainer  20   f.  So long as the annular collar  200   f  is positioned above the series of slots  50   f,  the chamfered edges  312  of the wall will guide the annular collar  200   f  into the slot  50   f.    
       FIGS. 17 and 18  illustrate a catheterization system configured in accordance with another embodiment of the present invention. Like the other embodiments of the catheterization system, this embodiment includes a catheter and an anchoring system that includes a retainer and an anchoring pad. Again, for consistency, like numbers with an “g” suffix have been used to indicate like parts of the anchoring system of  FIGS. 11  and of  16 . The above description of like components thus should be understood as applying equally to this embodiment, unless stated otherwise. 
     The present embodiment, like the previous embodiments, utilizes the concept of providing an adaptor and retainer which cooperate with each other to secure the catheter to the body of a patient and inhibit movement of the catheter in the longitudinal, transverse and lateral directions. Also, like the previous embodiments, the anchoring system can include the concept of not being position or technique sensitive. That is, the medical attendant can simply locate the catheter adaptor generally above the retainer and press the adaptor into the retainer. Engagement thus requires only coarse alignment of the adaptor with the retainer. 
       FIG. 17  shows the retainer  20   g  comprising a longitudinal channel  44   g  formed between a pair of substantially parallel walls  46   g  and configured to receive the tubular body of the adaptor  22   g  in a snap fit manner. The construction of the channel thus is similar to that described above and about a longitudinal axis L. 
     The retainer  20   g  additionally comprises at least one projection or protuberance  400  that extends from one of the walls  46   g  toward the longitudinal axis in the lateral direction. The projection  400  is sized and configured to cooperate with a recess on the catheter adaptor  22   g,  as explained below. The projection  400 , however, can extend into the channel  44   g  toward the longitudinal axis in the transverse direction. 
     In the illustrated embodiment, the retainer  20   g  includes a plurality of projections  400 . In one mode, two projections are positioned across from each other on opposite walls  46   g.  The set of projections  400  thus oppose each other. The retainer  20   g  also desirably includes a plurality of projection sets  400  which are spaced along a length of the channel  44   g.  The multiple projection sets  400  thus provide multiple positions in which the adaptor  22   g  can occupy within the retainer  20   g,  so as to require only coarse alignment between the retainer  20   g  and the adaptor  22   g  before engagement. Both laterally and transversely extending projections  400  can be used with the retainer. 
     The projections  400  desirably are positioned between a first portion of the channel  44   g  and a second portion of the channel  44   g.  In the illustrated embodiment, one channel portion is formed at a proximal end of the channel  44   g  and the other end is formed at a distal end of the channel  44   g.  Each of the channel portions desirably are sufficiently long and support a sufficient length of the adaptor  22   g  so as to prevent the adaptor  22   g  from rocking. 
     Each projection  400  desirably has sufficient thickness or bulk so as to resist nominal applied forces, i.e. not break when the medical attendant presses on it. Also, the portion of the projection  400  that projects into the channel  44   g  is of sufficient lateral or transverse dimension to inhibit movement of the catheter adaptor  22   g  in the longitudinal direction, without inhibiting placement of the catheter adaptor  22   g  into or out of the channel  44   g.  That is, the projections  400  extend into the channel by a sufficient amount to engage with corresponding structure on the catheter adaptor  22   g,  as described below. 
     In the illustrated embodiment, each projection  400  has generally a rectangular shape in a plane generally parallel to the retainer base  48   g.  Thus, the projections  400  generally form a series of square teeth along a section of each wall  46   g  at an upper rim of the channel  44   g.  The projection  400 , however, can be configured in a wide variety of other shapes, including, but not limited to, semi-circular, square, curvilinear, triangular or the like. Thus, the projection  400  may be linear, as illustrated, or curved or curvilinear to suit a particular application, so as to inhibit migration of the catheter adaptor  22   g  in the longitudinal direction. 
     Below the upper rim of the channel  44   g,  each projection tapers back toward the corresponding side wall  46   g.  In the illustrated embodiment, this taper  406  generally follows an arcuate path that desirably corresponds to a surface to the adaptor  22   g,  as described below. The projections  400 , however, can extend about the entire arc of the channel  44   g  (i.e., down one side wall, across the bottom of the channel and up the other side wall) or the projections  400  can extend downward to the channel bottom ( FIG. 18 ). 
     As noted above, the projections  400  are advantageously sized and configured to cooperate with a corresponding recess(es) on the catheter adaptor  22   g.  Without limitation, the catheter adaptor  22   g  can be a fitting on the end of either the fluid tube, as shown in  FIG. 17 , or the catheter as shown in  FIG. 18  (e.g., a catheter hub). 
     In one mode, the projections  400  fit into the recess(es) and engage the sides of the recess(es) so as to inhibit longitudinal movement of the adaptor  22   g  relative to the retainer  20   g.  In the illustrated embodiment, the adaptor  22   g  includes a plurality of annular grooves or depressions  408  (e.g., three grooves); however, any number of annular grooves  408  can be used with the adaptor  22   g.  In order to accommodate the adaptor  22   g  in multiple positions within the retainer  20   g,  however, the number of projection sets  400  should be less than the number of grooves  408 . 
     Each annular groove  408  is interposed between the proximal and distal ends  28   g,    26   g  of the adaptor  22   g  and extends radially inward while circumscribing the adaptor  22   g.  Each annular groove  408  also has a thickness measured in the longitudinal direction which is slightly less than the longitudinal length of the projection  400  so that at least a portion of the annular depression  408  fits around the projection  408  of the retainer wall  46   g,  as described above. 
     Each annular groove  408  thus defines an arcuate surface on the exterior of the adaptor  22   g.  In the illustrated embodiment, the radius of this arcuate surface desirably is not greater than the radius of curvature followed by the corresponding projection(s)  400  as it tapers toward the respective wall  46   g,  as noted above. 
       FIG. 18  is generally similar to  FIG. 17  except that the retainer  20   g  is configured to receive a frusto-conical shaped section  304   g  of the adaptor  22   g,  rather than an adaptor  22   g  having a uniform diameter, as shown in  FIG. 17 . To form the snap fit engagement between the retainer  20   g  and tapered adaptor  22   g,  the channel  44   g  extends through the retainer  20   g  along the longitudinal axis and between converging walls  46   g,  thus forming a tapered or stepped region. The illustrated embodiment also shows four projections  400  formed on the retainer  20   g,  however, it is understood that any suitable number of projections (2-20) can be used with the retainer  20   g.    
     The present embodiment of the catheterization system is used by first catheter is inserted into a body lumen, such as a vein, in accordance with the above description. The medical attendant then connects the catheter adaptors together so as to attach the catheter to the fluid line. The medical attendant may then interconnect the adapters by means of the above-described ratchet clip, or the lure-lock fitting formed between the threaded coupler on the proximal end of the catheter adaptor and the spin nut on the end of the adaptor attached to the fluid tube. 
     The medical attendant positions the adaptor  22   g  above the series of retainer projections  400 , and snaps the adaptor  22   g  into the retainer  20   g.  In doing so, the adaptor  22   g  is pressed between the longitudinal walls  46   g  of the retainer  20   g  with at least a portion of the annular depression  408  receiving a corresponding projection  400 . With at least a portion of the annular depression  408  positioned around one of the projections  400 , the adaptor  22   g  is inhibited from moving in a longitudinal direction. The medical attendant then removes the paper backing which initially covers an adhesive bottom surface of the anchor pad  16   g  and attaches the anchor pad  16   g  to the patient&#39;s skin proximate to the indwelling catheter, as described above. 
     As previously explained, the ergonomic design of the retainer  20   g  provides for various positions of the adaptor  22   g  in the retainer  20   g  so that the retainer  20   g  is not technique or position sensitive. That is, a medical attendant can simply press the adaptor  22   g  into the retainer  20   g,  irrespective of the position of the annular depression  408  relative to a particular projection  400  of the retainer  20   g.  Further, so long as the annular depression  408  is positioned above the series of projections  400 , the chamfered edges  312   g  of the wall  46   g  will guide the annular depression around at least a portion of the projection  400 . 
     Although this invention has been described in terms of certain preferred embodiments, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. It is also understood that various aspects of one embodiments can between with another embodiment. Accordingly, the scope of the invention is intended to be defined only by the claims which follow.