Abstract:
The intravenous catheter insertion apparatus has a catheter integral with a pre-slit injection site, a blunt cannula adapted for piercing the septum of the pre-slit injection site, and a tube slidably housing a needle. In a preferred embodiment, the needle tube and blunt cannula are integral with each other. In use, the needle is extended through the aligned bores of the catheter, injection site, and blunt cannula, leaving a portion of the needle tip projecting from the end of the catheter in order to insert the catheter into the patient&#39;s vein through venipuncture. The needle is withdrawn, the needle slide locking in the tube housing after use in order to prevent accidental needle puncture wounds. The blunt cannula is also removable, leaving the septum of the injection site sealed to prevent back flow or spurting of blood from the catheter. In an alternate embodiment, a T-connector having a pre-slit septum may be used in lieu of the of the injection site.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/106,058, filed Oct. 27, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to intravenous catheters, and particularly to an intravenous catheter insertion apparatus which prevents exposure of medical personnel to accidental needle sticks and to blood borne pathogens during the insertion of an IV catheter. 
     2. Description of Related Art 
     Intravenous (IV) therapy is a versatile technique used for the administration of fluids. It has been used for such purposes as the maintenance of fluid and electrolyte balance, the transfusion of blood, administration of nutritional supplements, chemotherapy, and the administration of drugs and medications. Fluids may be administered intravenously by injection through a hypodermic syringe, or intermittently or continuously by infusion using a needle or a plastic or silicon catheter. 
     Although there are many advantages to be derived from the intravenous administration of fluids, the past two decades have brought heightened awareness of the risks of propagating infectious diseases associated with the technique, particularly due to the HIV virus. One consequence of this heightened awareness has been the development of various devices to reduce the risk of spreading infectious diseases. Probably the majority of devices which have been developed are concerned with the danger of accidental puncture wounds occurring through use of the hypodermic syringe needle or to the particular needle or trocar used to introduce a continuous infusion IV catheter. 
     Continuous infusion IV therapy may be generally divided between peripheral IV therapy and central venous IV therapy, depending on the site of administration. Catheters used for peripheral IV therapy tend to be short, between ¾″ and 1¼″ long, or occasionally 2″ long for insertion into a deep vein. Catheters for central venous IV therapy tend to be much longer, and are outside the scope of the present invention. 
     A peripheral IV catheter is made of soft, flexible plastic or silicon, generally between 16 gauge and 24 gauge. In the conventional venipuncture the catheter is inserted into a vein in the patient&#39;s hand, foot, or the inner aspect of the arm or any vein in the body that will accept an IV catheter. When inserting a peripheral IV catheter, an IV infusion set is prepared, the IV tubing being filled with fluid and any air eliminated from the tubing, closing the fluid clamp. A tourniquet is applied proximal to the venipuncture site, and a variety of techniques are used to dilate the vein. Wearing disposable gloves, the venipuncture site is cleansed and a vein is retracted or anchored by placing a thumb over the vein about two to three inches distal to the site. A catheter with a stylet advanced through its lumen so that the pointed tip extends beyond the cannula of the catheter, or a butterfly needle, is introduced into the vein by inserting the bevel into the vein at about a 20° to 30° angle with the bevel facing up in order to pierce one wall of the vein. Blood return in the tubing of the butterfly needle or the flashback chamber of the over the needle catheter indicates that the vein has been entered, and the needle is lowered towards the skin and the catheter is advanced about ¼″ into the vein. The stylet is loosened and the catheter is gently advanced farther up into the vein until the hub of the catheter is against the venipuncture site. The tourniquet is loosened and the needle or stylet is removed from the catheter. The needle adaptor of the infusion tubing is secured to the hub of the catheter, and the roller clamp is opened. The flow rate may be controlled either by adjusting the roller clamp or an infusion pump, and the catheter is secured to the venipuncture site by gauze and adhesive tape. 
     During this process medical personnel are exposed to the possibility of an accidental needle puncture or to contamination from the back flow of the patient&#39;s blood from the venipuncture site. 
     Many protective devices have been developed to prevent accidental needle puncture during the insertion of the IV catheter. U.S. Pat. No. 4,444,203, issued Apr. 24, 1984 to A. Engleman, shows a combination device for inserting an IV catheter and withdrawing blood. The device includes a hub having a hypodermic needle at one end adapted for releasably holing an over the needle catheter, and a vacuum container penetrating needle covered by a resilient sleeve at the other end of the hub. A vacuum container for collecting blood slides over the vacuum needle, compressing the sleeve so the needle penetrates the sleeve. The catheter may be inserted with or without the vacuum container in place, blood samples are collected, and the entire assembly except the catheter itself are removed. 
     Other blood collection devices are shown in U.S. Pat. No. 4,509,534, issued Apr. 9, 1985 to M. J. Tassin, Jr. and U.S. Pat. No. 4,819,659, issued Apr. 11, 1989 to D. L. Sitar. The Tassin device describes a device for collecting blood which taps into an IV catheter system through an entry means, but does not describe a catheter insertion system or apparatus. The Sitar patent describes a blood withdrawing device with a needle guard to prevent accidental puncture wounds, including a guard which slides forward to cover the needle, locking on a lock which is molded onto the shaft of the needle to lock the guard in position. 
     Needle shields or sheathes have been developed which are slidable, e.g., U.S. Pat. No. 5, 011,475, issued Apr. 30, 1991 to Richard A. Olson (sheath slidable in slots defined in barrel of syringe); pivotal, e.g., U.S. Pat. No. 5,603,699, issued Feb. 18, 1997 to Jerry P. Shine (shield pivotally attached at base of syringe and pivotally operated by lever connected to gear mechanism); and frangible, e.g., U.S. Pat. No. 5,344,404, issued Sep. 6, 1994 to Carl L. Benson (shield in different segments secured by frangible means such as plastic shrink wrap). Some of the shields and sheathes are open over the tip of the needle, such as U.S. Pat. No. 5,267,972, issued Dec. 7, 1993 to Wayne W. Anderson (sheath spring biased to normally enclose needle, retracts around barrel of syringe when pressed against patient&#39; skin), while others lock over and enclose the tip of the needle after use, such as U.S. Pat. No. 5,366,447, issued Nov. 22, 1994 to Carol A. Gurley (sleeve sliding over barrel of hypodermic syringe, the sleeve having a seal at the end to seal the sleeve over the needle when fully extended) and U.S. Pat. No. 5,685, 860, issued Nov. 11, 1997 to Chang, et al. (needle with a cap attached by a sleeve to the needle hub, capping needle tip after the needle is removed from the catheter hub). 
     International Patent No. WO 92/04063, published Mar. 19, 1992, shows a protective assembly for use with a syringe or a Y-tube. The device includes a hollow body connecting to a syringe by a Luer Lok connector at one end and to a needle at the other end, the exterior of the hollow body having ratchet teeth, and a protective sleeve slidable over the hollow body, the interior of the protective sleeve having a pawl which engages the ratchet teeth to prevent retrograde movement of the protective sleeve once the protective sleeve has been covered by the sleeve. 
     The present invention is an intravenous catheter insertion apparatus which includes a catheter integral with an a pre-slit injection site, a blunt cannula adapted for penetrating the pre-slit injection site, and a needle tube having a needle of sufficient length to pass through the blunt cannula, injection site and catheter, leaving the tip end of the needle projecting through the end of the catheter. After the catheter has been inserted into the venipuncture site, the needle tube and blunt cannula may be removed, the septum on the injection site preventing blood from spilling or spurting out of the catheter, thereby preventing the spread of blood borne pathogens. 
     International Patent No. WO 90/12606, published Nov. 1, 1990, shows a pre-slit injection site used in combination with a blunt cannula (FIGS. 5A and 5B), the injection site used in combination with a catheter (FIGS. 2A and 2B), the injection site and blunt cannula used in combination with a syringe (FIG. 4A), and the injection site and blunt cannula used in combination with IV tubing. However, the patent does not disclose an injection site integral with a catheter. Further, the patent does not describe the use of the combination to perform a venipuncture. The syringe is only described in combination with the blunt cannula for use in injecting fluids, and is shown in use with the blunt cannula without a needle. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The intravenous catheter insertion apparatus has a catheter integral with a pre-slit injection site, a blunt cannula adapted for piercing the septum of the pre-slit injection site, and a tube slidably housing a needle. In use, the needle is extended through the aligned bores of the catheter, injection site, and blunt cannula, leaving a portion of the needle tip projecting from the end of the catheter in order to insert the catheter into the patient&#39;s vein through venipuncture. The needle is withdrawn, the needle slide locking in the tube housing after use in order to prevent accidental needle puncture wounds. The blunt cannula is also removable, leaving the septum of the injection site sealed to prevent back flow or spurting of blood from the catheter. Preferably, the needle tube is made integral with the blunt cannula to ensure that the tube and cannula are removed as a unit. In an alternate embodiment, a T-connector having a pre-slit septum may be used in lieu of the of the injection site. 
     Accordingly, it is a principal object of the invention to provide an intravenous catheter insertion apparatus which reduces the risk of contamination by blood borne pathogens by means of a trocar inserted through a blunt cannula and pre-slit injection site before insertion through the IV catheter for venipuncture. 
     It is another object of the invention to reduce the risk of contamination by blood borne pathogens by means of an integral pre-slit injection site and IV catheter, preventing loss of blood by back flow through the IV catheter. 
     It is a further object of the invention to reduce the risk of needle puncture during insertion of an IV catheter by use of a tube slidably housing a needle, the tube having a locking mechanism for locking the needle in a retracted position in the tube after use. 
     Still another object of the invention is to provide an intravenous catheter insertion apparatus which reduces or prevents the spread of infectious diseases by pathogens in the blood, the contamination of bedding and clothing with blood, and the risk of accidental needle puncture wounds during insertion of an intravenous catheter which may be easily manufactured from devices currently known and available. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded, perspective view of a intravenous catheter insertion apparatus according to the present invention. 
     FIG. 2 is a sectional view of the intravenous catheter insertion apparatus according to the present invention. 
     FIG. 3 is a plan view of the needle tube showing the locking mechanism. 
     FIG. 4 is an exploded, perspective view of an alternative embodiment of the intravenous catheter insertion apparatus according to the present invention. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is an intravenous catheter insertion apparatus, designated generally as  10  in the drawings. As shown in FIG. 1, the apparatus includes a catheter  20 A integral with a pre-slit injection site  20 B, a blunt cannula  40 , and a tube  50  housing a needle  52 , the needle  52  being slidable in the tube  50 . The catheter  20 A is of a conventional type well known in the art, and comprises a soft flexible cannula  22  made from plastic or silicon mounted on a hub  24 . The cannula  22  is generally between ¾″ and 1¼″ in length and between  16  and  24  gauge in diameter. Ordinarily, an IV catheter will have a pair of flanges  26 , as shown in FIG. 2, mounted transversely on the hub and spaced apart by 180°, being adapted for connection to a threaded Luer Lok. 
     The pre-slit injection site  20 B is also of a type already known, such as the Baxter InterLink™ Injection Site 2N3379 (patent pending) and the various embodiments described in International Patent WO 90/12606. As shown in FIG. 2, the injection site  20 B includes a cylindrical housing  28  defining a chamber  30  at one end and enclosing a fluid flow tube  32  at the other end, the chamber  30  and the fluid flow tube  32  defining a path for the flow of fluid through the injection site  20 B. The end of the injection site  20 B defining the chamber  30  is capped by a flexible, resilient septum  34  having a slit defined therein adapted for receiving the tip of a blunt cannula  40 , the slit closing to cap the chamber  30  to prevent the flow of fluid when the cannula  40  is removed. The fluid flow tube  32  is adapted for insertion into the catheter hub  24 . The exterior of the housing  28  has an annular groove  36  defined therein adapted for receiving the locking members of a blunt cannula  40  as set forth below. 
     It is known in the art to temporarily connect an injection site  20 B to a catheter  20 A temporarily and removably for the purpose of passing fluids through the catheter  20 A and injection site  20 B, such as by a Luer Lok connection  38  or other means adapted for engaging the hub  24  of the catheter  20 A. While such a connection will also work for the purpose of inserting an IV catheter according to the method of the present invention, it is preferred that the catheter  20 A and the pre-slit injection site  20 B be made integral with each other, either through use of an adhesive or thermosetting resin, or by molding the components together during fabrication. According to the present invention, the septum  34  caps the injection site  20 B to prevent the back flow of blood from the patient&#39;s vein from exiting through hub  24  of the catheter  20 A during venipuncture. By making the injection site  20 B integral with the catheter  20 A, accidental disconnection of the injection site  20 B from the catheter  20 A during venipuncture is avoided. No loss of flexibility is incurred, since the adaptors currently available permit any device (IV tubing, specimen collection devices, etc.) which may be directly connected to the catheter  20 A to be connected to the pre-slit injection site  20 B. 
     The blunt cannula  40  is also known in the art, such as the Becton Dickinson &amp; Co. No. 303370 and the various embodiments described in International Patent WO 90/12606. The blunt cannula  40  includes a hollow, cylindrical body  42  having a pair of Luer Lok flanges  44  at one end spaced apart by 180°, a penetrating tube  46  having a tapered tip end  48 , and a pair of flexible elongated locking members  49  attached to the exterior of the body  42 . The penetrating tube  46  is adapted for penetrating the septum  34  of the pre-slit injection site  20 B without damaging the septum  34 . The locking members  49  are adapted for engaging the annular groove  36  defined in the housing  28  of the pre-slit injection site  20 B in order to prevent accidental disconnection of the cannula  40  from the injection site  20 B. It will be seen from FIGS. 1 and 2 that when the blunt cannula  40  is connected to the injection site  20 B, a continuous passageway or bore is defined by the aligned bores  51 A,  51 B, and  51 C defined in the catheter  20 A, pre-slit injection site  20 B and blunt cannula  40  respectively. 
     Needle tubes  50  for the insertion of IV catheters, such as that shown in FIGS. 1 and 3, are also known in the art. Such tubes include a needle  52  mounted on a holder  54  adapted for grasping by the thumb and fingers, a sliding tube  56  having a locking device  58  being slidable on the holder  54  between a retracted position and an extended position so that the needle  52  is exposed for substantially its entire length in an extended position, and enclosed by the tube  56  in a retracted position, the tube  56  engaging a lock  58  in the retracted position which permanently locks the needle  52  so that it cannot be extended again. The needle tube  50  includes an outlet tube  60  adapted for snugly engaging the hub  24  of an IV catheter  20 A, but which also snugly engages the hollow body  42  of the blunt cannula  40 . The needle  52  of the conventional needle tube  50  is too short to be used with the present invention, being designed so that the tip of the needle  52  barely projects from the cannula  22  when the needle  52  is fully extended with the outlet tube  60  engaging the hub  24  of the catheter  20 A, and consequently a needle tube  50  having a length approximately 1½″ longer is required so that the needle  52  has sufficient length to extend through the continuous bore  51  formed by the blunt cannula  40 , pre-slit injection site  20 B, and catheter  20 A. 
     Although the needle tube  50  has been described as being separate from the blunt cannula  40 , in the preferred embodiment the needle tube  50  is made integral with the blunt cannula  40 , either through use of an adhesive or thermosetting resin, or by molding the components together during fabrication. According to the method of the present invention, the needle tube  50  and blunt cannula  40  should be removed from the injection site  20 B as a unit. If the needle tube  50  is removed from the blunt cannula  40  before the blunt cannula  40  is removed from the injection site  20 B, then blood or fluids may back up through the aligned bores  51 A,  51 B, and  51 C, spilling out through hollow body  42  of the blunt cannula  40 . Consequently, it is preferred that the needle tube  50  and blunt cannula  40  be made as an integral, one-piece unit to preclude accidental removal of the needle tube  50  from the blunt cannula  40  prior to removal of the blunt cannula  40  from the injection site  20 B. 
     An alternative embodiment of the intravenous catheter insertion apparatus  10  is shown in FIG. 4, in which the integral catheter-injection site  20  is replaced by an integral catheter  80 A and T-connector  80 B. The catheter portion  80 A is again of conventional design, including a cannula  82  and a hub  84 . The T-connector portion  80 B is also of conventional design, such as the Baxter InterLink® System T-Connector Extension Set, No. 2N3326. The T-connector  80 B includes a hollow, cylindrical body  81  capped by a pre-slit septum  83 , a side tube  86  connected to a side port  88  by a length of flexible tubing  90 , and fluid flow tube  92  adapted for engaging the hub  84  of a catheter  80 B. The septum  83  is flexible and resilient and has a slit defined therein adapted to receive the penetrating tube  46  of a blunt cannula  40 . The exterior of the hollow body  81  has a flange  94  adapted for engaging the locking members  49  of the blunt cannula  40 . The hollow body  81 , fluid flow tube  92 , catheter hub  84  and cannula  82  define a bore or first path for the flow of fluid, the first path being capped by the septum  83 , which closes to prevent the flow of fluid when the blunt cannula  40  is removed from the septum  83 . A second path is defined by the catheter cannula  82  and hub  84 , the fluid flow tube  92  and hollow body  81 , the side arm  86 , flexible tubing  90 , and outlet port  80 . The outlet port  88  may be capped by a pre-slit injection site (not shown) or other device to block the flow of fluid. 
     As with the first embodiment described above, the catheter  80 A, T-connector  80 B, and blunt cannula  40  define a continuous bore through which the needle  52  of a needle tube  50  may be extended in order to perform venipuncture for insertion of the catheter  80 A. The catheter  80 A and T-connector  80 B may be used as discrete components, but in the preferred embodiment, the catheter  80 A and T-connector  80 B will be formed as an integral component, either through being permanently joined by an adhesive or thermosetting resin, or by being molded as an integral unit during fabrication. 
     The method of using the intravenous catheter insertion apparatus according to the present invention includes the steps of: (1) selecting a pre-slit injection site-catheter  20  combination; (2) inserting a blunt cannula  40  into the pre-slit injection site  20 B; (3) extending the needle  52  of a locking needle tube  50  assembly through the bore defined by the blunt cannula-injection site-catheter combination so that the tip of the needle  52  projects beyond the end of the catheter  20 A (it will be noted that this step may be performed by the manufacturer or distributor of the insertion apparatus  10 , the apparatus  10  being distributed as a pre-assembled unit ready for use); (4) performing a venipuncture procedure in order to insert the catheter  20 A into a vein of a patient; (5) removing the needle  52  from the apparatus  10 ; (6) locking the needle  52  in order to prevent a needle puncture wound; and (8) removing the blunt cannula  40  from the injection site  20 B. 
     It will be understood that although a locking needle tube has been described, other devices with an extended needle or stylus may be used to penetrate the patient&#39;s skin during the venipuncture. It will also be understood that although a preferred combination of blunt cannula and pre-slit injection site have been described, blunt cannulae and injection sites having different configurations may be used provided they provide a continuous bore capable of receiving an extended needle for performing a venipuncture procedure in combination with a catheter, and provided the injection site has a resilient cap to prevent the back flow of blood with the blunt cannula removed. 
     It is to be understood that the present invention is not limited to the sole embodiments described above, but encompasses any and all embodiments within the scope of the following claims.