Abstract:
An appliance which removably stores a portion of a catheter and an adapter, where the indwelling portion of catheter is still inside the body tissue of a patient. The appliance has an aperture that permits connection of a vacuum source such as hospital suction. When the appliance containing the catheter is held against the portion of the body including the indwelling site of the catheter, the vacuum source is applied, having a tendency to hold the appliance in place against the body. An orthopedic cast can be fabricated around the appliance, after which time the vacuum can be deactivated and the appliance can be removed, revealing a channel formed in the orthopedic cast. Through the channel, the distal portion of the catheter and the adapter can be accessed, facilitating continued post-operative anesthesia, easy visual inspection for signs of infection or dislodgment of the catheter and permitting easy removal when needed.

Description:
PRIORITY CLAIM 
     This application claims the benefit of PCT application serial number US/2011/048175 filed Aug. 18, 2011. The foregoing application is incorporated by reference in its entirety as if fully set forth herein. 
     BACKGROUND 
     An orthopedic cast is used to protect and immobilize a portion of the human body. Often, an orthopedic cast is applied following a procedure to set one or more broken bones. In such cases, the portion of the body with the broken bone is encased in the orthopedic cast, holding the bone fragments in place so that the bone can heal. Other names by which an orthopedic cast is commonly known include a surgical cast, or often simply a cast. 
     The orthopedic cast is formed by wrapping cotton strips saturated with wet plaster of paris around the portion of the body with the broken bone. When the wet plaster dries, the hardened cast is formed. Other techniques or materials for constructing the cast are available, such as the use of thermoplastic- or fiberglass-infused bandages, but irrespective of the construction the desired end result is a hard shell about a limb or other portion of the human body that immobilizes and protects in order for a broken bone to heal. Casts can be used for conditions other than broken bones as well, including following repair of ligaments or other structures in the body. 
     Casts come in a variety of shapes. They may cover only a portion of a limb, or they can cover a larger portion of the body. For example, a spica cast is a cast which surrounds the trunk of the body and one or more limbs, and a hip spica cast is a cast surrounding the trunk of the body and one or both legs. Larger casts such as the hip spica are used, for example, where there has been a complex fracture requiring extensive surgery, or following surgery on a child to remedy a congenital dislocation of the hip. Other conditions requiring a larger cast, such as a spica cast, during healing are known. 
     In instances where an extensive surgery to repair a complex break or a congenital dislocation is required, it is often desirable to continue anesthesia to the patient following the surgery. Following the surgery and once the patient has awakened from the general anesthesia, a continuous infusion of local anesthesia to the area operated on can be delivered for post-operative pain relief. This technique is advantageous because it offers more granular control of pain, while reducing exposure to narcotic pain-killers and their side effects. The local anesthesia is delivered post-operatively utilizing the same nerve catheter used to numb the operative area during the surgery. 
     An issue can arise when the cast covering the operative area is fabricated, however, as the cast must also cover the site of the passage of the catheter into the body, where the catheter enters the body tissue. Once the cast hardens, the lumen of the catheter runs underneath the cast to the edge where it exits the cast. The site where the catheter enters the body, however, is completely covered underneath the hardened cast. 
     Covering the portion of the catheter that enters the body with the cast means that the site where the catheter enters the body can not be viewed during the post-operative delivery of anesthesia. Any visual indications of infection at the site are invisible. Additionally, if the anesthesia does not seem to be working well, there is no way to tell whether the catheter has become dislodged. Finally, at the end of hospitalization and before the patient goes home, it is difficult to remove the catheter, being buried under the cast. 
     What is needed is a manner of leaving a channel in a cast when the cast is fabricated. Such a channel would permit viewing of the site where the catheter enters the body tissue to enable a visual check for infections or dislodgment of the catheter. The channel would also permit easy access to the catheter for removal prior to the patient being sent home. 
     The cast and channel would be formed around the very nerve catheter inserted pre-operatively for local anesthesia, allowing the catheter to remain in place throughout the surgery, construction of the cast, and subsequent post-operative recovery. Such a channel could also be used for other devices or tubes which would be desirable to run through, rather than underneath, a cast. These other devices or tubes that could run through a channel in the cast might include a pre-existing drain or feeding tube, among other possibilities. But for the greatest structural integrity of the cast, the channel through the cast would need to be as small as possible. 
     Accordingly, this application discloses systems and methods for providing a channel through an orthopedic cast. 
     FIELD OF THE INVENTION 
     This invention relates generally to orthopedic casts, and more specifically, to systems and methods for providing a channel through an orthopedic cast. 
     SUMMARY 
     This invention relates generally to orthopedic casts, and more specifically, to systems and methods for providing a channel through an orthopedic cast. In some embodiments, an appliance for providing a channel through an orthopedic cast may have a generally oval shape, with a pair of flattened opposing sides, and a pair of curved opposing ends one of which is a catheter end and one of which is a vacuum end. In some embodiments, an appliance for providing a channel through an orthopedic cast may have a top surface and a bottom surface. In a preferred embodiment, an appliance for providing a channel through an orthopedic cast may have a bottom opening in the bottom surface, leading to a first interior section. In this embodiment, a portion of the catheter is rolled into a bundle, the bundle including an adapter and the distal end of the catheter, with the bundle being placed inside the first interior section. Then, the appliance is held against the patient, the appliance being held over the top of the body passage of the patient where the indwelling portion of the catheter is situated. A vacuum source is coupled to the appliance to keep the appliance in place while a cast is fabricated around a portion of the body of the patient. 
     In some embodiments, when a cast has been fabricated, the vacuum source is deactivated. Following the deactivation of the vacuum source, the appliance, with the bundle of the portion of the catheter and the adapter contained in the first interior section of the appliance, is removed from the cast, revealing a channel in the formed cast. Following removal of the appliance from the cast by pulling the appliance away from the patient, the bundle of the portion of the catheter and the adapter is removed from the first interior section of the appliance. Anesthesia can then be delivered to the patient by rejoining the connection between the infusion pump and the adapter, and activating the infusion pump. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  is a depiction of the prior art, in this case, a perspective view of an exemplary orthopedic cast; 
         FIG. 2  is a perspective view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 3  is a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 4   a  is a bottom cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 4   b  is a bottom cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 5  is a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an alternate embodiment of the invention; 
         FIG. 6  is a top view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 7  is a front cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 8  is a front cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 9   a  is a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 9   b  is a detail view of a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 10  is a side cutaway view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 11  is a perspective cutaway view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 12  is a perspective view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 13  is a perspective view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention; 
         FIG. 14  is a perspective view of a channel through an orthopedic cast, in accordance with an embodiment of the invention; and 
         FIG. 15  is a flow diagram of a method, in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     This invention relates generally to orthopedic casts, and more specifically, to systems and methods for providing a channel through an orthopedic cast. Specific details of certain embodiments of the invention are set forth in the following description and in  FIGS. 1-15  to provide a thorough understanding of such embodiments. The present invention may have additional embodiments, may be practiced without one or more of the details described for any particular described embodiment, or may have any detail described for one particular embodiment practiced with any other detail described for another embodiment. 
       FIG. 1  is a depiction of the prior art, in this case, a perspective view of an exemplary orthopedic cast. At  100 , a child recovering from surgery is shown with a double-hip spica cast, with a nerve catheter still inserted into the body exiting the spica cast at the top of the spica cast. 
     Orthopedic casts and their use are well understood in the art. An orthopedic cast may be formed by surrounding a portion of the body with cotton bandages infused with wet plaster of paris and allowing the plaster to harden, forming a hard shell. An exemplary orthopedic cast  12  may be a hip spica cast as depicted at  12 . Alternatively, an orthopedic cast may be a body cast, or be a cast covering only a limb, a wrist, or any other portion or portions of the body. Differently, an orthopedic cast can be a different type of cast. The present invention encompasses any construction of a shell covering a portion of the body, irrespective of materials which may include fiberglass, thermoplastics, polyurethane, or other materials known in the art to be used to fabricate a cast. 
     Beneath the exemplary orthopedic cast  12  surrounding a portion of the body of the patient  2  is a catheter  4 . The catheter has a forward end  6 , which may also be known as the insertion end. The catheter  4  enters the body of the patient  2  through a body passage  14  of the patient  2 . The portion of the catheter  4  situated inside the body passage  14  is also known in the art as the indwelling portion of the catheter  4 . The catheter  4  has a distal end  8 , which may also be known as the rearward end. Adjoining the distal end  8  of the catheter  4  may be an adapter  10 , such as an industry-standard SnapLock adapter. Anesthesia being provided to the patient flows from its source, which may be an infusion pump or other source for delivering anesthesia, through a lumen joined to the adapter  10 , then through the distal end  8  of the catheter  4 , to the forward end  6  of the catheter  4 , and into the body of the patient  2  through the indwelling portion of the catheter which is inserted into a body passage  14  of the patient  2 . For a hip surgery, the body passage  14  of the patient  2  into which the indwelling portion of catheter  4  may be inserted is generally the front of the body at the crease between the leg and the hip. A catheter  4  may be a nerve catheter. Differently, a catheter  4  may be any tube, lumen, drain, or other device inserted in a body passage of the patient  14 . The present invention encompasses the channeling of any catheter, tube, lumen, drain, or other device known in the art through a cast, from the site of its insertion or other coupling with a patient to the exterior of the cast. 
       FIGS. 2 ,  3 ,  4   a  and  4   b  are a perspective view, a side cross-sectional view, and two bottom cross-sectional views of an appliance for providing a channel through an orthopedic cast, in accordance with a preferred embodiment of the invention.  FIG. 5  is a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an alternate embodiment of the invention. 
     It will be appreciated by those with skill in the art that the terms “appliance for providing a channel through an orthopedic cast” or “container,” as used in the instant application including in the preamble to the claims, do not limit the function of the apparatus to being an appliance, or to containing anything, nor do the terms limit the use of the apparatus to channels in orthopedic casts. Use of the term “appliance for providing a channel through an orthopedic cast” in any claim preambles is not intended to give life, meaning, or vitality to the claims. Further, applicant intends to use the terms “appliance” and “container” interchangeably. 
     In some embodiments, an appliance for providing a channel through an orthopedic cast  200  may have a generally oval shape, with a pair of flattened opposing sides  44 , and a pair of curved opposing ends one of which is a catheter end  46  and one of which is a vacuum end  48 . In some embodiments, an appliance for providing a channel through an orthopedic cast  200  may have a top surface  34  and a bottom surface  30 . 
     In different embodiments, an appliance for providing a channel through an orthopedic cast  200  may have a shape other than a generally oval shape, such as a circular shape, a rectangular shape, a spherical shape, or any other geometric shape having any number of surfaces. The different embodiments will have at least an opening in a first surface, the opening leading to an interior section. In some embodiments, the interior section may therefore comprise a means for containing at least a portion of a medical device during construction of an orthopedic cast about the appliance. The different embodiments will also have at least a portion for removably coupling a vacuum source. In such embodiments the portion for removably coupling a vacuum source will include an opening in a second surface of the appliance  200  with which a vacuum source can be coupled. In some embodiments, the portion for removably coupling a vacuum source may therefore comprise a means for receiving a source of vacuum for suctionably adhering the appliance to a portion of a body about which an orthopedic cast is constructed. A divider is present in the embodiments for separating the first interior portion from the portion of the appliance to which the vacuum source is coupled, the portion being at least a second surface with an opening in the second surface with which a vacuum source is coupled. 
     In a preferred embodiment, an appliance for providing a channel through an orthopedic cast  200  may have a bottom opening  32  in the bottom surface  30 . In such an embodiment, the bottom opening  32  leads to a first interior section  22 . ( FIGS. 11 and 12  may aid in comprehension of the remainder of this paragraph). In this embodiment, a portion of catheter  4  is rolled into a bundle, the bundle including an adapter  10  and the distal end  8  of the catheter  4 , with the bundle being placed inside the first interior section  22 . Then, appliance  200  is held against the patient  2 , the appliance being held over the top of the body passage of the patient  14  where the indwelling portion of the catheter is situated. A vacuum source  300  is coupled to appliance  200  to keep appliance  200  in place while a cast is fabricated around a portion of the body of the patient  2 . 
     In some embodiments, a divider separates the first interior section  22 , the first interior section  22  containing the bundled distal portion  8  of the catheter  4  and adapter  10 , from a portion of the appliance  200  for removably coupling a vacuum source. An opening in the divider permits the vacuum to create suction within the first interior section  22 , the suction having a tendency to hold the appliance  200  against the patient  2 . 
     In some embodiments, such as that shown in  FIG. 3 , a portion of the appliance  200  for removably coupling a vacuum source is a second interior section  24  for removably coupling a vacuum source. In such embodiments, a top surface  34  of the appliance  200  has a top opening  36  leading to the second interior section  24 . In such embodiments, the divider between the first interior section  22  and the second interior section  24  is at a base of the second interior section  24 , the divider being opposite to the top surface  34  of the appliance  200 . As shown clearly in  FIG. 3 , in some embodiments, the appliance  200  has a divider separating the first interior section  22  from the second interior section  24 , the divider including a first interior wall  26  and a second interior wall  28 , the two interior walls  26  and  28  being joined with one another at adjacent edges of the interior walls to form a corner. Other configurations of divider are possible, for example, a divider being made up of only a single interior wall. Such design choices for a divider are within the grasp of those with skill in the art. 
     As shown in  FIG. 5 , in an alternate embodiment, an appliance  200  has a first interior section  22  for removably storing at least a portion of a catheter. In this alternate embodiment, there is no second interior section. In this embodiment, a portion of the appliance for removably coupling a vacuum source is a second surface of the appliance other than the bottom surface  30 . In this embodiment, a second surface is a top surface  34 . Top surface  34  includes a top opening  36  with which a vacuum source can be coupled. In this embodiment, a divider separating the first interior section  22  and the portion for removably coupling the vacuum source  36  is the top surface  34 , the top surface  34  being the second surface including an opening with which a vacuum source can be coupled. 
     It will be apparent to those with skill in the art that the invention encompasses appliances including a container with at least a first interior section in which at least a portion of a catheter is stored, a portion of the appliance for removably coupling a vacuum source, a divider separating the first interior section from a portion of the appliance with which a vacuum source is coupled, and an opening in the divider separating the first interior section and the portion of the appliance for removably coupling a vacuum source. In some embodiments, such as that depicted in  FIGS. 2 ,  3 ,  4   a  and  4   b , the portion of the appliance with which a vacuum source is coupled is a second interior section. In different embodiments, such as that depicted in  FIG. 5 , the portion of the appliance with which a vacuum source is coupled is a surface of the appliance other than a bottom surface of the appliance. In different embodiments, an opening is any passage through which a vacuum can be induced, which may be one or more openings or any other type of passage. The design choice of such alternate embodiments including the configuration of the one or more interior sections, divider, surfaces and opening is within the grasp of those with skill in the art. All alternate embodiments meeting the above requirements are claimed within this appliance. However, the remainder of the application will focus on a preferred embodiment depicted in  FIGS. 2 ,  3 ,  4   a  and  4   b , among other figures. 
     In some embodiments, an appliance  200  includes a container having a generally oval shape in the horizontal cross-section, as seen in  FIGS. 4   a  and  4   b . The generally oval shape has a major axis  50  disposed between opposing ends of the generally oval shape. The generally oval shape has a minor axis  52  disposed between opposing sides of the generally oval shape. In a preferred embodiment, the length of the appliance  200  measured along the major axis  50  is approximately 9 centimeters, the width of the appliance  200  measured along the minor axis  52  is approximately 7 centimeters, and the height of the appliance  200  measured between the top surface  34  and the bottom surface  30  is approximately 8 centimeters. It will be appreciated by those with skill in the art that other dimensions of the appliance  200  are possible. In fact, for patients of varying size ranging from babies to full-grown adults, different dimensions of the appliance  200  are likely. Or, for catheters or other tubes inserted in a passage of the body in different parts of the body, different dimensions of the appliance  200  are likely. For example, it will be appreciated by those with skill in the art that an embodiment for use with an arm splint would likely be sized differently than an embodiment for use with a hip spica. In some embodiments, the length of the appliance  200  measured along the major axis  50  could range from 3 centimeters to 30 centimeters, while the width of the appliance  200  measured along the minor axis  52  could range from 2 centimeters to 30 centimeters, and the height of the appliance  200  measured between the top surface  34  and the bottom surface  30  could range from 2 centimeters to 30 centimeters. 
     In some embodiments, an appliance  200  has exterior walls of the flattened sides  44 , catheter end  46  and vacuum end  48  having a thickness of approximately 5 millimeters. In some embodiments, an appliance  200  has a first interior wall  26  having a thickness of approximately 5 millimeters. In some embodiments, an appliance  200  has a second interior wall  28  having a thickness of approximately 10 millimeters. It will be appreciated by those with skill in the art that the thickness of the walls of the appliance  200  may be varied as needs for use of the appliance with various portions of the body or differently sized patients change. Accordingly, the thickness of the exterior and interior walls of the appliance may be as thin as 1 millimeter or as thick as 10 centimeters. 
     In some embodiments, the exterior and interior walls of the appliance  200  are made of plastic. In different embodiments, the exterior and interior walls of the appliance  200  are made of metal. In certain embodiments, the exterior and interior walls of the appliance  200  are made of material that render the appliance  200  suitable for autoclaving or otherwise sterilizing the appliance  200 . 
     In some embodiments, the end of appliance  200  along the major axis  50  that is adjacent to the first interior section  22  is a catheter end  46 , while the opposing end of the appliance that is adjacent to the second interior section  24  is a vacuum end  48 . In the preferred embodiment, the opposing sides disposed at either end of the minor axis  52  are flattened sides  44 , giving the horizontal cross-section the generally oval shape. 
     In some embodiments, a second interior wall  28  contains the plane of a horizontal cross-section  54  near the bottom surface  30  of the appliance  200 . Viewing the side cross-section of  FIG. 3 , it can be seen that the divider separating the first interior section  22  from the second interior section  24  has a first interior wall  26  and a second interior wall  28  with a circular opening  38  in the second interior wall  28 . This design permits the second interior section  24  to receive a hose from a vacuum source, while maximizing the size of the first interior section  22 . Particularly, the base of the first interior section  22 , the base being disposed adjacent to the bottom surface  30  of the appliance  200 , covers the complete lateral area between the opposing ends and opposing sides of the appliance. This maximizes the coverage of the portion of the body  14  in which the indwelling portion of the catheter is contained by the appliance  200 . The second interior wall  28  has a circular opening  38 , which is the passage through which the vacuum source draws air out of the first interior section  22 , the drawing of air having a tendency to adhere the appliance  200  to the patient  2  when the vacuum source is activated. The circular opening  38  has a top aperture  40  and a bottom aperture  42 . In some embodiments, the circular opening  38  is a threaded circular opening  38 . In such embodiments, the threaded circular opening  38  is configured to removably receive a threaded fitting which facilitates the coupling of a vacuum source. 
     Looking up into the appliance as seen in the bottom view of  FIG. 4   b , it can be seen that in the preferred embodiment, the appliance  200  has a bottom portion of the second interior wall  28  closest to the bottom surface  30  of the appliance  200 , and a bottom portion  56  of the top surface  34  which constitutes the top of the first interior section  22 . At the first interior wall  26 , the first interior section  22  “steps up” in size from the portion of the first interior section  22  that is directly below the second interior section  24  to the portion of the first interior section  22  that is directly below the bottom portion  56  of the top surface  34 . The first interior section  22  is “substantially” adjacent to the catheter end  46  of the appliance  200 , where substantially means that the larger portion of the first interior section  22 , the larger portion being the portion that extends from the bottom surface  30  to the top surface  34  of the appliance  200 , is adjacent to the catheter end  46 . A portion of the first interior section  22  is adjacent to the vacuum end  48  of the appliance  200 , but that portion is a much smaller portion because it extends only from the bottom surface  30  to the second interior wall  28 . It is the larger portion of the first interior section  22  that is adjacent to the catheter end  46 ; thus, the first interior section  22  is “substantially” adjacent to the catheter end  46  of the appliance  200 . 
     In the preferred embodiment, the configuration of the first interior section  22 , second interior section  24 , and the circular opening  38  in the second interior wall  28  all serve to maximize the volume of space available for the bundled catheter  4  and adapter  10 , while permitting connection of the vacuum source without having to turn the hose for the vacuum source inside the second interior section  24 . 
       FIG. 6  is a top view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention.  FIG. 7  is a front cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. 
     In some embodiments, the “front” of the appliance  200  is defined by the vacuum end  48  of the appliance  200 . This cross-sectional view of  FIG. 7  shows a cross-section that slices through the appliance  200  at the center of the circular opening  38 . In some embodiments, an appliance for providing a channel through an orthopedic cast  200  includes a top surface  34 , the top surface  34  having a top opening  36  in the top surface  34 . The top opening  36  leads to a second interior section  24 , where the base of the second interior section  24  is formed by a second interior wall  28  that is parallel to the top surface  34 . The second interior wall  28  is in a horizontal cross-section  54  that is near, but not in, the plane of the bottom surface  30  of the appliance  200 . The second interior section  24  is also bounded by the inside wall of the vacuum end  48  of the appliance, and the portion of the first interior wall  26  and flattened sides  44  that are disposed nearest the vacuum end  48  of the appliance. The section interior wall  28  has a circular opening  38  through which air passes when the vacuum source is activated. The circular opening  38  has a top aperture  40  and a bottom aperture  42 . Below the second interior section  24 , adjacent to the opposing side of the second interior wall  28 , is a portion of the first interior section  22 , the portion of the first interior section  22  being located between the second interior wall  28  and the bottom opening  32  in the bottom surface  30  of the appliance  200 . 
       FIG. 8  is a front cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. (Continued reference to  FIG. 6  will aid in comprehension of the remainder of this paragraph). This cross-sectional view of  FIG. 8  shows a cross-section that slices through the appliance  200  at a point inside the first interior section  22  that is between the catheter end  46  and the first interior wall  26  of the appliance  200 , the cross-section being further from the “front” of the appliance defined by the vacuum end  48  than the cross-section of  FIG. 7 , but near the first interior wall  26  of the appliance  200 . In some embodiments, an appliance for providing a channel through an orthopedic cast includes a top surface  34 . Below the solid portion of the top surface  34 , that is, the portion of the top surface  34  that does not include the top opening  36  of the top surface  34 , is the first interior section  22 . The first interior section is also bounded by the inside walls of the catheter end  46  and flattened sides  44  of the appliance, and the portion of the first interior wall  26  that is disposed nearest the catheter end  46  of the appliance. A portion of the first interior section  22  extends below a horizontal cross section  54  that is near, but not in, the plane of the bottom surface  30  of the appliance  200 . This portion of the first interior section  22  also extends towards and is bounded by the interior wall of the vacuum end  48  of the appliance  200 . Above this portion of the first interior section  22  is the second interior wall  28 , the second interior wall  28  having a circular opening  38  through which air passes when the vacuum source is activated. 
       FIG. 9   a  is a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention.  FIG. 9   b  is a detail view of a side cross-sectional view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. In some embodiments, an appliance for providing a channel through an orthopedic cast  200  includes a first interior section  22 , in which a bundle is placed, the bundle containing the distal portion  8  of a catheter  4  and a SnapLock adapter  10  attached to the catheter  4 . The interior section  22  of the appliance  200  is accessed via a bottom opening  32  in the bottom surface  30  of the appliance. The portion of the catheter  4  that is not bundled or placed inside the appliance  200  remains in the tissue of the patient  2 , inserted into a body passage  14  of the patient  2 . This “indwelling” portion of the forward insertion end  6  of the catheter  4  is covered by a piece of tape  16  or other dressing adhered to the patient  2 . 
     In some embodiments, a fitting  72  is inserted through the top opening  36  of the top surface  34  into the second interior section  24  of the appliance  200 . The fitting is threaded into the circular opening  38  in the second interior wall  28  of the appliance  200 , where the circular opening  38  is a threaded circular opening  38  with a diameter of 9/16″. The fitting  72  may be a Diss-style 9/16″ Male Hex Nut Vacuum/Suction Fitting with ¼″ Hose Barb, or its equivalent. Such fittings are well known in the art. One source for such a fitting is Pneumatic Services, Inc., of Clearwater, Fla. The fitting  72  may have a hex nut section  76 , which is disposed adjacent to the top aperture  40  of the circular opening  38 . The 9/16″ threaded portion  74  of the fitting  72  is threaded into the threaded circular opening  38  in the second interior wall  28  of the appliance  200 . Opposing the threaded portion  74  of the fitting  72  is a ¼″ hose barb  78 , the hose barb  78  permitting the coupling of a hose  80  with an inside diameter of ¼″. 
     In some embodiments, a vacuum source  300  is coupled with the appliance  200 . In some embodiments, the vacuum source is the hospital suction  84  which is connected by hose  80  to the appliance  200  at the fitting  72 . In some embodiments, a Dura Clamp  82  is threaded over the hose before the hose is connected to the hospital suction  84  or the fitting  72 . A Dura Clamp is a “pinch clamp” which closes a hose threaded through the Dura Clamp by pinching the interior walls of the hose together. A Dura Clamp and its use are well known in the art. One source for a Dura Clamp is U.S. Plastic Corp., of Lima, Ohio. In some embodiments, when the appliance  200  is placed over the portion of the body including the body passage  14  of the patient  2  containing the indwelling portion of the catheter  4 , hospital suction  84  is activated, creating a vacuum inside the hose  80  and the first interior section  22  of the appliance  200 . The vacuum has a tendency to hold the appliance  200  in place against the patient  2 , with the bundle contained within the first interior section  22  of the appliance  200 . The Dura Clamp  82  can be closed, pinching off the hose  80 . This permits the hospital suction  84  to be deactivated while maintaining the vacuum within the first interior section  22  of the appliance  200 , and maintaining the position of the appliance  200  against the patient  2 . A cast can then be fabricated around a portion of the patient  2 . Other means of inducing a vacuum within the first interior section  22  of the appliance  200  are well known in the art, and all such means are encompassed within the  410  disclosure of this invention. 
       FIG. 10  is a side cutaway view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. In  FIG. 10 , a preferred embodiment is shown in which the bundle of the portion of the catheter  4  and the adapter  10  are shown in cutaway in the interior of the appliance  200 . Below the appliance  200  are the forward insertion end  6  of the catheter  4 , inserted into a body passage  14  of the patient  2 , the indwelling portion of the catheter  4  being covered by a piece of tape  16  or other dressing. 
       FIG. 11  is a perspective cutaway view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. In some embodiments, an appliance  200  is pressed against a portion of the body of the patient  2 , the portion of the body including the body passage  14  of the patient  2  that contains the indwelling site of the catheter  4 . The indwelling portion is covered with a piece of tape  16  or other dressing. The remainder of the catheter  4  and the SnapLock adapter  10  are bundled and tucked inside the first interior portion  22  of the appliance  200 , prior to pressing the appliance  200  against the patient  2 , with the bottom opening  32  of the appliance  200  covering the indwelling site of the catheter  4 . The site where the catheter is inserted into a body passage  14  of the patient may be the crease where the leg and hip of the patient  2  are joined. Once the appliance  200  is held in position, a vacuum source  300  such as hospital suction  84  can be activated, drawing air out of the first interior section  22  and creating a vacuum in the first interior section  22 , having a tendency to hold the appliance  200  in place against the body of the patient  2 . 
       FIG. 12  is a perspective view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. Once the vacuum source  300  is activated, holding the appliance  200  in place against the body of the patient  2 , the orthopedic cast  12  can be formed. In one embodiment, cotton bandages impregnated with plaster of paris that are dampened are applied around a limb or other portion of the body of the patient  2 . The cast  12  is formed when the individual cotton bandages dry. Other materials and methods for forming a cast are well known in the art and are encompassed by the present invention. In some embodiments, portions of the exterior walls of the appliance  200  are spread with Surgilube lubricating jelly. Practitioners often cover their hands in Surgilube to ensure the bandages that form the cast  12  do not adhere to the hands of the practitioner. Likewise, in some embodiments, Surgilube spread over portions of the exterior walls of the appliance  200  will ensure that the bandages that form the cast  12  do not adhere to the appliance  200 . Surgilube is well known in the art. One source for Surgilube is Allegro Medical, of Bolingbrook, Ill. 
       FIG. 13  is a perspective view of an appliance for providing a channel through an orthopedic cast, in accordance with an embodiment of the invention. In some embodiments, when a cast  12  has been fabricated and hardened, the vacuum source  300  is deactivated. In some embodiments, deactivating the vacuum source  300  may comprise releasing the Dura Clamp  82 . Following the deactivation of the vacuum source  300 , the appliance  200 , with the bundle of the portion of the catheter  4  and the SnapLock adapter  10  contained in the first interior section  22  of the appliance  200 , is removed from the cast  12 , revealing a channel  18  in the formed cast, the channel  18  having a perimeter substantially corresponding to a perimeter defined by exterior wall(s) of the appliance  200 . In some embodiments, the exterior wall(s) of the appliance  200  therefore may comprise a means for facilitating the formation of a channel in an orthopedic cast constructed about the appliance. Through the channel  18 , the body passage  14  into which the catheter  4  is inserted can be viewed beneath the piece of tape  16  or other dressing. 
       FIG. 14  is a perspective view of a channel through an orthopedic cast, in accordance with an embodiment of the invention. In some embodiments, following removal of the appliance  200  from the cast  12  by pulling it away from the patient  2 , the bundle of the portion of the catheter  4  and the SnapLock adapter  10  is removed from the first interior section  22  of the appliance  200 . The appliance  200  can be autoclaved or otherwise sterilized and re-used. Utilizing the channel  18 , anesthesia can then be delivered to the patient  2  by rejoining the connection between the infusion pump and the adapter  10  and activating the infusion pump. 
       FIG. 15  is a flow diagram of a method, in accordance with an embodiment of the invention. Method  400  may include one or more operations including operation  402 ,  404 ,  406 ,  408 ,  410 ,  412 ,  414 ,  416  and/or  418 . 
     At operation  400 , a method includes: bundling a portion of a catheter beginning at a distal end of the catheter, said bundling occurring without dislodging an insertion end of the catheter from a body passage through which the insertion end of the catheter is disposed, thereby rolling the portion of the catheter into a small bundle at  402 ; tucking the small bundle of the portion of the catheter into a first interior section of an appliance for providing a channel through an orthopedic cast at  404 ; holding a bottom surface of the appliance for providing a channel through an orthopedic cast against a first portion of the body, where the first portion of the body includes the body passage through which the insertion end of the catheter is disposed, and where an aperture in the bottom surface of the appliance for providing a channel through an orthopedic cast is disposed adjacent to the first portion of the body, said aperture leading to the first interior section of the appliance for providing a channel through an orthopedic cast, said first interior section containing the small bundle of the portion of the catheter at  406 ; removably coupling a vacuum source with the appliance for providing a channel through an orthopedic cast at  408 ; releasing the hold on the appliance for providing a channel through an orthopedic cast, thereby allowing the vacuum source to maintain the position of the appliance for providing a channel through an orthopedic cast against the first portion of the body at  410 ; applying strips of material around a second portion of the body and around the appliance for providing a channel through an orthopedic cast, thereby forming a cast around the second portion of the body with the appliance for providing a channel through an orthopedic cast protruding through a channel in the formed cast at  412 ; removing the vacuum source from the appliance for providing a channel through an orthopedic cast at  414 ; removing the appliance for providing a channel through an orthopedic cast from the channel formed in the cast at  416 ; and unrolling the catheter from its small bundle at  418 . 
     While preferred and alternative embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of these preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.