Abstract:
A luer fitting is disclosed. The luer fitting includes a body having a first end and a second end, wherein the first end comprises an antibacterial component disposed therewith. The luer fitting is connected over a catheter that has been primed with a locking solution. The antibacterial component is fluidly engaged with the locking solution such that the antibacterial component diffuses through the locking solution. A method of reducing antibacterial activity in a catheter utilizing the fitting is also disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/527,260, filed on 5 Dec. 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Catheters are used to provide repeated access to a vascular system in a patient. A catheter may be used to infuse a fluid, such as a medication or a saline solution, or withdraw a fluid, such as blood. Multiple lumen catheter assemblies, such as those used for hemodialysis, include at least one catheter for the withdrawal of blood from a blood vessel to be sent for processing in a hemodialysis machine, while another catheter returns the blood to the vessel after processing.  
         [0003]     Catheters may be inserted into a patient for acute care, where the catheter is intended to be in the patient for a short duration, such as for only a few days, or for chronic care, where the catheter is intended to be in the patient for a much longer duration, such as over several months.  
         [0004]     One of the biggest obstacles to catheterization of a patient is the risk of infection. It is important to maintain sterility in and around the catheter to reduce the risk of infection. One way to maintain sterility around the exterior of the catheter in between uses is to swab the dermal area around the catheter and the exposed portions of the catheter itself with a disinfectant, such as iodine or alcohol, depending on the material used to fabricate the catheter. However, it is possible for pathogens to grow within the catheter, which may cause infections within the vascular system of the patient.  
         [0005]     Various locking solutions have been used inside the catheter to prevent clotting within the catheter in between uses. However, heparin, the most popular anti-coagulant that is used as a locking solution, is at best, minimally successful as an antibacterial agent. It would be beneficial to be able to impart antibacterial properties into a catheter lock solution to minimize the risk of infection within the catheter in between uses.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     Briefly, the present invention provides a luer fitting. The luer fitting comprises a body having a first end and a second end, wherein the first end comprises an antibacterial component disposed therewith.  
         [0007]     The present invention also provides a luer fitting comprising a body having a first end and a second end. The first end includes a stylet extending therefrom. The stylet includes an antibacterial component disposed on an exterior thereof.  
         [0008]     Additionally, the present invention also provides a method of reducing antibacterial activity in a catheter comprising: providing a catheter having a lumen and a connector connected thereto; inserting a lock solution into the lumen; releasably affixing a luer fitting to the connector, wherein the luer fitting includes an antibacterial component; and exposing the antibacterial component to the lock solution, wherein the antibacterial component disperses through at least a portion of the lock solution. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:  
         [0010]      FIG. 1  is a perspective view of a luer cap according to a first embodiment of the present invention.  
         [0011]      FIG. 2  is an end view of the luer cap of  FIG. 1 .  
         [0012]      FIG. 3  is a sectional view of the luer cap taken along line  3 - 3  of  FIG. 2 .  
         [0013]      FIG. 4  is a sectional view of the luer cap connected to a catheter lumen.  
         [0014]      FIG. 5  is a perspective view of a luer cap according to a second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The following describes a preferred embodiment of the invention. However, it should be understood based on this disclosure, that the invention is not limited by the preferred embodiment described herein.  
         [0016]     Referring to  FIGS. 1-3 , a luer cap  100  according to a first embodiment of the present invention is shown. The luer fitting  100  includes a preferably generally cylindrical body  102  that includes an open first end  110  a closed second end  130 , and a longitudinal axis  103  extending therethrough. The body  102  includes a plurality of flats  104  disposed about the open first end  110 . The flats  104  generally provide surfaces for a user (not shown) to grip the luer fitting  100  to twist the luer fitting  100  onto or off of a female luer connection (not shown).  
         [0017]     The first end  110  includes a generally cylindrical opening  112 . The interior of the cylindrical opening  112  preferably includes a female threaded connection  114 . A tapered male luer connection  116  extends through the cylindrical opening  112  along the longitudinal axis  103 . The luer connection  116  includes a silver matrix  118  that is embedded in the luer connection  116 , with a portion of the silver matrix  118  being in fluid communication with the exterior of the luer connection  116 . While a silver matrix  18  is preferred, those skilled in the art will recognize that other metals, such as gold, titanium, platinum, or other suitable metal may be used, alone or in combination with the remaining metals, in a matrix form. As an additional alternative, a matrix containing a lyophilyzed antimicrobial agent embedded therein may be used. The matrix may be a filament, a polymer, such as polyurethane, or some other suitable, biocompatible material.  
         [0018]     While two pieces of the silver matrix  118  are shown in  FIGS. 1 and 2 , those skilled in the art will recognize that more or less than two pieces of the silver matrix  118  may be incorporated into the luer fitting  100 . The silver matrix  118  may be in the form of silver coated nylon filaments or some other known method of providing silver in a matrix. The luer connection  116  also includes a passage  119  that extends into the body  102  toward the closed second end  130 .  
         [0019]     The second end  130  includes a seal  122  that closes the second end  130 . The seal  122  fluidly communicates with the passage  119  so that a needle (not shown) may be inserted into the seal  122  from the second end  130  and pushed through the seal  122  to the passage  119 .  
         [0020]     Preferably, the body  102  and the male luer connection  116  are both constructed from a polymer, such as polyvinylchloride, polystyrene, polypropylene, or other suitable materials. The seal  122  is preferably constructed from a fluid impermeable material that may be relatively easy to pierce with a needle and is self-sealing, such as latex or silicone.  
         [0021]     In use, the luer fitting  100  is connected to a separate device, such as a hemodialysis catheter  300 , as shown in  FIG. 4 . Preferably, the catheter  300  includes a lumen  302  having a connector  304  fixedly connected to a proximal end of the lumen  302 . The connector  304  includes male threads  306  that are sized to threadingly engage the female threaded connection  114  and a tapered female luer connector  308  that frictionally engages the male luer  116  on the luer fitting  100 .  
         [0022]     Preferably, the catheter  300  is inserted into a patient so that a distal end of the lumen  302  is inserted into the patient, such as in a blood vessel. While a preferred blood vessel is the internal jugular vein, and the catheter  300  is used for hemodialysis, those skilled in the art will recognize that the catheter  300  may be used for other applications and may be inserted in other locations in the patient.  
         [0023]     Prior to connecting the luer fitting  100  to the catheter  300 , a locking solution  310 , such as heparin, alcohol, or other anticoagulant compound is injected into the lumen  302 . The locking solution  310  must be biocompatible with the silver matrix  18 , and allow silver ions to diffuse through the locking solution  310 . Such a preferred locking solution  310  includes heparin, water, alcohol, or other suitable fluid.  
         [0024]     The luer fitting  100  is releasably connected to the catheter  300  by inserting the male luer connection  116  into the female luer connection  308  and engaging the female threads  114  of the luer fitting  100  with the male threads  304  of the catheter  300 . The locking solution  310  backflows into the luer fitting  100  due to hydrostatic pressure of the blood in the vessel, putting the silver matrix  118  into fluid communication with the locking solution  310 . Silver ions diffuse at least partially into the lock solution  310  in sufficient quantity, preferably greater than approximately 30 micrograms/milliliter, to provide antibacterial effectiveness against all nosocomial pathogens. Preferably, the luer fitting  100  is connected to the catheter  300  only between dialysis treatments, which tend to take place within a 96 hour timeframe. When the luer fitting  100  is removed to perform dialysis, a replacement luer fitting  100  with a fresh silver matrix  118  replaces the original luer fitting  100  after the hemodialysis treatment is completed, thus providing a sustained concentration of silver ions in the lock solution  310  between hemodialysis treatments. IT is believed by the inventors that the silver matrix  118 , in fluid communication with the locking solution  310 , will provide at least 20 micrograms per milliliter of lethality over the 96 hour timeframe against nosocomial pathogens.  
         [0025]     Referring now to  FIG. 5 , a second embodiment of a luer cap  200  according to the present invention is shown. The luer cap  200  includes a first end  210  having a male luer connector and female threads  214 , similar to the luer cap  100  described above, but with an added antibacterial component, such as a silver matrix  218 , extending distally from the first end  210 . The silver matrix  218  may be embedded in a stylet  220  that is fixedly connected to the luer cap  200 . Preferably, the stylet  220  is generally an elongate tube with a preferably tapered distal end  222 . The stylet  220  is manufactured from a polymer, such as nylon, or a thermoplastic polyurethane elastomer, such as PELLETHANE®, or some other suitable, biocompatible material. Also preferably, a passage  224  extends longitudinally through the stylet  220 , with the passage fluidly communicating with a second end  230  of the luer cap  200  that is open.  
         [0026]     The luer cap  200  also includes a threaded luer fitting  232  disposed at the second end  230  of the luer cap  200 . The luer fitting  232  allows a standard luer cap or the luer cap  100  to be threadingly engaged with the luer fitting  232 . The passage  224  also extends through the luer fitting  232  so that fluid may communicate between the first end  210  and the second end  230  of the luer cap  200 . Optionally, although not shown, the second end  230  of the luer cap  200  may be sealed with a fluid impermeable material that may be relatively easy to pierce with a needle and is self-sealing, such as latex or silicone.  
         [0027]     In between hemodialysis treatments, the catheter lumen  302  is primed with the locking solution  310 . The stylet  220  on the luer cap  200  is then inserted into the proximal end of the catheter  300  and at least partially through the catheter lumen  302 . The female threads  214  on the luer cap  230  are threadingly connected to the male threads  304  on the proximal end of the catheter  300 , as is well known in the art. In between catheter uses, when the catheter  300  is primed with the locking solution  310 , the silver matrix on the stylet  220  diffuses into the locking solution  310  to provide antibacterial protection throughout the length of the catheter  300 .  
         [0028]     While the silver matrix  218  shown in  FIG. 5  is shown as bands spaced along the length of the stylet  220 , those skilled in the art will recognize that the silver matrix  218  may include additional and/or wider bands, or may be disposed along the entire length of the stylet  220 . Further, the stylet  220  is preferably sufficiently long so as to extend a significant distance into a catheter  300  when the luer cap  200  is connected to the catheter  300 . Preferably, the silver matrix  218  is disposed on the stylet  220  to provide greater than 25 mcg/ml of silver diffusion into the locking solution for a period of approximately 72 to 96 hours.  
         [0029]     The silver matrix  218  may be disposed on the stylet  220  by adhesive, by bonding the silver matrix  218  to a polymer substrate and then ultrasonically welding the polymer substrate to the stylet  220 , by chemical vapor deposition or by some other method known to those skilled in the art for depositing a metal onto a surface.  
         [0030]     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.