Abstract:
A lock for an outpatient&#39;s peripherally inserted central catheter (PICC) line limits access to the catheter by patients seeking to abuse injectable narcotics. The lock has two plastic housing halves which slide together, and which define an interior enclosure which receives the catheter line injection port. The housing halves have overlying flanges, through which a fastener extends to secure the device in a closed configuration. The fastener interacts with the flanges in such a way that it cannot be removed without distorting the device and giving evidence of tampering. A zippered sleeve may be provided which surrounds the line leading to the injection port and which has a pull tab which may be engaged within the housing to further prevent access to the line directly.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. provisional patent app. No. 61/809,440, filed Apr. 8, 2013, the disclosure of which is incorporated by reference herein. 
    
    
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates generally to catheters with injection ports, such as peripherally inserted central catheters, and more particularly to devices for securing access to them for outpatient safety. 
     Abusers of intravenous drugs such as heroin are susceptible to severe infections which must be treated by intravenous injection of antibiotics over a course of many weeks. To facilitate this treatment, the drug abuser may be provided with an intravenous peripherally inserted central catheter or PICC line. This catheter, while usually inserted in the hospital, can remain in place for weeks or months, and makes it a simple matter to rapidly inject the necessary antibiotics without difficulty in finding a vein. This ease of intravenous access, however, can be a serious hazard for outpatients who are habitual drug abusers, who can take advantage of this catheter to self-administer unprescribed quantities of narcotics or other controlled substances. Providing a drug abuser with an unsupervised PICC line for outpatient care can lead to illegal drug overdose and death. To protect these high risk patients, who might otherwise not need full-time nursing care, they must be hospitalized and retained under supervision for the multiple weeks that the antibiotics are needed. Hospitalization is vastly more costly than outpatient care, and represents a less than optimal utilization of health care resources. 
     What is needed is an arrangement which allows drug abusing patients to be safely outfitted with PICC lines for outpatient care. 
     SUMMARY OF THE INVENTION 
     The device of the present invention serves as a lock for an outpatient&#39;s peripherally inserted central catheter (PICC) line which limits access to the catheter by patients seeking to abuse injectable narcotics. The lock has two plastic housing halves which slide together and which define an interior enclosure which receives a catheter line injection port. The housing halves have overlying flanges, through which a fastener extends to secure the device in a closed configuration. The fastener interacts with the flanges in such a way that it cannot be removed without distorting the device and giving evidence of tampering. The locking mechanism may be a dumbbell shaped metal pin, which is inserted through aligned openings in the aligned flanges by a small handheld press. Each time an intravenous treatment is administered, the pin is extracted by the press and the locking device is destroyed and replaced with a new one. Should the patient remove the box to defeat its restrictions, the damage to the box provides ready evidence to the nurse that the patient has tampered with the device, providing grounds for returning the patient to the hospital. 
     It is an object of the present invention to provide a device which limits undetected access to the inlet ports of a PICC line. 
     It is another object of the present invention to provide a tamper-evident lock for a PICC line. 
     Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a PICC line in connection with a patient and the function of the PICC line lock of this invention. 
         FIG. 2  is an exploded isometric view of the PICC line lock of this invention. 
         FIG. 3  is an enlarged fragmentary cross-sectional view of the PICC line lock of  FIG. 2  as a locking member is being inserted within a hand press. 
         FIG. 4  is a side elevational view of a the device of  FIG. 3  in a locked configuration. 
         FIG. 5  is a fragmentary cross-sectional view of an alternative embodiment locking mechanism for the PICC line lock of this invention, using a one-way screw. 
         FIG. 6  is a perspective view of a sleeve assembly for protecting the PICC line between the inlet port and the base. 
         FIG. 7  is a fragmentary cross-sectional view of the device of  FIG. 6  received within a locked housing. 
         FIG. 8  is a fragmentary cross-sectional view of an alternative embodiment locking mechanism for the PICC line lock of this invention, using a zip tie. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring more particularly to  FIGS. 1-7 , where like numbers refer to similar parts, a PICC line lock  20  for use with conventional PICC line assemblies  24  is shown in  FIG. 2 . A PICC line assembly  24 , as shown in  FIG. 1 , has a catheter  26  which is inserted into an upper extremity  28  of the patient  30 , for example an arm. The assembly  24  will typically have a base  32  which is taped to the patient. One or more injection lines  34  extends from the base, each of which is terminated by an inlet port  36 . The inlet ports  36  provide an entryway to the injection lines  34  for delivery of fluids from an injection source such as a syringe  40  or a total parenteral nutrition bag or whatever injectable the patient requires. The inlet ports may be provided with a positive displacement connector  37 , such as the MaxPlus® clear needleless connector made by Carefusion Corporation of San Diego, Calif., and such as disclosed in U.S. Pat. No. 5,730,418, the disclosure of which is incorporated by reference herein. The lock  20  provides a mechanism for blocking access to the inlet ports  36  by the patient. The injection lines  34  may be provided with one or more mechanical clamps  42  which serve to prevent the escape or entry of liquids into the lines unless the clamps  42  are removed. 
     As shown in  FIG. 2 , the lock  20  comprises a box or housing  44  formed by the assembly of a first housing half  46  and a second housing half  48 . The housing halves  46 ,  48  may be injection molded plastic parts formed, for example, of high density polyethylene. The housing halves have cooperating structures which allow the halves to be slid together to define a housing compartment  50  of adequate dimensions to receive an inlet port  36  and any associated connector  37  and to protect the port from access by the patient. The housing  44  may thus be long enough to include a 2-inch long combined inlet port and connector. The second housing half  48  may have two parallel projecting T-rails  52 , which are received in two parallel T-slots  54  allowing the two halves to slide together. The second housing half  48  has a bottom wall  56  with a projecting side wall  58  in which is formed a tapered V-shaped slot  60  which serves as a clamp for the injection line leading out of the inlet port which is received within the housing compartment  50 . This slot acting as a clamp provides another opportunity to stop the flow of liquids through the line, even if an intermediate clamp should fail. 
     The second housing half  48  may be provided with an intermediate wall  62  located within the housing compartment  50  which defines a channel  64  between the end wall and the intermediate wall which will receive the conventional clamp  42  that locks the PICC line and which is typically a part of the PICC line assembly. The housing  44  is dimensioned to create a snug fit for the PICC line assembly comprised of the inlet port  36 , the positive displacement connector  37 , if any, and the attached inlet line  34 , so that these components do not have the space to rotate and become dislodged. Even if rotational forces act on the end assembly, the lack of space to expand will not allow the clamps to become dislodged. 
     The second housing half  48  may have two thin molded lower tabs  102 , shown in  FIG. 2 . The tabs extend from opposite sides of the second housing half and are flexible to conform to a patient&#39;s limb to allow adhesive tape to extend over the tabs to permit the housing  44  to be taped to a patient&#39;s body. 
     The first housing half  46  has a first flange  66  which protrudes away from the housing, and the second housing half  48  has a second flange  68  which protrudes beneath the first flange  66 . As shown in  FIG. 3 , the first flange has a cylindrical opening  70  which aligns with a blind cylindrical opening  72  in the second flange  68  when the two housing halves are slid together into a locked configuration. A metal locking fastener  74  is inserted into the aligned openings  70 ,  72 , with a hand press  76 , shown in  FIG. 3 . The hand press  76  has a mechanism similar to a conventional two-hole press, with a lever  77  which may be depressed to drive the locking fastener  74  into place. The fastener  74  may have a narrower-diameter segment  78  which gives it a dumbbell-like shape which allows the plastic of the flanges  66 ,  68  to deform into the narrower-diameter segment and thus lock the fastener  74  in place and connect the first housing half  46  to the second housing half  48  in such a fashion that the fastener cannot be removed without distorting the device  20  and giving evidence of tampering with the device. To open the housing  44  and remove the fastener  74 , the housing is returned to the hand press  76 , and the lever  77  is fully depressed to engage the fastener  74  and to drive it out through the lower flange  68  of the housing. A through hole  79  in the lower member  81  of the press  76  allows passage for the fastener therethrough. 
     A housing with an alternate locking mechanism  103  is shown in  FIG. 5 , which uses a fastener  104  similar to a conventional one-way screw, such as is used in bathroom stalls. The housing has a first flange  106  with a through hole  107  which overlies a second flange  108  with a blind hole  110 . The one-way screw fastener can be turned in one direction to be tightened, but cannot be removed without a special tool. When the fastener  104  is fully inserted, portions of the plastic of the upper first flange  106  expand over the outside diameter of the screw head. The base of the screw head&#39;s outside diameter acts like a small washer that is integral to the screw head. The lip will expand over the integral washer and lock the screw in place. An authorized person can use a specialized screwdriver to remove the screw. Even if the patient were to gain access to the specialized screwdriver, the deformation of the plastic around the screw head would provide evidence that the housing had been tampered with. 
     It should be noted that other fasteners may be used the removal of which gives evidence of tampering, for example, as shown in  FIG. 8 , a zip tie  122  or tie-wrap extending through openings  124 ,  126  in the halves  128 ,  130  of the housing  132 . A zip tie is a nylon cable tie comprised of a tape section with triangular teeth that slope in one direction. The head of the cable tie has a slot with a flexible pawl that irreversibly rides up the slope of these teeth when the tape is inserted. The pawl engages the backside of these teeth to stop removal of the tape. Typically these ties must be cut to be removed. 
     Once an injection has been made through the PICC line by an authorized person, the two housing halves are slid together about the inlet port, and then connected with the fastener to lock out access to the inlet port. The lock  20  will stay in place until the authorized person returns on the next visit to administer another injection. To remove the lock  20 , the hand press  76  is used to punch out the fastener  74  and thereby allow the housing halves to be slid apart and the inlet ports to be accessed. When the lock  20  is opened, it is destroyed, and cannot be reused. Should a patient attempt to pry apart the housing or otherwise tamper with the lock to separate the housing halves, it would be apparent to the authorized person on the next visit, indicating that the patient was not a suitable candidate for in-home care, and should be returned to hospital care. 
     To prevent access to the lines  34  between the inlet ports and the base  32  a sleeve assembly  80 , shown in  FIGS. 6-7 , may be provided. The sleeve assembly  80  has a wrap-around sleeve  82  made out of a puncture resistant material, such as plastic or fabric formed of KEVLAR® para-aramid synthetic fibers. The sleeve assembly  80  has an axially extending zipper closure  84  fixed to the sleeve  82 . By actuating the zipper closure, the sleeve is rolled up into a tube which surrounds and receives the line  34  to thus cover the line as it extends to an inlet port  36 . The zipper closure  84  has a protruding pull tab  92 , which serves to advance the zipper to engage the two strips of zipper teeth  93  and close the sleeve. The pull tab  92  and portions of the sleeve are received within a box or housing  98 . The protruding pull tab  92  is larger than the opening  100  in the housing, thus preventing the sleeve assembly from being extracted from the housing  98  once it is locked closed in a manner similar to the device  20  described above. Once locked inside the housing  98  the sleeve assembly  80  may not be removed without destroying the housing. Because the opening  100  must be large enough to admit the sleeve without obstruction, it does not serve as a line clamp. Hence an internal clamp may be provided in an internal wall  105 . In addition, the line may have its own clamp  42 . As shown in  FIG. 7 , the base  32  may be mounted to the limb of the patient by a bandage or dressing  112 . 
     It should be noted that additional clamps similar to the ones  42  shown in  FIG. 2 , can be provided within the housing. Two clamps can be positioned within each compartment  116 ,  118 , defined by the dividing walls  120 . In each pair of clamps, one clamp  42  can have the clamp opening facing in one direction, and the other clamp  114  can have the clamp opening facing in the other direction. 
     It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.