Abstract:
A single-use, snap-over cap for use primarily in healthcare settings in order to maintain the integrity of a medication solution. The cap has a tapered cylindrical skirt, a puncture resistant lid portion, and one or more latch tabs. When placed onto a flanged injection port such as is found on a conventional fluid container, the latch tabs engage and flex about the port flange. After the cap is placed, the latch tabs engage the port flange to prevent upward axial movement relative to the port, thereby preventing removal of the cap and thus deterring unwanted or erroneous drug administrations or withdrawals.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority based upon U.S. Provisional Application Ser. No. 60/976,586 filed Oct. 1, 2007, which is expressly incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to the field of containers for administering medical fluids to patients. More particularly, the present invention relates to a snap-over port cap for intravenous (IV) fluid containers. 
         [0003]    Access ports are commonly used in infusion solution containers to administer solutions to a patient, or to add medicaments or other solutions to the container prior to administration. Current solution containers typically may include a dedicated outlet port for solution administration to a patient and a dedicated inlet port for the addition of diluent or other ingredients to the container. These ports are conventional in the art and may be of different types of construction but typically have an annular flange. The ports are in fluid communication with the container, usually via an attached tube having a diameter smaller than the port flange. 
         [0004]    The outlet port is intended to be coupled to an administrative set and is therefore commonly referred to as the administrative port, whereas the inlet port is designed to permit the injection of therapeutic agents and nutrients into the partially filled container and is sometimes identified as the additive or injection port. Such a container may contain a partial filling of a sterile solution such as saline or dextrose to function as a diluent for the injected additive. The diluted drug or nutrient is then administered to a patient by means of the administrative set that may be either directly or indirectly (i.e., through another solution set) coupled to the patient. 
         [0005]    Maintaining the integrity of medication solutions to be administered to a patient is of major importance. It has been found, however, that careless or inattentive handling of a solution container may create significant risks of drug administration errors. Such errors include duplicate administrations of the same substance (overdosing) as well as mis-administration of the wrong substance. These risks may be increased where emergency situations are presented that require quick manipulation of the various components and quick addition of one or more substances to a container via the additive port. In extreme circumstances, a person may intentionally seek to harm a patient by adding one or more agents. Likewise, one could deliberately remove properly mixed solutions via the additive port for illicit purposes. It is imperative that evidence of such tampering be readily apparent to caregivers or their supervisors. 
         [0006]    Current methods of making notification of a previous drug administration include placing an adhesive label over the face of the port or onto the container itself. Adhesive labels are not mechanically attached to the port or the container, may be removed, and do not offer any resistance to subsequent needle penetration. 
         [0007]    Therefore, an object of this invention is to provide an additive port cap closure that is readily available and easy to place on a port, fully covering the same, upon the completion of prescribed drug admixtures. 
         [0008]    A further object of the invention is to provide an additive port cap that cannot be removed without damaging the cap and/or the underlying port, and/or leaving visible evidence of tampering. 
         [0009]    Another object of the invention is to provide an additive port cap that is puncture resistant so as to deter the administration or removal of one or more substances via syringe after the cap is in place. 
         [0010]    Yet another object of the invention is to provide an additive port cap that is easy and inexpensive to manufacture. These and other objects will be apparent to those skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0011]    A snap-over port cap is provided for use primarily in clinical healthcare settings, such as hospital pharmacies. Specifically, the cap is designed to be placed over an injection or additive port on a conventional IV fluid container or the like. 
         [0012]    In a typical scenario, one or more substances are added to the container through the injection port using a conventional syringe. In order to deter unwanted or erroneous drug administrations or withdrawals, the snap-over port cap is immediately placed over the injection or additive port. The cap is intended for a single use, is disposable and cannot be removed, tampered with or compromised without damaging the cap or at the very least conspicuously stressing or deforming the cap material to give a visible indicator of the disrupting activity. 
         [0013]    The cap comprises a puncture resistant lid portion, a tapered cylindrical skirt, and one or more latch tabs provided about the cylindrical skirt. The latch tabs flex under moderate pressure, typically as the cap is manually placed downward over an annular flange situated about the port. The diameter of the lid portion is larger than the diameter of the access site about the port, covering that portion of the port utilized for administrations. The base of the tapered skirt is of slightly larger diameter than the flange. As the latch tabs flex, one or more projections engage the annular flange. As the cap is further depressed, the projections clear the flange and return to a non-flexed or relaxed position. Upward axial movement relative to the port is deterred by the engagement between the projections and the flange, and the cap is maintained in place. 
         [0014]    Attempts to forcibly remove the cap from the port will cause visible deformation or destructive change to the cap, particularly to the latch tabs, and possibly to the port and/or the container. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a front view of a port cap; 
           [0016]      FIG. 2A  is top-plan view of a port cap; 
           [0017]      FIG. 2B  is a partial cross-section of a port cap taken along line A-A of  FIG. 2A ; 
           [0018]      FIG. 3A  is a top-plan view of an alternative embodiment of a port cap; 
           [0019]      FIG. 3B  is a partial cross-section of a port cap taken along line B-B of  FIG. 3A ; 
           [0020]      FIG. 4  is a perspective view illustrating a port cap being positioned about a conventional port; 
           [0021]      FIG. 5  is a cross-section of a port cap in an intermediate position while being placed about a conventional port; and 
           [0022]      FIG. 6  is a cross-section of a port cap in place about a conventional port. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    The embodiments discussed herein are merely illustrative of specific manners in which to make and use the invention and are not to be interpreted as limiting the scope of the instant invention. 
         [0024]    While the invention has been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the invention&#39;s construction and the arrangement of its components without departing from the scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification. 
         [0025]    Referring to  FIG. 1 , cap  10  comprises a closed end or lid portion  12  and a tapered cylindrical skirt  14 . Skirt  14  has a base  16  opposite said lid portion  12 . One or more latch tabs  18  are situated about base  16  of skirt  14 . In a preferred embodiment, three axisymmetric latch tabs  18  are provided, spaced evenly about the circumference of base  16 . It should be appreciated, however, that virtually any number of latch tabs may be provided in any number of orientations. Separating each latch tab  18  from lid portion  12  is an aperture  20 . It will be appreciated that the presence of one or more apertures  20  facilitates molding. An optional outwardly protruding rim  21  can be provided on the base  16  for strength and stress control. 
         [0026]    Skirt  14  is tapered such that the diameter of lid portion  12  is less than the diameter of base  16 . Skirt  14  is constructed of a substantially rigid material, such as polypropylene or suitable plastic. Lid portion  12  is also constructed of a rigid material, such as polypropylene or suitable plastic, and is preferably of sufficient thickness to provide puncture resistance to conventional hypodermic needles. Lid portion  12  and skirt  14  may be molded as a unitary cap  10  using conventional techniques. 
         [0027]    Turning to  FIGS. 2A and 2B , each latch tab  18  comprises a first projection  22 . Projection  22  extends and is angled upwardly and inwardly from base  16  toward lid portion  12 . Projection  22  is preferably conical, frusto-conical or in the shape of a smooth partial cone. First projection  22  has a terminal end  24  that is situated wholly within the diameter of tapered skirt  14 , forming a ledge at the bottom of aperture  20 . 
         [0028]    An alternative embodiment of cap  10  is illustrated in  FIGS. 3A and 3B , wherein a second projection  26  is provided. Second projection  26  extends upward from base  16  toward lid portion  12 . Second projection  26  is essentially vertical, forming a plane that is roughly perpendicular to the plane defined by lid portion  12 . Second projection  26  has a terminal end  28  that defines a bottom edge of aperture  20 . The ledge formed by terminal end  24  of first projection  22  sits beneath terminal end  28  of second projection  26 . 
         [0029]    Now referring to  FIG. 4 , conventional solution container  30  has an additive or inlet port  32 , an access site  33  about inlet port  32 , an inlet tube  34 . Situated about inlet port  32  is annular flange  40 . Access site  33  is typically centrally located about inlet port  32  and commonly includes a reseal element or reseal member that is elastomeric and self-resealing; ‘access site’ is used herein to denote that portion of the port through which substances are added or withdrawn, without limitation. 
         [0030]    The diameter of lid portion  12  is larger than the diameter of access site  33 . Accounting for apertures  20 , the surface area of lid portion  12  is still greater than the surface area of access site  33  such that when cap  10  is in place, lid portion  12  (or at least a diameter thereof by the aperture  20 ) fully covers access site  33 . The diameter of base  16  is slightly larger than the diameter of flange  40 . Terminal ends  24  of first projections  22  define an internal diameter within cap  10  that is smaller than the diameter of flange  40 . 
         [0031]    Once all desired medications, drugs and other substances have been added to container  30  in any conventional manner, cap  10  is placed over the additive or inlet port  32  with lid portion  12  facing outward and with the interior of cap  10  facing inlet port  32 . First projections  22  are in a non-flexed or relaxed position, as best shown in  FIGS. 2B and 3B . Referring again to Fig., pressure is applied to cap  10  in the direction of arrow  42 , causing latch tabs  18  to flex outwardly to allow flange  40  to pass through. Thereafter, first projections  22  deter removal of cap  10  due to interference between flange  40  and first projections  22 . Minimum pressure to cause flexion of first projections  22  as described herein is preferably between 10-14 pounds per square inch. 
         [0032]    As latch tabs  18  engage flange  40 , first projections  22  flex or bend upwardly and outwardly, as best shown in  FIG. 5 . First projections  22  bend within range of flex travel  44 . As cap  10  continues downward in direction  42 , flange  40  clears terminal end  24  of first projection  22 , and first projection  22  returns to its non-flexed or relaxed position, angled inwardly and upwardly toward lid portion  12 . See  FIG. 6 . A segment of flange  40  is received within aperture  20 . Access site  33  of inlet port  32  is fully covered by lid portion  12 . 
         [0033]    Still referring to  FIG. 6 , it should be appreciated that if one attempts to remove cap  10  by applying axial pulling force in the direction of arrow  46 , terminal end  24  of first projection  22  will engage flange  40  and deter further axial movement. Rotational movement of cap  10  about inlet port  32  is possible, but this is not a limitation. Depending upon the structure of inlet port  32  and/or the thickness of flange  40 , cap  10  may or may not freely rotate. 
         [0034]    Latch tabs  18  serve as tensile stress concentrators. Attempts to force cap  10  in direction  46 , as well as attempts to force first projections  22  open, will result in the fracture of first projections  22  or at the very least cause a visible deformation of one or more portions of latch tab  18 , including second projections  24 , as well as surrounding skirt  14  and base  16 . Deformations could include, but are not limited to, discoloration, stressing, and creasing. Likewise, persons skilled in the art will appreciate that attempts to pry cap  10  away from inlet port  32  will result in deformations to cap  10 , and could additionally result in deformations and/or destructive changes to inlet port  32 , inlet tube  34  or even container  30 . 
         [0035]    Caps  10  may be color coded to facilitate identification of certain types of medical solutions. For example, red caps may be provided for hazardous agents such as oncolytics, while purple caps may be provided for general drug administrations. Persons skilled in the art will appreciate that there are a number of color-coding conventions in the clinical setting, and that there are potentially limitless color combinations. 
         [0036]    Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the scope of this invention.