Abstract:
Syringe assemblies comprising a disinfecting reservoir collar to ensure adherence to aseptic techniques for use in flush procedures for vascular access devices (VAD&#39;s) are described. Also described are methods of disinfecting vascular access devices.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to syringe assemblies and particularly to syringe assemblies comprising a disinfecting reservoir collar to ensure adherence to aseptic techniques for use in flush procedures for vascular access devices (VAD&#39;s). 
       BACKGROUND 
       [0002]    VAD&#39;s are commonly used therapeutic devices and include intravenous (IV) catheters. There are two general classifications of VAD&#39;s, peripheral catheters and central venous catheters. To ensure VAD&#39;s are used and maintained correctly, standards of practice have been developed, which include a cleaning procedure, commonly referred to as flushing a catheter. 
         [0003]    VAD standards of practice usually recommend that flush procedures be performed after catheter placement, before fluid infusion, and before and after drug administration, blood sampling, transfusions and parenteral nutrition. The goal of these flush procedures is to confirm catheter patency, avoid drug incompatibilities, ensure complete drug dose administration, prevent thrombus formation and minimize the risk of blood stream infections. Flush procedures require different types and amounts of flush solutions. The most commonly used flush solutions are saline and/or heparin lock solution. The type of flush solution and amount vary depending on the specific type of catheter. Flush solution volumes between 5 and 10 ml are most common but can range from 1 ml to 20 ml. 
         [0004]    For flush procedures, an IV line refers to a system that can include a VAD, a tubing set with clamp and a VAD connector as a termination. Common types of VAD connectors are covered by pierceable septums or pre-slit septums made of rubber or another elastomeric material, which permits insertion of a sharp needle cannula in order to infuse fluids into or to withdraw fluids from the catheter. Upon withdrawal of the needle cannula, the septum seals itself. Ports having pre-slit septums are used with blunt plastic cannula or the frusto-conically shaped tip of a syringe barrel. The syringe tip or the blunt plastic cannula (which is usually attached to a syringe) is gently pushed through the pre-slit septum to establish fluid communication. 
         [0005]    IV valves, another type of VAD connector that does not require a needle having a sharp tip, are activated by the frusto-conically shaped tip of a syringe barrel to allow fluid communication between the interior of the syringe and the catheter. These valves may contain features for delivering fluid from a storage compartment in the valve to the catheter, and are referred to in the art as positive displacement valves. Such a valve is taught in U.S. Pat. No. 6,206,861. 
         [0006]    Bacteria and other microorganisms may gain entry into a patient&#39;s vascular system from access hubs and ports/valves upon connection to the VAD to deliver the fluid or pharmaceutical. Each access hub (or port/valve or connection) is associated with some risk of transmitting a catheter related bloodstream infection (CRBSI), which can be costly and potentially lethal. 
         [0007]    Throughout the sequence of procedures associated with the transmission of a microorganism that can cause a CRBSI, there are many risks of contact or contamination. Contamination can occur during drug mixing, attachment of a cannula, and insertion into the access hub. Because the procedure to connect to a VAD is so common and simple, the risk associated with entry into a patient&#39;s vascular system has often been overlooked. Presently, the risk to hospitals and patients is a substantial function of the diligence of the clinician performing the connection, and this diligence is largely uncontrollable. 
         [0008]    Current “recommended practice” for aseptic IV line maintenance and IV drug delivery practices require adherence to a stepwise process referred to as “SASH.” During the first step of the process, the clinician cleans/disinfects (generally with an alcohol swab) the VAD connector. Second, a syringe containing saline is used to flush the IV line or catheter (Saline flush), and then the VAD connector is disinfected a second time. Third, the fluid or pharmaceutical therapy is administered through the IV line or catheter (Administer therapy), the VAD connector is disinfected a third time, followed by a second Saline flush step. The final step, which is dependent upon the patient&#39;s need and institutional policy, is a final disinfection of the VAD connector followed by a Heparin lock step, where a small amount of heparin is injected into the IV line or catheter to prevent the formation of thrombi or blood clots. At the conclusion of this tedious stepwise process, the inlet port of the VAD connector is left exposed to the environment. This “recommended practice” requires disinfecting the VAD connector after each step, and makes IV line maintenance a very burdensome and time consuming process. Because the process is so cumbersome, clinicians very rarely implement this “recommended practice” in its entirety, and, thus, patients are exposed to the risk of contracting CRBSIs. Microorganisms populate exposed connector inlet surfaces, and, when the “recommended practice” is not adhered to, the microorganisms can enter the IV line during flushing. Furthermore, blood reflux into the IV line or catheter can cause clot formation inside the lines, and microorganisms from the connector inlet surfaces can colonize blood clots inside the lines and infect the patients during flushing. 
         [0009]    A product currently available that aims to combat the problems associated with contaminated VAD connectors is the SwabCap®. This device disinfects a VAD connectors by covering the connector and protecting it from touch and airborne contamination after the cap has been applied. As the SwabCap® is twisted onto VAD connector, a foam pad inside the cap is compressed, releasing the isopropyl alcohol that bathes and passively disinfects the top and threads of the VAD connector while the cap is in place. Friction between the SwabCap® and VAD connector is essential to ensure proper swabbing and disinfecting as the twisting action helps focus the alcohol on the targeted areas. However, for several reasons, the SwabCap® falls short of accomplishing the desired goal of effectively cleaning and disinfecting the VAD connector. First, the caps do not always engage the threads on the catheter hub, so that friction during swabbing may be inefficient. Additionally, the caps are small, and thus, may result in touch contamination when they are being removed. Despite the fact that the caps are bright orange in color so that compliance can be visually confirmed, because the SwabCap® is a separate entity, only the most diligent clinician will utilize the cap after every step of the flush process. Thus, the cap does not ensure compliance with aseptic technique. 
         [0010]    Substantial morbid and mortal risk is, therefore, associated with a number of routine procedures defined primarily by the uncontrollable diligence of the clinician administering the therapy. Unfortunately, the result is that a substantial degree of unnecessary risk and injury, in the form of CRBSIs, to patients occurs. There is a need, therefore, for a flush syringe assembly that promotes compliance with aseptic technique by eliminating the additional swabbing and disinfecting steps. 
       SUMMARY 
       [0011]    Embodiments of the present invention are directed to a syringe assembly for use in flush applications. Syringe assemblies according to a first aspect of the present invention include a plunger rod, a syringe barrel, and a reservoir collar that permit disinfection of the hub of a VAD connector upon connection to the device. The features providing for disinfection allow the clinician to substantially achieve the effects of aseptic techniques without the need for added swabbing steps and diligence on the part of the clinician. 
         [0012]    In one or more embodiments, the disinfection is provided by a reservoir collar that contains a disinfectant housed within a compartment in the reservoir collar. 
         [0013]    In one variant, the reservoir collar contains an absorbent material that surrounds a tip that is adapted for connection to a VAD. The absorbent material absorbs the disinfectant, and, upon connection to the hub of a VAD connector, compresses toward the syringe barrel while disinfecting the hub. The disinfectant can be a fluid, a foam, or a gel. 
         [0014]    In a specific embodiment, the reservoir collar surrounds a connector collar adapted for connection to the hub of a VAD connector. In another specific embodiment, the connector collar is a luer connector. 
         [0015]    A second aspect of the present invention pertains to a method of disinfecting a VAD connector. The method according to one embodiment comprises connecting a flush syringe assembly to the hub of a VAD connector, wherein the flush syringe assembly includes a plunger rod, a syringe barrel, and a reservoir collar that permits disinfection of the hub of a VAD connector upon connection to the device. The method allows the clinician to substantially achieve the effects of aseptic techniques without the need for added swabbing steps and diligence on the part of the clinician. 
         [0016]    In a specific embodiment, the method comprises connecting a flush syringe assembly to a hub of the vascular access device, wherein connecting includes frictionally engaging a reservoir having a collar and a tip on the flush syringe with the hub vascular access device such that the hub contacts an antimicrobial agent contained within the reservoir. As noted above, the reservoir can contain an absorbent material, and the reservoir can include a first tip and a second tip, and the flush syringe includes a seal covering the reservoir and the first and second tip. In such construction, upon connecting the flush syringe assembly to the hub, the seal is broken to expose the second tip to the antimicrobial agent. The reservoir further can comprises threads that engage threads on the hub, and connecting occurs by engaging the threads on the hub and the reservoir by twisting the vascular access device with respect to the flush syringe. Upon connection, the hub contacts the antimicrobial agent and the absorbent material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a perspective view of a flush syringe assembly according to an embodiment of the present invention; 
           [0018]      FIG. 2  is an enlarged partially cross-sectioned side elevation view of the assembled reservoir collar attached to flush syringe assembly of  FIG. 1 ; 
           [0019]      FIG. 3  is an enlarged partially cross-sectioned side elevation view of the components of the reservoir collar which attaches to the flush syringe assembly of  FIG. 1 ; 
           [0020]      FIG. 4  is an enlarged partially cross-sectioned side elevation view of the assembled reservoir collar for attachment to flush syringe assembly of  FIG. 1 ; 
           [0021]      FIG. 5  is an enlarged partially cross-sectioned side elevation view of the assembled reservoir collar being attached to the flush syringe assembly of  FIG. 1 ; 
           [0022]      FIG. 6  is an enlarged partially cross-sectioned side elevation view of the reservoir collar attached to the flush syringe assembly of  FIG. 1 , illustrating how the first tip of the syringe barrel attaches interlocks with the second tip of the reservoir collar; 
           [0023]      FIG. 7  is an enlarged partially cross-sectioned side elevation view of the reservoir collar illustrating removal of the seal over the end of the reservoir collar for attachment to a VAD; 
           [0024]      FIG. 8  is an enlarged partially cross-sectioned side elevation view of the reservoir collar illustrating attachment of the reservoir collar to the hub of a VAD connector; 
           [0025]      FIG. 9  is an enlarged partially cross-section side elevation view of the reservoir collar illustrating compression of the absorbent material upon connection to the hub of a VAD connector; 
           [0026]      FIG. 10  is an enlarged partially cross-sectioned side elevation view of an alternative embodiment of the reservoir collar; and 
           [0027]      FIG. 11  is an enlarged partially cross-sectioned side elevation view of the flush syringe assembly, illustrating an alternative embodiment of the reservoir collar for connection to the syringe assembly of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways. 
         [0029]    With respect to terms used in this disclosure, the following definitions are provided. 
         [0030]    Reference to “flush syringe assembly” includes syringes that are indicated for use in the flushing of VADs. The practice of flushing ensures and maintains catheter patency and helps prevent the mixing of incompatible pharmaceuticals. 
         [0031]    As used herein, the use of “a,” “an,” and “the” includes the singular and plural. 
         [0032]    As used herein, the term “catheter related bloodstream infection” or “CRBSI” refers to any infection that results from the presence of a catheter or IV line. 
         [0033]    As used herein, the term “microorganism” refers to a microbe or organism that is unicellular or lives in a colony of cellular organisms. Microorganisms are very diverse; they include, but are not limited to bacteria, fungi, archaea, and protozoans. Microorganisms are often the cause of CRBSIs. The most common microorganisms associated with CRBSIs include, but are not limited to,  Staphylococcus aureus  and epidermis,  Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa,  and  Candida albicans.    
         [0034]    As used herein, the terms “antimicrobial agent” or “antimicrobial” refers to substances that kill or inhibit the growth of microorganisms such as bacteria, fungi, archaea, or protozoans. Antimicrobial agents either kill microbes, or prevent the growth of microbes. 
         [0035]    As used herein, the term “disinfectant” refers to antimicrobial substances that are used on non-living objects or outside the body, e.g., on the skin. 
         [0036]    In one or more embodiments, disinfectants or antimicrobial agent include, but are not limited to, ethanol, 2-propanol, butanol, methylparaben, ethylparaben, propylparaben, propyl gallate, butylated hydroxyanisole (BHA), butylated hydroxytoluene, t-butyl-hydroquinone, chloroxylenol, chlorohexidine, dichlorobenzyl alcohol, dehydroacetic acid, hexetidine, triclosan, hydrogen peroxide, colloidal silver, and mixtures thereof. 
         [0037]    As used herein, the term “absorbent material” refers to a material having capacity or tendency to absorb or soak up another substance. In one or more embodiments, the absorbent material has a tendency to absorb a disinfectant or antimicrobial. Absorbent materials may include sponges, absorbent cottons, other absorbent fabrics, and synthetic polymer matrices. 
         [0038]    As used herein, the term “Luer connector” refers to a connection collar that is the standard way of attaching syringes, catheters, hubbed needles, IV tubes, etc. to each other. The Luer connector consists of male and female interlocking tubes, slightly tapered to hold together better with even just a simple pressure/twist fit. Luer connectors can optionally include an additional outer rim of threading, allowing them to be more secure. The Luer connector male end is generally associated with a flush syringe and can interlock and connect to the female end located on the VAD. A Luer connector comprises a distal end, a proximal end, an irregularly shaped outer wall, a profiled center passageway for fluid communication from the chamber of the barrel of a syringe to the hub of a VAD. A Luer connector also has a distal end channel that releasably attaches the Luer connector to the hub of a VAD, and a proximal end channel that releasably attaches the Luer connector to the barrel of a syringe. 
         [0039]    Provided are syringe assemblies that include a plunger rod and a syringe barrel, that incorporate an element for disinfecting the hub of a VAD. The assembled syringe assembly is shown in  FIGS. 1 and 2 , with the components shown separately in  FIGS. 3-9 . Alternative embodiments of the present invention are shown in  FIGS. 10-11  Referring to  FIGS. 1-3 , a syringe assembly  20  according to the present invention generally comprises a barrel  21 , including a side wall having an inside surface defining a chamber for retaining fluid. The barrel  21  further includes an open proximal end  27  and a distal end  28  having a distal wall  29  with an elongated first tip  31  extending distally therefrom and having a first passageway  32  therethrough in fluid communication with the chamber, the tip adapted for connection to a reservoir collar  40 . The distal wall  29  may comprise a plurality of threads for attachment to the reservoir collar  40 . 
         [0040]    An plunger rod  37  includes distal portion  38  and a proximal portion  39 , the plunger rod further comprising a distal end including a stopper slidably positioned in fluid-tight engagement with the inside surface of the barrel for drawing fluid into and driving fluid out of the chamber by movement of the stopper relative to the barrel, the plunger rod  37  extending outwardly from the open proximal end  27  of the barrel, the stopper having a distal surface. 
         [0041]    A reservoir collar  40  mounted on the distal end  28  of the barrel and surrounding the first tip  31 , the reservoir collar  40  including at least one side wall  41  having an inside surface  42  defining a compartment  43  containing a disinfectant or antimicrobial agent, a sealed distal end  45 , and a proximal end  46  adjacent the distal wall  29  of the barrel, with a second tip  51  extending distally therefrom having a second passageway  52  therethrough in fluid communication with said first passageway  32 , the second tip  51  adapted for connection to a hub of a vascular access device. The reservoir collar  40  may comprise a plurality of threads  47  on the inside surface for connection to a vascular access device. The reservoir collar  40  may comprise a plurality of threads on the proximal end for attachment to the distal wall  29  of the barrel. Referring to  FIG. 5 , upon manufacture, the flush syringe assembly  20  can be provided with the reservoir collar  40  partially threaded at the proximal end  46  onto the distal wall  29  of the barrel. The seal  49 , is not yet pierced. Referring to  FIG. 6 , to activate the reservoir collar  40 , the clinician can twist the proximal end  46  onto the distal wall  29  such that the threads tightly interlock and the first tip  31  pierces the seal  49 . The first tip  31  then becomes interlocked with the second tip  51 , and the first passageway  32  and the second passageway  52  become one integral passageway for fluid communication from the barrel  21  to a VAD. 
         [0042]    The reservoir collar  40  may comprise an absorbent material  44  surrounding the second tip  51  for soaking up the disinfectant or antimicrobial agent that is housed within the compartment  43 . The disinfectant or antimicrobial agent can be a fluid or a gel selected from the group consisting of selected from the group consisting of ethanol,  2 -propanol, butanol, methylparaben, ethylparaben, propylparaben, propyl gallate, butylated hydroxyanisole (BHA), butylated hydroxytoluene, t-butyl-hydroquinone, chloroxylenol, chlorohexidine, dichlorobenzyl alcohol, dehydroacetic acid, hexetidine, triclosan, hydrogen peroxide, colloidal silver, and mixtures thereof. 
         [0043]    The sealed distal end  45  of the reservoir collar  40  may comprise a removable seal  48 . The removable seal  48  can comprise an aluminum peal back top. The seal can be a plastic sealed aluminum, and can be chemically-resistant, light-blocking, non-permeable, or sterile. 
         [0044]    The reservoir collar  40  may comprise an aluminum lining adhered to the inside surface  42  of at least one side wall  41 . The aluminum lining can prevent degradation of the disinfectant or antimicrobial agent, and can also provide a mechanism for ensuring compliance with aseptic conditions. 
         [0045]    The reservoir collar  40  may be removable from the syringe assembly  20 . When removable, the reservoir collar  40  comprises a pierceable seal  49  on the proximal end  46  of the reservoir collar  40 . The pierceable seal  49  can be pierced by the first tip  31  upon connection to the distal wall  29  of the barrel. The pierceable seal  49  can comprise an aluminum seal. The aluminum seal can be a plastic sealed aluminum, and can be chemically-resistant, light-blocking, non-permeable, or sterile. 
         [0046]    In an embodiment, the reservoir collar  40  surrounds a connector collar adapted for connection to the hub of the vascular access device. The connector collar can further comprise an absorbent material  44  for soaking up the disinfectant or antimicrobial agent dispersed within the connector collar. The disinfectant or antimicrobial agent can be a fluid or a gel. In a further embodiment, the reservoir collar  40  surrounds a connector collar adapted for connection to the hub of the vascular access devices, wherein the connector collar is a Luer connector. 
         [0047]    Referring to  FIGS. 4-6 , in operation, the assembled, removable reservoir collar  40  is attached via the proximal end  46  to the distal wall  29  of the syringe barrel  21  such that the proximal end  46  of the reservoir collar  40  is adjacent to the distal wall  29  of the syringe barrel  21 . The first tip  31  interlocks with the second tip  51  such that the first passageway  32  and the second passageway  52  become one integral passageway for fluid communication to a vascular access device. Referring to  FIG. 5 , upon manufacture, the flush syringe assembly  20  can be provided with the reservoir collar  40  partially threaded at the proximal end  46  onto the distal wall  29  of the barrel  21 . The seal  49  is not yet pierced. Referring to  FIG. 6 , to activate the reservoir collar  40 , the clinician can twist the proximal end  46  onto the distal wall  29  such that the threads tightly interlock and the first tip  31  pierces the seal  49 . The first tip  31  then becomes interlocked with the second tip  51 , and the first passageway  32  and the second passageway  52  become one integral passageway for fluid communication from the barrel  21  to a VAD. Once the reservoir collar  40  has been activated by threading it onto the distal wall  29 , it is now ready to be used to disinfect the hub of a VAD. 
         [0048]    The syringe assembly  20  is filled with flush solution using known methods. Additionally, the syringe assembly  20  may be provided pre-filled from the manufacturer or supplier. The flush solution may be any solution intended for flushing or maintaining performance of VAD&#39;s. It is preferred that the flush solution be selected from the group consisting of saline flush solution and heparin lock flush solution. These solutions are known in the art and are readily available. An example of a saline flush solution includes, but is not limited to, 0.9% sodium chloride USP for injection. An example of a heparin lock flush solution includes but is not limited to 0.9% sodium chloride with 100 USP units of heparin sodium per mL or 10 USP units of heparin sodium per mL. When the first tip  31  interlocks with the second tip  51 , the flush solution is communicated from the barrel  21  through the now integral first passageway  32  and second passageway  52  to a vascular access device. 
         [0049]    The syringe assembly  20  is now ready for use in flushing a vascular access device such as a catheter or IV set. IV sets can be very complex and may include multiple injection ports, valves, and/or other components. For the purpose of illustrating the present invention, a simplified IV set or catheter hub  60  is illustrated in  FIGS. 8 and 9 . The hub  60  includes a housing hollow interior and a septum  61  at its proximal end  62 . A hollow IV line or catheter  64  extends from the distal end  63  from the housing. The IV site may be a valve having structure for accepting the second tip  51  and being activated by the insertion of the second tip  51  to establish fluid communication with the IV line or catheter  64 . 
         [0050]    There are two general classifications of VAD&#39;s, peripheral catheters and central venous catheters. Peripheral catheters are used to access veins in the peripheral extremities such as the hand and ann. Peripheral catheters are relatively short in length ranging from about 14 mm to 48 mm in length, and are available in gauge sizes from about 16 to 24. It is believed that the most commonly used peripheral catheters are 20 gauge having an ID of about 0.81 mm (0.032 inch) and 22 gauge having an ID of about 0.66 mm (0.026 inch), and having a length of about 25 mm to 32 mm. As used herein, the term “peripheral catheter” is intended to refer to a 20 or 22 gauge catheter having a length of about 25 mm. Central venous catheters are substantially longer than peripheral catheters and are inserted in the patient and terminate near the heart. 
         [0051]    Referring to  FIGS. 7-9 , the syringe assembly  20  when connected with reservoir collar  40  has a second tip  51  that is rendered antimicrobial because it is surrounded by an absorbent material  44  that soaks up disinfectant or antimicrobial agent contained within compartment  43 . The now antimicrobial tip  51  can be connected to a vascular access device. The seal  48  is removed from the distal end  45  of the reservoir collar  40 , exposing the second tip  51 . As the syringe assembly  20  is connected to the hub of a vascular access device  60 , the absorbent material  44  compresses creating friction. The disinfecting properties of the disinfectant or antimicrobial agent contained within the chamber  43  that has been absorbed by absorbent material  44 , disinfect the hub  60 , thus ensuring compliance with aseptic technique. The friction created by the compression of the absorbent material  44  is necessary to provide disinfection of the hub  60 . Once the connection of the syringe assembly  20  to the hub  60  is completed, the hub is properly disinfected, and fluid communication from the barrel  21  of the syringe to the vascular access device can occur. Fluid is drawn from the barrel  21  through the integral first passageway  32  and second passageway  52  through the hub  60  and into the IV or catheter  64 . Because of the presence of the reservoir collar  40 , fluid communication through a vascular access device and into a patient is conducted under aseptic conditions without any additional swabbing steps and diligence on the part of the clinician. 
         [0052]      FIG. 10  illustrates an alternative embodiment of the reservoir collar  40 . Additional space  70  between the plurality of threads  47  and the proximal end  46 , allows the clinician to fully rotate the syringe assembly  20  and completely disinfect the hub  60  of a vascular access device upon connection of the syringe assembly  20  to the hub  60 . 
         [0053]      FIG. 11  illustrates another embodiment of the syringe assembly  20 . The reservoir collar  40  can be integrally formed on the distal wall  29  of the syringe barrel  21  with a second tip  51  with a second passageway  52  extending therethrough for fluid communication to the vascular access device. A seal  48  will contain the disinfectant or antimicrobial agent within the chamber  43  until the seal  48  is removed and the syringe assembly  20  is connected to a vascular access device. The absorbent material  44  will soak up the disinfectant or antimicrobial agent and will disinfect the hub of a vascular access device upon connection. This alternative syringe assembly is simpler to manufacture compared to the assembly of  FIGS. 1-3 . However, extractables may increase. 
         [0054]    Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as disclosed.