Abstract:
A syringe assembly for connecting to an intravenous (“IV”) line includes: a syringe barrel having an actuation end and a discharge end; a syringe plunger moveable within the syringe barrel, the syringe plunger including a plunger head connected to a plunger arm; a seal between the plunger arm and the syringe barrel, the seal residing on an actuation end side of the syringe plunger; and a tube in fluid communication with the syringe barrel at a location between the seal and the plunger head, the tube having a distal end configured to be connected to the IV line.

Description:
BACKGROUND 
       [0001]    Certain drug infusion patients are considered flow restricted or volume restricted, meaning they can only receive a certain amount of medical fluid or drug over a given period of time. Neonatals or babies are one class of fluid restricted patients. Their bodies are too small to receive more than a certain amount of medical fluid or drug over a given infusion period. 
         [0002]    There are circumstances in which a drug infusion patient, including fluid restricted patients, needs an infusion of a second drug or medical fluid in addition to the primary drug or medical fluid that the patient is currently receiving. In the situation in which the patient is fluid restricted, needing a second drug or medical fluid can present a problem if the primary drug or medical fluid that the patient is receiving is at or close to the maximum allowable flowrate for the patient. 
         [0003]    In the above scenario, one solution is to inject the second drug or medical fluid into the primary fluid administration or intravenous (“IV”) bag. Here, the second fluid mixed with the first fluid in the bag upstream of the pump or the gravity-feed tube such that the flowrate through the pump or the gravity-feed tube does not vary despite the fact that a portion of the flowrate now includes the second medical fluid or drug. There are a number of problems with this approach however. First and foremost is that the patient may need the entire dose of the medical fluid or drug quickly and does not have the time to wait for the bag of primary fluid to be delivered to receive the full dose. 
         [0004]    The second problem is effectiveness. That is, even if the patient has the time to allow the second drug to be delivered from the primary IV bag, the second drug may not be effective if diluted in the primary IV bag. In addition, the drug may have a lower specific gravity than the primary drug or solution and thus may tend to be delivered last to the patient. 
         [0005]    A solution to the above-described scenario is needed accordingly. 
       SUMMARY 
       [0006]    The present disclosure sets forth an apparatus and method to address the above-stated scenario. The apparatus includes an administration or intravenous (“IV”) line set and a syringe assembly that attaches to the IV line set. The IV line set extends from a bag or container holding a drug or medical fluid for infusion into the patient to a patient access device, e.g., catheter, cannula or needle for accessing the patients vascular system. The IV line may or may not operate with an infusion pump, such as an infusion pump provided by the assignee of the present disclosure. 
         [0007]    The IV line includes a y-site located downstream of the IV bag and in one embodiment downstream of a section of the tubing that would operate with an infusion pump. The y-site provides a secondary access to the IV line. The y-site is provided in one embodiment with a check valve that prevents fluid from backflowing or traveling upstream to the IV bag. In an alternative embodiment, the check valve is provided for the same purpose, upstream of the y-site, between the y-site and the IV bag. 
         [0008]    A multi-way valve or stopcock is located in the IV line downstream of the y-site, between the y-site and the patient access device. The valve in one embodiment includes a first, “normal flow” position in which fluid flows to the patient access device. The valve in a second, “secondary fluid” position instead flows fluid out a secondary fluid port. The valve optionally has a third position in which all fluid flow is stopped. 
         [0009]    A syringe assembly is provided, which includes a tube is connected fluidly to an actuation end of a barrel of the syringe. The second fluid port of the multi-way valve is configured to connect, e.g., via a female or male luer connector, fluidly and sealingly with the tube of the syringe assembly, which can be provided with a male or female luer connector. The discharge end or outlet nozzle of the syringe is configured to connect fluidly and sealingly with a mating connector located at the free y-site administration port, which under normal flow conditions is capped. 
         [0010]    The syringe head plunger is provided with a movable or slideable discharge or nozzle end seal to the inside of the syringe barrel. The barrel of the syringe is also fitted with a second, actuation end seal that is in one embodiment fixed. The discharge end and actuation end seals provide a sealed, variable volume within the syringe barrel. 
         [0011]    In normal operation, the syringe assembly is not connected to the IV line. The free y-site administration port is capped. The multi-way valve or port is set to the normal flow position, so that fluid flows from the valve to the patient access device and not to the secondary fluid point of the multi-way valve. 
         [0012]    When a fluid restricted patient needs a volume (e.g., small volume) of secondary medical fluid or drug, the syringe assembly is connected to the IV line to create a secondary closed-loop bypass. The discharge end or outlet nozzle of the syringe is connected fluidly and sealingly, e.g., threadingly, to the y-site administration port. The connector, e.g., male or female luer connector, located at the end of the tube extending from the syringe barrel is connected fluidly and sealingly to the mating connector, e.g., female or male luer connector, of the secondary port of the multi-way valve or stopcock. 
         [0013]    To inject the secondary medical fluid or drug, the user sets the valve so the fluid does not flow to the patient access device and instead flows through the secondary port of the multi-way valve to the connected tube of the syringe assembly. When the user injects the secondary drug or medical fluid from the syringe to the IV line, the IV line between the y-site and the multi-way valve or stopcock fills with the secondary fluid. A like volume of the primary fluid is moved through the multi-way valve into the tube of the syringe assembly and potentially into the sealed expanding volume within the syringe barrel located behind the syringe plunger. Once a desired volume of the secondary fluid is delivered to the IV line, the multi-way valve is switched so that “normal” flow resumes but now with a volume of the secondary fluid or drug residing in the IV line. 
         [0014]    The syringe assembly enables the secondary fluid or drug to replace a like volume of primary fluid instead of adding to the volume, resulting in an overall zero net total volume change. Also, the multi-way valve and y-site are located downstream of the IV bag, so that only the small volume of primary fluid left in the tubing downstream of the secondary fluid volume has to be delivered to the patient before the patient receives the secondary fluid or drug. 
         [0015]    It is accordingly an advantage of the present disclosure to provide an improved intravenous administration system and method. 
         [0016]    It is another advantage of the present disclosure to enable a secondary fluid or drug to be delivered effectively to a fluid restricted patient. 
         [0017]    It is a further advantage of the present disclosure to enable a secondary fluid or drug to be delivered to a patient without increasing an overall volume of fluid delivered. 
         [0018]    It is still another advantage of the present disclosure to provide a system and method for allowing a patient receiving a first medical fluid or drug to quickly and safely receive a second medical fluid or drug. 
         [0019]    Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0020]      FIG. 1  is a schematic elevation view of one embodiment of an intravenous (“IV”) administration set of the present disclosure. 
           [0021]      FIG. 2  is a schematic elevation view of one embodiment of a syringe assembly usable with the set of  FIG. 1 . 
           [0022]      FIGS. 3A and 3B  are schematic elevation views of alternative embodiments for an IV administration set of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
     Syringe Assembly Embodiment 
       [0023]    Referring now to the drawings and in particular to  FIG. 1 , one embodiment of the intravenous (“IV”) administration set and associated syringe assembly of the present disclosure is illustrated by IV administration set  10 . Administration set  10  includes a supply container or bag  12 , which holds a primary medical fluid/drug  14 . As discussed herein, administration set  10  is particularly useful for a restricted flow patient, such as a baby or neonatal. Common primary medical fluids or drugs  14  for such patients include 0.9% NaCl or 5% dextrose solution, for example. Supply container  12  can be made of any suitable medical grade material, such as PVC. 
         [0024]    Fluid leaving supply container  14  enters an upstream tubing section  16 . Upstream tubing section  16  as well as any of the other tubing segments and associated connectors discussed herein are likewise made of a suitable medically accepted material, such as polyvinyl chloride (“PVC”) or non-di(2-ethylhexyl)phthalate (“DEHP”) materials. Upstream tubing section  16  is shown operating with an infusion pump  18 , which can be a rotary or linear peristaltic pump. Alternatively, pump  18  can use a shuttle and platen, such as one provided by the COLLEAGUE™ infusion pump made by the assignee of the present disclosure. In an alternative embodiment, system  10  is gravity fed, such that infusion pump  18  is not used or needed. 
         [0025]    In the illustrated embodiment, upstream tubing  16  includes or provides a check valve  20 , which prevents medical fluid or drug  14  from flowing up tube  16  and back into supply container  12 . Check valve  20  is provided alternatively with a y-site  30  connected to the end of upstream tubing  16 . 
         [0026]    Y-site  30  includes a main flow branch  32  and a secondary administration port  34 . As illustrated, main flow branch  32  is connected to the distal end of upstream tubing  16 . Administration port  34  includes a suitable connector, such as a female or male luer tip connector, which may be provided with a cap  36 . Y-site  30  includes an outlet port  38 , which is connected to a proximal end of an intermediate piece of tubing  26 . The inlet fluid port  32  and outlet port  38  connect respectively to tubing sections  16  and  26  via a suitable tubing type connection, such as a barbed, glued, or press-fit tubing connection. The length and diameter of intermediate tubing  26  are sized in one embodiment so to be able to receive the entire contents from a syringe barrel  52  of bypass syringe assembly  50 . 
         [0027]    A distal end of intermediate tubing section  26  connects via a suitable tubing type connection to a multi-way valve or stopcock  40 . Multi-way valve  40  in an embodiment is a two-way valve. In an alternative embodiment, multi-way valve  40  can have an additional position in which flow through the valve is stopped completely. Multi-way valve  40  is provided with a primary fluid flow outlet  42  and a secondary fluid flow outlet  44 . Secondary fluid flow outlet  44  can be a female or male luer connector. Secondary fluid flow outlet  44  may be capped via a suitable cap  46 . 
         [0028]    The user selects whether fluid flowing into valve  40  flows to main fluid outlet  42  or secondary fluid outlet  44  using a lever or other type of manually operated selector  48 . When the user maneuvers selector  48  to a first position, fluid flows from intermediate tubing section  26 , through multi-way valve  40  and its moving fluid outlet  42 , through a downstream tubing section  86 , to a patient access device  80 , such as a catheter, cannula or needle. Alternatively, if the user maneuvers selector  48  to a second position, fluid flows instead from intermediate tubing section  26 , through multi-way valve  40  and alternatively out secondary port and connector  44 . Again, in one embodiment valve  40  includes a third position for selector  48 , in which fluid entering valve  40  flows through neither outlet  42  nor outlet  44 . 
         [0029]    Patient access device  80 , can be any suitable catheter, cannula or needle. Further, although not illustrated, any of tubing sections  16 ,  26  or  76  can operate with one or more line clamp, such as a Robert&#39;s type line clamp. 
         [0030]    IV administration set  10  is operable with a syringe assembly  50 , which includes a syringe  52  connected via a tubing connection port  54  to a bypass tube  56 , which terminates at its distal end with a connector  58 , such as a male or female luer connector, which is configured to mate with and connect to connector  44 , e.g., a female or male luer connector, of multi-way valve  40 . 
         [0031]      FIG. 2  shows syringe assembly  50  in more detail. Syringe barrel  52  includes a discharge end  62 , which can be a male or female luer connector or luer lock that connects to secondary administration port  34  of y-site  30 . A cap  64  is provided initially on discharge end  62  of syringe barrel  52 . Likewise, a cap  66  is provided initially for covering distal port  58 , e.g., a male or female luer connector, located at distal end of bypass tubing  56 . Syringe barrel  52  also includes markings or indicia  68 , that allow the user to fill syringe barrel  52  with a desired amount of the secondary medical fluid or drug. Examples of a secondary fluid/drug filled at syringe barrel  52  include antibiotics. Syringe barrel  52  further includes or defines a stationary flange  69  that the user can grasp to help push the secondary medical fluid/drug out discharge end  62  of syringe barrel  52 . 
         [0032]    As illustrated in  FIG. 2 , port  54  of syringe barrel  52  can be a hose barb or other type of compression connector for sealingly receiving the proximal end of bypass tubing  56 . A plunger  70  is fitted inside syringe barrel  52 . Plunger  70  includes a plunger rod  72 , which is fitted at its discharge end with a plunger head  74 . Plunger head  74  translates sealingly within syringe barrel  52 , sealing to the inner wall of the syringe barrel. In an embodiment, an outer wall  74   a  of plunger head  74  is made of a material that is compliant enough and sized appropriately, so as to seal directly to the inner wall of syringe barrel  52  in such a manner that plunger head  74  and plunger  70  can slide within syringe barrel  52 . In an alternative embodiment, a separate o-ring  74   b  is fitted into a groove (not seen) provided in, plunger head  74  for sealing the plunger head to the inside wall of syringe barrel  52 . 
         [0033]    A second seal  76  is fitted at the actuation end of syringe barrel  52 . Second seal  76  is in one embodiment formed with or otherwise fixedly secured to the inside wall of syringe barrel  52 . Actuation end seal  76  creates a sliding seal with plunger rod  72 . Seal  76  remains sealed to rod  72  as the user translates rod  72  back and forth via fixed flange  69  and plunger flange  78 . 
         [0034]    One actuation end seal  76  creates a sliding seal with plunger rod  72 . Seal  76  remains sealed to rod  72  as the user translates rod  72  back and forth via flange  69  and plunger flange  78 . Actuation end seal  76 , o-ring  74   b , and/or outer wall  74   a  in an embodiment are made of a medical grade compliant sealing material, such as closed-cell, silicone. 
         [0035]    Administration end seal  76  is located closer to the administration end of syringe barrel  52  than is bypass port  54  of syringe barrel  52 , so that administration end seal  76  and the seal made by plunger head  74  form a closed and sealed changing volume about the secondary fluid or bypass port  54  of syringe assembly  56 . A plunger flange  78  is provided at the actuation end of plunger rod  72 , so as to allow the user&#39;s thumb to press flange  78  while the user&#39;s fingers wrap about stationary flange  69  to allow the user to compress flange  78 , plunger rod  72  and plunger head  74  into syringe barrel  52  to dispel the secondary medical fluid or drug through discharge outlet  62 . 
       Method of Operation 
       [0036]    To operate system  10  as it has been described in connection with  FIGS. 1 and 2 , under normal operation the extra connectors, e.g., luer connectors, are capped such that cap  46  caps luer connector  44 , cap  66  caps luer connector  58 , cap  64  caps luer connector  62  and cap  36  caps the luer connector of administration port  34 . The user places selector  48  of multi-way valve  40  in a position that enables fluid flowing from supply container  12  to flow through tubing sections  16 ,  26  and  86 , through patient access device  80  to the patient. Again, primary medical fluid/drug  14  can be pumped via pump  18  or gravity fed through the tubing and multi-way valve  40  to the patient. 
         [0037]    When is it desired to give the patient a dose of a secondary fluid or drug, the user moves selector  48  into the position in which fluid flows instead out secondary port  44 , or in an alternative embodiment moves selector  48  to a position in which no fluid flows out multi-way valve  40 . The user removes cap  64  from discharge end  62  of syringe barrel  52 , connects discharge end  62  to a vial or other container of the secondary medical fluid or drug (not illustrated) and pulls plunger  70  via plunger flange  78 , such that a desired amount of the secondary medical fluid or drug enters syringe barrel  52  according to indicia  68  provided on the side of syringe barrel  52 . The user then pulls cap  36  from administration port  34  of y-site  30  and connects connector  62  to the meeting connector at the administration port  34 . 
         [0038]    The user then removes caps  46  and  66  from connectors  44  and  58 , respectively, and connects bypass tubing connector  58  to the mating valve connector  44 . It should be appreciated that the connection sequence can be done differently than just described, e.g., by connecting syringe assembly  50  to valve  40  first, then connecting the assembly to y-site  30 . In a further alternative embodiment, syringe assembly  50 , with a pre-loaded syringe barrel  52 , is pre-attached to y-site  30  and multi-way valve  40  prior to the administration of any primary medical fluid/drug  14  to the patient. It should be appreciated however that while system  10  requires tubing  16 ,  26  and  86  to be primed before delivery of primary fluid  14  to the patient, bypass line  56  and the sealed air volume in syringe barrel  52  between the plunger seal and actuation seal  76  of assembly  50  do not have to be primed. It may be desirable however to sterilize, e.g., via ethylene oxide, gamma radiation or steam sterilization, the inside of syringe assembly  50  prior to its use, in addition to sterilizing the remainder of IV administration set  10  prior to use. 
         [0039]    Once syringe assembly  50  is connected fluidly to y-site  30  and multi-way valve  40 , the user injects a desired amount of secondary medical fluid or drug from syringe barrel  52 , through y-site administration port  34  and into intermediate tubing  26 . Selector  48  of multi-way valve  40  is positioned such that primary medical fluid or drug residing in intermediate tubing  26  is pushed by the incoming secondary medical fluid or drug out secondary port  44  and into bypass tubing  56 . If multi-way valve  40  has a totally off position and the user has forgotten to move selector  48  from the totally off position to the bypass position, the user will feel resistance at plunger flange  78 , which will prompt the user to move selector  48  to the proper position. It should be appreciated that multi-way valve  40  can have suitable indicia informing the user of where to move selector  48  for normal flow, bypass flow and potentially no flow. 
         [0040]    In an embodiment, the secondary medical fluid/drug delivered via syringe assembly  50  is delivered all at once, in a one-shot type of injection. Alternatively, it is possible to deliver fractions of the total volume of the secondary drug pulled into syringe barrel  52  at different points in time. In any case, the volume of secondary medical fluid or drug injected from syringe barrel  52  into intermediate line  26  moves a like volume of primary medical fluid or drug  14  through multi-way valve  40 , bypass line  56  and if needed into the sealed air volume provided in syringe barrel  52 . It may occur that some of the displaced primary fluid still resides in intermediate tube  26  and/or multi-way valve  40 . This is unimportant, however, so long as there is enough volume in intermediate tube  26  to accept the entire volume of the secondary medical fluid or drug. That is, it is undesirable to push the secondary medical fluid or drug into bypass tube  56 . 
         [0041]    Once the volume of secondary medical fluid or drug is delivered to intermediate tubing  26 , the user moves selector  48  to the position that allows IV flow to exit main flow outlet  42  and in turn prevents fluid from flowing out of secondary port connector  44  of multi-way valve  40 . Normal flow then proceeds either by gravity or by infusion pump  18  action, but now with the segment of secondary medical fluid or drug located in intermediate tubing  26  flowing to the patient via access device  80  instead of a like volume of primary medical fluid or drug  14 , which has instead been displayed into bypass tubing  56  in the previous step. 
         [0042]    Three features of administration set  10  and the procedure just described should be noted. First, the overall volume of fluid delivered to the patient does not increase via the dose delivery of the secondary medical fluid or drug. Instead, as described, the secondary medical fluid or drug displaces and accordingly replaces a like amount of the primary medical fluid  14 . Second, the entire volume of secondary medical fluid/drug is introduced at a point in the administration set  10  that is close to patient access device  80 , such that the patient receives the entire volume of the secondary medical fluid or drug quickly after it is introduced into intermediate tubing section  26 . Such delivery is desirable over the introduction of the secondary medical fluid or drug directly into solution container  12 , which will dilute the secondary medical fluid/drug, in a worst case rendering the secondary drug ineffective, and in a best case slowing the injection of the secondary drug to the patient. Third, once connected the device maintains closed system efficacy. 
         [0043]    It is contemplated to leave syringe assembly  50  connected to the remainder of IV administration set  10  until the delivery of primary medical fluid/drug  14  to the patient is completed. Alternatively, syringe assembly  50  can be removed and y-site  30  and multi-way valve  40  recapped. In this second situation, the patient can receive multiple injections of one or more secondary medical fluid/drug at different times using different syringe assemblies  50  if needed. 
       Alternative Embodiments 
       [0044]    Referring now to  FIG. 3A , an alternative administration set  110   a  is illustrated. Administration set  110   a  is the same as administration set  10  in many respects and like element numbers are used where possible. With set  110   a , however, bypass line  56  is connected to an additional port  13  extending from supply bag or container  12 . The configuration of set  110   a  allows syringe  150  to be a standard syringe without an additional bypass port  54  and actuation and seal  76 . It is contemplated here to pre-connect bypass line  56  to multi-way valve  40  and port  13  of solution bag  12 . In this manner the entire assembly is sterilized via one of the methods discussed above prior to use. Bypass line  56  can be reused as many times as needed with one or more standard syringes  150  delivering one or more secondary medical fluid or drug as needed. It is also contemplated to eliminate the breakable connection between male or female luer  58  and female or male luer  44  and instead provide a permanent connection between multi-way valve  40  and bypass line  56 . 
         [0045]    The operation of alternative system  110   a  is in essence the same as the operation of IV administration set  10 , except that bypass line  56  is presumably longer, which if needed compensates for the additional volume provided in the sealed area of syringe barrel  52  for IV administration set  10 , which does not exist for alternative set  110   a . The operation of multi-way pass valve  40  via selector  48  is the same as described above for IV administration set  10 . 
         [0046]    System  110   b  of  FIG. 3B  operates the same way as  FIG. 3A . Here, however, port  13  of system  110   a  is moved to the position of injection port  13   b , which is located adjacent to the administration port  13   a  connected to upstream tubing section  16 . Injection port  13   b  includes a female or male luer connector  22 , which connects removeably and sealingly to a mating male or female luer connector  24  located at the end of bypass tube  56 . Connectors  22  and  24  can be capped initially. Tube  56  can also be clamped, removeably or permanently, near connector  24  to prevent primary fluid  14  from filling line  56  and to prevent air in line  56  from entering container  12 . 
         [0047]    In still another alternative embodiment (not illustrated) bypass tube  56  is replaced with the vial or container configured to connect removeably and sealingly to port  44  of multi-way valve  40  for collecting the displaced primary fluid  14  and air. The vial or container can have, if needed, a hydrophobic filter or membrane for allowing air to escape from the vial or container. In any of the alternative embodiments described herein, it is contemplated to sterilize the entire system with the bypass apparatus connected or disconnected (e.g., disconnected but held in the same packaging for sterilization). 
         [0048]    It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.