Patent Publication Number: US-2010130918-A1

Title: Systems and methods for removing air from supply containers and associated fill tubing

Description:
BACKGROUND 
     The present disclosure relates to medical fluid treatment and in particular to the prevention and removal of air from a patient&#39;s peritoneal cavity. 
     One problem that patients undergoing peritoneal dialysis (“PD”) treatment or a laparoscopic procedure can encounter is air becoming trapped in the patient&#39;s peritoneal cavity or pneumoperitoneum. Introduction of air into the patient&#39;s peritoneal cavity can cause pain. The gas can exert pressure on the patient&#39;s diaphragm and affect breathing. The air or gas pressure can also exert pressure on the patient&#39;s phreuic nerve, which produces a sensation of pain that may extend all the way to the patient&#39;s shoulders. 
     One source of air entering the patient is air from solution bag lines. The air becomes trapped in the solution bag lines (sometimes called pigtails), for example, during manufacture, shipping or upon connection of the lines for treatment. If the solution bag lines are not purged properly, the trapped air can enter the patient. This is especially true for longer pigtail or solution bag lines. A first need accordingly exists to prevent air from becoming trapped in the patient line during manufacture or therapy setup. 
     When the patient does experience air trapped in his/her peritoneal cavity, current practice is to wait for the gas to be absorbed by the patient&#39;s body. Such procedure can take a number of days depending on the amount of air that needs to be absorbed. Another need therefore exists for quickly removing air from the patient&#39;s peritoneal cavity when such situation does occur, so that the patient does not have to wait for his/her body to absorb the air volume. 
     SUMMARY 
     The present disclosure provides multiple embodiments for preventing air from entering tubes or pigtails that extend from peritoneal dialysis (“PD”) solution bags. Multiple embodiments are also provided for removing air from the solution bag tube prior to therapy hookup. Also described herein is an apparatus and method for removing air from the patient&#39;s peritoneal cavity when such an entrapment unfortunately occurs. 
     In a first embodiment, an autoconnection device is provided having a first position in which a U-shaped or semi-circular shunt spike spikes or pierces the supply and the drain bags simultaneously to allow a portion of fresh solution to flow from the supply bag to the drain bag to prime both supply and drain bag lines and purge air from same. The lines are each fed through an occluder valve, such as an electromechanical pinch valve. Once the lines are pierced, the valves are each opened to allow the supply bag and line to communicate with the drain bag and line to prime the supply line. 
     Next the occluder valves are closed and the autoconnection device rotates or otherwise moves the shunt spike awake from the closed-off supply and drain lines. The autoconnection device then connects the patient&#39;s transfer set to the supply line. Such disconnection and connection can be made under ultraviolet radiation to ensure the sterility of the final supply connection to the patient. Therapy can now proceed. 
     In a second embodiment, a fluid receptacle or reservoir is placed on the supply line or pigtail, so as to be in communication with the fluid located in the supply line. The receptacle is made of the same material as the supply line tubing in one embodiment and is relatively flexible, strong and resilient. The receptacle is located at or near the connector or distal end of the supply line, opposite the bag or container end of the supply line. The receptacle or reservoir is an at least substantially circular pillow in one embodiment. 
     The reservoir Fills with fluid, such that the patient can press the reservoir to push the fluid and thus the air trapped in the fluid towards the supply bag. When the patient releases the reservoir, the reservoir expands and fills again with fresh dialysis fluid, so that the reservoir can be pressed again to further move the trapped air into the supply container. This procedure is repeated until the patient visually determines that all the air has been pushed to the supply bag and collected at an air collection portion of the bag. The supply line can be pre-connected to at least one of a supply bag and a disposable pumping cassette. 
     In a third embodiment, the autoconnection device holds the connector end of the supply line and a disposable air trap. The autoconnect device connects (i) the patient transfer set to one side of the air trap and (ii) the fluid line to the other side of the air trap. The air trap has a fluid inlet, which is located near the bottom of the reservoir in one configuration. When supply fluid reaches the reservoir, air entrained in the fluid accumulates within the air trap, allowing air to migrate vertically upwardly in the air trap and to degas into the vertically elevated air collection area of the trap or reservoir. 
     In one embodiment, the patient&#39;s transfer set spikes the air trap, while the air trap spikes the fill bag line simultaneously or virtually simultaneously. Here, the air trap is a separate disposable piece that is inserted into the autoconnection device. The autoconnection device also serves to support the disposable for spiking. Making the air trap separate from the fill bag allows the autoconnection device to hold the air trap in an operating position and the fill bag line to be moved freely to the air trap. 
     In a fourth embodiment, the supply bag includes a separate fill tube and a one-way valve is placed in the supply bag line. During manufacturing, the fill bag is Filled from the fill tube. Eventually, supply fluid flows from the supply bag to the supply bag line through the one-way valve, priming the line and purging air from it. The one-way valve prevents any liquid that contacts non-sterile air while the supply bag line is open for purging from flowing back into the supply bag. The valve also prevents air in the bag from entering the supply line because fluid from the supply line cannot flow to the bag to displace such air. When the supply bag line is fully primed and purged of air, the line is capped, making the supply bag ready for use. The entire assembly can be sterilized using gamma radiation or steam, for example. 
     In a fifth embodiment, which is similar to the fourth embodiment, the supply tube is filled with fluid and primed before being connected to the supply bag. The supply line includes a one-way valve on its proximal or bag end. The line is filled from this end. The one-way valve prevents fluid from exiting the fill end before the supply line is spiked to the bag but allows fresh dialysis to flow from the supply tube through the supply line during use. Because the tube is filled with fluid, there is no room for air to enter the tube. The valve prevents fluid residing within the tube from migrating back into the bag, making room in the tube for air to potentially enter it. The distal or patient end of the supply line is capped when the supply line is fully primed. The proximal end of the supply line is then spiked to the bag. In one embodiment the entire bag and fill line is sterilized after the supply line is spiked to the bag. 
     In a sixth embodiment the supply line is filled with carbon dioxide (“CO 2 ”) gas to purge air from the supply bag line prior to its connection to the supply bag. CO 2  is heavier than air and is therefore suitable for the inerting or purging of air from the supply tube. CO 2  gas is also common to the human body. The patient readily absorbs CO 2  gas and exhales same through the patient&#39;s lungs. Both the distal (patient) and proximal (bag spike) ends of the supply tube are capped. The spike cap is removed and the supply bag is spiked. The supply bag and supply lines are sterilized after connection. 
     In a seventh embodiment, a y-connector is provided at the distal or patient end of the supply line. One branch of the y-connector is fitted with a hydrophobic membrane. A one-way or check valve is provided at the proximal end of the supply line. After manufacturing the supply bag and filling bag with fresh dialysate, air may become trapped in the supply line. The hydrophobic membrane fitted at the end of the y-connector allows air but not fluid to escape the supply line. The hydrophobic valve can be capped and uncapped as needed. 
     The supply bag is suspended vertically with the supply line extending downwardly from the supply bag. Fresh dialysate in the supply bag presses downwardly on the fluid in the supply line, forcing gas pockets through and out of the supply line via the hydrophobic membrane on the bag of the y-connector. The one-way valve prevents air from migrating upwardly into the supply line and supply bag. The hydrophobic filling of the v-connector is capped when the air purge is completed. 
     In an eighth embodiment, the patient&#39;s transfer set is fitted with a connector having a hydrophobic filter, which again allows air but not liquid to be purged from the patient. A cap is provided that covers the hydrophobic membrane. When the patient feels air in his/her peritoneum, the patient reclines, allowing the air to accumulate towards the exit point of the catheter. The patient removes the air-tight cap, allowing the air inside the peritoneum to escape via the hydrophobic membrane. The patient then replaces the air-tight cap after feeling the discomfort subside. In one embodiment, the patient&#39;s catheter includes perforations or holes near the exit point of the catheter (inside the patient, near the stomach wall). The holes or perforations allow air trapped in the peritoneum to flow into the catheter via the holes and travel through the fluid and the hydrophobic membrane to atmosphere. 
     In light of the above-described embodiments, it is accordingly an advantage of the present disclosure to provide various embodiments for removing air from a supply bag, or preventing air from entering the line, at the time of the manufacturing of the supply bag and the patient line. 
     It is another advantage of the present disclosure to provide various embodiments for removing air from a supply bag line, or preventing air from entering the line, at the time of connection of the supply line to the patient&#39;s transfer set. 
     It is a further advantage of the present disclosure to provide various embodiments for removing air from a supply bag line that operates with a patient autoconnection device (“PAC”). 
     It is yet another advantage of the present disclosure to provide an apparatus and method for removing air trapped in a patient&#39;s peritoneal cavity. 
     Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS. 1A and 1B  are schematic elevation views illustrating one embodiment of a patient auto connection (“PAC”) system having a shunt connector that allows air from a fill container to be delivered drain, the PAC system also connecting the patient&#39;s transfer set to the supply line,  FIGS. 1A and 1B  showing the PAC system in two different states. 
         FIG. 2  is a side elevation view showing one embodiment of a fill container and fill container line having a reservoir configured to receive fluid, such that a patient can squeeze the reservoir to drive medical fluid and any air contained therein up the fill container line and into the fill bag before the supply fluid is delivered to the patient. 
         FIG. 3  is a side elevation view of one embodiment of a PAC device having an air trap positioned between a fill bag line and the patient transfer set, such that the air trap can collect air from a pooled supply fluid before the supply fluid is delivered to patient. 
         FIG. 4  is a side elevation view of one embodiment of a fill bag having a fill tube inlet and a supply fluid outlet connected via a one-way or check valve to a supply fluid line, the configuration allowing the fill container to act as an air trap, preventing air from being delivered via the supply line to the patient. 
         FIG. 5  is an elevation view of one embodiment of a solution bag connected to a supply tube that has been pre-primed and capped so as not to deliver air to the patient. 
         FIGS. 6A to 6D  illustrate different steps in priming the patient&#39;s supply line used in connection with the embodiment illustrated in  FIG. 5 . 
         FIG. 7  is a side elevation view of one embodiment of a supply bag connected to a patient supply line that has been purged with a physiologically safe gas, such as carbon dioxide (“CO 2 ”), which is heavier than air and therefore readily purges air from the supply line. 
         FIG. 8  is a side elevation view of one embodiment of a supply container connected to a patient&#39;s supply line, which has a Y-connection to a hydrophobic valve for purging air bubbles from the patient&#39;s supply line. 
         FIG. 9  is a side elevation view of one embodiment of a patient transfer set having a hydrophobic vent for enabling the patient to purge air from the patient&#39;s peritoneum during a peritoneal dialysis treatment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings and in particular to  FIGS. 1A and 1B , patient auto connection (“PAC”) system  10  illustrates one embodiment for removing air from the patient&#39;s supply or fill line prior to the patient connecting to such line, PAC system  10  includes a housing  12  that is motorized to automatically rotate or flip components after the supply line has been purged and sterilized to a position such that the patient&#39;s transfer set can be automatically connected to the fill or supply line. Housing  12  is configured alternatively to allow the patient to mechanically rotate or flip components after the supply line has been purged and sterilized into a position, such that the patient&#39;s transfer set can be connected to the fill or supply line. Various embodiments for automatic and mechanically rotatable PAC systems, which can be modified for use with system  10  are disclosed in U.S. patent application Ser. No. 11/773,750 (“the 750 Application”), entitled “Dialysis System Having Supply Container Autoconnection”, filed Jul. 5, 2007, especially at  FIGS. 12 ,  13 A to  13 I and  14  and associated text (automated); and U.S. patent application Ser. No. 11/773,795, entitled “Dialysis System Having Dual Patient Line Connection And Prime”, filed Jul. 5, 2007, especially at  FIGS. 15A to 15E  and associated text (manual). Each of the referenced applications is assigned to the assignee of the present disclosure and is incorporated herein expressly by reference. 
     Priming with system  10  can be performed while undergoing a sterilization process. In one embodiment, sterilization is performed via ultraviolet (“UV”) radiation. The &#39;750 application incorporated above discusses one suitable embodiment for combining the UV irradiator with a PAC device. 
     Housing  12  includes a fill bag occluder valve  14   a  and a drain bag occluder valve  14   b . Housing  12  can be metal or plastic as desired. Valves  14   a  and  14   b  in one embodiment are normally closed, e.g., spring closed, energized open, and are actuated electrically. In an alternative embodiment, valves  14   a  and  14   b  are operated pneumatically. Valve  14   a  is positioned and arranged within housing  12  so as to receive a fill line  16   a , which is connected to a fill container  18   a  Occluder valve  14   b  in turn receives a drain bag line  16   b , which is connected fluidly to a drain bag  18   b.    
     For any of the embodiments described herein, the fill bag can be made of a suitable medical grade material, such as polyvinal chloride (“PVC”). Tubing  16   a  and  16   b  likewise can be made of the same or different medical grade material, such as PVC. Tubes  16   a  and  16   b  each terminate at a pierceable cap  20   a  and  20   b , respectively. Caps  20   a  and  20   b  are each fitted with a spikeable or pierceable membrane (not illustrated), which holds fluid within tubing  16   a  or  16   b  until spiked and allows a sterile connection to be made via a shunt spike  22  upon spiking. 
     Housing  12  holds shunt spike  22  in a position relative to caps  20   a  and  20   b , such that shunt pike  22  can be translated to simultaneously puncture the pierceable membranes of both caps  20   a  and  20   b . Shunt spike  22  in an embodiment is made of a suitable flexible or rigid medical grade plastic, such as Acrylic or chlorotrifluoroethylene (“CTFE”). Shunt spike  22  can have a substantially “U-shape” as shown or alternatively have a “V-shape” and can otherwise be rounded or having straight pieces as desired. 
     Housing  12  also holds a patient transfer set  24 , which is initially capped via a cap  26 . Patient transfer set  24  is in turn connected to a patient line  28 , which leads to a catheter (not illustrated) inserted into the patient&#39;s peritoneal cavity. Patient line  28  can be made of one of the materials described above for fill line  16   a  and drain line  16   b.    
     In operation, tubes  16   a  and  16   b  having unobstructed caps  20   a  and  20   b , respectively, are positioned into housing  12 . Occluder valves  14   a  and  14   b  are then closed (e.g., de-energized), clamping lines  16   a  and  16   b , respectively. Shunt spike  22  is then mechanically or manually translated, so as to puncture the membranes sealing caps  20   a  and  20   b . The connection of shunt spike  22  to caps  20   a  and  20   b  is made such that caps or portions of tubing  16   a  and  16   b  are sealed to the ends of shunt spike  22  when connected, and so that liquid cannot escape from the fill line  16   a  or drain line  16   b  around shunt spike  22  and into housing  10 . Once the sealed connection is made, and occluder valves  14   a  and  14   b  are opened, dialysis fluid can flow from supply bag  18   a , through supply line  16   a , connector  20   a , shunt spike  22 , connector  20   b , and drain line  16   b  to drain bag  18   b . Such action forces any air in supply line  16   a  to be pushed to drain bag  18   b . Once supply line  16   a  is purged sufficiently, occluder valves  14   a  and  14   b  are closed. 
     The UV radiation in one embodiment takes place just prior to and during the spiking operation of shtnt spike  22  to connectors  20   a  and  20   b . Such timing ensures that the spiking of shunt spike  22  to connectors  20   a  and  20   b  is done aseptically. The spiking of shunt spike  22  to connectors  20   a  and  20   b  is also done electromechanically in one embodiment by snap-fitting shunt spike  22  into a block of housing  12 , which is translated via a lead screw, which is turned by an electric motor. To drive shunt spike  22  in a spiking direction, the motor shaft of the motor is turned in a first direction. Once valves  14   a  and  14   b  have closed after proper flushing of fill line  16   a , the motor drives the motor shaft in the opposite direction, causing the lead screw driven block of housing  12  and shunt spike  22  to be pulled away from connectors  20   a  and  20   b.    
     At some point during the spiking and flushing operation, cap  26  is removed from transfer set  24 . If cap  26  and shunt spike  22  are moved manually, such operation is done with a lid of housing  12  open. The lid of housing  12  is then closed and the UV radiation is applied to irradiate both the exposed end of transfer set  24  and the spike ends of fill tube  16   a  and drain tube  16   b . Otherwise, if cap  26  and shunt spike  22  are removed and moved electromechanically, the electromechanical movement can be done just prior to the movement of either shunt spike  22  or cap  26 , here with a lid of housing  12  closed. The automatic removal of cap  26  can again be done via a translated block that is moved on a small lead screw to capture cap  26  and then translated in the opposite direction to pull cap  26  off of transfer set  24 . Cap  26  can be held within housing  12  and then reinserted onto transfer set  24  when the patient has filled himself or herself with fresh dialysate from the supply bag  18   a.    
       FIG. 1B  illustrates that once cap  26  is removed, shunt spike  22  and transfer set  24  are switched, so that transfer set  24  is now aligned with connector  20   a  of supply container  18   a . The same translation mechanism that drives shunt spike  22  into connector  20   a  now drives patient transfer set  24  into that connector. The same sealing mechanism of connector  20   a  that seals about shunt spike  22  also seals about a spike end of transfer set  24 . After the sealed connection between transfer set  24  and shunt spike  20   a  is made, occluder valve  14   a  is opened, allowing fluid to flow from fill bag  18   a  through patient transfer set  24  and patient line  28  to the patient&#39;s peritoneal cavity. The connection of patient transfer set  24  to connector  20   a  of the supply line  18   a  can again be done under UV radiation, so as to kill any pathogens that may be present on the spike end of transfer set  24  prior to insertion into connector  20   a.    
     When the fill to the patient has been completed, occluder valve  14   a  is closed and the solution is allowed to dwell within the patient for a sufficient amount of time. Afterwards, shunt spike  22  is removed from housing  12  and patient transfer set  24  is rotated or translated into alignment with drain bag connector  20   b . Transfer set  24  is then spiked into that connector, allowing the spent or effluent fluid to flow into drain bag  18   b  once drain valve  14   b  is opened. 
     Referring now to  FIG. 2 , filling apparatus  40  illustrates another embodiment for removing air from the fill solution, so that the air is not delivered to the patient. Apparatus  40  includes supply line  16   a , fill bag  18   a  and connector  20   a , which are at least substantially the same as described above in connection with  FIGS. 1A and 1B . The materials for these structures can be any of those discussed above for  FIGS. 1A and 1B . Here however, supply line or pigtail  16   a  includes a flexible reservoir  42 , which fills with supply fluid, enabling the patient to squeeze the fluid to build pressure in supply line  16   a . Reservoir  42  in one embodiment is attached directly to fill line  16   a . For example, reservoir  42  can be welded directly to the fill line. Alternatively, reservoir  42  is formed with fill line  16   a . In a further alternative embodiment, reservoir  42  is formed with a connector, which is in turn spliced into fill line  16   a  or connected to one end of the fill line. For example, reservoir  42  could be formed with connector  20   a . The receptacle or reservoir  42  is an at least substantially circular pillow in one embodiment. 
     Reservoir  42  collects a relatively small amount of fluid. As illustrated, reservoir  42  is located adjacent to or near, if not at the distal end of fill line  16   a . After reservoir  42  is filled with fluid, the patient squeezes the reservoir prior to connecting the patient&#39;s transfer set to connector  20   a . Squeezing reservoir  42  therefore forces fluid and any air trapped therein up patient line  16   a  and into fill bag  18   a . The air is pushed up into fill bag  18   a , towards a top or air reservoir portion of the bag. Fill line  16   a  is connected towards the bottom of the bag  18   a , allowing air to migrate to the air reservoir, away from the connection of fill line  16   a , such that when connected to fill line  16   a , only supply fluid is delivered to the patient. Apparatus  40  can be pre-connected to at least one of a fill bag  18   a  and a disposable pumping and/or valving cassette (not illustrated). 
     Referring now to  FIG. 3 , PAC system  50  illustrates another embodiment for removing air from the supply line or pigtail  16   a  prior to delivery of the fresh solution to the patient. PAC system  50  includes a housing  52 , which can be metal or plastic, as is the case with housing  12  of system  10 . System  50 , like system  10 , includes a fill bag  18   a  connected fluidly to a supply line or supply pigtail  16   a . Supply line  16   a  terminates at a sealed and pierceable connector  20   a . System  50  also includes a patient transfer set  24 , which is connected to a patient line or catheter  28  that runs to the patient&#39;s peritoneal cavity. Patient transfer set  24  is initially capped via cap  26 , which has been removed for the illustration of  FIG. 3 . 
     System  50  further includes an air trap  54 , which is held within housing, such that any air coalescing in a reservoir portion  56  of air trap  54  is held elevationally above a spiked fluid inlet  58   a  and a pierceable connector outlet  58   b . Pierceable connector  58   b  in an embodiment is configured in substantially a same manner as supply line connector  20   a . In both cases, the connectors include a pierceable sealing membrane and also apparatus for sealing about either the spike end of patient transfer set  24  or the spike inlet  58   a  of air trap  54 . Although not illustrated, air trap  54  can have one or more internal baffle for aiding in the separation of air from the liquid that pools in the air trap. Suitable configurations for air trap  54  are disclosed in co-pending patent application Nos. 11/865,577, entitled “Dialysis Systems Having Air Traps With Internal Structures To Enhance Air Removal”; 11/865,583, entitled “Dialysis Systems Having Air Separation Chambers With Internal Structures To Enhance Air Removal”: 11/865,552, entitled “Dialysis System Having Air Separation Chambers With Internal Structures To Enhance Air Removal”; and 60/976,731, entitled “Fluid And Air Handling In Dialysis Circuit Air Removal System”, each filed on Oct. 1, 2007, assigned to the eventual assignee of the present disclosure, the entire contents of each of which are incorporated expressly herein by reference. Air trap  54  can be part of a disposable with a supply line  16   a  and supply container  18   a  and/or be connected to a disposable pumping/valving cassette (not illustrated). The Supply line  16   a  is pre-connected to air trap  54  in one embodiment. 
     PAC system  50 , similar to system  10 , can have a UV irradiating source, which irradiates the spike of transfer set  24  and the spike end  58   a  of air trap  54  and associated connectors  58   b  and  20   a , respectively, just prior to the spiking of connectors  58   a  and  20   a . Housing  52  in one embodiment provides for a single translational movement of patient transfer set  24  to cause a virtual simultaneous spiking of connectors  58   b  and  20   a . If such spiking is done alternatively manually, a cover of housing  52  can be placed over air trap  54  and patient transfer set  24  just after such spiking, at which point the UV radiation source irradiates the spike connections of connectors  58   a  and  58   b . If spiking is performed automatically or electromechanically, the cover of housing  52  is placed over patient transfer set  24  and air trap  54  and UV irradiation is performed just prior to and during the automatic spiking of connectors  58   b  and  20   a . Housing  52  is configured alternatively to carry at least one of a (i) shuttle that moveably connects the patient transfer set to the patient transfer set connector of the air trap and (ii) a shuttle that moveably connects the supply line to the air trap, the at least one shuttle being (a) manually activated and (b) motorized. 
     After the spiking of the connectors is performed, fresh dialysis fluid flows from fill bag  18   a , through fill line  16   a , through connector  20  and pools inside air trap  54 . Air migrates upwardly in the denser solution and coalesces in upper reservoir  56 , such that only fresh solution travels from air trap  54 , through patient transfer set  24  and patient line or catheter  28  into the patient&#39;s peritoneum. 
     Referring now to  FIG. 4 , apparatus  60  illustrates another embodiment for preventing air from being delivered to the patient&#39;s peritoneum during a patient fill. Apparatus  60  includes an alternative fill container or fill bag  62  having a fill port ( 4 . An alternative fill line  66  is provided, which includes an inline check valve or one-way valve  68 , which allows fresh dialysis fluid to only flow from fill bag  62  towards a purge connector  70  located at a distal end of fill line  66 . Fill bag  62  and fill line  66  are made of any of the materials discussed above for bag  18   a  and fill line  16   a . Fill port  64  in one embodiment is a rigid piece of tubing that is welded to fill bag  62 . Check valve  68  can be welded directly to a similar port extending from fill bag  62 . Alternatively, check valve  68  is spliced into fill line  66 , which is then sealed to fill bag  62 . Purge connector  70  in an embodiment is a portion of connector  20   a , which after the manufacturing sequence next described is capped with a pierceable membrane to form a connector  20   a.    
     During manufacturing, fill bag  62  is filled with fresh fluid via fill port  64 . Fluid fills bag  62  and becomes pressurized, forcing one way valve  68  to open, allowing fluid to flow through fill line  66 , pushing air out of the fill line via purge connector  70 . In an embodiment, the manufacturing process is performed while fill tube  64 , check valve  68  and supply line  66  are housed elevationally above fill bag  62 . Such arrangement allows the fill bag at its lower end  72  to be filled first, pushing air towards a top end  74  of fill bag  62 . When the entire fill bag  62  and fill line  66  are completely filled with fresh dialysis fluid, fill port  64  is capped, which can be done under a sterilized or sterilizing environment. 
     One-way valve  68  during prime prevents fluid in line  66  from reentering fill bag  62  once the air has been pushed past one-way valve  68 . Thus any air trapped in the fluid held within fill line  66  cannot re-center bag  62 . Also, fluid cannot flow from line  66  to bag  62 , creating space that can potentially be filled with air. At the end of the patient fill, purge connector  70  is likewise capped with a pierceable membrane to form connector  20   a . Such procedure is also performed under a sterilized environment in one embodiment. The entire assembly can then be sterilized via a suitable process, such as gamma radiation, ethylene oxide or steam, at the manufacturing facility. 
     Referring now to  FIG. 5 , apparatus  80  illustrates still another alternative embodiment for preventing air from being delivered to the patient&#39;s peritoneum during PD fill. Apparatus  80  includes a supply bag or container  82  having a port  84  sealed via a pierceable membrane. Port  84  is spiked with a spike  88  of a fill line  86 , which has been filled and purged of air. Once fill line  86  is connected to solution container  82 , solution container  82  can be hung such that pierceable port  84  is located elevationally at the bottom of solution bag  82 , and such that only fluid and not air is delivered to the patient. As illustrated, fill line  86  is connected to a check or one way-valve  68 , which in turn is connected to a spike  88  that spikes a membrane seal of port  84 , e.g., under a sterilized environment. A distal end of supply line  86  is capped via a pierceable membrane cap  20   a.    
       FIGS. 6A to 6D  show the filling and flushing of supply line  86 .  FIG. 6A  illustrates an empty section of pigtail tubing  86 .  FIG. 6B  illustrates the sealed connection of one way-valve  68  to tubing  86  and an additional sealed connection of a spike  88  to one way valve  68 . In  FIG. 6C , fluid is injected into spike  88 , which flows through check valve  68  and supply line tubing  86  until the supply line is filled completely. Tube  86  is positioned vertically in the embodiment illustrated in  FIG. 6C , such that fluid injected from the bottom pushes air out the top of the tubing  86 . The Check valve  68  then prevents the filled fluid from flowing out of fill line  68 , through the check valve.  FIG. 6D  illustrates that after solution tube  86  has been filled completely, cap  20   a  having a pierceable membrane is sealed to a distal end of supply tube  86 , e.g., under a sterilized environment. The entire apparatus  80  (connected or not connected) can then be sterilized via gamma radiation or steam sterilization, for example. 
       FIG. 5  illustrates the final step in which the solution-filled supply tube  86  is spiked into membrane sealed port of  84  of supply container  82 . Port  84  is configured to seal about spike  88 . Check valve  68  prevents accidental movement of fluid from the tube to the bag, which could facilitate the entry of the air from bag to the tube. The check valve ensures that no room becomes available in the tube for air, e.g., during shipping. It is contemplated to package and ship apparatus  80  with filled tube  86  separated from container  82  or to package and ship apparatus  80  with filled tube  86  connected to container  82 . 
     Referring now to  FIG. 7 , apparatus  90  illustrates yet a further alternative embodiment for preventing air from a supply bag or supply tube from entering a patient&#39;s peritoneal cavity during a PD fill. Apparatus  90  includes solution bag  82  having a membrane-sealed delivery port  84  described above in connection with apparatus  80  of  FIGS. 5 and 6A  to  6 D. Delivery port  84  is spiked via a spike  88  connected to a supply tube  92 , which is capped via a membrane pierceable cap  20 . Supply line  92  is filled with carbon dioxide (“CO 2 ”), which is a suitable gas from a number of standpoints. In a first instance, CO 2  is heavier than air such that filling supply tube  92  with CO 2  allows the CO 2  to “settle” within the tube and displace air or inert air from tube  92 . Also, CO 2  is a gas that is common to the human body. The patient absorbs the CO 2  from tube  92  via the patient&#39;s peritoneum and exhales the CO 2  through the patient&#39;s lungs. CO 2  does not remain in the patient&#39;s peritoneum for days as does air. 
     Once the CO 2  is tilled with line  92  and capped via cap  20  under a suitable sterilized environment, port  84  is spiked via spike  88  and seals around said spike, allowing the apparatus  90  to be delivered for use with a patient. It should be appreciated that spike end  88  is capped until the time for spiking membrane port  84 , which can also be done under a suitable sterilizing environment. The entire apparatus  90  (connected or not connected) can then be sterilized via gamma radiation, ethylene oxide or steam sterilization. Although not illustrated, spike  88  could be coupled alternatively to a check valve (or the check valve could be located at proximal end of line  92 ), allowing CO 2  filled line  92  and supply bag  82  to be shipped separately. 
     Referring now to  FIG. 8 , apparatus  100  illustrates yet a further alternative embodiment for preventing air from being delivered to the patient&#39;s peritoneal cavity during a PD fill. Apparatus  100  includes a supply bag or container  102  which includes a port  104  for sealed connection to a check or one way valve  68 . Supply container  102  also includes a holder  106  for orienting bag  102  and associated supply line  110  during a purge process performed during the manufacture of apparatus  100 . 
     Supply line  110  is connected sealingly to the outlet of check valve  68  and includes a y-connector  112  at its distal end. One branch of y-connector  12  terminates at a hydrophobic membrane or valve  114 , which allows air but not dialysis solution to be passed through such membrane. One suitable hydrophobic membrane is provided by Millipore Corp., 290 Concord Road, Billerica, Mass. 01821, USA. The other end of the branch of y-connector  112  is capped via a pierceable membrane cap  20   a , as has been described herein. 
     After the manufacturing and filling of apparatus  100 , air bubbles will be trapped via one way valve  68  in supply line  100 . Apparatus  100  is suspended vertically via holder  106 , such that the weight of supply fluid within supply container  102  will flow through check valve  68  and force air out the bottom of y-connector  112  via hydrophobic valve  114 . One-way valve  68  also prevents air remaining at the top of supply container  102  from permeating through the solution within the container and flowing into supply tube  110 . That is, one-way valve  68  prevents liquid in the tube  110  from entering the bag, hence creating space for the air in the bag to enter the tube  110 . When the purge of supply tube  10  is completed, hydrophobic valve is capped, e.g., under a suitable sterilized environment. Capping may also be done under non-sterile conditions, for example, when the hydrophobic filter pores are small enough to not allow pathogens from entering tube  110 . The process of purging can therefore also be done at home by the patient. The entire apparatus  100  can then be sterilized, e.g., via gamma radiation, ethylene oxide or steam. 
     Referring now to  FIG. 9 , apparatus  110  illustrates one apparatus and method for enabling the patient to remove air from the patient&#39;s peritoneal cavity when the patient feels discomfort. Apparatus  110  provides the fluid connection between the patient&#39;s transfer set and the patient as opposed to the fluid connection between the transfer set and the solution bag as has been described previously. Apparatus  110  can accordingly be operated with any of the other systems and apparatuses described herein. 
     Apparatus  110  includes a patient transfer set  124 , which is capped in the illustrated embodiment via a cap  126 . Cap  126  can be removed to expose a spike that spikes a sealed membrane cap  20   a  of a supply line, as has been described herein. Patient transfer set  124  also includes a twist clamp  130 , which the patient turns to open or close fluid delivery to or from the patient&#39;s peritoneum. Apparatus  110  also illustrates a catheter  128 , which extends from patient transfer set  124  the patient&#39;s peritoneal cavity. 
     Apparatus  110  further includes a t-type connector  132 , which in the illustrated embodiment is spliced sealingly between patient tube  128  and twist clamp  130 . Connector  132  could alternatively be formed as part of clamp  130  and be placed in sealed fluid communication with patient tube  128 . Connector  132  includes a hydrophobic filter  134 , which can be of the type described above for system  100  of  FIG. 8 . Hydrophobic filter  134  is fitted within a threaded connection, which receives a thread-on air tight cap  136 . Cap and filter  134  can be sealed together via an o-ring or other suitable seal (not illustrated), which for example fits either within the inside of cap  136  or fitted around the outside of hydrophobic filter  134 . Cap  136  threads around the hydrophobic filter and seals the o-ring to the body of connector  132 . Alternatively, cap  136  can snap-fit onto hydrophobic filter  134  and thereby comprise a seal. 
     Catheter  128  is fixed to patient  140  at access site  142  and catheter is implanted within patient  140 . An implanted portion  144  of catheter  128  is formed with apertures or perforations  146  located along the catheter such that the apertures  146  are located within patient  140 , directly adjacent access cite  142 . Apertures  146  allow air that is trapped within patient  140  to enter catheter  144  and flow through patient tube  128 , connector  132  and out filter or vent  134 . 
     When the patient feels discomfort, the patient removes cap  136  from connector  132 , exposing hydrophobic filter  134 . Gas, including air, residing within the patient&#39;s peritoneal cavity is then able to migrate through the patient&#39;s PD catheter  128  and through hydrophobic filter to ambient. In this manner, a patient can remove air from the patient&#39;s peritoneal cavity without having to undergo the painstakingly long current procedure for removing such air. The patient can move around, lie down, sit up or perform some other exercise to help push the air within the patient&#39;s peritoneal cavity through the catheter, patient tube  128  and out filter  134 . As seen in  FIG. 9 , perforations or holes are formed in the patient catheter, which when fixed to the patient locates the holes inside the patient near the access site. The perforations allow air to enter the catheter at one end (e.g., elevated end when the patient is lying down) of the patient&#39;s peritoneal cavity. When the patient no longer feels discomfort, the patient seals hydrophobic filter  134  with cap  136  and resumes treatment or other desired activity. 
     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.