Abstract:
An apparatus for exchanging heat in a patient has a first elongated heat exchange catheter carrying circulating working fluid to and from a heat exchange system and a second elongated heat exchange catheter carrying circulating working fluid to and from the heat exchange system. The apparatus has a connector supporting proximal portions of both catheters while distal portions of the catheters are disposed inside a patient&#39;s vasculature to exchange heat with the patient.

Description:
FIELD OF THE INVENTION 
     The present application relates generally to patient temperature control systems. 
     BACKGROUND OF THE INVENTION 
     It has been discovered that the medical outcome for a patient suffering from severe brain trauma or from ischemia caused by stroke or heart attack or cardiac arrest is improved if the patient is cooled below normal body temperature (37° C.). Furthermore, it is also accepted that for such patients, it is important to prevent hyperthermia (fever) even if it is decided not to induce hypothermia. Moreover, in certain applications such as post-CABG surgery, it might be desirable to rewarm a hypothermic patient. 
     As recognized by the present application, the above-mentioned advantages in regulating temperature can be realized by cooling or heating the patient&#39;s entire body using a closed loop heat exchange catheter placed in the patient&#39;s venous system and circulating a working fluid such as saline through the catheter, heating or cooling the working fluid as appropriate in an external heat exchanger that is connected to the catheter. The following U.S. patents, all of which are incorporated herein by reference, disclose various intravascular catheters/systems/methods for such purposes: U.S. Pat. Nos. 6,881,551 and 6,585,692 (tri-lobe catheter), U.S. Pat. No. 6,551,349 and U.S. Pat. No. 6,554,797 (metal catheter with bellows), U.S. Pat. No. 6,749,625 and U.S. Pat. No. 6,796,995 (catheters with non-straight, non-helical heat exchange elements), U.S. Pat. No. 6,126,684, U.S. Pat. No. 6,299,599, U.S. Pat. No. 6,368,304, and U.S. Pat. No. 6,338,727 (catheters with multiple heat exchange balloons), U.S. Pat. No. 6,146,411, U.S. Pat. No. 6,019,783, U.S. Pat. No. 6,581,403, U.S. Pat. No. 7,287,398, and U.S. Pat. No. 5,837,003 (heat exchange systems for catheter), U.S. Pat. No. 7,857,781 (various heat exchange catheters). 
     As understood herein, such catheters often cannot be customized for each individual patient when manufactured, and therefore must be made in a standard size. As further understood herein, this observation means that, in some patients, unused space may exist in the blood vessel beyond that needed to ensure adequate blood flow around the catheter. 
     SUMMARY OF THE INVENTION 
     Accordingly, an apparatus has a first elongated heat exchange catheter carrying circulating working fluid to and from a heat exchange system. The apparatus also has a second elongated heat exchange catheter carrying circulating working fluid to and from the heat exchange system. The apparatus has a connector supporting proximal portions of both catheters while distal portions of the catheters are disposed inside a patient&#39;s vasculature to exchange heat with the patient. If desired, the connector may be a Y-shaped connector. 
     The catheters may each have a heat exchange segment established by an elongated generally cylindrical balloon in non-limiting embodiments. Also other non-limiting embodiments, the catheters may each have at least one heat exchange segment established by a series of non-straight, non-helical links through which the working fluid flows serially from link to link. In still other non-limiting embodiments, the catheters may each have at least one heat exchange segment established by a straight central supply tube surrounded by three helical return tubes. Alternatively, the catheters may each have at least one heat exchange segment established by alternating segments of bellows regions and fluted regions, where the fluted regions have helical flutes in non-limiting embodiments. 
     However, it is to be understood that the heat exchange segments may be combined in a single embodiment such that one catheter may have one of the above-described heat exchange segments while the other catheter may have another of the above-described heat exchange segments. It is to be further understood that, in non-limiting embodiments, both catheters may have substantially similar heat exchange segments as described above. Even further, it is to be understood that each catheter May have more than one heat exchange segment, where the plural heat exchange segments of a single catheter may be any of the above-described segments without limitation. 
     In another aspect, a method includes providing a first elongated heat exchange catheter carrying circulating working fluid to and from a heat exchange system. The method also includes providing a second elongated heat exchange catheter carrying circulating working fluid to and from the heat exchange system. Last, the method includes using a connector supporting proximal portions of both catheters and disposing distal portions of the catheters inside a patient&#39;s vasculature to exchange heat with the patient. 
     In still another aspect, a system includes plural elongated heat exchange catheters carrying circulating working fluid to and from a heat exchange system. The system also includes a connector supporting proximal portions of the catheters while distal portions of the catheters are disposed inside a patient&#39;s vasculature to exchange heat with the patient. 
     The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing an example catheter engaged with an example heat exchange system; 
         FIG. 2  is a schematic diagram of two catheters advanced in concert with each other through a Y-connector and having distal portions to be disposed in a patient; 
         FIG. 3  is a schematic diagram of two catheters advanced in concert with each other through a Y-connector with the distal portions disposed in a patient; 
         FIG. 4  is a perspective view of a first example catheter with a first example heat exchange member with plural non-straight, non-helical links, with portions of the heat exchange member broken away; 
         FIG. 5  is a perspective view of a second example catheter with second example heat exchange members configured as hollow balloons; 
         FIG. 6  is a side view of a third example catheter with a third example heat exchange member formed from a straight central supply tube surrounded by three helical return tubes; 
         FIG. 7  is a perspective view of a fourth example catheter with fourth example heat exchange members that consist of alternating segments, along a metal tube, of bellows regions and fluted regions, with portions of the catheter broken away; and 
         FIG. 8  is a cut-away view of the catheter shown in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to  FIG. 1 , an intravascular temperature management catheter  10  is in fluid communication with a catheter temperature control system  12  that includes a processor executing logic described in one or more of the patents referenced herein to control the temperature of working fluid circulating through the catheter  10  in accordance with a treatment paradigm responsive to patient core temperature feedback signals. In accordance with present principles, the catheter  10  can be used to induce therapeutic hypothermia in a patient  14  using the catheter, in which coolant such as but not limited to saline circulates in a closed loop, such that no coolant enters the body. Such treatment may be indicated for stroke, cardiac arrest (post-resuscitation), acute myocardial infarction, spinal injury, and traumatic brain injury. The catheter  10  can also be used to warm a patient, e.g., after bypass surgery or burn treatment, and to combat hyperthermia in, e.g., patient suffering from sub-arachnoid hemorrhage or intracerebral hemorrhage. 
     As shown, working fluid may be circulated between the heat exchange system  12  and catheter  10  through supply and return lines  16 ,  18  that connect to the proximal end of the catheter  10  as shown. Note that as used herein, “proximal” and “distal” in reference to the catheter are relative to the system  12 . A patient temperature signal from a catheter-borne temperature sensor may be provided to the system  12  through an electrical line  20  or wirelessly-if desired. Alternatively, a patient temperature signal may be provided to the system  12  from a separate esophageal probe or rectal probe or tympanic sensor or bladder probe or other temperature probe that measures the temperature of the patient  14 . 
     The catheter  10 , in addition to interior supply and return lumens through which the working fluid is circulated, may also have one or more infusion lumens connectable to an IV component  22  such as a syringe or IV bag for infusing medicaments into the patient, or an instrument such as an oxygen or pressure monitor for monitoring patient parameters, etc. 
     The catheter  10  can be positioned typically in the vasculature of the patient  14  and more preferably in the venous system of the patient  14  such as in the inferior vena cava through a groin insertion point or the superior vena cava through a neck (jugular or subclavian) insertion point. 
     Now in reference to  FIG. 2 , a schematic diagram of two catheters such as two of the catheters  10  shown in  FIG. 1 , can be advanced in concert with each other through, e.g., a Y-connector and having distal portions/ends to be disposed in a patient is shown. A first elongated heat exchange catheter  24  and a second elongated heat exchange catheter  26  are in fluid communication with a catheter temperature control system  30 . A Y-connector  28  is also shown in  FIG. 2 , the Y-connector  28  supporting proximal portions of both the catheters  24  and  26 . It is to be understood that the control system  30  includes a processor executing logic described in one or more of the patents referenced herein to control the temperature of working fluid circulating through the catheters  24  and  26  in accordance with a treatment paradigm responsive to patient core temperature feedback signals. 
     In accordance with present principles, the catheters  24  and  26  can be used to induce therapeutic hypothermia in a patient  32  using the catheter, in which coolant such as, but not limited to, saline circulates in closed loops as similarly described in reference to  FIG. 1 . The catheters  24  and  26  can also be used to warm a patient in accordance with present principles. Regardless, it is to be appreciated that the plural catheters of  FIG. 2  can more effectively and efficiently cool or warm the patient  32  when advanced into the patient  32  in concert at the same insertion site than can a single catheter. 
     Still in reference to  FIG. 2 , working fluid may be circulated between the heat exchange system  30  and the catheters  24  and  26  through respective supply and return lines  34  and  36  (for the catheter  24 ) and  40  and  42  (for the catheter  26 ), thereby providing fluid to both catheters  24  and  26 . As may be appreciated from  FIG. 2 , the Y-connector  28  supports proximal portions of the catheters  24  and  26 . Thus, the catheters  24  and  26  may enter the divided end of the Y-connector  28 , extend through respective arms of the Y-connector  28 , and closely exit the other end of the Y-connector  28  such that distal portions of the catheters  24  and  26  may be disposed in concert into the patient  32  to exchange heat with the patient. It may be appreciated that the Y-connector  28  serves to stabilize the catheters  24  and  26  in, close juxtaposition to each other. Not that as used herein, “proximal” and “distal” in reference to the catheters  24  and  26  are relative to the system  30 . 
     Additionally, patient temperature signals from catheter-borne temperature sensors may also be provided to the system  30  through respective electrical lines  38  and  44 , or wirelessly if desired, such that the electrical lines  38  and  44  may be connected to temperature sensors in the catheters  24  and  26 . However, it is to be understood that a single temperature sensor may be placed in only one of the catheters  24  or  26  in non-limiting embodiments. Alternatively, a patient temperature signal may be provided to the system  30  from a separate esophageal probe or rectal probe or tympanic sensor or bladder probe or other temperature probe that measures the temperature of the patient  32 . 
     One or both catheters  24  and  26 , in addition to interior supply and return lumens through which the working fluid is circulated, may also have one or more infusion lumens connectable to an IV component  46 , such as a syringe or IV bag for infusing medicaments into the patient, or an instrument such as an oxygen or pressure monitor for monitoring patient parameters, etc. Although the IV component  46  as shown in  FIG. 2  is connected only to the catheter  26  for clarity, it is to be understood that the IV component  46  may be connected to both catheters  24  and  26 . 
     The catheters of  FIG. 2  are also shown in  FIG. 3 , with  FIG. 3  showing the distal portions of the catheters  24  and  26  disposed in the patient  32 . Thus, proximal portions of the catheters  24  and  26  are still fluidly connected to the heat exchange system  30  in  FIG. 3 , and the catheters  24  and  26  may also still be connected to the IV component  46 . 
     It may now be further appreciated that distal portions of the catheters  24  and  26  can be positioned in concert into the same insertion site of a patient  32 , typically in the vasculature of the patient  32  and more preferably in the venous system of the patient  32  such as in the inferior vena cava through a groin insertion point or the superior vena cava through a neck (jugular or subclavian) insertion point. The positioning of distal portions of the catheters  24  and  26  into the patient  32  allows for more effective and efficient heat exchange with the patient  32  than a single catheter would. Furthermore, it is to be understood that the catheters  24  and  26  may be any of the catheters described below, or may be another type of catheter not described in reference to  FIGS. 4-8  in other non-limiting embodiments. 
     Moving on,  FIGS. 4-8  show example non-limiting embodiments of the catheters  10 ,  24  and  26 . In  FIG. 4  a catheter  100  has a heat exchange segment  102  established by a series of non-straight, non-helical links  104  through which the working fluid flows serially from link to link. Further details of the construction and operation of the catheter  100  are set forth in the above-referenced U.S. Pat. No. 6,796,995. 
       FIG. 5  shows a catheter  200  that has one or more axially-spaced cylindrical balloons  202  that carry circulating working fluid to and from a heat exchange system  204 . The catheter  200  shown in  FIG. 5  includes two additional infusion lumens connected to respective infusion tubes  206 , with the various external tubes joining respective internal catheter lumens at a hub  208  which may be formed with suture wings  210  for suturing the hub  208  to the skin of the patient. The infusion lumens may terminate at respective axially-spaced infusion ports  212 . Further details of the construction and operation of the catheter  100  are set forth in the above-referenced U.S. Pat. No. 6,368,304. 
     Yet again,  FIG. 6  shows a catheter  300  that has a straight central supply tube  302  surrounded by three helical return tubes  304 . Further details of the construction and operation of the catheter  300  are set forth in the above-referenced U.S. Pat. Nos. 6,881,551 and 6,585,692. 
       FIGS. 7 and 8  show a catheter  400  that may be made of a metal such as gold and that has alternating segments of bellows regions  402  and helically fluted regions  404 . Further details of the construction and operation of the catheter  400  are set forth in the above-referenced U.S. Pat. Nos. 6,551,349 and 6,554,797. 
     While the particular SYSTEM AND METHOD FOR DOUBLED USE OF PATIENT TEMPERATURE CONTROL CATHETER is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.