US20220031498A1 - Managing Patient Body Temperature Using Endovascular Heat Exchange in Combination With Body Surface Heat Exchange - Google Patents

Abstract

The present disclosure includes devices, systems and related methods useable for controlling a patient's body temperature by endovascular heat exchange as well as body surface heat exchange.

Description

FIELD OF THE INVENTION
• The present disclosure relates generally to the fields of medicine and biomedical engineering and more particularly to devices, systems and related methods useable for controlling a patient's body temperature by endovascular heat exchange as well as body surface heat exchange.
BACKGROUND
• Pursuant to 37 CFR 1.71(e), this patent document contains material which is subject to copyright protection and the owner of this patent document reserves all copyright rights whatsoever.
• Various devices and methods for altering or maintaining the body temperature of a patient exist. These include endovascular systems wherein heat exchange catheters are inserted into a patient's blood vessel and used to warm or cool the patient's flowing blood as well as body surface heat exchange systems wherein heat exchange pads, garments or blankets are used to non-invasively warm or cool the patient's body.
• Examples of commercialized endovascular heat exchange systems include the Thermogard XP Temperature Management System (ZOLL Circulation, Inc., San Jose, Calif.) and InnerCool RTx Endovascular Temperature Modulation System (ZOLL Circulation, Inc., San Jose, Calif.). Examples of body surface heat exchange systems include the STx Surface Pad System (ZOLL Circulation, Inc., San Jose, Calif.), the ARCTIC SUN 5000 Temperature Management System (Bard Medical Division, Covington, Ga.), the Criticool System (MTRE Advanced Technologies, Ltd., Feasterville-Trevose, Pa.) and the BAIR HUGGER. BAIR PAWS and POLAR AIR Systems (3M, St. Paul, Minn.).
SUMMARY
• In accordance with the present disclosure, there are provided devices and systems useable for endovascular and body surface heat exchange and related methods for using such devices and systems.
• The present disclosure describes systems and methods useable for endovascular and/or body surface heat exchange as well as new clinical treatment methods for advantageously utilizing such dual capability for endovascular and/or body surface heat exchange.
• In accordance with one embodiment, there are provided devices, systems and methods for controlling body temperature of a subject wherein a system comprises: (a) an endovascular heat exchange device (e.g., a heat exchange catheter), (b) a body surface heat exchange device (e.g., pad(s), blanket(s), garment(s). etc.), (c) at least one source of heat exchange fluid(s); (d) at least one heater/cooler, (e) at least one pumping apparatus and (f) at least one controller programmed to control operation of the system in alternate modes. The alternate modes may comprise 1) a first mode wherein heated or cooled heat exchange fluid is circulated through only the endovascular heat exchange device, 2) a second mode wherein heated or cooled heat exchange fluid is circulated through only said at least one body surface heat exchange device and 3) a third mode wherein heated or cooled heat exchange fluid is circulated through both the endovascular heat exchange device and the body surface heat exchange device. The controller may include a user interface (e.g., a touch screen display) which is useable to select the mode in which the system is to be operated. Optionally, whenMode 3 is selected, the controller may be further programmed to permit or prompt the use to select from a plurality of sub-modes in which the endovascular and body surface heat exchange devices are operable. Such sub-modes may comprise i) a first sub-mode wherein the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm; ii) a second sub-mode wherein one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms. In at least some embodiments, the selectable sub-modes may further comprise iii) a third sub-mode wherein, for an initial period, the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm and, for a subsequent period, one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms. This third sub-mode, when and if operational, may in some cases, be employed to initially cause both the endovascular heat exchange device and the body surface heat exchange device to begin lowering of a subject's body temperature and, at a desired time, switch the body surface heat exchange device to a warming mode to apply warming to the subject's body surface (e.g., for comfort or deterrence of shivering) while causing the endovascular heat exchange device to continue lowering the subject's core body temperature to an intended hypothermic target temperature.
• In accordance with another embodiment, there is provided a kit for enabling surface cooling which comprises a) a source of heat exchange fluid, b) a heater/cooler, c) pumping apparatus and d) a programmable controller for circulating heated or cooled heat exchange fluid through an endovascular heat exchanger to a system that is useable for circulating heated or cooled heat exchange fluid through a body surface heat exchanger. Such kit may comprise at least a second source of heat exchange fluid, a second pumping apparatus useable for circulating fluid through body surface heat exchange device(s) and a storage medium containing code for reprogramming the system's programmable controller such that it will additionally control the kit's pumping apparatus and potentially other components that participate in circulation of temperature-controlled heat exchange fluid through added body surface heat exchange device(s). In some embodiments, the kit may additionally include body surface heat exchange device(s) through which the kit's second pumping apparatus will circulate the temperature-controlled heat exchange fluid. In some embodiments, the kit may also include a second heater/cooler to augment the system's heater/cooler in providing sufficient temperature-controlled heat exchange fluid for circulation through the body surface heat exchange device(s).
• Further, there are provided systems and methods wherein energy that is produced by a heater/cooler of an endovascular heat exchange system (e.g., exhausted heat) is used directly or indirectly for circulation of warm or cool heat exchange fluid (e.g., gas or liquid) through body surface heat exchange device(s). In some embodiments, warm air that is exhausted from a heater/cooler condenser or other component of the endovascular heat exchange system may be captured and channeled through a warm-air blanket or other body surface heat exchange device which utilizes a flow of warm air. In other embodiments such exhausted warm air may be captured and channeled through a gas/liquid heat exchanger to warm a suitable liquid which is in turn circulated through a body surface heat exchanger of a type which utilizes a flow of warm liquid.
• Still further aspects and details of the present invention will be understood upon reading of the detailed description and examples set forth herebelow.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 generally shows a body temperature management system which comprises a control console, endovascular heat exchange catheter and body surface heat exchange apparatus.
• FIG. 2 is a schematic diagram showing certain components of one embodiment of a body temperature management system of the type generally shown inFIG. 1.
• FIG. 3 is a schematic diagram showing certain components of another embodiment of a body temperature management system of the type generally shown inFIG. 1.
• FIG. 4 is a schematic diagram showing certain components of yet another embodiment of a body temperature management system of the type generally shown inFIG. 1.
• FIG. 5 is a schematic diagram showing certain components of still another embodiment of a body temperature management system of the type generally shown inFIG. 1.
• FIGS. 6A and 6B are schematic diagrams showing certain components of another embodiment of a body temperature management system.
• FIG. 7 is a diagram of an endovascular temperature management system equipped with add-on components to render it capable of operating body surface heat exchange apparatus as an alternative to endovascular heat exchange apparatus.
• FIGS. 8A through 8C are partial cross-sectional views of the pump raceway and tubing components of certain embodiments of peristaltic pumps. Specifically.FIG. 8A shows a peristaltic pump having a first raceway with tubing of a first size for pumping heat exchange fluid through an endovascular heat exchange catheter and a second raceway with tubing of a second size for pumping heat exchange fluid through body surface heat exchange apparatus;FIG. 8B shows a peristaltic pump which has first and second raceways with different sized tubes therein to allow for variable compression of the different sized tubes;FIG. 7C shows a peristaltic pump which has a single raceway within which one or more tubes are positioned to allow for variable compression of tube(s).
• FIGS. 9A and 9B show cross-sectional views of peristaltic pump tubes having multiple lumens. Specifically,FIG. 9A dhows a tube having two lumens andFIG. 9B shows a tube having four lumens.
DETAILED DESCRIPTION
• The following detailed description and the accompanying drawings to which it refers are intended to describe some, but not necessarily all, examples or embodiments of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The contents of this detailed description and the accompanying drawings do not limit the scope of the invention in any way.
• FIG. 1 shows a bodytemperature management system10 which generally includes a control console10awhich is useable to control both an endovascularheat exchange catheter44 and a body surface heat exchange apparatus which, in this non-limiting example, comprises a heat exchange vest46vand a set of heat exchange thigh pads46t.
• The control console10acomprises a housing30 within which, or on which, there are positioned heating/cooling apparatus32 for alternately heating and cooling a heat exchange fluid, at least onepump34 for pumping the heat exchange fluid and aprogrammable controller36. Auser interface38, such as a liquid crystal display (LCD), is in communication with thecontroller36. The user interface displays system information and also receives user input and displays information, as described more fully herein.
• At least one reservoir or source ofheat exchange fluid40 is connected by tubing to the heater/cooler32. Typically, heat exchange fluid for circulation through theheat exchange catheter44 will comprise sterile 0.9% NaCl solution and the heat exchange fluid for circulation through the body surface heat exchange apparatus46v,46tmay comprise non-sterile water or any other suitable fluid. In some embodiments, a common heat exchange fluid (e.g., sterile 0.9% NaCl solution) may be circulated through both the endovascularheat exchange catheter44 and the body surface heat exchange apparatus46v,46t.
• At least one body temperature sensor TS is connected, by way of a temperature lead TL or alternatively by wireless connectivity, to thecontroller36. This body temperature sensor TS may be positioned at any suitable location on or in the patient's body to monitor body temperature. In some embodiments, a plurality of temperature sensors TS may be employed. In some embodiments the temperature sensor TS may be positioned on or in the heat exchange catheter10bor may be inserted through a lumen of the heat exchange catheter10b. In other examples, the temperature sensor TS may be positioned elsewhere in or on the patient's body, such as on the patient's skin (e.g., axillary temperature sensor) or in the patient's vasculature, esophagus, rectum, bladder, ear canal or other suitable location.
• The heater/cooler32 may in some embodiments comprise common apparatus useable for heating/cooling heat exchange fluid for circulation through thecatheter44 as well as heat exchange fluid for circulation through the body surface heat exchange apparatus46x,46t. In other embodiments the heater/cooler32 may comprise separate heater/cooler apparatus, e.g., one for heating/cooling heat exchange fluid for circulation through thecatheter44 and one for heating/cooling heat exchange fluid for circulation through the body surface heat exchange apparatus46v,46t. In certain embodiments, the heater/cooler or heating/cooling apparatus may include a refrigerant circuit including heat exchange plates having chambers through which refrigerant and/or other fluids flow. The heat exchange plates may be configured to receive a heat exchange cassette through which heat exchange fluid flows, such that the refrigerant, other fluid, e.g., water, and/or the heat exchange fluid are in thermal contact with each other to facilitate heat exchange between the fluids. In other embodiments, the heater/cooler or heating/cooling apparatus may include a refrigerant circuit, cold well, and/or heat exchange coil, which may be positionable within the cold well.
• In the non-limiting example ofFIG. 1, the endovascularheat exchange catheter44 is connected to a catheter inflow line CI through which temperature controlled heat exchange fluid circulates from the heater/cooler32 into thecatheter44 and a catheter outflow line CO through which heat exchange fluid circulates from thecatheter44 back into theheater cooler32. The body surface heat exchange apparatus46v,46tis connected to a surface or surface pad inflow line PL and a surface or surface pad outflow line PO. In the specific example shown, the surface pad inflow line PL and a surface pad outflow line PO are connected to a manifold42 or other flow dividing apparatus. A portion of the heat exchange fluid from the surface pad inflow line PI is channeled bymanifold42 to vest46vthroughline50. Returning heat exchange fluid then flows back to the manifold42 from the vest46vthroughreturn line52. The thigh pads46tare interconnected bytubes58,60 to facilitate circulation of heat exchange fluid through both thigh pads46t. Temperature controlled heat exchange fluid that enters the manifold42 from surface pad inflow line PI then circulates from the manifold42 throughlines54 and58 and through the thigh pads46t. Spent heat exchange fluid then returns from the thigh pads46t, throughlines56 and60, tomanifold42. The manifold42 combines the flows of returning heat exchange fluid fromlines52 and56 and circulates such combined fluid back to the heater/cooler32 through surface pad outflow line PO.
• The control console10amay, in some embodiments, be programmed and equipped with components for alternate operation in either an IVTM (intra-vascular) mode wherein heat exchange fluid is circulated through theheat exchange catheter44 or a SURFACE mode wherein heat exchange fluid is circulated through the body surface heat exchange apparatus46v,46t. In other embodiments, the control console10amay be programmed and equipped to operate not only in the IVTM mode or SURFACE mode, but additionally in a third IVTM+SURFACE mode wherein heat exchange fluid is circulated simultaneously through theheat exchange catheter44 as well as the body surface heat exchange apparatus46v,46t. As explained more fully below, in some applications of IVTM+SURFACE mode, both the endovascularheat exchange catheter44 and the body surface heat exchange apparatus46v,46tmay simultaneously warm or simultaneously cool the subject's body. In other applications of IVTM+SURFACE mode, one of the endovascularheat exchange catheter44 and the body surface heat exchange apparatus46v,46tmay be warming while the other is cooling. For example, in applications where it is desired to rapidly induce hypothermia in a subject, the system may be operated in IVTM+SURFACE mode with both the endovascularheat exchange catheter44 and the body surface heat exchange apparatus46v,46tcooling the subject so as to lower the subject's core body temperature as rapidly as possible. In applications where it is desired to maintain mild hypothermia while providing some comfort to the subject, the system may be operated in IVTM+SURFACE mode with the endovascularheat exchange catheter44 operating mainly in cooling mode to maintain the hypothermic core body temperature while the body surface heat exchange apparatus46v,46toperates in a warming mode to warm the subject's body surface. In applications where it is desired to rapidly induce hypothermia while deterring or delaying shivering, the system may be operated in IVTM+SURFACE mode with both the endovascularheat exchange catheter44 and the body surface heat exchange apparatus46v,46tcooling the subject for an initial period of time. Then, upon reaching a point in the procedure where shivering is imminent or likely, the body surface heat exchange apparatus46v,46tmay switch from cooling to warming while the endovascularheat exchange catheter44 continues to cool the subject's body core. Such warming of the subject's body surface may deter or minimize a shivering response as the subject's core temperature continues to lower to the hypothermic target temperature.
• FIGS. 2 through 6B are schematic diagrams which show examples of ways in which certain components of thesystem10 may be configured. Specifically,FIG. 2 shows an embodiment in which a common reservoir R, common heater/cooler apparatus H/C and common pump P are controlled bycontroller36 to separately or simultaneously circulate heat exchange fluid through aheat exchange catheter44 and/or bodysurface heat exchanger46. In such embodiment, the reservoir R contains a sufficient amount of a single heat exchange fluid for circulation through theheat exchange catheter44 and/or the bodysurface heat exchanger46. The heater/cooler H/C has variable capacity for heating/cooling varying volumes of the heat exchange fluid as needed for circulation through theheat exchange catheter44 and/or the bodysurface heat exchanger46. Also, the pump P is a variable throughput pump useable for pumping varying volumes of the heat exchange fluid at varying volume flow rates as needed for circulation through theheat exchange catheter44 and/or the bodysurface heat exchanger46.
• FIG. 3 diagrams an embodiment wherein one or more controller(s)36 is/are programmed to control the operation of two discrete circuits. In one circuit, a first reservoir R1, first heater/cooler H/C1 and first pump P1 circulate a heat exchange fluid through theheat exchange catheter44. In the other circuit, a second reservoir R2, second heater/cooler H/C2 and second pump P2 circulate the same or different heat exchange fluid through the bodysurface heat exchanger46. Both circuits may be located on or in asingle console31. The ability to control each circuit may be independent of one another. For example, while the first circuit is causing the heat exchange catheter to cool the subject's core the second circuit may be operating to warm the subject's body surface or vice versa.
• FIG. 4 illustrates a hybrid example which includes separate discrete first and second circuits as shown inFIG. 3 as well as an alternative common pump P and thecontroller36 is programmed to alternately operate the circuits separately or in a combined mode. For example, the first heater/cooler H/C1 could be for only cooling and the second heater cooler H/C2 could be for only warming. When the system is operating in a mode where both theheat exchange catheter44 and bodysurface heat exchanger46 are being used to cool the body, thecontroller36 may cause cooled heat exchange fluid from the first heater/cooler H/C1 to be pumped by common pump P through both theheat exchange catheter44 and bodysurface heat exchanger46. Alternatively, when the system is operating in a mode where theheat exchange catheter44 is cooling the subject's body core while the bodysurface heat exchanger46 is warming the subject's skin, thecontroller36 may cause fluid from first reservoir R1 to be cooled by first heater/cooler H/C1 and pumped by the first pump P1 through theheat exchange catheter44. At the same time, thecontroller36 may cause fluid from the second reservoir R2 to be warmed by the second heater/cooler H/C2 and circulated by second pump P2 through the bodysurface heat exchanger46. AlthoughFIG. 4 shows separate first and second reservoirs R1, R2, a single reservoir R containing a common heat exchange fluid could alternatively be used.
• FIG. 5 shows another embodiment wherein a primary heat exchange circuit having a reservoir R, heater/cooler H/C and pump P circulates warmed or cooled heat exchange fluid through aheat exchange catheter44 and exhausted heat or other energy emitted from the heater/cooler H/C is captured and/or otherwise used by an energy capturing/convertingapparatus45 to provide a flow of temperature controlled heat exchange fluid (liquid or gas) to the bodysurface heat exchanger46. The energy capturing/convertingapparatus45 may comprise a gas-liquid heat exchanger in which warm air exhausted from a condenser of the heater/cooler H/C is used to warm a heat exchange liquid which is then circulated, by way of a second pump (not shown), through the bodysurface heat exchanger46. Alternatively, the energy capturing/convertingapparatus45 could be a shroud, duct or other air capturing/channeling apparatus that would capture warm air exhausted from the heater/cooler H/C and circulate it through a warm air type of body surface heat exchanger (e.g., a Bair Hugger blanket or Bair Paw garment). In some embodiments the heater/cooler H/C may comprise a radiator style heat exchanger, e.g., a metal heat exchanger, where air from a condenser can blow over adjacent channels or chambers in cold plates or a cold well holding saline, water or other fluid for a body surface heat exchanger. The fluids may be isolated but in adjacent chambers such that heat transfer between the chambers occurs. The chambers may be convoluted or have several fins to increase surface area and heat exchange between fluids, e.g., between saline and glycol or refrigerant, similar to a radiator.
• To add improved control of the fluid or water temperature for a surface system, water or other fluid flowing through the heater/cooler could be on a controlled valve to potentially mix with the water or other fluid coming from the heat transfer surface system until the desired temperature is achieved for flow through the body surface heat exchanger, e.g., surface pads. The surface system plumbing, through which water or other fluid would flow, can be heated by condenser air (as discussed above) or simply by heaters. To fine tune or adjust the temperature, water or other fluid flowing through chambers in the cold plate or heat exchanger of the heater/cooler could be mixed with, or placed in heat exchange contact with the water or other fluid from the surface system, to adjust the surface pad water/fluid temp (e.g., cool it). A valve may be used to control mixing or contact between the two fluids.
• FIGS. 6A and 6B show a schematic diagram of a system wherein a plurality of pumps P1, P2, P3 may alternately be operated in series (FIG. 6a) to provide an increase in fluid pressure to optimize a temperature management system when the system has a higher resistance to fluid flow, i.e., when the system is circulating fluid through aheat exchange catheter44 or in parallel (FIG. 6B) to provide an increase in volume flow rate to optimize a temperature management system when the system has a lower resistance to fluid flow and requires a higher volume flow rate, i.e., when the system is circulating fluid through a bodysurface heat exchanger46.
• The system inFIGS. 6A and 6B includes pumps P1, P2 and P3. Although this example shows three pumps, any desired number of 2 or more pumps may be used. Depending on the arrangement and position of tubing lines or segments, valves or clamps, which control fluid flow through the tubing lines or segments and pumps within the system, the fluid pressure, flow velocity and/or volume flow rate in the system may be altered. For example,FIG. 6A shows three pumps P1, P2 and P3 in the system connected bytubing segments66,6601, and6602, through which fluid flows into endovascularheat exchange catheter44. When valves and tubing segments are positioned as shown inFIG. 6A, the pumps are connected in series, providing a higher fluid pressure through the system than if the pumps were connected in parallel.
• When the valves and tubing segments are positioned as shown in Figure GB,tubing segments66,6601, and6602 are decoupled from pumps P1, P2 and P3, and the pumps are connected in parallel, providing a higher volume flow rate through the system than if the pumps were arranged in series. When the pumps are connected in parallel, fluid flows fromtubing60 through pump P1 then onto body surfaceheat exchange device46, fromtubing62 through P2 then onto body surfaceheat exchange device46 viatubing70, and fromtubing64 through P3 then onto body surfaceheat exchange device46 viatubing72.
• Therefore, the system can support either an endovascularheat exchange catheter44 by opening or closing the valves and/or tubing lines/segments such that the pressure across the pumps is added, or a body surfaceheat exchange device46 by opening or closing valves and/or tubing lines/segments such that volume flow through the pumps is added. The valves, tubing lines/segments and/or clamps may be manipulated, e.g., using a controller programmed to control operation of the system, depending on whether endovascular heat exchange and/or surface heat exchange is desired, allowing a user to switch between the two modes of heat exchange.
• More specifically, in the non-limiting example ofFIG. 6a, valves are positioned to closelines60,62,70 and72 such that heat exchange fluid flows from reservoir R, through heater/cooler HO, throughlines64 and66, through pump P3, throughline6601, through pump P2, throughline6602, through pump P1, throughline68 and to theendovascular heat exchanger44. In the non-limiting example ofFIG. 6B, valves are positioned toopen lines60,62,70 and72 such that heat exchange fluid flows from reservoir R, through heater/cooler HC and through each oflines60,62 and64. Fluid fromline60 is pumped by pump P1 intoline68, fluid fromline62 is pumped by pump P2 intoline70 and fluid fromline64 flows throughline66 and is pumped by pump P3 intoline72. Fluid from each oflines70 and72 enterline68 in combination with the fluid that has been piped intoline68 by pump P1, and all of the fluid then flows through the bodysurface heat exchanger46.
• In an alternative embodiment, P1 may pump fluid through a first line to an endovascular catheter, while P2 and P3 (arranged in parallel) may pump fluid through a second line to a body surface heat exchanger. When separate lines for endovascular and body surface heat exchangers are utilized, a single system may operate both endovascular and body surface heat exchangers simultaneously where each line is coupled to one or more pumps arranged to optimize fluid circulation through either an endovascular or body surface heat exchanger.
• FIG. 7 shows an endovascular heat exchangesystem control console92 that has been equipped with a surface cooling kit. The surface cooling kit, which may be fully or partially disposable, additionally renders thisconsole92 capable of controlling a body surfaceheat exchange device46 instead of or in addition to an endovascular heat exchange catheter.
• In theconsole92 depicted in this example, the circulating heat exchange fluid is warmed or cooled by acirculation coil98 or other heat exchanger that is submersed within a well96 that contains warmed or cooled fluid (e.g., a “cold well”). A system of his type is commercially available as the Thermogard XP System (ZOLL Circulation, Inc.). In other embodiments, the surface cooling kit may be modified to include another type of cooling/warming component or heat exchanger instead of the coil to render it useable with other types of endovascular heat exchange system consoles. For example, the surface cooling kit may also be useable with other consoles, where the kit includes different cooling/warming components and/or heat exchangers, such as a cassette through which a working fluid, e.g., saline flows. The cassette can be positioned between cold plates through which a coolant or refrigerant may flow, such that the refrigerant or coolant comes into thermal contact with the working fluid. In this example, the surface cooling kit includes areservoir106, apump110, acoil98, associated tubing and a software modification. Optionally, the kit may also include anair trap108. Also optionally, the kit may include an air separator (not shown) to prevent air from entering thepump110 or a dual lumen IV spike similar to that included in the commercially available Thermogard XP Start Up Kit (ZOLL Circulation, Inc., San Jose, Calif.) and that shown in U.S. Pat. No. 6,878,156 (Noda) entitled Portable Cooler For Heat Exchange Catheter, the entire disclosure of which is expressly incorporated herein by reference. Such dual lumen IV spike will cause air to collect at the top of thereservoir106 as the liquid level in the reservoir lowers.
• Typically, the volume of fluid required for priming and operation of a body surface heat exchange device is much greater than the volume required for priming and operation of a heat exchange catheter. Thus, thereservoir106 may be an appropriately sized bag (e.g., a 2 liter IV bag) or other vessel that is pre-filled or finable with heat exchange fluid (e.g., water, saline or other suitable liquid) in an amount sufficient to prime and operate the intended body surface heat exchange device(s)46.
• Thepump110 may be a peristaltic roller pump, centrifugal pump, screw pump, gear pump, or diaphragm pump or other suitable pump. In this example, thepump110 is connected to apower outlet100 on theconsole94. Thepump110 may have an integrated motor which, along with thepump110, may be disposable. Alternatively, thepump110 may be powered by a separate motor, which could be of a reusable type.
• The software modification will program or reprogram the console's existingcontroller36 to facilitate operation of the system in either endovascular heat exchange mode or a body surface heat exchange mode.
• After the software modification, upon powering on the system, thecontroller36 may prompt the user to select, viauser interface104, either SURFACE mode or IVTM (intra-vascular) mode. Alternately thecontroller36 may be programmed to detect whether thepump110 or other component of the surface cooling kit has been connected to the system and, on that basis, automatically set or suggest the appropriate mode setting. Additionally, in some embodiments, software modification may provide for selection and operation of a third mode wherein both SURFACE and IVTM modes operate simultaneously as described in this application.
• Once SURFACE mode has been selected, the pump within theconsole92 typically used for catheter-based heat exchange will no longer turn. Instead thepump110 of the surface cooling kit would be used.
• In some embodiments, before commencing the selected mode of heat exchange, thecontroller36 may prompt a user to initialize a primary or initial set up mode for priming and removal of air from the system. Alternately the system may self-prime during the normal course of use. If the optional air-trap108 is used, this is unlikely to be feasible. Once the system is primed with heat exchange fluid, it could be used to manage patient temperature in essentially the same manner as it would typically do when performing endovascular heat exchange through a catheter (i.e., regulating the temperature of the fluid in the well96 or in or between cold plates to alter the rate of heat transfer to-from the patient. The control algorithm may be adjusted to satisfactorily control the patient's temperature. (e.g. PID parameters)
• Thus, the use of this surface cooling kit may enable an existing or newly designed endovascular heat exchange system so that it may alternatively be used for body surface heat exchange. Hardware modifications to the original system would be limited. Moreover, the water in the system would be single use and therefore much cleaner than a competitive system. In other embodiments, for example, an existing or newly designed surface cooling system could use this kit, e.g., to provide an alternate treatment pathway which uses, e.g., sterile water as the working fluid within the surface pads. This may be of benefit during situations where the treatment providers are particularly concerned about patient infection.
• As explained above, some of the systems described herein may incorporate multichannel or variable throughput pumps that are capable of pumping heat exchange fluid(s) at either or both of 1) a relatively high fluid pressure and high flow velocity for circulation through an endovascular heat exchange catheter and/or b) a lower fluid pressure and a relatively high volume flow rate for circulation through body surface heat exchange device(s). In this regard,FIGS. 8A through 8C show partial cross-sectional views of pump raceways and tubing components of certain embodiments of peristaltic pumps. Specifically,FIG. 8A shows aperistaltic pump70ahaving araceway72awith a first groove and tubing of afirst size 74 for pumping heat exchange fluid through an endovascular heat exchange catheter and a second grove and tubing of asecond size 75 for pumping heat exchange fluid through a body surface heat exchange apparatus.FIG. 8B shows aperistaltic pump70bhaving a slopedraceway72bwith a first groove andtubing76 and a second groove andtubing77 wherein thetubing76 and77 may be of the same or differing sizes and wherein the pump is adapted for variable compression of the tubes.FIG. 8C shows a peristaltic pump70cwhich has a raceway72cwith a single groove in whichmultiple tubes78,79 are positioned.
• In the embodiment ofFIG. 8A, variable compression and/or fluid pressure and volume flow rate are achieved due to the different size tubing that is utilized. Thelarger diameter tubing75 will hold a larger volume of fluid than thesmaller diameter tubing74, Compression of thesmaller tubing74 will result in higher fluid pressure and higher flow velocity (to optimize circulation of fluid through an endovascular catheter) than compression of thelarger diameter tubing75. Compression of thelarger diameter tubing75 will result in a lower fluid pressure and lower flow velocity, but a higher volume flow rate (to optimize circulation of fluid through a body surface heat exchanger) than compression of thesmaller diameter tubing74. InFIG. 8B, the raceways are offset and/or have different diameters and thetubing76 and77 have the same diameter, so a pump roller will compress one tubing to a greater degree than the other tubing, resulting in a differentiation in fluid pressure, flow velocity and/or volume flow rate in one tubing compared to the other. For example,tubing76 would be compressed to a greater degree thantubing77, resulting in higher fluid pressure and flow velocity intubing76 than in tubing77 (to optimize circulation of fluid through an endovascular catheter coupled to tubing76). Whiletubing76 and77 have generally the same diameter, different sized tubing may be used to further affect the fluid in the respective tubing. InFIG. 8C, two tubes,tubing78 and79, are positioned within a single raceway. As a result, twice as much fluid volume and a higher volume flow rate is achieved using the same pump roller contact than would otherwise be achieved using a single tube.
• The raceway and tubing embodiments described above may be used with a pump having one or more rotors with rollers, and having symmetrical or nonsymmetrical rollers. For example, a nonsymmetrical roller may include one end having a larger diameter than the other end, thereby making it capable of effecting variable compression of two different tubes (whether the tubes are the same size or differ in size) depending on which end of the roller contacts a particular tube. This may result in a differentiation in fluid pressure, flow velocity and/or volume flow rate in one tube compared to the other tube.
• FIGS. 9A and 9B show cross-sectional views ofperistaltic pump tubes80aand80bhaving multiple lumens. Specifically,FIG. 9A shows atube80ahaving twolumens84aand84bseparated by an extrusion wall orother bulkhead85.FIG. 9B shows atube80bhaving four lumens86a-86dseparated by crossed extrusion walls or bulkheads88.Tube80aortube80bmay be used in a temperature management system capable of performing endovascular and/or surface heat exchange, as described herein, where a single tube can supply fluid for both endovascular and surface heat exchange. For example, intube80a, fluid for endovascular heat exchange may flow throughlumen84aand fluid for surface heat exchange may flow throughlumen84b. Thetube80amay be positioned in the raceway of a pump such that the pump rollers compresslumen84ato a greater degree than lumen84b, resulting in higher fluid pressure and a higher flow velocity of the fluid that flows throughlumen84a, which is supplied to a catheter, and lower fluid pressure and lower flow velocity of the fluid that flows throughlumen84b, which is supplied to a surface heat exchange device or pad. In another example, intube80b, fluid for endovascular heat exchange may flow throughlumen86aand fluid for surface heat exchange may flow throughlumens86b-86d, providing a larger volume of fluid and higher volume flow rate supplied to the surface heat exchange device. Thetube80bmay also be positioned in the raceway of a pump such that the pump rollers compresslumen86ato a greater degree thanlumens86b-86d, resulting in higher fluid pressure and a higher flow velocity of the fluid that flows throughlumen86a, which is supplied to a catheter, and lower fluid pressure and lower flow velocity of fluid that flows throughlumens86b-86d, which is supplied to a surface heat exchange device. In other embodiments, tubes may include two or more lumens, and each lumen may vary in size/diameter or two or more lumens may be identical in size/diameter.
• The devices and systems of the present invention provide for advanced body temperature control using combination(s) of endovascular heat exchange and body surface heat exchange. The following are non-limiting examples of just a few of the various potential clinical applications of the systems described in this patent application.
Example 1Induction and Maintenance of Hypothermia by Simultaneous Endovascular and Body Surface Heat Exchange
• In this example, a heat exchange system as described herein is used to attain and maintain a lowered body temperature in a human or other mammalian animal subject. A heat exchange catheter is inserted into the subject's vasculature (e.g., into the inferior vena cava or other suitable blood vessel) and one or more body surface heat exchange device(s) is/are positioned on one or more body surface(s) of the subject. A body temperature sensor is placed on or in the subject's body to monitor and transmit to the system's controller real time indicia of the subject's body temperature. The user enters a target body temperature which is lower than the subject's current monitored body temperature and selects operation in a mode/sub-mode whereby combined endovascular and body surface heat exchange will occur. The system's controller then causes the system to circulate controlled-temperature heat exchange fluid(s) through both the heat exchange catheter and body surface heat exchanger to lower the body temperature monitored by the temperature sensor(s) to the target body temperature. Thereafter, the controller causes the system to further circulate controlled-temperature heat exchange fluid(s) through both the heat exchange catheter and body surface heat exchanger as needed to maintain the monitored body temperature at (or within a predetermined range of) the target body temperature for a desired period of time. This technique may be used to induce and maintain a desired degree of hypothermia (e.g., a lowered body temperature in the range of 34.5-36.5 degrees C. or 32-36.5 degrees C. or less than 37 degrees C.) or to restore and maintain normothermia in a subject who is initially febrile.
• In alternative embodiments, a portable body surface heat exchange device may be utilized during patient transport, prior to insertion of a heat exchange catheter into a subject's vasculature. For example, one or more body surface heat exchange device(s) may be positioned on one or more body surface(s) of the subject in the back of an ambulance or other emergency response vehicle to initiate cooling. Upon arrival at a hospital, the portable body surface heat exchange device may be coupled to an endovascular system, such that heat exchange fluid(s) can be circulated through both a heat exchange catheter and the body surface heat exchanger simultaneously to continue cooling and lower the body temperature. Alternatively, the portable body surface heat exchange device may be removed and another combined (endovascular+surface) heat exchange system as described herein may be used to continue cooling. At a later point in time, e.g., at the commencement of surgery, the one or more body surface heat exchange devices may be removed, and cooling performed solely using the endovascular heat exchange catheter.
Example 2Rapid Induction of Hypothermia by Simultaneous Endovascular and Body Surface Heat Exchange Followed by Hypothermia Maintenance by Only Endovascular Heat Exchange
• In this example, a heat exchange system as described herein is used to rapidly induce and maintain therapeutic hypothermia in a human or other mammalian animal subject who is initially normothermic. A heat exchange catheter is inserted into the subject's vasculature (e.g., into the inferior vena cava or other suitable blood vessel) and one or more body surface heat exchange device(s) is/are positioned on one or more body surface(s) of the subject. A body temperature sensor is placed on or in the subject's body to monitor and transmit to the system's controller real time indicia of the subject's body temperature. The user enters a target hypothermic body temperature (e.g., less than 37 degrees C.) and selects operation in a mode/sub-mode whereby combined endovascular and body surface heat exchange will occur. The system's controller then causes the system to circulate controlled-temperature heat exchange fluid(s) through both the heat exchange catheter and body surface heat exchanger to lower the body temperature monitored by the temperature sensor(s) to the target hypothermic temperature. Thereafter, the user (manually) or the controller (automatically) may cause the system to shift to a mode and sub-mode wherein controlled-temperature heat exchange fluid(s) continue to circulate only through the endovascular heat exchange catheter as needed to maintain the monitored body temperature at (or within a predetermined range of) the target hypothermic body temperature for a desired period of time. At this stage, the body surface heat exchange device(s) may be disconnected and/or removed from the subject's body. This technique may be used to effect speedy induction of therapeutic hypothermia in subject's who are suffering an acute event that may benefit from rapid induction of hypothermia, for example an ischemic or traumatic event such as acute myocardial infarction, embolic stroke, traumatic brain or spinal cord injury, multiple organ trauma or failure, etc. The initial use of body surface heat exchange in combination with endovascular heat exchange enhances the rapidity with which the desired level of hypothermia may be induced. Thereafter, cessation of use of the body surface heat exchange device(s) while using the endovascular heat exchange catheter to maintain the induced hypothermia may allow for removal of the body surface heat exchange device(s) thereby fully exposing the subject's body surfaces as may be important for performance of needed interventional or surgical procedures or other indicated diagnostic or therapeutic endeavors.
Example 3Hypothermia Induction with Subsequent Deterrence of Discomfort and/or Shivering Using Combined Endovascular and Body Surface Heat Exchange
• In this example, a heat exchange system as described herein is used to rapidly induce and maintain moderate to deep hypothermia in a human or other mammalian animal subject while providing some warming of the subject's body surface (e.g., the skin) to deter discomfort and/or shivering. A heat exchange catheter is inserted into the subject's vasculature (e.g., into the inferior vena cava or other suitable blood vessel) and one or more body surface heat exchange device(s) is/are positioned on one or more body surface(s) of the subject. A body temperature sensor is placed on or in the subject's body to monitor and transmit to the system's controller real time indicia of the subject's body temperature. The user enters a target hypothermic body temperature (e.g., 32-36.0 degrees C. or less than 37 degrees C.) and selects operation in a mode/sub-mode whereby combined endovascular and body surface heat exchange will occur. The system's controller then causes the system to circulate controlled-temperature heat exchange fluid(s) through both the heat exchange catheter and body surface heat exchanger to rapidly lower the body temperature for an initial period. Thereafter, for a subsequent period, the controller will cause the body surface heat exchange device(s) to apply warming to the subject's body surface while the endovascular heat exchange catheter continues to lower the core body temperature to the target hypothermic temperature and to thereafter maintain the core body temperature at or within a permitted variation range of that target hypothermic body temperature. Such shifting of the body surface heat exchange device(s) from cooling to warming may deter discomfort or the onset of a physiological shivering response as the subject's core body temperature continues to lower. Shifting of the body surface heat exchange device(s) from cooling to warming may be effected manually by the user or the system's controller may be programmed to cause such sift from surface cooling to surface warming to occur in response to the attainment of an initial amount of body temperature lowering (e.g., initial lowering of the body temperature to a temperature that is near the threshold for occurrence of shivering) or upon sensing of some predetermined event such as a change in a physiological variable or occurrence of a predetermined symptom (e.g., the onset of significant cold-induced discomfort or pre-shivering symptoms). In some embodiments, one or more sensor(s) may sense the occurrence of the event that causes this shift from surface cooling to surface warming. For example, copending U.S. patent application Ser. No. 14/783,912 entitled Detecting and Responding to Preshivering, the entire disclosure of which is expressly incorporated herein by reference, describes sensors and methods which may be used with the systems and devices described herein to sense when a shivering response is likely to occur but has not yet fully or actually commenced. Also, U.S. Pat. No. 8,475,509 (Dae) entitled Devices and Methods for Using Endovascular Cooling to Treat Septic Shock and Other Disorders, the entire disclosure of which is also expressly incorporated herein by reference, describes sensors and methods that may be used with the systems and devices described herein to detect other changes in a physiological variable or occurrence of a symptom which triggers the shift from surface cooling to surface warming. This technique may be used to optimize the rate of initial body temperature lowering (e.g., to provide for speedy induction of hypothermia in cases where time is of the essence) followed by the use of body surface warming to provide comfort or ward off untoward effects of the hypothermia.
• Other heat exchange devices and systems are described in U.S. Pat. No. 7,070,612 (Collins et al.) entitled System And Method For Bringing Hypothermia Rapidly Onboard and United States Patent Application Publication No. 2015/0223972 (Dabrowiak, et al.) entitled Heat Exchange System For Patient Temperature Control With Multiple Coolant Chambers For Multiple Heat Exchange Modalities, the entire disclosure of each such patent and application being expressly incorporated herein by reference.
• It is to be appreciated that, although the invention has been described hereabove with reference to certain examples or embodiments of the invention, various additions, deletions, alterations and modifications may be made to those described examples and embodiments without departing from the intended spirit and scope of the invention. For example, any elements, steps, members, components, compositions, reactants, parts or portions of one embodiment or example may be incorporated into or used with another embodiment or example, unless otherwise specified or unless doing so would render that embodiment or example unsuitable for its intended use. Also, where the steps of a method or process have been described or listed in a particular order, the order of such steps may be changed unless otherwise specified or unless doing so would render the method or process unsuitable for its intended purpose. Additionally, the elements, steps, members, components, compositions, reactants, parts or portions of any invention or example described herein may optionally exist or be utilized in the absence or substantial absence of any other element, step, member, component, composition, reactant, part or portion unless otherwise noted. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims.

Claims (21)

1.-55. (canceled)

56. A system for controlling a body temperature of a subject, the system comprising:

a first source of a heat exchange fluid;

a first heat exchange device configured to heat or cool the body temperature of the subject by transferring heat between the heat exchange fluid and the subject;

a first pump configured to circulate the heat exchange fluid through the first heat exchange device from the first source of the heat exchange fluid;

a controller configured to control the first pump to circulate the heat exchange fluid; and

a removable secondary heat exchange system that is configured to interface with the controller, the removable secondary heat exchange system comprising:

a second source of a heat exchange fluid;

a second pump;

a second heat exchange device through which the second pump is configured to circulate heat exchange fluid from the second source; and

an electronic storage medium storing instructions configured to cause the controller to control the second pump to control the body temperature of the subject.

57. The system ofclaim 56, wherein the second heat exchange device comprises a body surface heat exchange device, and wherein the first heat exchange device comprises an endovascular heat exchange device.

58. The system ofclaim 56, further comprising:

an air trap configured to remove air from a first fluid loop in communication with the first pump or a second fluid loop in communication with the second pump.

59. The system ofclaim 56, wherein the controller is configured to detect that the second pump, the second source, or the second heat exchange device is connected for heating or cooling the body of the subject, wherein the controller automatically controls the second pump to circulate the heat exchange fluid from the second source in response to the detecting.

60. The system ofclaim 56, wherein the controller is configured to perform operations comprising:

receiving, through a user interface, a selection of a mode of operation, the mode of operation comprising one of:

a first mode wherein heated or cooled heat exchange fluid is circulated through the first heat exchange device comprising an endovascular heat exchange device;

a second mode wherein heated or cooled heat exchange fluid is circulated through the second heat exchange device comprising a body surface heat exchange device; and

a third mode wherein heated or cooled heat exchange fluid is circulated through both the endovascular heat exchange device and the body surface heat exchange device; and

in response to receiving the selection of the mode of operation, controlling the body temperature of the subject in accordance with the selected mode of operation.

61. The system ofclaim 60, wherein the third mode comprises at least two sub-modes selected from:

a first sub-mode wherein the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm;

a second sub-mode wherein one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms; and

a third sub-mode wherein, for an initial period, the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm and, for a subsequent period, one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms.

62. The system ofclaim 56, further comprising a heater or cooler configured for heating or cooling one or both of the first source of the heat exchange fluid and the second source of the heat exchange fluid.

63. The system ofclaim 62, wherein the heater or cooler comprises a coldwell, and wherein the second heat exchange device comprises a circulation coil through which the heat exchange fluid from the second source flows, the circulation coil configured to be disposed within the coldwell.

64. The system ofclaim 62, wherein the heater or cooler comprises heat exchange plates, and wherein second heat exchange device comprises a cassette through which the heat exchange fluid from the second source flows, the cassette configured to be disposed between the heat exchange plates.

65. The system ofclaim 56, wherein the removable secondary heat exchange system comprises an air separator that prevents air from entering the second pump.

66. The system ofclaim 56, wherein the removable secondary heat exchange system comprises a dual lumen spike that for connecting tubing to the second source of the heat exchange fluid, the dual lumen spike configured to cause air to collect at a top of a reservoir of the second source of the heat exchange fluid as a liquid level lowers in the reservoir.

67. The system ofclaim 56, wherein the removable secondary heat exchange system comprises a capture device that captures warm air that exhausts from a heater that warms the a heat exchange fluid from the first source; and

a conduit for channeling warm air from the capture device to the second heat exchange device that comprises a body surface warming device.

68. A removable secondary heat exchange system that is configured to interface with a controller of a primary heat exchange system that controls a body temperature of a subject, the removable secondary heat exchange system comprising:

a source of a heat exchange fluid;

a pump;

a heat exchange device through which the pump is configured to circulate heat exchange fluid from the source of the heat exchange fluid; and

an electronic storage medium storing instructions configured to cause the controller to control the pump to control the body temperature of the subject.

69. The system ofclaim 68, wherein the heat exchange device comprises a body surface heat exchange device.

70. The system ofclaim 68, further comprising:

an air trap configured to remove air from a fluid loop in communication with the pump.

71. The system ofclaim 68, wherein the controller is configured to detect that the pump, the source, or the heat exchange device is connected for heating or cooling the body of the subject, wherein the controller automatically controls the pump to circulate the heat exchange fluid in response to the detecting.

72. The system ofclaim 71, wherein the controller is configured to perform operations comprising, in response to the detecting:

receiving, through a user interface, a selection of a mode of operation, the mode of operation comprising one of:

a first mode wherein heated or cooled heat exchange fluid is circulated through a second heat exchange device comprising an endovascular heat exchange device;

a second mode wherein heated or cooled heat exchange fluid is circulated through the heat exchange device comprising a body surface heat exchange device; and

a third mode wherein heated or cooled heat exchange fluid is circulated through both the endovascular heat exchange device and the body surface heat exchange device; and

in response to receiving the selection of the mode of operation, controlling the body temperature of the subject in accordance with the selected mode of operation.

73. The system ofclaim 72, wherein the third mode comprises at least two sub-modes selected from:

a first sub-mode wherein the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm;

a second sub-mode wherein one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms; and

a third sub-mode wherein, for an initial period, the endovascular heat exchange device and the body surface heat exchange device simultaneously cool or warm and, for a subsequent period, one of the endovascular heat exchange device and the body surface heat exchange device cools while the other of the endovascular heat exchange device and the body surface heat exchange device warms.

74. The system ofclaim 68, wherein the heat exchange device comprises a circulation coil through which the heat exchange fluid flows, the circulation coil configured to be disposed within a coldwell having a temperature that is controlled by the controller.

75. The system ofclaim 68, wherein the heat exchange device a cassette through which the heat exchange fluid flows, the cassette configured to be disposed between heat exchange plates having a temperature that is controlled by the controller.

Images