Central venous catheter with heat exchange properties

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DESCRIPTION

Central venous catheter with heat exchange properties

Field of the invention

The present invention relates generally to apparatus for cooling patients for therapeutic purposes, and more particularly to systems for establishing central venous access while providing a means for cooling a patient.

Background

Medical outcomes for a patient suffering from severe brain trauma or ischemia caused by stroke or heart attack have been found to be impaired if the patient's body temperature rises above normal (38 ° C). It is further believed that the medical outcomes for many of these patients could be significantly improved if the patients were to cool down relatively quickly for a short period of time, eg, 24-72 hours. Aside from the therapeutic benefits of hypothermia, outcomes for patients with traumatic brain injury or ischemia who develop fevers are worse than for patients who do not develop a fever. Therefore, temperature management in these patients is important, even when hypothermia is not intended to be used to treat patients. On the other hand, short-term prophylactic hypothermia could help patients undergoing cardiac surgery and minimally invasive aneurysm surgery.

The affected organ, in any case, is the brain. Accordingly, systems and methods have been described that propose the cooling of the blood flowing to the brain through the carotid artery. An example of such systems and methods is described in US Patent Application Serial No. 09 / 063,984, filed April 21, 1998, owned by the present assignee and published as US 6 126 684. In the aforementioned application, various catheters are described that can be introduced into the carotid artery of a patient and through which coolant can be pumped in a closed circuit, to remove heat from the blood in the carotid artery and thereby cool the brain. . The aforementioned devices have the advantage over other methods of cooling (for example, wrapping patients in cold blankets) of being controllable, relatively easy to use, and of being able to achieve rapid cooling and maintain the temperature of the blood at a certain point. desired fixed.

As recognized in US Patent Application Serial No. 09 / 133,813, filed August 13, 1998, owned by the present assignee and published as US 6,338,727, the aforementioned advantages in the treatment of patients With brain trauma / ischemic cooling can also be achieved by cooling the entire body of the patient, that is, by inducing systemic hypothermia. The advantage of systemic hypothermia is that, as recognized by the present assignee, inducing systemic hypothermia does not require introducing a cooling catheter or other cooling device into the brain's blood supply, but can be easily and rapidly placed in the brain. relatively large vena cava of the central venous system.

In addition, since many patients are already intubated with central venous catheters for other clinically approved purposes, the introduction of a central venous catheter that can also cool the blood, if only to control temperature and thus improve fever peaks, does not require additional surgical procedures for patients.

The invention provides a central venous access system that includes a multi-luminal catheter, at least one membrane or balloon for heat exchange located distally in the catheter and in communication with at least one cooling lumen of the catheter, and an exchange system. of heat that is communicated with at least the cooling lumen as claimed in claim 1. The refrigerant is circulated between the heat exchange system and the membrane or balloon to perform the heat exchange with a patient. Preferred embodiments are described in the dependent claims. At least one holder may be attached to the catheter to hold the catheter in a patient. In addition, a central venous system is in communication with at least one lumen of the catheter.

The details of the present invention, both in terms of its structure and its operation, can be better understood with reference to the accompanying drawings, in which like reference numerals refer to corresponding parts, and in which :

Brief description of the drawings

Figure 1 is an exploded perspective view of a first example of a venous catheter inlet sheath, schematically showing a cooling system in communication with the catheter;

Figure 1A is a longitudinal cross-sectional view taken along line 1A-1A in Figure 1 of an alternative configuration for the catheter balloon shown in Figure 1;

Figure 2 is a perspective view of a second example of the inlet sheath, configured to provide cooling capacity in the central venous system of a patient;

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Figure 3 is a cross-sectional view taken along line 3-3 in Figure 2;

Figure 3A is a cross-sectional view of an alternative sheath including a distal cooling balloon, taken along line 3-3 in Figure 2;

Figure 4 is a perspective view of a so-called jugular bulb catheter configured for patient cooling, schematically showing various components of the jugular bulb and a cooling system connected to the catheter;

Figure 5 is a cross-sectional view taken along line 5-5 in Figure 4;

Figure 6 is a perspective view of a dialysis catheter configured to cool a patient, schematically showing various dialysis components and a cooling system connected to the catheter;

Figure 7 is a cross-sectional view taken along line 7-7 in Figure 6;

Figure 8 is a perspective view of a Foley catheter configured to cool a patient, schematically showing various components of the Foley catheter and a cooling system connected to the catheter; Y

Figure 9 is a cross-sectional view taken along line 9-9 in Figure 8.

Detailed description of the preferred embodiment

Referring initially to Figure 1, a therapeutic catheter system, generally designated 10, is shown for establishing and maintaining hypothermia in a patient, or for attenuating a feverish peak in a patient and subsequently maintaining normal body temperature in the patient, or to return a hypothermic patient to normothermia. Starting from the description of the system 10 at the proximal end, as shown the system 10 includes a cooling system 12 that can be a water-bathed system or a TEC-based system such as any of the systems described in the patent application. US Serial No. 09 / 220,897, filed December 24, 1998 and published as US 6 146 411, or US patent application Ser. Serial No. 09 / 260,950, filed March 2, 1999, published as US 6 019 783. In either case, the cooling system 12 provides a coolant such as saline water through a coolant supply line 14, and the refrigerant is returned to source 12 through a refrigerant return line 16. A catheter, generally designated 18, includes respective coolant supply and return lumens that communicate with lines 14,16 to establish a closed-loop coolant path between catheter 18 and coolant source 12.

In a preferred embodiment, catheter 18 is any one of the catheters described in the aforementioned applications. For example, catheter 18 may be the catheter described in US Patent Application Serial No. 09 / 253,109, filed February 19, 1999, which catheter includes a holder 18a for holding the catheter in a patient. underwent long-term intubation. The aforementioned application describes an exemplary anchoring system that the bracket 18a can establish. In addition to the structure described in the aforementioned application, the growing flange set forth in US Patent No. 4,578,063 can be used as a support for the present invention, or the anchoring systems set forth in the present invention can be used. US Patent No. 5,693,032 or 5,192,274, or the anchor tape disclosed in US Pat. No. 3,677,250, or suture could be wrapped around the catheter body and connected to the patient to establish support. In addition, one or more central venous tracking or delivery systems 19 are communicated with one or more lumens of catheter 18 through respective tubes 19a (only a single system 19 is shown for clarity). The central venous monitoring or delivery system 19 may be, for example, a source of a drug to be infused into the central venous system of a patient, or a syringe or other device for the collection of central venous blood from a patient, or a system for monitoring pressure or for monitoring blood gases or for monitoring temperature.

Alternatively, catheter 18 may be modified catheter 20 shown in Figure 1A, which is essentially identical to the two-balloon catheter set forth in U.S. Patent Application Serial No. 09 / 305,613, filed on 5 May 1999, published as US 6,368,304, with the following exceptions.

As shown in Figure 1A, each of the two cooling balloons (only a single cooling balloon 22 is shown for clarity of description) of catheter 2D surrounds the respective inflation balloon 24. Coolant from a cooling system 26 or other coolant source enters each cooling balloon 22 through a coolant supply lumen 28 and the coolant supply port (s) 30 and exits the cooling balloon 22 through a refrigerant outlet port or ports 32 and the refrigerant return lumen 34.

Additionally, inflation fluid such as air may be directed into the inflation balloon 24 from an air source 36 through an inflation lumen 38 and the air port (s) 40 to inflate the inflation balloon 24. The air is drawn. it can eject inflation balloon 24 back through inflation lumen 38 until inflation balloon 24 collapses. With this structure, the inflation balloon 24 can be selectively moved between an inflated configuration (shown), in which the inflation balloon 24 causes the coolant to flow near the outer surface of the respective cooling balloon 22 and thereby produces a relatively superior heat exchange with blood, and a deflated configuration, wherein the coolant tends to flow through the cooling balloon 22 with a characteristic laminar flow closer to the catheter body 20 than the external surface of the catheter.

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Referring again to Figure 1, catheter 18 can be introduced into a patient through an elongated, hollow plastic introducer sheath 42 having a hollow body 42A and a side port 43 connected to body 42A. The sheath 42 is preferably coated with an antimicrobial agent, and may also be coated with an anticoagulant substance, such as heparin.

As shown, sheath 42 includes a proximal end 44 and an open distal end 46, it being understood that a working lumen extends, through which catheter 18 (or other catheter, conventional or otherwise) can be inserted, between proximal end 44 and distal end 46 of sheath 42. A barrier 48 such as a septum or hemostasis valve or other barrier selectively blocks the working lumen. Catheter 18 can be inserted through barrier 48, barrier 48 which is sealed against catheter 18. Upon removal of catheter 18, barrier 48 is closed to prevent backflow through the working lumen out of the proximal end 44 of sheath 42.

In the example shown, a temperature sensor 50 is mounted on sheath 42 at or near distal end 46 to detect the temperature of blood flowing past distal end 46. Sensor 50 may be a thermistor or thermocouple or other suitable temperature sensing device. In either case, sensor 50 is functionally connected to cooling system 12 as indicated schematically by dashed line 52, to provide temperature information to system 12. This connection can be made via wireless transmission or via cable or fiber extending through the wall of the sheath 42. Sensor 50 may be mounted to sheath 42 by solvent bonding or disposed in a lumen of sheath 42, or attached to a wire that is disposed in a lumen of sheath 42, with the sensor hanging out of sheath 42.

Figure 2 shows that instead of an 18/20 cooling catheter, a non-cooling catheter 54 such as a conventional central venous catheter or a Swan-Ganz catheter not according to the invention can be provided, as exemplified in US Patent No. USA No. 3,995,623. In this case, a sheath 56 can be provided that is in all essential respects identical to sheath 42 shown in Figure 1, with the following exceptions. Sheath 56 includes a central working lumen 58 (Figure 3) for receiving catheter 54 upon itself by sliding engagement, and at least along a distal segment of sheath 56 coolant supply and return lumens 60, 62 they surround working lumen 58 to establish a distally located heat transfer zone. Accordingly, in the example shown in Figures 2 and 3, a heat transfer zone is established by at least one distally located fluid conduit (eg, either or both lumens 60, 62) that is formed in body 66. sheath 56.

As best shown in Figure 3, working lumen 58 is defined by a wall of central lumen 64, with supply and return lumens 60, 62 being established between wall 64 and an outer wall 66 of the sheath. 56. Separator tabs 68, 70 extend laterally between walls 64, 66 along the length of the refrigerant supply and return lumens 64, 66 to separate the refrigerant supply and return lumens 60, 62.

The refrigerant supply and return lumens 60, 62 communicate, via a side port 72 featuring supply and return tubes 74, 76, with a refrigeration system 78 that is in all essential respects identical to that of the system 12 shown in Figure 1. If desired, a temperature sensor 80 may be mounted on the sheath 56 to provide temperature information to the refrigeration system 78 in accordance with the principles set forth above.

Alternatively, as shown in Figure 3A, a thin-walled cooling membrane or balloon 82 may surround a distal segment of outer wall 66 of sheath 56, to establish a cooling chamber 84 between outer wall 66 and the balloon. or membrane 82. The embodiment of sheath 56 shown in Figure 3A would then function essentially the same as the cooling catheters described in the aforementioned patent applications, with refrigerant from system 78 entering and exiting chamber 84 through respective conduits. supply and return coolant in sheath 56. In the example shown in Figure 3A, the distally located heat transfer zone is established by the balloon or membrane 82.

Referring now to Figures 4 and 5, a jugular vein catheter system, generally designated 100, includes a jugular catheter body 102 carrying an oxygen sensor, shown schematically in

104. The jugular catheter can be the intravascular fiberoptic catheter sold under the trademark Opticath by Abbot Critical Care Systems, or a jugular catheter manufactured by Baxter International, with the exceptions noted below.

An optical fiber 106 is connected to the oxygen sensor 104, and the fiber 106 terminates in an optical connection 108. In turn, the connector 108 can be connected to an oxygen measurement system 110. In addition, a temperature sensor, which is shown schematically at 112, is supported by the body, and is functionally connected via a sensor lumen 113 (Figure 5) with a tracking system 114. Both the oxygen and temperature sensor connection lines can extend through the sensor lumen 113. In addition, a pressure sensor, shown schematically at 116, is supported on the body 102, and the pressure sensor 116 is communicated through a pressure / infusion lumen 118 and a Luer adapter 120 with a pressure sensing system 122 or with a drug infusion device 124, such as a syringe or a

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However, unlike conventional jugular bulb catheters, catheter 102 shown in Figures 4 and 5 includes a distally located balloon or membrane 126. The balloon or membrane 126 is attached to the catheter body and communicates with the coolant supply and return lumens 128, 130 that are formed in the catheter body. In turn, the coolant lumens 128, 130 are communicated through the coolant supply and return lines 132, 134 with a cooling system 136. With this structure, the coolant can be circulated through the balloon or the membrane 126 to effect heat exchange with the body of a patient.

In addition to the above heat exchange structures, an arterial catheter system, generally designated 150 in Figures 6 and 7, may be provided to effect heat exchange with a patient. System 150 includes arterial catheter body 152. In accordance with the principles of arterial catheters, the body 152 includes a blood supply lumen 154 and a blood return lumen 156, both of which are communicated with a blood dialysis source 158 through the supply and delivery tubes. return of blood 160, 162 to carry out dialysis of a patient's blood.

Arterial catheter system 150 also includes a heat exchange zone associated with a distal segment of catheter body 152. Body 152 includes coolant supply and return lumens 164, 166 that are communicated with a cooling system 168 through supply and return tubes 170, 172, with lumens 164, 166 establishing the heat exchange zone. Or, the heat exchange zone may be established by at least one distally located balloon or membrane 174 that is communicated with the supply and return lumens 166, 168 in accordance with present principles.

Figures 8 and 9 show a Foley catheter, generally designated 200, which is adapted for use for cooling the interior of a patient's bladder to effect cooling of the patient. As shown, catheter 200 includes a strong, flexible catheter body 202 terminating in a central fluid drainage tube 204 that communicates with a urine drainage lumen 206 (Figure 9) in body 202. Drainage tube 204 may be connected to a fluid collection receptacle 208 in accordance with Foley catheter principles known in the art. In addition, body 202 terminates in a temperature connector tube 210, and a temperature probe 212 extends through connector tube 210 and the lumen of a temperature probe 214 (Figure 9) for connection of a temperature sensor 216. which is located distally in body 202 with a temperature monitoring system 218. In addition, a drug infusion tube 220 can be connected to a drug infusion source 222 to infuse drugs into a patient's bladder through drug infusion tube 220 and a drug infusion lumen 224 communicating with the drug infusion tube 220.

In addition to the conventional Foley catheter structure described above, catheter 200 shown in Figures 8 and 9 includes coolant supply and return lumens 226, 228 that communicate with at least one balloon or membrane 230 that is distally located in catheter body 202 in accordance with the principles set forth above. Refrigerant, for example saline, is circulated from a refrigeration system 232 through refrigerant supply and return lines 234, 236, refrigerant lumens 226, 228, and balloon or membrane 230 in a closed loop. to remove heat from a bladder of a patient into which catheter 200 has been inserted. It is to be understood that although one lumen design is illustrated in Figure 9, other designs may be used. Furthermore, it is to be understood that the refrigeration system 232 is in all essential respects identical in operation and construction to the refrigeration systems described above. If desired, the temperature monitoring system 218 can be connected to the refrigeration system 232, as indicated on line 236 to provide temperature information to the refrigeration system 232.

Although the CENTRAL VENOUS CATHETER WITH PARTICULAR HEAT EXCHANGE PROPERTIES as shown and described in detail in the present specification is fully capable of achieving the objects of the invention described above, it is to be understood that it is the embodiment of the present invention presently preferred and thus representative of subject matter that is generally contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments that may be obvious to those skilled in the art, and that accordingly the scope of the present invention should be limited only by the appended claims, in which reference to an element in the singular is not intended to mean one and only one unless explicitly stated, but rather one or more. All structural and functional equivalents of elements of the preferred embodiment described above known or likely to become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed. in the present claims. Furthermore, it is not necessary for a device or method to address each and every one of the problems that the present invention is intended to solve, in order for it to be included in the present claims. Furthermore, no element or component of the present description is intended to be dedicated to the public regardless of whether the element or component is explicitly mentioned in the claims.