Methods and devices for non-invasive cerebral and systemic cooling
A method for providing and adjusting cerebral cooling in response to changes in a physiological parameter. A spray having a boiling point between 38-300° C. is delivered to the surface of a patient's nasal cavities. The spray causes cooling by direct heat transfer through the nasopharynx and hematogenous cooling through the carotids and the Circle of Willis. A physiological parameter, such as cerebral temperature, changes in cerebral blood flow or brain oxygenation is monitored. The delivery rate of the spray is adjusted in response to the physiological parameter.
1. A method for cerebral cooling, comprising the steps of:
inserting a cooling assembly into a nasal cavity of a patient through patient's nostril, the cooling assembly comprising an elongate member comprising a proximal end, a distal end, a first lumen extending therebetween, and a plurality of ports in fluid communication with the first lumen;
delivering a spray comprising a nebulized liquid having a boiling point of between 38-300° C. and a gas onto the surface of the patient's nasal cavity through the cooling assembly;
monitoring a physiological parameter; and
adjusting the delivery of the spray through the cooling assembly in response to the physiological parameter,
wherein the liquid is nebulized at the plurality of ports within the nasal cavity, wherein the gas enhances evaporation of the liquid from the nasal cavity and wherein a cerebral temperature of the patient is reduced by at least 1° C in one hour by evaporation of the liquid in the nasal cavity.
2. The method of claim 1 , wherein the step of monitoring a physiological parameter comprises measuring the patient's temperature, and wherein the step of adjusting delivery of the spray comprises adjusting the delivery of the spray in response to the patient's temperature.
3. The method of claim 2 , wherein the step of measuring the patent's temperature comprises measuring one of the patient's cerebral temperature, nose temperature, tympanic temperature, body temperature or rectal temperature.
4. The method of claim 3 , wherein the step of measuring the patient's temperature further comprises continuously monitoring the patient's temperature.
5. The method of claim 3 , wherein adjusting the delivery of the spray further comprises using the patient's temperature to stop and/or start delivery of the spray.
6. The method of claim 3 , wherein adjusting the delivery of the spray further comprises using the patient's temperature to adjust the rate of delivery of the spray.
7. The method of claim 3 , wherein the step of measuring the patent's temperature comprises measuring the patient's cerebral temperature.
8. The method of claim 7 , further comprising the step of setting a target temperature for the cerebral temperature, wherein the step of delivering of the spray further comprises delivering a spray onto the surface of the patient's nasal cavity until the cerebral temperature reaches the target temperature.
9. The method of claim 8 , further comprising automatically stopping delivery of the spray when the patient's cerebral temperature reaches the target temperature.
10. The method of claim 8 , further comprising automatically restarting delivery of the spray when the patient's cerebral temperature rises more than 0.5° C. above the target temperature.
11. The method of claim 8 , wherein the target temperature is set by an operator within a range of about 30-37° C.
12. The method of claim 8 , wherein the step of adjusting the delivery of the spray further comprises restarting delivery of the spray when the patient's cerebral temperature reaches substantially greater than the target temperature.
13. The method of claim 1 , wherein the step of monitoring a physiological parameter comprises monitoring the patient's cerebral blood flow, and wherein the step of adjusting delivery of the spray comprises adjusting the delivery of the spray in response to changes in the patient's cerebral blood flow.
14. The method of claim 1 , wherein the step of monitoring a physiological parameter comprises monitoring the patient's brain oxygenation, and wherein the step of adjusting delivery of the spray comprises adjusting the delivery of the spray in response to changes in the patient's brain oxygenation.
15. The method of claim 1 wherein the nebulized liquid is a perfluorocarbon.
16. The method of claim 1 , wherein the gas is oxygen.
17. The method of claim 1 , wherein the elongate member further comprises a second lumen extending between the proximal and distal ends.
18. The method of claim 17 , further comprising the steps of:
infusing the liquid into the first lumen of the elongate member;
infusing the gas into the second lumen of the elongate tubular member; and
combining the liquid and gas at the plurality of ports to form a nebulized spray liquid.