OBJECTIVES: We tested the hypothesis that vasoconstriction and shivering thresholds are sufficiently reduced by acute stroke to permit induction of therapeutic hypothermia without additional pharmacological inhibition of thermoregulatory control. METHODS: We studied eight patients 2 +/- 1 days after ischemic stroke. Forced-air cutaneous cooling was administered until the patients shivered continuously or reached a tympanic membrane (ie, core) temperature of 34 degrees C. The tympanic membrane temperatures triggering vasoconstriction and shivering identified the thresholds for each response. RESULTS: Patients had a mean age of 68 +/- 8 years and a mean National Institutes of Health Stroke Scale (NIHSS) score of 5. No patient reached the target core temperature of 34 degrees C. Vasoconstriction and shivering thresholds were 37.1 +/- 0.4 degrees C and 36.6 +/- 0.4 degrees C, respectively. CONCLUSIONS: Vasoconstriction and shivering were initiated at roughly normal temperatures in ischemic stroke patients, and these thermoregulatory responses prevented induction of therapeutic hypothermia. Pharmacological reduction of the vasoconstriction and shivering thresholds will be required if therapeutic hypothermia for stroke patients is to be induced easily by surface cooling.
OBJECTIVES: We tested the hypothesis that vasoconstriction and shivering thresholds are sufficiently reduced by acute stroke to permit induction of therapeutic hypothermia without additional pharmacological inhibition of thermoregulatory control. METHODS: We studied eight patients 2 +/- 1 days after ischemic stroke. Forced-air cutaneous cooling was administered until the patients shivered continuously or reached a tympanic membrane (ie, core) temperature of 34 degrees C. The tympanic membrane temperatures triggering vasoconstriction and shivering identified the thresholds for each response. RESULTS:Patients had a mean age of 68 +/- 8 years and a mean National Institutes of Health Stroke Scale (NIHSS) score of 5. No patient reached the target core temperature of 34 degrees C. Vasoconstriction and shivering thresholds were 37.1 +/- 0.4 degrees C and 36.6 +/- 0.4 degrees C, respectively. CONCLUSIONS: Vasoconstriction and shivering were initiated at roughly normal temperatures in ischemic strokepatients, and these thermoregulatory responses prevented induction of therapeutic hypothermia. Pharmacological reduction of the vasoconstriction and shivering thresholds will be required if therapeutic hypothermia for strokepatients is to be induced easily by surface cooling.
Authors: Julia Koehn; Ruihao Wang; Carmen de Rojas Leal; Bernd Kallmünzer; Klemens Winder; Martin Köhrmann; Rainer Kollmar; Stefan Schwab; Max J Hilz Journal: Neurol Sci Date: 2020-03-26 Impact factor: 3.307