Document Detail

Rate and gender dependence of the sweating, vasoconstriction, and shivering thresholds in humans.
MedLine Citation:
PMID:  8024131     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The range of core temperatures not triggering thermoregulatory responses ("interthreshold range") remains to be determined in humans. Although the rates at which perioperative core temperatures vary typically range from 0.5 to 2 degrees C/h, the thermoregulatory contribution of different core cooling rates also remains unknown. In addition, sweating in women is triggered at a slightly greater core temperature than in men. However, it is unknown whether the vasoconstriction and shivering thresholds are comparably greater in women, or if women tolerate a larger range of core temperatures without triggering thermoregulatory responses. Accordingly, the authors sought to (1) define the interthreshold range; (2) test the hypothesis that, at a constant skin temperature, the vasoconstriction and shivering thresholds are greater during rapid core cooling than during slowly induced hypothermia; and (3) compare the sweating, vasoconstriction, and shivering thresholds in men and women. METHODS: Eight men and eight women participated. The men participated on 2 separate days; no anesthesia or sedatives were administered. On each day, they were cutaneously warmed until sweating was induced and then were cooled by a central venous infusion of cold fluid. The cooling rates were 0.7 +/- 0.1 degrees C/h on 1 day and 1.7 +/- 0.4 degrees C/h on the other, randomly ordered. Skin temperature was maintained near 36.7 degrees C throughout each trial. The women were studied only once, in the follicular phase of their menstrual cycles, at the greater cooling rate. RESULTS: The interthreshold range was approximately 0.2 degrees C in both men and women, but all thermoregulatory response thresholds were approximately 0.3 degrees C higher in women. All thresholds were virtually identical during slow and fast core cooling. CONCLUSIONS: Our findings confirm the existence of an interthreshold range and document that its magnitude is small. They also demonstrate that the interthreshold range does not differ in men and women, but that women thermoregulate at a significantly higher temperature than do men. Typical clinical rates of core cooling do not alter thermoregulatory responses.
M Lopez; D I Sessler; K Walter; T Emerick; M Ozaki
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Anesthesiology     Volume:  80     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  1994 Apr 
Date Detail:
Created Date:  1994-08-04     Completed Date:  1994-08-04     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  780-8     Citation Subset:  AIM; IM    
Department of Anesthesia, University of California, San Francisco 94143-0648.
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MeSH Terms
Body Temperature Regulation / physiology*
Sensory Thresholds / physiology*
Sex Factors
Shivering / physiology*
Skin / blood supply*
Skin Temperature / physiology*
Sweating / physiology*
Tympanic Membrane / physiology
Vasoconstriction / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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