Skin surface cooling improves orthostatic tolerance in normothermic individuals

S. Durand, J. Cui, K. D. Williams, C. G. Crandall

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Previous studies suggest that skin surface cooling (SSC) preserves orthostatic tolerance; however, this hypothesis has not been experimentally tested. Thus the purpose of this project was to identify whether SSC improves orthostatic tolerance in otherwise normothermic individuals. Eight subjects underwent two presyncope limited graded lower-body negative pressure (LBNP) tolerance tests. On different days, and randomly assigned. LBNP tolerance was assessed under control conditions and during SSC (perfused 16°C water through tube-lined suit worn by each subject). Orthostatic tolerance was significantly elevated in each individual due to SSC, as evidenced by a significant increase in a standardized cumulative stress index (normothermia 564 ± 58 mmHg·min; SSC 752 ± 58 mmHg·min; P < 0.05). At most levels of LBNP, blood pressure during the SSC tolerance test was significantly greater than during the control test. Furthermore, the reduction in cerebral blood flow velocity was attenuated during some of the early stages of LBNP for the SSC trial. Plasma norepinephrine concentrations were significantly higher during LBNP with SSC, suggesting that SSC may improve orthostatic tolerance through increased sympathetic activity. These data demonstrate that SSC is effective in improving orthostatic tolerance in otherwise normothermic individuals.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume286
Issue number1 55-1
StatePublished - Jan 2004

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Lower Body Negative Pressure
Skin
Cerebrovascular Circulation
Blood Flow Velocity
Syncope
Norepinephrine
Blood Pressure
Water

Keywords

  • Blood pressure
  • Lower-body negative pressure
  • Norepinephrine
  • Syncope

ASJC Scopus subject areas

  • Physiology

Cite this

Skin surface cooling improves orthostatic tolerance in normothermic individuals. / Durand, S.; Cui, J.; Williams, K. D.; Crandall, C. G.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 286, No. 1 55-1, 01.2004.

Research output: Contribution to journalArticle

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