Limb Skin Temperature as a Tool to Predict Orthostatic Instability.
Oliver Opatz1, Michael Nordine1, Helmut Habazettl1
1Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.
Frontiers in Physiology
|September 21, 2018
Summary
Elevated skin temperatures in fighter pilot candidates predict orthostatic instability and almost loss of consciousness during G-force exposure. This finding may help prevent such events in high-stress environments and patient care.
Area of Science:
- Aerospace Medicine
- Cardiovascular Physiology
- Human Factors Engineering
Background:
- Orthostatic instability is a significant health concern, exacerbated by gravity challenges and aging.
- Heat stress and peripheral vasodilation can impair orthostatic stability and cerebral perfusion, particularly under G-forces.
- Peripheral cooling demonstrates potential in preventing orthostatic intolerance.
Purpose of the Study:
- To quantify orthostatic instability risk in fighter pilot candidates.
- To assess the predictive value of cutaneous limb temperatures for G-force-induced almost loss of consciousness (ALOC).
- To investigate the relationship between peripheral skin temperature and ALOC during a push-pull maneuver.
Main Methods:
- Continuous measurement of peripheral skin temperatures (upper/lower extremities) and core body temperature in 20 pilot candidates.
- Utilized a head-down tilt combined with lower body negative pressure push-pull maneuver.
- Compared baseline temperatures between subjects who experienced ALOC and those who remained stable.
Main Results:
- Subjects experiencing ALOC (55%) exhibited higher baseline upper arm and thigh temperatures than stable subjects (45%).
- No significant differences in baseline core body temperature or distal limb skin temperatures were observed between groups.
- Peripheral skin temperature emerged as a potential predictor of ALOC before acceleration.
Conclusions:
- Baseline peripheral skin temperature, particularly in proximal limbs, may serve as a predictive factor for orthostatic instability and ALOC in fighter pilot candidates.
- These findings have implications for preventing G-force-induced syncope in aviation.
- The results may also inform patient care strategies in settings like intensive care units.
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