Effects of thermal stimuli during simulated hemorrhaging on aspects of cognitive performance

Warming a hemorrhaging victim is the standard of care due to the adverse effects of combined hemorrhage and hypothermia on survival. However, it has been found that heating can be detrimental to the maintenance of arterial pressure, cerebral perfusion, and may also impact cognitive function. PURPOSE: To test the hypothesis that mildly heating an otherwise normothermic individual can be detrimental to cognitive function during a simulated mild hemorrhagic insult. METHODS: Nine men (mean ± SD: age, 29.9 ± 8.4 y; body mass, 79.4 ± 15.2 kg) underwent a randomized, crossover experimental design. Following 15 min of supine rest, 10 min of 30 mmHg of lower body negative pressure (LBNP) was applied to simulate a mild hemorrhagic challenge while subjects were normothermic. With LBNP continuing, subjects were exposed to mild whole-body heating (mean skin temperature (Tsk): 36.7 ± 0.5°C), skin surface cooling (Tsk: 29.6 ± 1.0°C), or remained thermoneutral (Tsk: 33.5 ± 0.6°C) for an additional 40 min via a water-perfused suit. A modified Erikson Flanker task was used as a measure of cognitive function. Affective valence and thermal sensations were also assessed. Upon completion of trials, subjects remained supine for 15 min for Tsk to return to baseline temperatures. RESULTS: Interaction between thermal perturbations and LBNP time did not reveal changes in cognitive function, as reflected in response accuracy (P = 0.19), reaction time (P = 0.09) or performance variability (P = 0.16) on the Flanker task. This suggests that LBNP with and without thermal perturbations had little influence on cognitive function. CONCLUSIONS: For the applied level of simulated hemorrhage (30 mmHg LBNP), these data suggest that mild heating of a hemorrhaging victim does not compromise cognitive function, while cooling is not beneficial. It remains unknown whether mild heating would be detrimental during a more profound simulated hemorrhagic challenge.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Poh, Paula

Contributors dc:contributor

• Crandall, Craig G.
• Petruzzello, Steven J.
• Boppart, Marni D.
• Horn, Gavin P.

• Thermoregulation
• Trauma

Statement dc:rights

• Copyright 2015 Paula Yen Shan Poh

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/78771

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/78771