Abstract
STUDY DESIGN
Single trial using matched subjects under tightly-controlled experimental conditions.
OBJECTIVE
Humans with spinal-cord injury have a reduced ability to dissipate heat. The current project examined the possibility that, in such people, an elevated ventilatory response (panting) may act as a supplementary avenue for heat loss.
SETTING
Australia, New South Wales.
METHODS
Breathing frequency was measured during a resting heat exposure (<or=2 h) in 10 subjects with spinal-cord injury (C4-L5), and in 10 mass- and age-matched, able-bodied subjects.
RESULTS
Subjects with spinal-cord injury displayed a ventilatory sensitivity, relative to mean body temperature change (2.4 breaths/min/ degrees C +/-0.9), more than twice that of able-bodied subjects (1.1 breaths/min/ degrees C +/-0.6; P=0.042). Furthermore, the higher the level of spinal-cord injury, the greater was the ventilatory response (r2=0.51, P=0.048).
CONCLUSION
While these ventilatory changes were apparently thermally mediated, they did not represent a true panting response, nor did the increased breathing frequency confer a physiologically significant thermoregulatory benefit that may help compensate for the loss of sympathetic flow to eccrine sweat glands and cutaneous blood vessels in people with spinal-cord injury.
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