Introduction Although rapid cooling and management of
circulatory failure are crucial to the prevention of irreversible
tissue damage and death in heatstroke, the evidence supporting
the optimal cooling method and hemodynamic management has
yet to be established.
Methods A systematic review of all clinical studies published in
Medline (1966 to 2006), CINAHL (Cumulative Index to Nursing
& Allied Health Literature) (1982 to 2006), and Cochrane
Database was performed using the OVID interface without
language restriction. Search terms included heatstroke,
sunstroke, and heat stress disorders.
Results Fourteen articles reported populations subjected to
cooling treatment for classic or exertional heatstroke and
included data on cooling time, neurologic morbidity, or mortality.
Five additional articles described invasive monitoring with
central venous or pulmonary artery catheters. The four clinical
trials and 15 observational studies covered a total of 556
patients. A careful analysis of the results obtained indicated that
the cooling method based on conduction, namely immersion in
iced water, was effective among young people, military
personnel, and athletes with exertional heatstroke. There was no
evidence to support the superiority of any one cooling technique
in classic heatstroke. The effects of non-invasive, evaporative, or
conductive-based cooling techniques, singly or combined,
appeared to be comparable. No evidence of a specific endpoint
temperature for safe cessation of cooling was found. The
circulatory alterations in heatstroke were due mostly to a form of
distributive shock associated with relative or absolute
hypovolemia. Myocardial failure was found to be rare.