Cold stress, near drowning and accidental hypothermia: a review.

This paper reviews literature on the topic of cold stress, near-drowning and hypothermia, written mainly since the last review of this type in this journal. The main effects of cold stress, especially in cold water immersion, include the "cold shock" response, local cooling causing decrements in physical and mental performance, and ultimately core cooling as hypothermia occurs. The section on cold-water submersion (near-drowning) includes discussion regarding the various mechanisms for brain and body cooling during submersion. The mechanisms for cold-induced protection of the anoxic brain are discussed with attention given to decreased brain temperature and the Q10 principle, the mammalian dive reflex and a newly considered mechanism; cold-induced changes in neurotransmitter release (i.e., glutamate and dopamine). The section on the post-cooling period includes the post-rescue collapse and subsequent rewarming strategies used in the field, during emergency transport or in medical facilities. Recent research on topics such as inhalation warming, body-to-body warming, radio wave therapy, warm water immersion, exercise, body cavity lavage, and cardiopulmonary bypass is reviewed. Information on new methods of warming, including arteriovenous anastomoses (AVA) warming (by application of heat- with or without negative pressure application-to distal extremities in an effort to increase AVA blood flow), forced-air warming, and peripheral vascular extracorporeal warming, are discussed.