The Detrimental Effects of Prolonged Hypothermia and Rewarming in the Dog

Open Access
Publisher Website
Google Scholar
Abstract
A deleterious cerebrovascular effect of prolonged hypothermia was previously observed in primates and cats. The systemic and cerebral hemodynamic and metabolic effects of 24 h of hypothermia in the dog were examined. With decreases in temperature to 29.degree. C, cardiac output (.ovrhdot.Q) and whole-body O2 consumption (.ovrhdot.VO2) initially decreased 52 and 42%, respectively. Despite a stable temperature, .ovrhdot.Q and .ovrhdot.VO2 continued to decrease, and at 24 h values were 7 and 28% of control, respectively. Cerebral blood flow (CBF) and cerebral O2 consumption responded similarly. At 24 h inhomogeneous perfusion of both brain and skeletal muscle was observed. Without warning, cardiovascular collapse with severe tissue hypoxia and acidosis developed; CBF became grossly inadequate, resulting in depletion of brain energy stores.