Question

To prevent brain damage, a standard procedure is to lower the body temperature of someone who has been resuscitated after suffering cardiac arrest. What is the physiochemical basis for this procedure?

Answer 1

When a patient is resuscitated, reperfusion sets off a series of chemical reactions that can continue for up to 24 hours, possibly causing significant inflammation in the brain. Inducing mild hypothermia decreases intracranial pressure, the cerebral metabolic rate, and the brain's demand for oxygen consumption. In addition, it is thought to suppress many of the chemical reactions associated with reperfusion injury, including free radical production, excitatory amino acid release, and calcium shifts, which can in turn lead to mitochondrial damage and apoptosis

If your just looking for a basic chemistry to this question I would say that higher temperature increases rate of reactions. By lowering the temperature you are decreasing the rate of reaction of specific reactions. Your slowing down the metabolic rate and thus slowing the rate at which brain cells die once they have been starved of oxygen. This improves chance of survival.