Magnesium deficiency: an unrecognized cause of convulsions, arrhythmias, and neuromuscular impairment

Hypoglycemia is but one of a number of causes of hypothermia, but is important to keep in mind as a possible precipitating or concurrent event even in those cases in which there are other obvious explanations for decreased body temperature (exposure, alcoholism, starvation, sepsis or hypothyroidism). Hypoglycemia may occur in as many as 40 percent of very cold patients, and be clinically unrecognized because symptoms are masked by the hypothermia itself. Although serum glucose levels are depressed, a cold-induced renal tubular glycosuria may occur. Glucose in the urine, therefore, cannot be used as assurance of hyperglycemia in a hypothermic patient. And, although cold protects against serious end organ damage from hypoglycemia by decreasing tissue metabolic need for glucose, a serum specimen should be drawn for glucose determination in all hypothermic patients and a 50 percent glucose solution immediately given intravenously. If this is not done, serum glucose levels may plummet as the patient is rewarmed and begins to shiver.