Mortality in elderly patients with thermoregulatory failure.

Fifty-four elderly patients with thermoregulatory failure were evaluated retrospectively. The most commonly associated cause was underlying sepsis, which occurred in 78% of cases. Underlying conditions that increased the incidence of hypothermia were hypoproteinemia (50%), cachexia (30%), and neuroleptic medications (21%), most commonly thioridazine. Digoxin toxicity was a common finding (20% of all cases). One third of the patients developed hypothermia in warm months and half of them developed it while in the hospital. Patients who presented with hypothermia from out of the hospital had lower temperatures, were more bradycardic and hemoconcentrated, and died more rapidly than the in-hospital group. This could be explained by lower outside temperature or delay in diagnosis and treatment of the underlying disease. The overall mortality rate was extremely high (74%) in both groups. The mortality rate was not affected by age, sex, or degree of hypothermia. We conclude that thermo-regulatory failure in the elderly can occur in warm as well as cold environments or climates. The development of hypothermia in elderly patients should be promptly treated as sepsis unless proven otherwise, in light of the poor prognosis of this condition.