HEAT EXCHANGE IN MEN AND WOMEN FOLLOWING INTRAVENOUS INJECTION OF ENDOTOXIN.

Abstract

An assessment was made of heat exchange during the course of an induced febrile episode following injection of endotoxin. Experiments were performed on either normal subjects or patients with recurrent fever. They were given intravenously either saline or a dose of 1 or 2 mμg Lipexal (the lipopolysaccharide of Salmonella abortus equi) per kilogram approximately 15 min before being exposed for 3–6 hr to 27.7 C air while wearing minimal clothing. Continuous measurements were made of: oxygen consumption, carbon dioxide production, core temperatures, skin temperatures, muscle surface temperature, and heat flow from the lateral surface of the upper and lower arm and the back of the hand. Three distinct patterns of reactivity were found: a) nonreactors (N = 2), b) those in whom elevated heat production preceded a rise in core temperature (N = 8), and c) those in whom thermal redistribution produced a rise in core temperature prior to an increase in heat production (N = 5). The results suggest that endotoxin may produce fever by alteration of either vasomotor control of heat redistribution or heat production at independent rates. Fever patients, in comparison to normal subjects, appeared to have an exaggerated metabolic response per equal increment in core temperatur Note (With the Technical Assistance of D. Thrasher) cold; fever; temperature regulation Submitted on December 23, 1963