Correction of perioperative hypothermia decreases experimental sepsis mortality by modulating the inflammatory response

Abstract

The objective of this study was to investigate if the correction of perioperative hypothermia improves sepsis survival. Mice with anesthesia-induced perioperative hypothermia had sepsis induced by cecal ligation and puncture and were treated with fluid resuscitation and antibiotics. The mice were either warmed (35 degrees C) or kept at room temperature for 1 hr in the immediate postoperative period. This study was conducted at a university research laboratory. This study included adult, female outbred mice. Immediately after surgery, mice were randomized to 1 hr of warming or maintained at room temperature. Warming was accomplished by placing the mice in a cage preheated to 35 degrees C. The anesthesia-induced hypothermia resolved within 10 hrs, and perioperative warming reestablished normothermia within 1 hr. Restoring normothermia improved sepsis survival from 42% to 60% (p < .02). Warming also significantly corrected the changes in body weight, reflecting improved overall physiological status. To examine the mechanism of this beneficial response, plasma levels of interleukin-6 were assessed. Warming was associated with a decrease in interleukin-6 levels in both those mice that died as well as survivors, reflecting a blunting but not complete inhibition of the inflammatory response. Among surviving mice, warming also significantly increased the peripheral blood cell count, including the neutrophils, an indication that warming augmented innate immunity. Correction of perioperative hypothermia improves survival after sepsis by appropriately modulating the early inflammatory response.