Dexamethasone decreases the incidence of shivering after cardiac surgery: a randomized, double-blind, placebo-controlled study

Abstract

Shivering after cardiac surgery is common, and may be a result of intraoperative hypothermia. Another possible etiology is fever and chills secondary to activation of the inflammatory response and release of cytokines by cardiopulmonary bypass. Dexamethasone decreases the gradient between core and skin temperature and modifies the inflammatory response. The goal of this study was to determine whether dexamethasone can reduce the incidence of shivering. Two hundred thirty-six patients scheduled for elective coronary and/or valvular surgery were randomly assigned to receive either dexamethasone 0.6 mg/kg or placebo after the induction of anesthesia. All patients received standard monitoring and anesthetic management. After arrival in the intensive care unit (ICU), nurses unaware of the treatment groups recorded visible shivering, as well as skin and pulmonary artery temperatures. Analysis of shivering rates was performed by using chi2 tests and logistic regression analysis. Compared with placebo, dexamethasone decreased the incidence of shivering (33.0% vs 13.1%; P = 0.001). It was an independent predictor of reduced incidence of shivering and was also associated with a higher skin temperature on ICU admission and a lower central temperature in the early postoperative period.

Implications: Dexamethasone is effective in decreasing the incidence of shivering. The effectiveness of dexamethasone is independent of temperature and duration of cardiopulmonary bypass. Shivering after cardiac surgery may be part of the febrile response that occurs after release of cytokines during cardiopulmonary bypass.