Fever Is Associated with Reduced, Hypothermia with Increased Mortality in Septic Patients: A Meta-Analysis of Clinical Trials

BACKGROUND: Sepsis is usually accompanied by changes of body temperature (T(b)), but whether fever and hypothermia predict mortality equally or differently is not fully clarified. We aimed to find an association between T(b) and mortality in septic patients with meta-analysis of clinical trials. METHODS: We searched the PubMed, EMBASE, and Cochrane Controlled Trials Registry databases (from inception to February 2016). Human studies reporting T(b) and mortality of patients with sepsis were included in the analyses. Average T(b) with SEM and mortality rate of septic patient groups were extracted by two authors independently. RESULTS: Forty-two studies reported T(b) and mortality ratios in septic patients (n = 10,834). Pearson correlation analysis revealed weak negative linear correlation (R(2) = 0.2794) between T(b) and mortality. With forest plot analysis, we found a 22.2% (CI, 19.2–25.5) mortality rate in septic patients with fever (T(b) > 38.0°C), which was higher, 31.2% (CI, 25.7–37.3), in normothermic patients, and it was the highest, 47.3% (CI, 38.9–55.7), in hypothermic patients (T(b) < 36.0°C). Meta-regression analysis showed strong negative linear correlation between T(b) and mortality rate (regression coefficient: -0.4318; P < 0.001). Mean T(b) of the patients was higher in the lowest mortality quartile than in the highest: 38.1°C (CI, 37.9–38.4) vs 37.1°C (CI, 36.7–37.4). CONCLUSIONS: Deep T(b) shows negative correlation with the clinical outcome in sepsis. Fever predicts lower, while hypothermia higher mortality rates compared with normal T(b). Septic patients with the lowest (< 25%) chance of mortality have higher T(b) than those with the highest chance (> 75%).