Core temperature--the intraoperative difference between esophageal versus nasopharyngeal temperatures and the impact of prewarming, age, and weight: a randomized clinical trial.
Unplanned perioperative hypothermia is a well-known complication to anesthesia. This study compares esophageal and nasopharyngeal temperature measured in the same patient for a period of 210 minutes of anesthesia. Forty-three patients undergoing colorectal surgery were randomly assigned in 2 groups, with or without a prewarming period (group A = prewarming [n = 21] or group B = no prewarming [n = 22]). Demographics were similar in both groups. Mean temperatures at 210 minutes were statistically different between the groups at both sites of measurement. Esophageal temperature in group A was 36.5 ? 0.6 vs 35.8 ? 0.7 in group B (P = .001), and nasopharyngeal temperature was 36.7 ? 0.6 and 36.0 ? 0.6 in group A and group B, respectively (P = .002). A negative correlation was found between esophageal temperature and age (r2 = -.381, P