The Accuracy of a Wireless Axillary Thermometer for Core Temperature Monitoring in Pediatric Patients Having Noncardiac Surgery: An Observational Study

A wireless and wearable axillary thermometer (iThermonitor) has been validated for perioperative core temperature monitoring in adults. The purpose of this study was to evaluate its accuracy in pediatrics having non-cardiac surgery.Prospective observational study.From January 2019 to December 2019, 70 children aged younger than 14 years undergoing surgery in a tertiary hospital were selected. Pairs of esophageal temperatures (TEso), rectal temperatures (TRec), and axillary temperatures monitored by the iThermonitor (TiTh) were collected every 5 min during surgery. Taking TEso as reference, the bias between TEso and TiTh and the proportion of bias within ±0.5°C were calculated. Bland-Altman method was used to analyze the 95% of limits of agreement (LOA) between TiTh and TEso. The same analyses were done for TRec. FINDINGS: A total of 2232 pairs of temperatures were collected. The bias (mean ± SD) between TiTh and TEso was -0.07 °C ± 0.25°C, and 95% LOA was -0.07°C ± 0.50°C. The proportion of bias within ±0.5°C accounted for 96% (95% Confidence Interval [CI], 92-98%). Higher bias and 95% LOA, and lower proportion of bias within ± 0.5°C were found between TRec and TEso than those between TiTh and TEso.During pediatric non-cardiac surgery, axillary temperature derived from iThermonitor is in good agreement with esophageal temperature and can be used as an alternative to core temperature.