Correlation, accuracy, precision and practicability of perioperative measurement of sublingual temperature in comparison with tympanic membrane temperature in awake and anaesthetised patients

Background and objective The prevention of inadvertent perioperative hypothermia requires precise, reliable and practical methods of temperature measurement in both awake and anaesthetised patients. Different methods and sites of monitoring have been evaluated, but many are imprecise, unusable in awake patients, difficult to apply or too invasive, especially for minor surgery. The aim of this study was to evaluate the performance of perioperative sublingual and tympanic temperature measurement in awake and anaesthetised patients. Methods We enrolled 171 patients, aged 18-75 years, scheduled for surgery with duration less than 1 h under general anaesthesia. Spearman's rank correlation and Bland-Altman analysis for assessment of correlation, accuracy and precision of both methods were determined analysing 171 independent paired values at three different measurement times. Results Sublingual temperatures were significantly higher than tympanic temperatures by 0.1-0.2 degrees C. The coefficient of determination (r(2)) of both methods was between 0.50 and 0.59, and Bland-Altman analysis revealed a bias (SD) of between 0.09 (0.21) and 0.15 (0.24)degrees C. Conclusion The accuracy and precision of sublingual temperature measurement were adequate for clinical use, and there was a high correlation with tympanic temperature monitoring. Sublingual temperature measurement has been demonstrated as a good and practical modality for perioperative temperature monitoring in both awake and anaesthetised patients.