Comparison of tympanic and oral temperatures in surgical patients.

The purpose of this study was to compare tympanic and oral temperatures at four times during the perioperative period in 60 adults having major abdominal surgery. Tympanic temperature was measured with an infrared thermometer and oral temperature with a predictive thermistor thermometer. Measurements at the two sites were similar in pattern and moderately well correlated. Tympanic temperature was somewhat more sensitive to the effects of an intervention influencing body temperature. The tympanic-oral temperature offset was relatively stable over time, with tympanic readings having a smaller range of values at each measurement. Tympanic temperature measurement variation was fairly small, with 92% of readings reproducible within 0.5 degree F (0.3 degree C); comparable oral data were not available. The findings suggest that the tympanic site offers some advantage, but that either tympanic or oral readings would be satisfactory for routine intermittent monitoring of body temperature during the perioperative period.