Unreliability of the Infrared Tympanic Thermometer in Clinical Practice

Abstract

This study was designed to determine the magnitude and frequency of measurement errors with infrared tympanic thermometers in the clinical setting. In a convenience sample of 137 adult inpatients, we compared body temperatures measured by a Diatek 9000 Infrared Aural Thermometer and an IVAC 2090 CoreCheck Tympanic Thermometer between themselves, in right versus left ears, and against concurrently measured oral temperatures using both an electronic thermoprobe and conventional glass mercury thermometer. There was a significant between-brand difference of 0.6 degrees C (IVAC <Diatek) for both ears; right-versus-left ear temperature group differences were not statistically significant with either thermometer, but ear-to-ear temperature variation was large, with individual right-left differences as great as 2.5 degrees C; significant differences were found between oral and ear temperatures with the IVAC thermometer (0.5 degrees C, ear <oral) but not with the Diatek thermometer; no significant difference was found between oral electronic and mercury temperature measurements; and cerumen had no significant effect on ear temperature measurements. The variability and inaccuracy of temperatures measured by the infrared tympanic thermometers were sufficiently large to suggest that the use of these devices for routine thermometry may be potentially hazardous.