[Infrared tympanic thermometry compared to mercury thermometers]

Because of conflicting reports we examined the accuracy of infrared tympanic thermometry compared with mercury rectal thermometer and a digital rectal thermometer in a medical ward. We studied prospectively the accuracy of parallel measurements with infrared tympanic thermometer and the correlation between this method and the rectal mercury thermometer. Measurements with digital rectal thermometry are also compared with mercury thermometry. 191 adult inpatients were included. The median difference between infrared tympanic and rectal mercury thermometry in the whole material was -0.5 degree C, but increased to -1.4 degrees C in a selected group with rectal temperature 38 degrees C or more. The median difference between parallel measurements with infrared tympanic thermometer was 0.4 degree C. Digital rectal thermometry, however, was in strict accordance with the rectal mercury method. We found an unacceptable difference in body temperature between measurements with infrared tympanic thermometer and rectal mercury thermometer. In a clinical setting the infrared ear thermometer has a very low sensitivity for detecting fever. Digital rectal thermometry seems to be a good alternative to the rectal mercury thermometer.