Accuracy of digital tympanic, oral, axillary, and rectal thermometers compared with standard rectal mercury thermometers

Abstract

Objective: To compare a number of electronic tympanic, oral, axillary, and rectal measurements with those taken with a standard rectal mercury thermometer.

Design: Prospective open study.

Setting: County hospital, Denmark.

Subjects: 200 patients.

Interventions: Each of 200 patients had 6 electronic measurements of body temperature: 3 in the auditory canal using Ivac Core Check 2090A, Diateck 9000, and Genius 3000A, 1 in the axilla using Terumo Digital C202. 1 in the mouth using Terumo Digital C402, and 1 in the rectum using a Terumo Digital C402. These were compared with readings from a standard mercury glass thermometer in the rectum.

Main outcome measures: Accuracy of electronic thermometry.

Results: The rectal electronic measurements were closest to the rectal mercury readings, with a mean (SD) of -0.05 degrees C (0.12), whereas the other measurements gave unacceptable SDs of temperature differences ranging from 0.41 degrees C to 0.53 degrees C.

Conclusions: We conclude that electronic rectal temperature measurements are the most accurate. We do not recommend electronic tympanic, oral, or axillary measurements.