The accuracy of a new infrared ear thermometer in patients undergoing cardiac surgery

Purpose: To evaluate the equivalency of the prototype of a new infrared ear thermometer (IRT 4000) in comparison to the temperature measurements of a pulmonary artery catheter (PAC) and a continual contact probe on the tympanic membrane. Methods: After approval by the local Ethics Committee, 26 (six female and 20 male) patients undergoing elective cardiac surgery were included in a single center open trial. During surgery, temperature measurements were recorded with the IRT 4000 in the left ear, and with a tympanic contact probe in the right ear, as well as with a PAC as reference. Measurements with the infrared ear thermometers and continual PAC values were recorded every six minutes. Results: The average temperature measured with the IRT 4000 was 0.08 degrees C above the temperature of the PAC (95% confidence interval from -0.44-0.61 degrees C). Conclusion: Infrared ear thermometers 4000 temperature readings accurately reflect body core temperature and correlate well with the invasive PAC. Infrared ear thermometers may present a clinically useful alternative to the pulmonary artery thermometry for the measurement of core temperature in the perioperative setting or in the intensive care unit.