Use of modified infrared aural canal thermometers during cardiac surgery
Kawamura, A.; Matsukawa, T.; Ozaki, M.; Okuyama, K.; Ohkawa, I.; Kumazawa, T.
Masui. Japanese Journal of Anesthesiology 49(7): 792-795
2000
ISSN/ISBN: 0021-4892 PMID: 10933038 Document Number: 525875
Two kinds of modified infrared aural canal thermometers (Mimippi(R), Superthermo(R)) are currently available in Japan. We therefore evaluated their accuracy and precision for clinical use. For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was examined from the standard deviation of the difference between the test and reference values. We evaluated ten patients for cardiopulmonary bypass surgery under mild hypothermia (approximately 32degreeC). Aural canal temperatures were measured in a random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane. Compared with the thermocouple, the Mimippi(R) had regression slope 0.87 and correlation coefficient 0.79. In contrast, slope of the Superthermo(R) regression was 0.74. The correlation coefficient for the Superthermo(R) was 0.71. The accuracy (offset, or bias) was 0.91degreeC with the Mimippi(R). In contrast, it was 1.32degreeC with the Superthermo(R). The precision (standard deviation) of the Mimippi(R) was 0.65. In contrast, it was 0.73degreeC with the Superthermo(R). We conclude that both thermometers were moderately accurate and precise for perioperative use.