Objectives: To determine the accuracy of noninvasive infrared temporal artery thermometry compared with rectal, axillary, and pulmonary artery catheter measurements in pediatric intensive care patients, and to determine whether temporal artery temperatures are affected by circulatory shock or by vasopressor use. We hypothesized that temporal artery temperatures do not differ from axillary and rectal temperatures in critically ill children, but temporal artery accuracy is decreased by shock or vasopressor use.
Design: Observational study, unblinded.
Setting: Pediatric intensive care unit of a quarternary referral children's hospital.
Patients: Seventy-five temperature comparison pairs were obtained in 44 pediatric intensive care unit patients.
Interventions: Temperature measurements were made using a temporal artery thermometer with simultaneously obtained rectal, axillary, and, when available, pulmonary artery catheter measurements.
Measurements and main results: Mean bias was calculated between comparison pairs using each temperature method. Bland-Altman analysis demonstrated wide variability between methods. No significant differences in mean bias were seen between method pairs for all temperatures, but bias was significantly less in pulmonary artery catheter-rectal pairs compared with other method pairs. In febrile (> 38 degrees C) patients, bias in rectal-temporal artery and rectal-axillary was significantly greater than in temporal artery-axillary pairs (p < .001). Mean bias in pulmonary artery catheter-rectal pairs was also significantly smaller than in other pairs for all patients (p = .008) and febrile patients (p = .049). Presence of shock or vasopressor use did not significantly increase bias in any comparison pair. Sensitivity and specificity of both temporal artery and axillary for diagnosing fever were similar and improved with fever definition at temperatures > 38.5 degrees C.
Conclusions: Temporal artery and axillary temperature measurements showed variability to rectal temperatures but had marked variability in febrile children. Neither was sufficiently accurate to recommend replacing rectal or other invasive methods. As temporal artery and axillary provide similar accuracy, temporal artery thermometers may serve as a suitable alternative for patients in whom invasive thermometry is contraindicated.