Infrared tympanic thermometry in the pediatric intensive care unit

To determine the performance of two different commercially available, noncontact infrared tympanic thermometers in predicting core body temperature as measured by pulmonary artery catheters in pediatric intensive care unit (ICU) patients. The performance of the tympanic thermometers was compared with the performance of an indwelling rectal probe and digital axillary temperature determinations.

Prospective, consecutive sample, unblinded study.

Pediatric ICU of a tertiary care children's hospital.

Twenty patients requiring pulmonary artery catheter monitoring for clinical management.

Temperature measurements were made using each infrared tympanic thermometer unit in the core mode. These values were compared with simultaneously obtained pulmonary arterial, digital axillary, and rectal probe temperatures.

Bias and variability of each method compared with the pulmonary arterial temperature were calculated. Bias did not vary with temperature measured or age of the patient. Indwelling rectal probes showed the least bias and variability and axillary temperature the most. Neither infrared tympanic thermometer had clinically important bias; one model had variability similar to that of the rectal probes, and the other model had significantly greater variability.

In a pediatric ICU population, rectal probes reflect core temperature better than axillary determinations and both infrared tympanic models estimated core body temperature better than digital axillary temperature. One of the tympanic systems (Thermoscan Pro-1 infrared tympanic thermometer) performed in a similar way to the indwelling rectal probes and may be used to estimate core temperature in situations where a pulmonary artery catheter is not in place. The other test tympanic system (First Temp) had greater variability than the rectal probes.