Comparison of Tympanic, Axillar and Rectal Temperature Measurements in Newborns

Background: A tympanic membrane temperature measurements are in routine use also in neonates. Aim of our research was to evaluate the correlation between temperature measu­rements in the ear, axilla and in rectum of new-born infants.

Methods: 27 term infants (11 girls and 16 boys) who were hospitalised at the Neonatal Unit of the Paediatric Department in Ljubljana were included in study. All measurements of left and right ear, axilla and rectal temperature took place in incubator in thermally con­trolled environment. One hour after the first measurement the second measurement were repeated on the same places with the same instruments.

Results: The differences of the temperature measurements between left and right ear were on average 0.4 °C (with standard deviation ±0.3 °C). The differences of the temperature mea­surements in ear with one hour interval were on average 0.3 °C (±0.2 °C), in axilla 0.06 °C (±0,1 °C) and in rectum 0.09 °C (±0.1 °C). The difference between simultaneous tempera­ture measurements in ear and in the rectum were on average 0.4 °C (±0.25 °C). The differences between under the same conditions measured temperature at the axilla and rectum were on average 0.4°C (±0.22°C).

Conclusion: Taking newborn’s temperature from the ear or axilla is not very unpleasant for the infant, but the results of our and other published studies show that it could be unre­liable in comparison with the rectal temperature measurement.