Axillary and rectal temperature measurements poorly agree in newborn infants.
OBJECTIVE
Evaluation of the agreement between axillary temperature measurements and rectal temperature measurements in neonates.


METHODS
Rectal and axillary body temperatures were simultaneously measured for 3 min in 33 neonates (gestational age 25-42 weeks, weight 840-4,005 g). Two investigators performed paired measurements, one in each neonate. A single type of thermometer was used in this study: one thermometer for each rectal and another thermometer for each axillary measurement. The Bland-Altman method was used (95% 'limits of agreement': mean +/- 2 SD) to determine the level of agreement between axillary and rectal measurements.


RESULTS
The axillary temperature was significantly lower than the rectal temperature (mean +/- SD 0.27 +/- 0.20 degrees C, p < 0.05). The '95% limits of agreement' ranged from -0.13 to +0.67 degrees C. Increasing postnatal age (days) showed a significant increase in temperature difference (rectal minus axillary; r = 0.54; p < 0.05).


CONCLUSIONS
The mean difference between axillary and rectal temperature shows a wide variation. Axillary temperature measurements cannot be used interchangeably with rectal measurements in neonates.
Hissink Muller
P C E
PC
Neonatal Unit, Juliana Children's Hospital, The Hague, The Netherlands. p.hissinkmuller@lumc.nl
van Berkel
L H
LH
de Beaufort
A J
AJ
D001365:Axilla / Q000502:physiology*; D001831:Body Temperature / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D007234:Infant, Premature / Q000502:physiology*; D012007:Rectum / Q000502:physiology*; D015203:Reproducibility of Results; D013821:Thermometers