Axillary and Rectal Temperature Measurements Poorly Agree in Newborn Infants

Abstract

Aim: 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°C, p < 0.05). The ‘95% limits of agreement’ ranged from –0.13 to +0.67°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.

Axillary and rectal thermometry in the newborn: do they agree?

“…In the study of Friedrichs et al [10], temperature obtained from the left axilla had higher correlation with rectal measurements as compared to that of the right axilla. Our results also contradict those of Hissink et al [6], Hutton et al [7], and Lee et al [9]. Comparing the agreement between axillary and rectal thermometry using the Bland-Altman method, all above studies reported significant differences in healthy and sick term and preterm neonates (range: 25–42 weeks gestation), including those in NICU settings.…”

“…Comparing the agreement between axillary and rectal thermometry using the Bland-Altman method, all above studies reported significant differences in healthy and sick term and preterm neonates (range: 25–42 weeks gestation), including those in NICU settings. Moreover, Hissink et al found that axillary temperature was lower than rectal ones, and that increasing postnatal age increased the difference between the two measurements [6]. …”

A comparison of axillary with rectal thermometry in under 5 children

“…In the neonates, however, the findings are not uniform. While this present study and some other studies510 have found significant mean differences between the rectal and axillary temperatures in neonates, another11 found no significant difference. This raises another question as to whether the axillary route is accurate enough to be used as a surrogate to rectal thermometry in neonates in whom rectal thermometry is avoided because of accidents like perforations 12…”

Can skin temperature replace rectal temperature monitoring in babies undergoing therapeutic hypothermia in low‐resource settings?

“…and Muller et al. (11,12)found poor agreement between axillary and rectal temperatures. A systematic review of nine studies comparing axillary vs. rectal showed mean difference of 0.17°C with the limits of agreement of 0.15–0.5 °C, which may be acceptable in normothermic babies (9).…”