Body temperature measurement in VLBW infants by continuous skin measurement is a good or even better alternative than continuous rectal measurement

Background: An inadequate body temperature in preterm infants influences morbidity and mortality. Continuous rectal measurement is a reliable method to measure body temperature but might have adverse effects and is even contra‐indicated in case of low platelets or necrotising enterocolitis. A save and non‐invasive method to measure body temperature is the transcutaneous ‘zero heat flow’ method. Aim: We hypothesised that for monitoring body temperature in very low birth weight (VLBW) infants, central measurement of temperature by way of the zero heat flow principle is just as reliable as rectal temperature. Methods: Twenty‐six infants, birth weight between 520 g and 1250 g, gestational age 25.28–32.28 weeks were provided with an insulated continuous skin probe with ‘zero heat flow’ and a continuous rectal probe. Both measurements were registered every hour over a period of 48 h. The sample size was calculated to detect a difference of less than or equal to 0.20°C. Results: 1205 of the 1248 temperature measurements were analysed. At any moment, skin temperature was higher or equal when compared to rectal temperature. Mean skin temperature was 0.13°C (SD 0.33) higher than mean rectal temperature (t‐test, p < 0.001). Correlation between rectal and skin temperature was 0.82 (p ≤ 0.05). Conclusion: In VLBW infants, temperature measurement by ‘zero heat flow’ method is just as reliable as by rectal method.