NEUTRAL THERMAL CONDITIONS IN VLBW INFANT S CARED FOR AN OPEN BED UNDER AN INFRARED WARMING-UNIT

Background: Radiant warmers can be used to maintain body temperature O f premature infants. The performance of a heating device was evaluated in respect to neutral thermal environment, the levels of skin and rec tal temperature, and the behaviour of infants nursed on an open radian t warmer bed. Methods: Rectal, shoulder-mattress, abdominal, and foot temperatures were measured in 12 VLBW infants in 1 minute intervals us ing thermistors (YSI). We measured radiant power density (mW/cm2) usin g a thermopile (Eppley E6) and calculated net radiant power (W/kg) nec essary to reach and maintain neutral thermal conditions. The babies' b ehaviour was assessed using a scale (1-4) for recording activity. Resu lts: Rectal temperature was normal (median 37.1-degrees-C) and con-ela ted with shoulder-mattress temperature (p<0.01) which was almost ident ical (median 37.2-degrees-C). Abdominal skin temperature was 36.8-degr ees (median), mean skin temperature was 36.6-degrees-C (median). Neutr al thermal conditions could be maintained with only minor fluctuations of rectal and skin temperatures. Radiant warmer power density was 10. 26-1.41 (median 11.33) MW/cm2, net radiant power recieved was 2.74-3.7 3 (median 3.24) W/kg. A significant negative linear correlation was fo und between net radiant power and body weight (p=0.0006). 11 of 12 inf ants spent most of the time in quiet sleep. Conclusions: VLBW infants, older than 3 days of life, could be cared for under neutral thermal c onditions in open radiant warmer beds, delivering relatively low radia nt power density.