RELATIVE HUMIDITY(RH), TEMPERATURE(T), AND DISTURBANCE RESPONSE UNDER A RADIANT WARMER(RW) ARE AFFECTED BY SUPPLEMENTAL AIR TEMPERATURE AND FLOW.|[dagger]| 1449

Many nurseries provide supplemental humidity(SH) to premature infants under RWs to limit water and heat loss. Optimal airflow and T settings, and resultant RH and T are not known. The purpose of this study was to measure the effect of different Ts and airflows from a SH source on resultant RH and T of an enclosed RW environment. A RW was servo controlled to simulate normal clinical heat output and PVC film was stretched over the side walls. A Pediatric Conchatherm heater humidifier supplied airflow at 5 and 10 LPM and T at 34° and 38°C. Resultant T and RH were measured when stable with PVC, for 5 minutes without PVC, and for 10 minutes following PVC replacement. Ambient RH was 55% and T 24.5°C. RH was 34.9% and T was 32.7°C with PVC and no heater humidifier. The graph shows stable pre-disturbance values(zero time) and disturbance response. The combination of 38°C and 10 LPM gave the highest pre-disturbance RH(74.5%) and T(33.8°C), double the RH and 1.1°C higher T compared with unsupplemented air, and the quickest return toward baseline after PVC replacement. SH can substantially reduce evaporative water and heat loss of extremely immature infants under RWs by increasing RH, but appropriate settings are needed to fully utilize this equipment. Figure