Effect of prone and supine positioning on the diaphragmatic work of breathing in convalescent preterm infants.

Abstract

To compare the work of breathing in the prone and supine positions in convalescent prematurely born infants. The work of breathing would be lower in the prone compared to the supine position. Prospective observational cohort study. Consecutive preterm infants breathing unsupported in room air with a gestational age of 28-34 weeks in a tertiary neonatal intensive care unit were studied before discharge from neonatal care. The diaphragmatic pressure time product (PTPdi) was used to assess the work of breathing, calculated as the integration of transdiaphragmatic pressure over the inspiratory time. The PTPdi was measured in prone, supine, and supine with 45°head-up tilt (supine-tilt) positions. The mean (SD) PTPdi was lower in the prone (259 [68] cm H2 O*s/min) compared with the supine position (320 [78] cm H2 O*s/min, p= .005). The mean (SD) PTPdi was lower in the supine-tilt position (262 [76] cm H2 O*s/min) compared with the supine position (p = .032). The PTPdi was not different between the prone and supine-tilt positions (p = .600). The difference in PTPdi between prone and supine was not independently associated with gestational age (standardized coefficient = 0.262, adjusted p= .335), birth weight (standardized coefficient = -0.249, adjusted p= .394) or postmenstrual age at study (standardized coefficient = -0.025, adjusted p= .902). In convalescent preterm neonates, the work of breathing may be lower in the prone and supine-tilt positions, compared withsupine.