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

Abstract

Objectives To compare the work of breathing in the prone and supine positions in convalescent prematurely born infants. Working Hypothesis The work of breathing would be lower in the prone compared to the supine position. Study Design Prospective observational cohort study. Patient‐Subject Selection 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. Methodology 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. Results The mean (SD) PTPdi was lower in the prone (259 [68] cm H2O*s/min) compared with the supine position (320 [78] cm H2O*s/min, p= .005). The mean (SD) PTPdi was lower in the supine‐tilt position (262 [76] cm H2O*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). Conclusions In convalescent preterm neonates, the work of breathing may be lower in the prone and supine‐tilt positions, compared with supine.

Patient positioning and its impact on perioperative outcomes in children: A narrative review

“…24 More recently, infants' diaphragmatic work of breathing and inspiratory pressure was found to be significantly lower in both prone and supine 45° head up positions compared to supine. 30,42 The effects of intraoperative positioning on respiratory physiology in children has also been investigated. Head-down ("Trendelenburg") positioning reduces respiratory compliance, tidal volume 35 and significantly reduces functional residual capacity and ventilation homogeneity in children under general anesthesia.…”

“…Respiratory patterns in awake, spontaneously breathing neonates may also be affected by positioning, with a 20° head‐up tilt shown to increase tidal volume but reduce respiratory rate, with a small net reduction in minute ventilation 24 . More recently, infants' diaphragmatic work of breathing and inspiratory pressure was found to be significantly lower in both prone and supine 45° head up positions compared to supine 30,42 …”

Pediatric pulmonology year in review 2021 and 2022: Physiology

“…Prone positioning of preterm infants has been associated with improved oxygenation and respiratory mechanics, but the effect of changing body position on diaphragm activity has not been well defined. Dimitriou et al 57 if not, either through auscultation, a drop in oxygen saturation, or an increase in RR ≥ 50% from baseline. A positive adenosine test was associated with a significantly higher odds ratio (6.34) of asthma diagnosis at school age, while a positive methacholine test was not.…”

“…Prone positioning of preterm infants has been associated with improved oxygenation and respiratory mechanics, but the effect of changing body position on diaphragm activity has not been well defined. Dimitriou et al 57 hypothesized that the diaphragmatic work of breathing in preterm infants is lower in the prone position compared to supine. To test this hypothesis, they measured the diaphragmatic pressure‐time product (PTPdi) in 40 preterm infants in room air.…”

Higher awakening threshold of preterm infants in prone position may be a risk factor for SIDS

“…The prone position may still offer some physiological advantages. Ventilated neonates showed improved oxygenation, 6 reduced need for supplemental oxygen, 7 reduced work of breathing 8 and faster recovery from respiratory disease 2 . Furthermore in these neonates, a reduced number and density of apnoeas was observed 3,4 .…”