What you need to know:
- A multicenter cohort study found that an expiratory tidal volume of 4 mL/kg is linked to successful lung aeration during delivery room resuscitation of preterm neonates.
- In both the primary and confirmatory datasets, achieving this tidal volume was associated with a sustained increase in heart rate to 100 beats per minute or more within the first 10 minutes after birth.
- The findings suggest that volume-targeted positive pressure ventilation strategies could guide safer and more effective respiratory support in extremely preterm infants, pending further clinical trials.
Results from a study recently published in JAMA Pediatrics revealed that a tidal volume of 4 mL/kg could be a data-based target for successful lung aeration of preterm neonates during delivery room resuscitation.
Respiratory targets and successful lung aeration
The investigators noted that lung aeration is the most critical task for preterm neonates amid the transition to the extrauterine environment, which requires the newborn to clear fetal lung fluid and establish functional residual capacity.1,2 With virtually all extremely preterm neonates requiring continuous positive airway pressure (CPAP) or positive pressure ventilation (PPV) to support this process, lungs could be highly susceptible to injury from barotrauma, volutrauma, and atelectrauma.1
"Current guidelines recommend initiating noninvasive PPV via face mask using peak inflation pressures of 20 to 25 cm H2O and titrating pressures based on clinical response," wrote the study authors. "However, optimal parameters of PPV inflations to successfully achieve lung aeration in preterm neonates remain undefined. Determining the volumes and pressures needed to aerate the lungs during neonatal transition may better inform physiologic targets for health care professionals to deliver safe and effective PPV during neonatal resuscitation."
To determine respiratory parameters associated with successful lung aeration during delivery room resuscitation, the authors conducted a multicenter, prospective cohort study with a primary population of preterm neonates. The population was from 3 centers of 22 weeks to 31 weeks 6 days’ gestation with bradycardia who received PPV during resuscitation after birth. A confirmatory data set was included, which featured an independent population of preterm neonates aged 24 weeks to 27 weeks 6 days’ gestation.
The primary outcome of the study was a sustained increase in heart rate to at least 100 beats per minute, which indicated effective lung aeration, within the first 10 minutes of resuscitation. Rolling means of pressure, inspiratory and expiratory tidal volumes (VTE), and mask leak, as measured with a respiratory function monitor (RFM), were exposures.
Minimum VTE of 4 mL/kg linked to successful lung aeration
The primary dataset comprised 132 neonates with a median (IQR) gestational age of 26.6 [25.1-29.2] weeks, of whom 50.8% were male. Additionally, there were 115 neonates in the confirmatory dataset, median [IQR] gestation, 26.7 [25.6-27.4] weeks; 65 [56.5%] male.
Of the 132 primary dataset neonates, 125 achieved the primary outcome of sustained increase in heart rate of at least 100 beats per minute. Of the measured parameters, only VTE was associated with an increase in heart rate, with an adjusted hazard ratio (AHR) of 1.10 (95% CI, 1.01-1.20). AHR was higher for VTE increases up to mL/kg (AHR, 1.55 [95% CI, 1.20-2.00]) than for VTEs higher than 4 mL/kg (AHR, 1.04 [95% CI, 0.98-1.10]), results demonstrated. Results from the confirmatory dataset were consistent with these findings.
The median time followed, the time for heart rate to be 100 or more beats per minute or time until censored, was 116.5 (68.5-174.2) seconds from the start of resuscitation. Of the 7 neonates who did not achieve an increase in heart rate during the measurement period:
- Three achieved increase heart rate after 10 minutes
- Two died during resuscitation
- Two recordings were stopped early because of an increase in heart rate
"This cohort study observed in one population and confirmed in another a minimum expiratory tidal volume associated with successful lung aeration during preterm neonate resuscitation," the study authors concluded. "Further clinical trials are needed to establish the utility of volume-targeted resuscitation in preterm neonates."
References:
- Rub DM, Hsu JY, Weinberg DD, et al. Respiratory Targets Associated With Lung Aeration During Delivery Room Resuscitation of Preterm Neonates. JAMA Pediatr. Published online August 11, 2025. doi:10.1001/jamapediatrics.2025.2521
- Morton SU, Brodsky D. Fetal physiology and the transition to extrauterine life. Clin Perinatol. 2016;43(3):395-407. doi:10.1016/j.clp.2016.04.001
