Supplementary Material for: Colorimetric CO2 Detector to Improve Effective Mask Ventilations in Very Preterm Infants: A Pilot Randomized Controlled Study

Introduction: End tidal CO2 (ETCO2) detector is currently recommended for confirmation of endotracheal tube placement during neonatal resuscitation. Whether it is feasible to use ETCO2 detectors during mask ventilation to reduce risk of bradycardia and desaturations, which are associated with increased risk of death in preterm babies, is unknown.
Methods : This is a pilot randomized controlled trial ((NCT04287907) involving newborns 24+0/7 to 32+0/7 weeks gestation who required mask ventilation at birth. Infants were randomized into groups with or without colorimetric ETCO2 detectors. Combined duration of any bradycardia (<100bpm) and time below prespecified target oxygen saturations (SpO2) as measured by pulse oximetry were compared.
Results : Fifty participants were randomized, 47 with outcomes analysed (2 incomplete data, 1 postnatal diagnosis of trachea-esophageal fistula). Mean gestational age and birthweight were 28.5±1.9 vs 29.4±1.6 weeks, (p=0.1) and 1252.7±409.7g vs 1334.6±369.1g, (p=0.5) in the intervention and control arm respectively. Mean combined duration of bradycardia and desaturation was 276.7±197.7s (intervention) and 322.7±277.7s (control),(p=0.6). Proportion of participants with any bradycardia or desaturation at 5 minutes were 38.1% (intervention) and 56.5% (control), (p=0.2). No chest compressions, epinephrine administration or death occurred in the delivery room.
Conclusion: This pilot study demonstrates that the feasibility of a trial to evaluate colorimetric ETCO2 detectors during mask ventilation of very preterm infants to reduce bradycardia and low SpO2. Further assessment with a larger population will be required to determine if ETCO2 detectors usage at resuscitation reduces risk of adverse outcomes, including death and disability, in very preterm infants.