The Breathing Effort of Very Preterm Infants at Birth

Abstract

Objective: To compare the respiratory effort of very preterm infants receiving positive pressure ventilation (PPV) with infants breathing on continuous positive airway pressure (CPAP), directly after birth.

Study design: Recorded resuscitations of very preterm infants receiving PPV or CPAP after birth were analyzed retrospectively. The respiratory effort (minute volume and recruitment breaths [>8 mL/kg], heart rate, oxygen saturation, and oxygen requirement were analyzed for the first 2 minutes and in the fifth minute after birth.

Results: Respiratory effort was analyzed in 118 infants, 87 infants receiving PPV and 31 infants receiving CPAP (median gestational age, 28 weeks [IQR, 26-29] vs 29 weeks [IQR, 29-30; P < .001); birth weight, 1059 g [IQR, 795-1300] vs 1205 g [IQR, 956-1418; P = .06]). The minute volume of spontaneous breaths of infants receiving PPV was lower at 2 minutes (37 mL/kg/minute [IQR, 15-69] vs 188 mL/kg/minute [IQR, 128-297; P < .001]) and at 5 minutes (112 mL/kg/minute [IQR, 46-229] vs 205 mL/kg/minute [IQR, 174-327; P < .001]). Recruitment breaths occurred less in the PPV group at 2 minutes (0 breaths/minute [IQR, 0-1] vs 4 breaths/minute [IQR, 1-8; P < .001]) and 5 minutes (0 breaths/minute [IQR, 0-3] vs 2 breaths/minute [IQR, 0-11; P = .01). The heart rate was lower in the PPV group (94 beats/minute [IQR, 68-128] vs 124 beats/minute [IQR, 100-144; P = .02]) as was oxygen saturation (50% [IQR, 35%-66%] vs 67% [IQR, 34%-80%; P = .04]), but not different at 5 minutes (heart rate, 149 beats/minute [IQR, 131-162] vs 150 beats/minute [IQR, 132-160; P = NS]; oxygen saturation , 91% [IQR, 80%-95%] vs 92% [IQR, 89%-97%; P = NS]). The oxygen requirement was higher (at 2 minutes, 30% [IQR, 21%-53%] vs 21% [IQR, 21%-29%; P = .05]; at 5 minutes, 39% [IQR, 22%-91%] vs 22% [IQR, 21%-31%; P = .003]).

Conclusion: Very preterm infants breathe at birth when receiving PPV, but the respiratory effort was significantly lower when compared with infants receiving CPAP only. The reduced breathing effort observed likely justified applying PPV in most infants.

Keywords: birth; breathing effort; preterm infant; resuscitation.