Outcomes of delivery room resuscitation of bradycardic preterm infants: A retrospective cohort study of randomised trials of high vs low initial oxygen concentration and an individual patient data analysis.

Abstract

To determine whether hospital mortality (primary outcome) is associated with duration of bradycardia without chest compressions during delivery room (DR) resuscitation in a retrospective cohort study of randomized controlled trials (RCTs) in preterm infants assigned low versus high initial oxygen concentration. Medline and EMBASE were searched from 01/01/1990 to 12/01/2020. RCTs of low vs high initial oxygen concentration which recorded serial heart rate (HR) and oxygen saturation (SpO₂) during resuscitation of infants <32 weeks gestational age were eligible. Individual patient level data were requested from the authors. Newborns receiving chest compressions in the DR and those with no recorded HR in the first 2 min after birth were excluded. Prolonged bradycardia (PB) was defined as HR < 100 bpm for ≥2 min. Individual patient data analysis and pooled data analysis were conducted. Data were collected from 720 infants in 8 RCTs. Neonates with PB had higher odds of hospital death before [OR 3.8 (95% CI 1.5, 9.3)] and after [OR 1.7 (1.2, 2.5)] adjusting for potential confounders. Bradycardia occurred in 58% infants, while 38% had PB. Infants with bradycardia were more premature and had lower birth weights. The incidence of bradycardia in infants resuscitated with low (≤30%) and high (≥60%) oxygen was similar. Neonates with both, PB and SpO₂ < 80% at 5 min after birth had higher odds of hospital mortality. [OR 18.6 (4.3, 79.7)]. In preterm infants who did not receive chest compressions in the DR, prolonged bradycardia is associated with hospital mortality.