Predictors of 24-hour Outcome in Newborns In Need of Positive Pressure Ventilation at Birth.

Background: Birth asphyxia, defined as 5-minute Apgar score < 7 in apneic newborns, is a major cause of newborn mortality. Heart rate (HR) response to ventilation is considered an important indicator of effective resuscitation. Objectives: To describe the relationship between initial HR in apneic newborns, HR responses to ventilation and 24-h survival or death. Methods: In a Tanzanian hospital, data on all newborns >= 34 weeks gestational age resuscitated between June 2013-January 2017 were recorded using self-inflating bags containing sensors measuring ventilation parameters and expired CO2, dry-electrode electrocardiography sensors, and trained observers. Results: 757 newborns of gestational age 38 +/- 2 weeks and birthweight 3131 +/- 594 g were included; 706 survived and 51 died. Fetal HR abnormalities (abnormal, undetectable or not assessed) increased the risk of death almost 2-fold (RR = 1.77; CI: 1.07, 2.96, p = 0.027). For every beat/min increase in first detected HR after birth the risk of death was reduced by 2% (RR = 0.98; CI: 0.97, 0.99, p < 0.001). A decrease in HR to < 100 beats/minute when ventilation was paused increased the risk of death almost 2-fold (RR = 1.76; CI: 0.96, 3.20, p = 0.066). An initial rapid increase in HR to > 100 beats/min in response to treatment reduced the risk of dying by 75% (RR = 0.25; CI: 0.14, 0.44, p < 0.001). A 1% increase in expired CO2 was associated with 28% reduced risk of death (RR = 0.72; CI: 0.62,0.85, p < 0.001). Conclusions: The risk of death in apneic newborns can be predicted by the fetal HR (absent or abnormal), initial newborn HR (bradycardia), and the HR response to ventilation. These findings stress the importance of reliable fetal HR monitoring during labor and providing effective ventilation following birth to enhance survival.