Aim: To characterize the development of clinically relevant variables the first minutes after birth and identify early prognostic markers in newborn infants requiring resuscitation.
Methods: A database of 591 infants resuscitated with either 21% or 100% oxygen was analysed. Time to first breath, development in heart rate, Apgar scores, arterial oxygen saturation (SaO(2)), and base deficit (BD) are described in relation to different degrees of birth depression and outcomes.
Results: Heart rate and Apgar scores increased quickly even in the most depressed infants but were significantly lower in those having a poor outcome. By contrast, BD normalized at the same rate, 6-7 mmol/l/h, in the first hour of life regardless of the degree of birth depression and outcome. SaO(2) values increased as quickly in room air as in 100%-oxygen-resuscitated infants. Time to first breath was prolonged threefold, from 1 to 3 min, in the most depressed (1-min Apgar score < 4) compared with the less depressed infants. Highest odds ratio (OR) for death in the first week of life or for development of hypoxic-ischaemic encephalopathy (HIE) stage 2 and 3 was a 5-min heart rate < or =60 bpm (OR 16.5 for both death and HIE) and Apgar < 4 (OR 14 and 18.8). Neonatal survival for HIE stage 1, 2, and 3 was 93%, 63%, and 11%, respectively. OR for early neonatal death, if SaO(2) < or =60% at 1 min, was 8.6 (sensitivity 0.82 and specificity 0.65).
Conclusion: Apgar scores, heart rate, SaO(2), and time to first breath in newly born infants in need of resuscitation may be used for early identification of infants with a poor prognosis. These data may be helpful in describing the severity of depression in single infants and to select infants in need of interventional therapy.