Expiratory CO2 as the first sign of successful ventilation during neonatal resuscitation

Three‐lead electrocardiography and expired CO₂ monitoring were used during positive pressure ventilation of seven non‐intubated newborns (gestational age, 31–37 weeks; birthweight, 1503–2885 g). In all cases, adequate CO₂ (>15 mmHg) was detected prior to the achievement of stable heart rate (>100 beats/min). The delay between detection of adequate CO₂ and improvement of bradycardia ranged from 8 to 73 s (median, 15 s). Inadequate expired CO₂ during positive pressure ventilation indicates airway obstruction or poor aeration of the newborn lungs. Thus, positive expiratory CO₂ can be the first recognizable sign of successful ventilation during neonatal resuscitation.