The Administration of 100% Oxygen and Respiratory Drive in Very Preterm Infants at Birth

AIM: To retrospectively investigate the changes of SpO(2) and respiratory drive in preterm infants at birth after administration of 100% oxygen. METHODS: Respiratory parameters, FiO(2) and oximetry of infants <32 weeks gestation before and after receiving FiO(2) 1.0 were reviewed during continuous positive airway pressure (CPAP) or positive pressure ventilation (PPV). RESULTS: Results are given as median (IQR) or percentages where appropriate. Suitable recordings were made in 50 infants (GA 27 (26–29) weeks), 17 received CPAP and 33 PPV. SpO(2) increased rapidly in the first minute after FiO(2) 1.0 and remained stable. The duration of FiO(2) 1.0 tended to be shorter in the CPAP group than in the PPV group (CPAP vs. PPV: 65 (33–105) vs. 100 (40–280) s; p = 0.05), SpO(2) >95% occurred more often in PPV group (53% vs. 69%) and lasted longer (70(40–95) vs. 120(50–202) s). In CPAP group, minute volume increased from 134 (76–265) mL/kg/min 1 minute before to 240 (157–370) mL/kg/min (p<0.01) 1 minute after start FiO(2) 1.0 and remained stable at 2 minutes (252 (135–376) mL/kg/min; ns). The rate of rise to maximum tidal volume increased (from 13.8 (8.0–22.4) mL/kg/s to 18.2 (11.0–27.5) mL/kg/s; p<0.0001) to 18.8 (11.8–27.8) mL/kg/s; ns). In the PPV group respiratory rate increased from 0(0–4) to 9(0–20) at 1 minute (p<0.001) to 23 (0–34) breaths per minute at 2 minutes (p<0.01). CONCLUSION: In preterm infants at birth, a rapid increase in oxygenation, resulting from a transient increase to 100% oxygen might improve respiratory drive, but increases the risk for hyperoxia.