Efficacy of FiO2 increase during the initial resuscitation of premature infants < 29 weeks: an observational study.

OBJECTIVE To evaluate the heart rate (HR) and oxygen saturation (SpO2) at 15-second intervals within 60 seconds after incremental increases of fractional inspired oxygen (FiO2) during resuscitation of infants younger than 29 weeks requiring two different forms of ventilatory support. STUDY DESIGN Retrospective observational study. METHODS Forty-three infants were stabilized, 14 by continuous positive airway pressure exclusively (CPAP group), and 29 by positive pressure ventilation (PPV group). Both groups received ventilatory support in a special bed with two cameras enabling the evaluation of all interventions including HR, SpO2, FiO2, positive inflation pressure, and positive end-expiratory pressure values. FiO2 was commenced at 0.30 and titrated in 0.1-0.2 increments every 30-60 seconds. The relationships between the incremental increases of FiO2 and related SpO2 and HR changes were evaluated. RESULTS Although there was an inverse correlation between initial FiO2 and SpO2 in both groups, a significant positive correlation between the incremental increase of FiO2 and SpO2 changes after 30 seconds was found only in the CPAP group. Only higher initial levels of FiO2 had a positive effect on the improvement in SpO2 in the PPV group. CONCLUSION The efficacy of FiO2 titration in 0.1-0.2 increments may be attenuated and delayed in extremely preterm infants required PPV during the first 6 minutes of life.