Objective: To evaluate the heart rate (HR) and oxygen saturation (SpO(2)) at 15-second. intervals within 60 seconds after incremental increases of fractional inspired oxygen (FiO(2)) 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, SpO(2), FiO(2), positive inflation pressure, and positive end-expiratory pressure values.
FiO(2) was commenced at 0.30 and titrated in 0.1-0.2 increments every 30-60 seconds. The relationships between the incremental increases of FiO(2) and related SpO(2) and HR changes were evaluated.
Results: Although there was an inverse correlation between initial FiO(2) and SpO(2) in both groups, a significant positive correlation between the incremental increase of FiO(2) and SpO(2) changes after 30 seconds was found only in the CPAP group. Only higher initial levels of FiO(2) had a positive effect on the improvement in SpO(2) in the PPV group.
Conclusion: The efficacy of FiO(2) 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.