Oxygen and Resuscitation: Saturations, Oxidative Stress and Outcomes in Premature Infants

Vasantha H.S. Kumar*

Oxygen and Resuscitation: Saturations, Oxidative Stress and Outcomes in Premature Infants.

Fetus develops in a relatively hypoxemic environment in utero, however they need supplemental oxygen at birth when born prematurely ≤32 weeks’ gestation. Reduced antioxidant defenses from lack of induction of antioxidant enzymes at birth, predispose premature infant susceptible to toxic effects of oxygen such as bronchopulmonary dysplasia and brain injury. Studies have demonstrated that even short exposures to 100% oxygen at birth could have long term implications.

Fetus develops in a hypoxemic environment in utero and an abrupt transition to a normoxicextra-uterine environment can generate a physiologic oxidative stress even in term infants. Premature infants <32 weeks’ gestation, with functional and structural immaturity of the cardio-pulmonary system often require resuscitation at birth, which includes administration of supplemental oxygen.

The guidelines recommend preductal SpO2 of 60%- 65% at 1 min; 65%-70% at 2nd min; 70%-75% at 3rd min; 75%- 80% at 4th min and 80%-85% at the end of 5 minutes. The SpO2 values between 5 and 10 minutes after birth to be 85%-95%.9 The SpO2 guidelines were applicable for both term and premature infants, to be achieved by initiating resuscitation with air or blended oxygen and titrating the oxygen concentration to achieve a SpO2 in the target range using pulse oximetry.

Even though, antenatal steroids, gentle ventilation techniques and surfactant administration have
decreased the incidence and severity of BPD in more mature infants, it is still a major problem in extremely low birth weight infants.

Whether the oxygen load as determined by the concentration of oxygen delivered at resuscitation predisposes to BPD is not clear. Resuscitation studies have addressed this issue with BPD as the primary outcome measure (Table 3). There are conflicting results on the effects of oxygen concentration at resuscitation and BPD.

Pediatr Neonatal Nurs Open J. 2016; 3(1): 20-26. doi: 10.17140/PNNOJ-3-121