Significance of Intermittent Hypoxic Episodes in Premature Infants Prior to Discharge

Abstract

Objective The aim of this study was to determine the rate and severity of intermittent hypoxic episodes in premature infants who underwent overnight pulse oximetry prior to discharge. Methods Preterm infants with a birth weight of 1500 grams or less and who underwent overnight pulse oximetry prior to discharge were included. Maternal and neonatal demographic data and complications of prematurity were recorded. All infants underwent overnight pulse oximetry prior to discharge and the McGill score was used to categorize the degree of desaturations (categories 1-4; normal, mildly, moderately, and severely abnormal). Results Fifty infants underwent the overnight pulse oximetry The McGill score showed that 2% had no hypoxia, 50% had mild hypoxia, 20% had moderate hypoxia, and 28% had severe hypoxia. The frequency of desaturations (62.5%) was found more in infants with a birth weight of 1000 grams or less. The results showed that the O2 requirement at discharge was significant (p = 0.0341), and increased values of O2 at discharge were associated with more severe hypoxia. As a result of these findings, 40% of infants were discharged home on oxygen and 26% were discharged on caffeine. Fifty-two percent of infants were initially diagnosed to have stages 1 & 2 retinopathy of prematurity (ROP), 14% had stage 3, and 2% had stage 4 ROP. Eight percent of infants required surgical intervention for ROP. Conclusions Clinically inapparent significant episodes of intermittent hypoxia (IH) are frequent in preterm infants in the early postnatal age, and they may persist post-discharge. Knowledge of the association between IH and morbidity among all neonatal intensive care unit (NICU) caregivers would be of great benefit. Indications for screening preterm infants at risk of severe IH should be reconsidered.