Reference values of nocturnal oxygenation for use in outpatient oxygen weaning protocols in premature infants

Abstract

To define reference ranges for oxygen saturation (SpO(2) ) values in healthy full-term infants in the first days of life and in preterm infants off supplemental oxygen as they approach neonatal intensive care unit (NICU) discharge. From April 2009 to March 2010, we enrolled convenience samples of full-term infants from the newborn nursery and former preterm infants who did not require supplemental oxygen at the time of discharge from the NICU. Overnight SpO(2) and signal quality recordings were obtained and analyzed for duration of artifact-free recording time (AFRT), time (s) with SpO(2) less than several different target saturations (90-95%), and number of falls in SpO(2) by ≥4% and ≥10%. We studied 102 full-term infants and 52 preterm infants. Preterm and full-term infants spent similar amounts of time less than 90%, 91%, 92%, 93%, 94%, and 95% although preterm infants had more falls in SpO(2) by ≥4% per hour of AFRT. Over 67% of term and preterm infants spent less than 6% of their time below 93%. These data represent reference SpO(2) ranges for both preterm infants not requiring supplemental oxygen at NICU discharge and full-term infants in the first days of life. As we currently lack guidelines dictating the optimal target oxygen saturations for infants and the acceptable maximal time that they can safely spend below set target saturations, our data may serve as a guide to interpreting SpO(2) recordings of premature outpatient infants who are weaning from supplemental oxygen.