Pulse oximetry, severe retinopathy, and outcome at one year in babies of less than 28 weeks gestation

Abstract

Aim: To determine whether differing policies with regard to the control of oxygen saturation have any impact on the number of babies who develop retinopathy of prematurity and the number surviving with or without signs of cerebral palsy at one year.

Methods: An examination of the case notes of all the 295 babies who survived infancy after delivery before 28 weeks gestation in the north of England in 1990-1994.

Results: Babies given enough supplemental oxygen to maintain an oxygen saturation of 88-98%, as measured by pulse oximetry, for at least the first 8 weeks of life developed retinopathy of prematurity severe enough to be treated with cryotherapy four times as often as babies only given enough oxygen to maintain an oxygen saturation of 70-90% (27.2% v 6.2%). Surviving babies were also ventilated longer (31.4 v 13.9 days), more likely to be in oxygen at a postmenstrual age of 36 weeks (46% v 18 %), and more likely to have a weight below the third centile at discharge (45% v 17%). There was no difference in the proportion who survived infancy (53% v 52%) or who later developed cerebral palsy (17% v 15%). The lowest incidence of retinopathy in the study was associated with a policy that made little use of arterial lines.

Conclusions: Attempts to keep oxygen saturation at a normal "physiological" level may do more harm than good in babies of less than 28 weeks gestation.