Accuracy of pulse oximetry in hypothermic neonates and infants undergoing cardiac surgery

Abstract
To assess the accuracy of pulse oximetry under hypothermic conditions in neonates and infants undergoing cardiac surgery, and to assess the effect of probe site as well as probe site skin temperature on the reliability of pulse oximetry. Prospective Study. Cardiac operating room and intensive care unit of children's hospital. Twenty-five infants +3% or <-3%) in 45.5% of the readings at foot probe site temperatures of 29 degrees. There was no significant difference between oximeter readings obtained from two probe sites (hand and foot). Administration of phenoxybenzamine improved the accuracy of pulse oximetry in ten infants at skin temperature of <27 degrees. Pulse oximetry readings in small infants are likely to be unreliable at skin temperatures of <27 degrees, irrespective of probe site. Intravenous phenoxybenzamine appeared to improve the accuracy of pulse oximetry at low temperatures.