NON-INVASIVE MONITORING OF ARTERIAL 02 SATURATION IN NEWBORN INFANTS

Abstract

Ear oximetry is a simple non-invasive method for measurement of arterial O2 saturation (SaO2) in adults and older children. To evaluate the practicability and accuracy of ear oximetry in newborn infants, we have measured SaO2 in 12 newborns, ages 2.1 days ± 1 (SD) using Biox II-A oximeter and its small ear probe. 15 SaO2 measurements were done during mechanical ventilation (for HMD, diaphragmatic hernia, sepsis) and compared to actual (CO-OX) and calculated SaO2 from simultaneously obtained arterial blood. Blood pressure was in normal range at the time of study. Bilirubin and Hb levels were noted. There was excellent correlation between SaO2 measured by ear oximetry and CO-OX values (n=12; r=0.987) and calculated SaO2 (n=13; r=0.989)(range: 43-99%). SaO2 measured on the scrotum correlated equally well to CO-OX SaO2 (n=6; r=0.979). Bilirubin and Hb levels had no effect on differences between the various SaO2 measurement methods. Ear oximetry is an accurate and practical method for monitoring SaO2 especially in chronic hypoxemia situations during the neonatal period. Transcutaneous PO2 monitoring will be preferred for preterm infants at risk of hyperoxia. However ear oximetry has the advantages of easier application of the probe with less risk of skin burns, and thus longer continuous monitoring of SaO2 in hypoxemic newborn infants.