Title: 195 EVALUATION OF NONINVASIVELY MEASURED HEMOGLOBIN OXYGEN SATURATION IN NEONATES
Abstract: We compared hemoglobin-oxygen saturation measured noninvasively (NSO2) to spectrophotometrically determined hemoglobin-oxygen saturations (SO2) in 26 neonates. One-hundred forty-one paired measurements were made in patients ranging from 710 to 2890 gm. Noninvasive measurements were made using a Nelcor N-100 pulse oximeter. This microprocessor-controlled device provides a continuous display of NSO2, determined by the absorption of two light wave lengths during arterial pulsation. The light sensor was placed over the wrist, foot, or ankle. Arterial oxygen saturations were obtained from umbilical arterial catheters or by post-ductal arterial sampling. SO2 was determined with an IL282 co-oximeter. The range of NSO2 was 63–100%; SO2 values ranged from 8–100%. The average difference between NSO2 and SO2 was +3.23%. Twelve arterial specimens from 3 patients had SO2 <60%: the average difference between NSO2 and SO2 was +30%. When all values were compared by linear regression analysis, r = 0.85. We conclude that this noninvasive technique is reliable for measurement of hemoglobin-oxygenation saturation. At very low levels of SO2, noninvasive measurements were always higher than actual arterial values. These differences are likely due to a combination of physiologic and measurement artifacts. Further study in cyanotic patients may resolve this problem.