[Comparison of O2 saturation measurements by oximetry and by gas analysis]

For checking the reliability of pulse oximetry in the operating rooms, we compared values of arterial O2 saturation measured by a blood gas analyzer (SAT) with values monitored by pulse oximetry (SaO2). SaO2's were found to be significantly different from SAT's. The regression equation was SAT = 0.31 X SaO2 + 68.4 and the correlation coefficient was 0.66. P value of paired comparison was 0.0001 indicating that the two sets of values were not equal to each other. When one observer performed a similar study using a high-fidelity pulse oximeter, SaO2's were not different from SAT's. The regression equation in this case was SAT = 0.85 X SaO2 + 15.0 and the correlation coefficient was 0.95. P value of paired comparison was 0.3244. The reliability of pulse oximetry differs from one anesthesiologist to another and depends upon the accuracy of each pulse oximeter. In clinical experiment, using the data by pulse oximetry in operating room is misleading.