Accuracy of digital plethysmographic pulse oximetry

ABSTRACT

This study was designed to assess the accuracy of plethysmographic pulse oximetry in geriatrics. Thirty male patients underwent minor endoscopic urological procedures under subarachnoid block with 0.5% bupivacaine. They were premedicated with 5 mg diazepam orally, and their basal SpO2 and SaO2 were recorded following the arterial cannulation. At 10-minute intervals after the block and for the following 2 hours SpO2 was recorded simultaneously with arterial blood sampling for measuring arterial oxygen saturation with multiwave length by Radiometer 510 in vitro oximeter. Heart rate, blood pressure [systolic, diastolic, mean] and rectal temperature were recorded at the same time intervals. The results of this study indicated that oxygen saturation measurements by digital pulse oximeter used in this study was accurate and precise with bias of 0.6 +/- 1.56 compared with reference [Radiometer 510] six wave lengths in vitro co-oximeter. Age by itself had no dramatic negative effect on the oxygen saturation. There is no significant correlation between SaO2-SpO2 difference, hemodynamic variables and core body temperature changes