Heart & lung : the journal of critical care
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The purposes of the study were to: (1) describe the aggregate strength of the relationship of arterial oxygen saturation as measured by pulse oximetry with the standard of arterial blood gas analysis as measured by co-oximetry, (2) examine how various factors affect this relationship, and (3) describe an aggregate estimate of the bias and precision between oxygen saturation as measured by pulse oximetry and the standard in vitro measures. ⋯ Pulse oximeters were found to be accurate within 2% (+/- 1 SD) or 5% (+/- 2 SD) of in vitro oximetry in the range of 70% to 100% Sao2. In comparing ear and finger probes, readings from finger probes were more accurate. Pulse oximeters may fail to record accurately the true Sao2 during severe or rapid desaturation, hypotension, hypothermia, dyshemoglobinemia, and low perfusion states.