Inaccurate finger pulse oximetry oxygen saturation measurement Finger pulse oximetry higher than arterial blood gas analysis measurement of oxygen saturation 2025-03-09T11:22:14Z This feature may be observed with Carbon monoxide poisoning. Presently available pulse oximeters overestimate arterial oxygenation in patients with severe CO poisoning. An elevated COHb level falsely elevates the SaO2 measurements from pulse oximetry. Inaccurately elevated oxygen saturation as measured by finger or toe pulse oximetry compared to oxygen saturation as measured by venous or arterial blood gas analysis.