| There is a margin of error of 4% to 5% when using a pulse oximeter to determine the SaO2, or oxygen saturation, if it is above 90%. A normal value is 98% on room air. Normally values should be maintained above 90%, but in patients with hypercapnea, the saturation of oxygen may be maintained slightly below 90% to stimulate and maintain the respiratory drive. (1) | | | | |
