- Pulmonary Function: oxygen saturation ≥ 90% on room air and pulmonary function >50% corrected Diffusion lung capacity for carbon monoxide (DLCO) and Forced expiratory volume in one second (FEV1) Oxygen saturation [>92%] can be used in child where pulmonary function tests (PFT's) cannot be obtained. (Testing required only if symptomatic or prior known impairment.)