Oxygen saturation results generated in satellite laboratories (CCU, ICU, PICU) by Respiratory Therapy staff or using I-Stat instruments are calculated from PO2. Oxygen-saturation results in the lab at Marshfield are obtained by CO-Oximetry and reported as Percent Fractional Oxyhemoglobin (FHbO2) which includes the contribution of any dys-hemoglobins (carboxy-, met-). Accordingly, when dys-hemoglobins are present, (Lab) FHbO2 results may differ significantly from O2 saturation (SO2) obtained by calulation or using pulse oximetry.