Can You Really Trust Pulse Ox Readings? In Some Patients, Maybe Not

A new study published by JAMA Pediatrics suggests that pulse oximetry may be less reliable in Black patients with hypoxemia than in White patients, possibly resulting in undertreatment of hypoxemia in some patients. The authors based their findings on comparison of arterial blood oxygen saturation (SaO₂) and pulse oximetry (SpO₂) in 774 patients (74% classified as White and 26% classified as Black) between the 1 and 17 years of age at Children’s Hospital of Philadelphia. Looking at children with “true hypoxemia” (Sao₂ <88% for purposes of the study),  12% of Black patients had peripheral oxygen saturation levels suggesting normoxemia (SpO₂ ≥92%), compared with 4% of White patients—equating to a false negative rate three times greater in Black patients. The results echo previous research that attributed the discrepancy to the relative light absorption properties of dark vs light-skinned individuals.