Spurious Hypoxia: Consideration of Hemoglobinopathies

The use of the pulse oximeter to estimate oxygen saturation has revolutionized monitoring capabilities in medicine. However, there can be circumstances in which there is a discordance between oxygen saturation measurements via pulse oximeter (SpO2) and actual arterial oxygen levels (PaO2). In these situations, there is a possibility the patient could have a variant hemoglobin as the etiology of this discordance. This finding is generally incidental, and the patients are asymptomatic. However, knowledge of these variants is crucial and may spare patients unnecessary medical investigations. In this case report, two patients with variant hemoglobins found to have low oxygen saturations via pulse oximeter are presented, both of who underwent extensive medical workup and prolonged hospital stays.