Decreased Pulse Oximetry Readings in Asymptomatic Patient with Hemoglobin Grifton

Abstract

Hemoglobin Grifton presents as a decreased oxygen saturation as measured by pulse oximetry (SpO₂) reading despite a normal arterial oxygen saturation (SaO₂) in an asymptomatic patient. Hemoglobin Grifton is caused by a mutation on an alpha chain of hemoglobin at codon 87, which affects the absorption wavelength of its oxyhemoglobin. A standard pulse oximeter is designed to measure the absorption of light at specific wavelengths and perceives the hemoglobin Grifton oxyhemoglobin as a deoxyhemoglobin. In a patient with a known variant hemoglobin, ordering additional diagnostic or therapeutic testing can increase stress for a patient requiring routine medical interventions or emergencies. Careful evaluation of each individual case is warranted prior to proceeding with an anesthetic.