YH Law, MK Tay, DCY Lau

Abstract

Digital pulse oximetry is a useful non-invasive tool to monitor oxygen saturation. However, it has its own limitation and cannot reflect the true arterial oxygen saturation in case of unstable haemoglobin. We report a Chinese girl having unstable haemoglobin presenting with incidental finding of low oxygen saturation measured by pulse oximetry, its value in identifying affected family members and the importance of recognising unstable haemoglobin in patient with asymptomatic low oxygen saturation.