An asymptomatic swiss army professional with an oxygen saturation of 75% – a case report

Case report: We report on a 51 year old man referred for severe nocturnal oxygen desaturation revealed during investigation for suspected sleep apnoea due to daytime sleepiness. The former smoker, known for an allergic bronchial asthma, denied other respiratory or cardiac symptoms. Physical examination was unremarkable. Small airway obstruction was present in pulmonary function test (FEV1 89% pred./MEF50 66% pred.). Pulse oximetry at ambient air showed a peripheral O2 saturation of 75% that increased to 86% under 7 L/min O2. Directly measured oxygen saturation (SaO2) by arterial blood was slightly decreased (89%…