Nocturnal hypoxaemia in patients with Eisenmenger syndrome: a cohort study

Objectives The objective of the study was to find the prevalence of sleep-related disturbances in patients of Eisenmenger syndrome. Design Prospective observational study. Setting Tertiary care referral centre in North India. Participants The study included 25 patients with Eisenmenger syndrome (mean age 25.2±9.6 years, 18 men) and 12 patients with cyanotic congenital heart disease with pulmonary stenosis physiology (mean age 20.5±8.5 years, 8 men) as controls. Interventions All the patients underwent an overnight comprehensive polysomnogram study and pulmonary function testing. Main outcome measure Oxygen desaturation index, which is the number of oxygen drops per hour. Results The patients and controls had significant nocturnal hypoxaemia in the absence of apnoea and hypopnoea. The mean oxygen drop index in Eisenmenger syndrome group was 9.0±6.2 and in the control group was 8.0±5.9 (p=0.63). The apnoea–hypopnoea index was 3.37±5.0 in the Eisenmenger syndrome group and was 2.1±3.6 in the control group. Patients with >10 oxygen drops per hour had significantly higher haemoglobin (17.2±1.3% vs 14.4±1.5%, p