The effect of nightly nasal CPAP treatment on nocturnal hypoxemia and sleep disorders in mustard gas-injured patients

Introduction Sleep-related breathing disorders are associated with unusual respiratory pattern or an abnormal reduction in gas exchange during sleep that is common in sulfur mustard (SM) exposure. Methods We compared 57 Iranian male patients injured with SM and had any complaints of sleep problems with an age-matched group of 21 Iranian male patients who had complaints of sleep problems and were not chemically injured; this group had Epworth Sleepiness Scale (ESS) above 10 and whom referred for polysomnography. Split-night studies were performed for patients with diagnostic polysomnography for obstructive sleep apnea (OSA) and respiratory events. We then studied respiratory events including episodes of OSA, apnea–hypopnea index (AHI) and respiratory disturbance index (RDI). Results The mean age in mustard-exposed patients was 48.14 ± 8.04 years and in age-matched group, 48.19 ± 8.39 years. In mustard exposed patients, there were statistical differences for the episodes of OSA ( p = 0.001), AHI ( p = 0.001), and RDI ( p = 0.001) between two segments of split-night studies. In the age-matched group, there were statistically differences for each parameter (episodes of OSA ( p = 0.001), AHI ( p = 0.001), and RDI ( p = 0.001)). There were no significant differences between two groups. Conclusion This study indicated that the incidence of respiratory events and nocturnal hypoxemia during sleep in mustard-exposed patients were high and treatment with CPAP significantly reduced all these events.