This prospective observational study was conducted at the University Sleep Disorders Center (USDC) at King Saud University Medical City at King Saud University, Riyadh, Saudi Arabia; this project is a part of a larger research project, with prospectively collected information, to evaluate OHS.10 (link),17–19 (link) Consecutive ambulatory, PAP-naïve, newly diagnosed OHS patients (>18 years), with an AHI <30 events/h in the period between January 2010 and December 2019 were invited to participate (n=60). Exclusion criteria were chronic illnesses that may result in hypercapnia or impact breathing, including chronic neurological, muscular, or pulmonary conditions, skeletal deformities, decompensated congestive heart failure, and use of drugs that depress the respiratory drive.
All participants underwent spirometry based on the task force guidelines by the American Thoracic Society/European Respiratory Society (ATS/ERS) using a Master Screen (Jaeger, Germany).20 (link) Moreover, all participants had arterial blood analysis after 15 minutes of rest while awake, sitting, and at room-air employing a GEM® Premier™ 4000 analyzer (Instrumentation Laboratory, Lexington, MA). Daytime sleepiness was determined using the Epworth sleepiness scale (ESS).21 (link) Comorbidities were identified based on clinical histories and medical records.
All participants underwent spirometry based on the task force guidelines by the American Thoracic Society/European Respiratory Society (ATS/ERS) using a Master Screen (Jaeger, Germany).20 (link) Moreover, all participants had arterial blood analysis after 15 minutes of rest while awake, sitting, and at room-air employing a GEM® Premier™ 4000 analyzer (Instrumentation Laboratory, Lexington, MA). Daytime sleepiness was determined using the Epworth sleepiness scale (ESS).21 (link) Comorbidities were identified based on clinical histories and medical records.
