Obstructive sleep apnea

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By Carolina Lombardi MD PhD and Gianfranco Parati MD

Obstructive sleep apnea (OSA) is also known as or subsumes Obstructive sleep hypopnea syndrome, Primary snoring, and Upper airway resistance syndrome. -ed.

Some decades after pioneering reports of obstructive sleep apnea in the Pickwickian syndrome, obstructive sleep apnea is a recognized common clinical problem with important consequences such as excessive daytime sleepiness and cerebrovascular or cardiovascular disease (stroke, hypertension and myocardial infarct). In this clinical article, Professor Gianfranco Parati and Dr. Carolina Lombardi of the Sleep Lab, Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Istituto Auxologico Italiano, IRCCS, provide information on historical notes and physiology of respiration during sleep as well as pathophysiology and clinical aspects of sleep-related breathing disorders (particularly obstructive sleep apnea syndrome). The article also summarizes diagnostic methodologies, describes the most common complications of obstructive sleep apnea and their pathogenetic mechanisms, and outlines available therapeutic approaches and their indications, suggesting issues for future research.

Key Points

  • Obstructive sleep apnea syndrome is characterized by repeated upper airway obstructions leading to oxygen desaturations and sleep fragmentation. Narrowing and closure of the upper airway, specifically the pharynx, during sleep is the basis of the disease.
  • Obstructive sleep apnea is a clinical problem, occurring more frequently in men than in women, with important consequences such as excessive daytime sleepiness and a higher risk of cerebrovascular or cardiovascular disease (stroke, hypertension, and myocardial infarct).
  • Snoring is the first stage of the disease, which may progress into obstructive sleep apnea syndrome (mild, moderate, and severe), in particular after body weight increase, with obesity being the most important risk factor for the development of obstructive sleep apnea.
  • A nocturnal video-polysomnogram performed in a sleep laboratory is the gold standard for diagnosis of obstructive sleep apnea, but an easier approach, mainly when focusing on screening purposes, consists in the use of ambulatory devices recording various combinations of pulse oximetry, breathing effort, airflow, snoring, heart rate, EEG, or other measures.
  • The type of treatment for obstructive sleep apnea syndrome depends on the severity of the disorder. Treatment often includes losing weight, avoidance of alcohol and hypnotic drugs, and avoidance of the supine position during sleep. In moderate to severe obstructive sleep apnea, the treatment of choice is nasal continuous positive airway pressure (CPAP) application that functions as an air splint to maintain positive intraluminal pressure in the upper airway. Oral appliances and surgical procedures (uvulopalatopharyngoplasty, tracheostomy, maxillofacial surgery) designed to maintain nocturnal airway patency are additional options to be considered in selected cases.