Sahos

Obstructive Sleep Apnea Syndromes
Nancy A. Collop, M.D.1

ABSTRACT

Complete or partial collapse of the upper airway during sleep has different effects on the human body ranging from noisy breathing (snoring) to significant cardiovascular sequelae as seen in obstructive sleep apnea (OSA). Snoring is very common in the adult population and has been associated with morbidity in epidemiologicalstudies. A variety of treatments may be used for primary snoring (snoring without symptoms) but none are universally successful. The upper airway resistance syndrome is thought to occur when incomplete obstruction of the upper airway results in frequent disruptions in sleep. Whether it is a true ‘‘syndrome’’ or just one end of the continuum of OSA is unclear. Obstructive sleep apnea causes notonly sleep disruption but oxygen desaturation. It has been associated with numerous cardiovascular sequelae, including hypertension (systemic and pulmonary), arrhythmias, and stroke. Nasal continuous positive airway pressure (CPAP) is the current treatment of choice, with lesser alternatives including oral appliances, surgery, and weight loss. Further study on outcomes is required to determine howaggressively to treat these syndromes.
KEYWORDS: Obstructive sleep apnea, upper airway resistance syndrome, snoring, nasal CPAP, cardiovascular

Objectives: Upon completion of this article, the reader should be able to: (1) define primary snoring; (2) summarize the controversial aspects of the upper airway resistance syndrome; (3) understand the current knowledge on the pathophysiology andcardiovascular sequelae of obstructive sleep apnea; and (4) list the treatments available for OSA. Accreditation: The University of Michigan is accredited by the Accreditation Council for Continuing Medical Education to sponsor continuing medical education for physicians. Credits: The University of Michigan designates this educational activity for a maximum of 1 category 1 credit toward the AMAPhysician’s Recognition Award.

here are several forms of sleep-disordered breathing, including obstructive sleep apnea (OSA) syndromes, central sleep apnea syndromes, and hypoventilation syndromes. This article focuses on the OSA syndromes. Included in this categorization are primary snoring, upper airway resistance syndrome, and OSA. In common with all these entities is narrowing or complete obstructionof the upper airway. The comments herein will refer to adult populations.

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PRIMARY SNORING Snoring is a respiratory noise generated from the upper airway during sleep that typically occurs during inspiration but may also occur in expiration. Primary snoring is snoring that occurs regularly but does not result in significant daytime impairment or complaints or disruption of sleep.1 Snoring isvery common in OSA and is one of the cardinal symptoms. However, in some, snoring can occur without obvious

Sleep and Respiration; Editor in Chief, Joseph P. Lynch, III, M.D.; Guest Editors, Teofilo L. Lee-Chiong Jr., M.D., Nancy A. Collop, M.D. Seminars in Respiratory and Critical Care Medicine, volume 26, number 1, 2005. Address for correspondence and reprint requests: Nancy A. Collop, M.D.,Johns Hopkins University, DOM, 1830 East Monument St., Rm. 555, Baltimore, MD 21205. E-mail: ncollop@jhmi.edu. 1Johns Hopkins University, DOM, Baltimore, Maryland. Copyright # 2005 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 1069-3424,p;2005,26,01,013,024,ftx,en;srm00347x.

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SEMINARS IN RESPIRATORY AND CRITICAL CAREMEDICINE/VOLUME 26, NUMBER 1

2005

morbidity except to those who are kept awake by the noise. The oropharyngeal segment of the upper airway is the anatomical region from which snoring noises are generated. Decreased tone of the upper airway muscles results in constriction of the oropharynx and fluttering of the tissues, particularly the uvula and soft palate, although may also involve the faucial...