Identifying the Patient With Sleep Apnea

Obstructive sleep apnea (OSA) is a complex disease process whose etiology is multifactorial and incompletely understood. Because the final common pathway for this disease process, whether caused by neurologic, muscular, anatomic, or other etiology, is obstruction of the upper airway during nocturnal respiration, examination and assessment of the anatomy of the upper airway plays a central role in the patient evaluation. Examination of the patient with OSA is not confined to the upper airway, however, as other anatomic and physiologic processes can be important in managing patients with this disease. For example, blood pressure, height, and weight are critical in the general assessment. Close cooperation with the patient's primary physician is also important in managing a patient's blood pressure and general medical condition and can elucidate other causes of apnea such as increased alcohol consumption, recent weight gain, and metabolic conditions. Conditions might coexist that mimic or exacerbate symptoms of apnea. Depression, insomnias, and use of sedating medications are examples of other important information that can be obtained from the primary physician. Conceptually, the upper airway is composed of a semirigid bony and cartilaginous framework with attached soft tissue structures. Because the upper airway begins at the nose and lips and ends at the larynx, a complete assessment of the upper airway evaluates the entire length of this anatomic region including the framework and soft tissue. It must be remembered that office assessment of these structures does not necessarily mimic the appearance or behavior of these structures during sleep. These state dependent changes and the dynamic physiology of the upper airway during sleep represent a major limitation of the office examination. Nevertheless, the office examination provides important information as to the site of potential obstruction during sleep that can help to direct therapy.