Sleep Health Section
Obstructive Sleep Apnea: A General review for the Primary Care Physician Vandana Seeram, MD; Adil Shujaat, MD; Abubakr A. Bajwa, MD, FCCP; Lisa Jones, MD and James D. Cury, MD Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida College of Medicine, Jacksonville, FL Tracy Ashby, DO and Jesse Onyenekwe, MD
Division of Internal Medicine, University of Florida College of Medicine, Jacksonville, FL
Abstract: Obstructive sleep apnea (OSA) is a disease characterized by intermittent and repetitive narrowing of the airway during sleep. Risk stratification can be accomplished by identifying key history and physical examination findings which warrant further evaluation. The diagnosis of sleep apnea must be made before the initiation of treatment to correctly identify patients who should benefit from treatment, and monitor the risks associated with morbidity and mortality of OSA. Available treatments include behavioral, medical and surgical options. Primary care physicians can have a major impact on the morbidity and mortality associated with OSA through identification of high risk patients, timely diagnosis, and routine assessment of treatment and compliance.
Overview
AHI = 0–5 Normal range AHI = 5–15 Mild sleep apnea
Obstructive sleep apnea (OSA) is a chronic condition which is common in the primary care setting. With an estimated prevalence of two to four percent and many associated comorbidities, it is important to identify and treat patients early.1 Obesity, snoring and daytime sleepiness are classic signs of OSA. However, all patients do not present this typically, so providers must be vigilant in screening and treating patients. Untreated sleep apnea has been shown to cause substantial cognitive and cardiovascular morbidity and mortality.2 It is an independent risk factor for stroke, hypertension, cardiac ischemia, arrhythmias, pulmonary hypertension, insulin resistance, epilepsy and perioperative complications. Studies have also revealed the risk of motor vehicle accidents in OSA was increased two-fold.3 Recognition of risk factors, utilization of screening techniques, timely diagnosis and treatment, and monitoring of compliance are essential aspects of managing this chronic disorder. Here we attempt to give a general overview of OSA as it applies to the primary care physician (PCP).
Address correspondence: Vandana Seeram, MD, University of Florida Health, 655 West 8th ST, Suite 7-088, Jacksonville, FL 32209. Phone: (904) 244-4075 / Fax: (904) 244-5047 E-mail: Vandana.seeram@jax.ufl.edu 12 Vol. 64, No. 4 2013
OSA is caused by repeated collapse of the upper airway during sleep, which leads to sleep disturbance, hypoxemia and hypercapnia. The apnea-hypopnea index (AHI) is used to diagnose obstructive sleep apnea. Apnea is defined as absence of airflow for 10 seconds or more, whereas hypopnea is defined as reduced airflow by 30 to 50 percent with arousal or decreased oxygen saturation by three to four percent. The summation of apnea and hypopnea events per hour determines the apnea-hypopnea index (AHI). OSA is defined as an AHI of greater than five. Severity of OSA can further be categorized into:4
Northeast Florida Medicine
AHI = 15–30 Moderate sleep apnea AHI > 30 Severe sleep apnea Overnight polysomnography (PSG) is the best test for calculating the apnea hypopnea index and remains the gold standard for diagnosis. It uses multiple modalities to evaluate physiologic variables during sleep. More recently testing with portable monitors and split night study has become more popular. With portable monitors, airflow, respiratory effort, and oxygen saturation are collected to calculate the respiratory disturbance index (RDI) per hour rather than an AHI. This is because portable monitors do not permit identification of actual sleep time.3 Prior to referral for diagnostic testing, practitioners should perform a comprehensive evaluation which allows them to risk stratify the patients likelihood of OSA and determine severity of symptoms.
Comprehensive Evaluation By collecting a brief sleep history for all patients, identifying at risk patients, and obtaining more detailed information for patients with symptoms of OSA, practitioners will have a comprehensive approach to screening for OSA. Knowledge of common risk factors and associated conditions is paramount to this evaluation. Well established risk factors include obesity, advanced age, male gender, anatomic airway abnormalities, alcohol consumption, and tobacco use. Alcohol contributes to apnea by DCMS online . org