WEDNESDAY, April 23 (HealthDay News) -- A quick, self-administered test to identify surgical patients who may have potentially life-threatening obstructive sleep apnea (OSA) has been developed by a team of Canadian anesthesiologists.

People with OSA experience repeated episodes of breathing cessation while they sleep. The disorder affects 2 percent to 26 percent of the general population.

"Identifying patients with OSA is the first step in preventing postoperative complications. Untreated OSA patients are known to have a higher incidence of difficult intubation, postoperative complications, increased intensive care admissions and greater duration of hospital stay," Dr. Francis Chung, of the University of Toronto, said in a prepared statement.

The STOP questionnaire by Chung and colleagues includes four simple yes/no questions: Do you snore loudly?; Do you often feel tired, fatigued or sleepy during daytime?; Has anyone observed you stop breathing during sleep?; Do you have or are you being treated for high blood pressure?

If a patient answers "yes" to two or more of the questions, then he or she is considered to be at high risk for OSA. When other risk factors for OSA -- high body-mass index, age over 50, large neck circumference and being male -- were combined with the questions, the STOP questionnaire's ability to predict OSA was even greater, according to a study in the May issue of Anesthesiology.

"Identifying patients who are at risk of having OSA in advance of surgery is important to improve patient safety. In addition, when anesthesiologists are forewarned of the severity of a patient's sleep apnea, they can select appropriate anesthetic techniques and equipment, and ensure that surgery takes place in a facility which is equipped to deal with the potential complications," Dr. Jeffrey B. Gross, chairman of the American Society of Anesthesiologists Task Force for Perioperative Management of Patients With Obstructive Sleep Apnea, said in a prepared statement.

However, hospitals and clinics don't do routine OSA screening of surgical patients because there hasn't been a simple, practical method that's been proven to be effective.

"An overnight sleep study is the most reliable way to diagnose OSA, but it is too time-consuming and expensive for every patient to receive before surgery," Chung said.

In a companion study to their STOP questionnaire study, Chung and colleagues validated two other screening OSA screening tools for surgical patients -- the 11-question Berlin Questionnaire and the American Society of Anesthesiologists checklist, which contains 12 checkable items for adults and 14 for children.

More information

The U.S. National Heart, Lung, and Blood Institute has more about sleep apnea.

-- Robert Preidt

SOURCE: American Society of Anesthesiologists, news release, April 23, 2008

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