STOP- Undiagnosed Obstructive Sleep Apnea Is a High Risk for Surgery


Providing patients with the most current health care information empowers them to be proactive and make better decisions about their treatment. Studies have indicated that obstructive sleep apnea (OSA) may be a risk factor that leads to adverse or harmful events in patients who undergo surgery. A patient with sleep apnea is more likely to experience complications[i] during and following major surgery due to breathing problems associated with certain medications and general anesthesia. Problems are more prevalent when the patient is sedated and lying on their back. It is important for a doctor to know when a patient has been diagnosed with obstructive sleep apnea and how it is being treated.

Sleep apnea is the most common breathing sleep disorder,[ii] and occurs due to a blockage in the upper airway that interferes with the ability to breathe normally. Symptoms may include tiredness, excessive daytime sleepiness, snoring, gasping for air or choking while asleep, dry mouth, morning headaches, high blood pressure, and abnormal body jerks or sounds when asleep. High risk groups for OSA are: male; over the age of 65; black, Hispanic, or a Pacific Islander; related to someone who has sleep apnea; and being a smoker. More risk factors include certain physical attributes, such as having a thick neck, deviated septum, receding chin, or enlarged tonsils or adenoids. Medical problems such as insulin resistance, diabetes mellitus, systemic hypertension, pulmonary hypertension,congestive heart failure, strokes, irregular heart rhythm, nocturnal angina, heart disease, obesity, stroke, heart attack, and early death may be caused or worsened by OSA.[iii]

The STOP questionnaire is a concise and easy-to-use screening tool to identify patients with a high risk for OSA. It has been developed and validated in surgical patients at preoperative clinics. The patient answers four questions respectively related to snoring, tiredness during daytime, observed apnea, and high blood pressure (STOP). High risk of OSA is determined by answering yes to two or more questions. Low risk of OSA is determined by answering yes to less than two questions.[iv] STOP promotes an optimal outcome before, during and after the surgery period.

Follow- up should be considered for patients at high risk before their scheduled surgery. Follow- up should include a medical examination, sleep history questionnaire, use of the Epworth Sleepiness Scale (ESS)[v] to measure the level of daytime sleepiness, and a polysomnogram to diagnose the severity of OSA and to determine the appropriate treatment.

A sleep study is performed in a sleep disorders center and involves the monitoring and recording of physiological activity such as breathing patterns, brain wave activity to determine light or deep sleep including dreams, blood oxygen levels, heart rhythm, leg movements, and snoring.


STOP Questionnaire for Obstructive Sleep Apnea (OSA)

Height: _________ inches Weight: _________ lbs

Age: _______ Male / Female Body Mass Index (BMI): _________

Collar size of shirt: S M L XL or _________ inches

Neck Circumference: _________ cm

The STOP test consists of four questions:

1. Snoring

Do you snore loudly (louder than talking or loud enough to be heard through closed door)?

Yes   No

2. Tired

Do you often feel tired, fatigued or sleepy during the day?

Yes   No

3. Observed

Has anyone observed you stop breathing during your sleep?

Yes   No

4. Blood Pressure

Do you have or are you being treated for high blood pressure?

Yes   No

High risk of OSA: answering yes to two or more questions

Low risk of OSA: answering yes to less than two questions

Chung, F., Yegneswaran, B., Liao, P., Chung, S., Vairavanathan, S., Islam, S., Khajehdehi, A., Shapiro C. (2008). STOP questionnaire. A tool to screen patients for obstructive sleep apnea. Anesthesiology, 108 (5), 812-21.



[i] Mayo Foundation for Medical Education and Research (MFMER). (2010). Retrieved March 13, 2011, from

[ii] Kryger MH: Diagnosis and management of sleep apnea syndrome. Clin Cornerstone 2000; 2:39–47

[iii] Pagel JF. Obstructive sleep apnea (OSA) in primary care: evidence-based practice. J Am Board Fam Med 2007; 20: 392–8.

[iv] Chung, F., Yegneswaran, B., Liao, P., Chung, S., Vairavanathan, S., Islam, S., Khajehdehi, A., Shapiro C. (2008).    STOP questionnaire. A tool to screen patients for obstructive sleep apnea. Anesthesiology, 108 (5), 812-21.

[v] Copyright © MW Johns 1990-1997.  Used under license.

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The information provided is not a substitute for a consultation with a physician.