PreOp Screening for Patients with Sleep Apnea

With over 70% of Americans considered overweight or obese, ambulatory surgery centers are handling patients with higher BMIs than ever before. So how do we stay competitive with hospitals? Surgery centers need to know how to safely take care of obese patients that often have sleep apnea.

Detecting undiagnosed sleep apnea

With obesity comes a wide range of medical problems. Typically, obese patients have additional health conditions, such as high blood pressure, type 2 diabetes, and some degree of heart disease (though it may not be diagnosed or symptomatic). Additionally, a high percentage of these individuals also have obstructive sleep apnea (OSA). Some know they have sleep apnea; however, a large number of patients are undiagnosed.

Screening for undiagnosed sleep apnea is a crucial part of preop. Patients with sleep apnea who undergo sedation or general anesthesia have an increased risk for airway compromise and desaturation. Thus, identifying patients who need OSA screening at the preop appointment is extremely important for us.

Screening methods

A widely adopted tool for detecting undiagnosed sleep apnea is the STOP-Bang questionnaire. This screening tool was created to be a patient-friendly, concise evaluation for OSA. The first part of the questionnaire includes direct questions regarding snoring, tiredness, observed instances of interrupted breathing while asleep, and blood pressure. The second part goes over demographic questions that affect sleep apnea risk: BMI, age, neck circumference, and gender, with men being at higher risk than women. Each “yes” answer is worth one point. Patients who score 0-2 are at low risk and likely do not have sleep apnea. Patients with a score of 3 or higher may be at risk, with a score of 5-8 indicating high risk.

While STOP-Bang is the most popular screening method, you do have some additional screening tools that are also effective. For example, the STOP questionnaire asks only the first half of the STOP-Bang questionnaire. If your patient answers yes to 2 or more questions, they are recommended for diagnostic testing. The Berlin questionnaire was developed in 1999 and includes questions regarding snoring, daytime fatigue, and comorbidities such as hypertension, high BMI, and cardiovascular disease. If 2 or more of these 3 categories test positively, the patient is considered high risk for OSA.

Diagnosing sleep apnea

In the past, patients at moderate to severe risk were sent to a sleep lab. There, they were asked to participate in sleep studies where they needed to be videotaped, hooked up for EKG testing, and fully monitored. Today, we can send patients home with a pulse oximeter that records a patient’s oxygen saturation. The small device can be worn on a patient’s finger, forehead, nose, foot, or ears and will detect if a patient desaturates during the night. With this information, the surgical team can then identify what practical considerations to take into account for performing surgery on a patient with obstructive sleep apnea.

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