Evidence-based Practice and Quality Improvement
Background and Goal of Study: Obstructive sleep apnea (OSA) is common in morbidly obese patients and a practical screening tool for surgical patients is required. This study was conducted to validate the STOP-Bang questionnaire in patients scheduled for bariatric surgery.
Materials and Methods: During a 18 month period, consecutive preoperative morbidly obese patients without previously diagnosis OSA were recruted. The STOP-Bang included 8 yes/no questions: 1-Do you snore loudly? 2-Do you often feel tired, fatigued, or sleepy during daytime? 3-Has anyone observed you stop breathing during your sleep? 4-Do you have or are you being treated for high blood pressure? 5-BMI more than 35 kg/m2? 6-Age over 50 yrs old? 7-Neck circumference greater than 40 cm? 8-Gender male? A high risk of having OSA was considered if at least 3 items were answered yes. The score from the STOP-Bang questionnaire was evaluated versus the apnea-hypopnea index (AHI) from monitored polysomnography preoperatively performed in all the patients.
Results and Discussion: Patients characteristics (n=184) were age 35±12 yrs, body mass index 45±7 kg/m2 and ASA score 2 [1–3]. 142 (77%) patients were classified as being at high risk of OSA. The AHI was 12 [4–27] (median [IC 25–75]) The sensitivity (Se), specificity (Sp), positive (PPV) and negative (NPV) predictive value of the STOP-Bang questionnaire with different AHI cutoffs or the need for CPAP therapy are showed in table: n=184 Se; Sp; PPV; NPV; AHI>15 (n=80) 96%; 38%; 54%; 93%; AHI>30 (n=40) 100%; 29%; 28%; 100%; CPAP (n=74) 99%; 37%; 51%; 98%;
Conclusion(s): The STOP-Bang questionnaire is a valuable and easy-to-use screening tool for OSA in obese patients scheduled for bariatric surgery. In our population, it allowed to rule out OSA diagnosis (AHI>30) with a VPN of 100%.
1 Anesthesiology 2008; 108:812-21.