Abstract:
Background: Obstructive sleep apnea (OSA) is characterized by cessation of breathing during sleep. Conscious sedation (CS) induces sleep and may uncover sleep-related breathing disorders. Objective: To determine whether snoring during CS is a sensitive predictor of OSA. Design: Matched cohort study. Setting: University-based ambulatory endoscopy center. Patients: Consecutive patients undergoing colonoscopy completed a detailed sleep questionnaire and physical examination geared toward detecting OSA (body mass index [BMI], neck circumference, and the presence of craniofacial abnormalities). The endoscopist was blinded to the information. Interventions: Portable nocturnal polysomnography. Main Outcome Measurements: Patients who snored during CS in the left lateral decubitus position for 10 seconds or longer were referred for polysomnography. Sex- and BMI-matched patients who did not snore served as control subjects. Results: A total of 131 patients were enrolled, and 24 (18.3percent) of them snored. These patients (22 men, 2 women) had a predominance of Mallampati grade III-IV, higher Stanford and Epworth scale scores, and greater BMI and neck circumference and were more likely to report daytime sleepiness, decreased vigilance, and personality and mood changes (all P values .05). All investigated patients who snored during CS had evidence of OSA versus 4 of 18 control subjects (mean apnea-hypopnea index: 40 events vs 5 events; P .0001) (100percent positive predictive value; 77.8percent negative predictive value). Moderate or severe OSA was detected in 14 of 20 patients versus 1 of 18 control subjects (P .001; 70percent positive predictive value; 94.4percent negative predictive value, 93percent sensitivity, 74percent specificity). Data obtained from sleep questionnaires and physical examination failed to accurately predict OSA. Limitations: Single-center nature and relatively small number of patients developing the outcome variable. Conclusions: Snoring during CS is a strong predictor of OSA. Given the medical and financial burden of undiagnosed OSA, these patients should be carefully identified and referred for sleep medication evaluation. © 2010 American Society for Gastrointestinal Endoscopy.