Persistent snoring under conscious sedation during colonoscopy is a predictor of obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized by cessation of breathing during sleep. Conscious sedation (CS) induces sleep and may uncover sleep-related breathing disorders.

To determine whether snoring during CS is a sensitive predictor of OSA.

Matched cohort study.

University-based ambulatory endoscopy center.

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.

Portable nocturnal polysomnography.

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.

A total of 131 patients were enrolled, and 24 (18.3%) 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) (100% positive predictive value; 77.8% negative predictive value). Moderate or severe OSA was detected in 14 of 20 patients versus 1 of 18 control subjects (P < .001; 70% positive predictive value; 94.4% negative predictive value, 93% sensitivity, 74% specificity). Data obtained from sleep questionnaires and physical examination failed to accurately predict OSA.

Single-center nature and relatively small number of patients developing the outcome variable.

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.