Conscious sedation : clues for diagnosing obstructive sleep apnea syndrome

Background and aims: The use of anesthetic agents for endoscopic sedation has recently increased. However, sedation introduces additional risks in patients with obstructive sleep apnea syndrome (OSAS). The presence of sleep apnea is not often enough questioned in clinical practice. The purpose of this study was to determine whether patients with sedation-induced snoring and decreased arterial oxygen saturation during gastroscopy are more likely to have OSAS. Methods: This study considered 600 consecutive patients undergoing elective outpatient upper gastrointestinal endoscopy under conscious sedation for evaluation of dyspepsia. Ten patients with observed snoring and decreased arterial saturation during the gastroscopy procedure were enrolled in the study. The control group was comprised of 13 patients matched by sex, age, and body mass index (BMI) who did not snore and had a more stable oxygen saturation under conscious sedation during an elective outpatient gastroscopy for the evaluation of dyspepsia and were selected using a computer-generated randomized sequence. Patients were monitored and an overnight polysomnography was performed in the study group. Statistically significant differences between groups were assessed using the nonparametric Wilcoxon and independent-samples t-tests. Results: There was no significant difference in age or BMI between the two groups (p>0,05) Mean minimum oxygen saturation was significantly different between the two groups (p=0.011). In the study group, 7 patients were found to have moderate OSAS necessitating a continuous positive airway pressure device. Conclusion: Patients with hypoxia and snoring, under conscious sedation are more likely to have OSAS. "Out-of-operating-room" sedoanalgesia is therefore critical.