Do patients at risk of sleep apnea have an increased risk of cardio-respiratory complications during endoscopy procedures?

BACKGROUND: Patients with sleep apnea (OSA) have an increased risk of perioperative complications. AIM: The purpose of this study is to assess whether OSA increases the risk of cardio-respiratory complications in patients undergoing endoscopic procedures with conscious sedation.
METHODS: A prospective study over a 7-month period was performed. All patients undergoing upper, lower, or combined endoscopy were asked to fill in the Berlin questionnaire. The questionnaire was scored, and patients were classified as high or low risk for sleep apnea based on the suggested scoring criteria. Patients who had previously undergone a sleep study were excluded. Demographics and co-morbidities were identified from the electronic medical record. Procedure type, amount of sedation, and minor and major complications were identified from the endoscopy flow sheet. The minor complications were defined as hypertension, hypotension, bradycardia, tachycardia, hypoxemia, and bradypnea (respiratory rate <8 breaths/min). Major complications included chest pain, arrhythmia, altered mental status, respiratory distress, and a minor complication that required a significant intervention, such as use of a reversal agent, atropine, up-titration of oxygen for hypoxemia, or prolonged observation.
RESULTS: Procedures were performed in 904 patients: colonoscopies, 68.0%; upper endoscopies, 22.8%; and combined procedures, 9.2%. Five hundred fifty-three patients were identified as low risk (61.2%), and 351 were identified as high risk (38.8%). The mean age was 59.5 ± 10.5 years, mean body mass index was 28.9 ± 6.6, mean neck circumference was 16.2 ± 6.3 in., and 91.4% were males. The median Charlson co-morbidity index was 1 (25-75% percentage range 0-2). All patients received midazolam and fentanyl during endoscopy. The median and 25-75% range for midazolam and fentanyl dosages were 5 mg, 4-6 mg and 100 μg, 75-125 μg, respectively. Minor complications were observed in 10.56% of low-risk patients and 10.63% of high-risk patients (p = not significant (NS); odds ratio, 1.01; 95% confidence interval 0.65-1.56). Major complications were observed in 3.25% of low-risk patients and 1.9% of high-risk patients (p = ns; odds ratio, 0.6; 95% confidence interval 0.26-1.46).
CONCLUSION: For patients undergoing endoscopy procedures under conscious sedation, the presence of OSA does not clearly increase the risk of cardiopulmonary complications.