Capnographic monitoring of midazolam and propofol sedation during ERCP: a randomized controlled study (EndoBreath Study)

Background and study aims: This was to determine whether intervention based on additional capnographic monitoring reduces the incidence of hypoxemia during midazolam and propofol sedation for endoscopic retrograde cholangiopancreatography (ERCP). Methods: Patients (American Society of Anesthesiologists [ASA] I-IV) scheduled for ERCP under midazolam and propofol sedation were randomly assigned to a control arm with standard monitoring or an interventional arm with additional capnographic monitoring. In both arms detection of apnea prompted withholding of propofol administration, stimulation of the patient, insertion of a nasopharyngeal tube, or further measures. The primary study end point was incidence of hypoxemia (oxygen saturation [Sao(2)] below 90%); secondary end points included occurrences of severe hypoxemia (Sao(2 <=)85%), bradycardia, and hypotension, and sedation quality (patient cooperation and satisfaction). Results: 242 patients were enrolled at three German endoscopy centers. Intention-to-treat analysis revealed no significant reduction in hypoxemia incidence in the capnography arm compared with the standard arm (38.0% vs. 44.4 %, P=0.314). Apnea was more frequently detected in the capnography arm (64.5% vs. 6.0 %, P<0.001). There were no differences regarding rates of bradycardia and hypotension. Per-protocol analysis showed lower incidence of hypoxemia in the capnography arm compared with the standard arm (31.5% vs. 44.8 %, P=0.048). There was one death related to sedation in the standard arm. Sedation quality was similar in the two groups. Conclusion: Intention-to-treat analysis showed hypoxemia incidence was not significantly lower in the additional capnography arm compared with standard monitoring. Additional capnographic monitoring of ventilatory activity resulted in improved detection of apnea.