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.