ERCP requires deep sedation due to pain and discomfort, but propofol-commonly used with opioids-often causes respiratory and cardiovascular complications, especially in elderly or high-risk patients. Dexmedetomidine offers sedation without respiratory depression but may lower blood pressure and heart rate. Current monitoring often relies only on SpO₂, while capnography and the Integrated Pulmonary Index (IPI) provide earlier detection of respiratory events but are underused in ERCP studies.

This study compares dexmedetomidine and propofol in high-risk ERCP patients, focusing on respiratory and hemodynamic effects, propofol consumption, recovery, and discharge times. The hypothesis is that dexmedetomidine will cause fewer adverse respiratory and hemodynamic effects.

Endoscopic Retrograde Cholangiopancreatography (ERCP) is uncomfortable and painful for patients. Moreover, immobility is required for procedural success, which necessitates deep sedation. Recently, propofol combined with an opioid has been frequently used for this purpose . However, propofol is associated with respiratory depression, hypoxemia, and hypotension, leading to increased cardiopulmonary complications. These risks become more significant in elderly patients and those with high comorbidity. The use of alternative sedative agents or combinations aims to reduce propofol dosage and minimize cardiopulmonary complications.

Dexmedetomidine is a highly selective α2-adrenoceptor agonist that reduces noradrenergic neuronal activity and is widely used for its sedative and anxiolytic properties. Unlike propofol, dexmedetomidine provides sedation without causing respiratory depression, even at loading doses. Several studies have evaluated the effects of dexmedetomidine and propofol on sedation in gastrointestinal endoscopic procedures . However, dexmedetomidine infusion alone has been shown to be less effective than propofol in terms of sedation quality, and it is associated with significant decreases in blood pressure and heart rate. These adverse events raise concerns regarding the use of dexmedetomidine in high-comorbidity patients requiring stable hemodynamics . Therefore, further studies are needed to evaluate the efficacy and safety of dexmedetomidine versus propofol in high-risk patients undergoing ERCP.

During endoscopy, monitoring of heart rate (HR), arterial blood pressure (BP), and pulse oximetry (SpO₂) is commonly used. Capnography with end-tidal CO₂ (ETCO₂) monitoring enables early detection of hypoventilation and apnea. Accordingly, both national and international guidelines (US and Europe) recommend capnography for monitoring during endoscopic procedures . The Integrated Pulmonary Index (IPI) incorporates HR, respiratory rate, SpO₂, and ETCO₂ parameters into an algorithm (14). It is considered the earliest method for detecting respiratory events and has been shown to be effective during endoscopic sedation.

However, studies evaluating the respiratory effects of sedative agents used in ERCP have been limited to SpO₂ values and adverse events, without assessment of ETCO₂ or IPI parameters.

In the study, the investigator primarily aimed to compare the respiratory and hemodynamic effects of dexmedetomidine versus propofol in high-risk patients undergoing ERCP. Secondarily, we evaluated total propofol consumption, recovery time, and discharge time from the endoscopy unit. Our hypothesis was that dexmedetomidine sedation in high-risk ERCP patients would result in fewer respiratory and hemodynamic side effects compared to propofol.

Inclusion Criteria:

• patients over 18 years of age
• ASA physical status III-IV
• scheduled for ERCP in the Gastroenterology Endoscopy Unit of our hospital

Exclusion Criteria:

• pregnant women;
• patients with neuropsychiatric disease,
• substance abuse, or known allergy to the sedatives used;
• patients with baseline heart rate ≤50 bpm;
• those who did not provide consent.