Alfentanil vs Remifentanil in Patient-controlled Sedation During ERCP.A Randomized Double-blind Study

Deep sedation with propofol has been suggested necessary for successful performance of endoscopic retrograde cholangiopancreatography (ERCP).Airway obstruction, hypoventilation and hypoxemia occurs in deeply sedated patients with a high incidence of 12-30%.As a result of frequent hypoxemia events, deep sedation is associated with increased morbidity and mortality.Careful monitoring of vital signs and involving of anesthesia-trained personal are recommended for deeply sedated patients.Self-administration of propofol by the patient him- or herself (patient-controlled sedation, PCS)could be a safer way to use propofol without the presence of an anesthesiologist. In comparison to the anesthesiologists managed deep sedation the main advantages of PCS are reduced consumption of anesthetics and faster recovery.A combination of propofol and different opioids is widely used for PCS however, it is not known which opioid would be the most suitable one. Remifentanil is a potent opioid with ultra short duration of action and usually administered as a constant infusion. The elimination half-life of alfentanil is 8-32 minutes being about 3 times longer, than that of remifentanil. Both opioids have been evaluated previously in PCS but comparative studies are lacking. This study was carried out in order to compare remifentanil and alfentanil in PCS during ERCP in terms of propofol consumption, sedation levels, endoscopist´s and patient's satisfaction. The investigators also sought information about frequency of sedation related complications associated with the different opioids.