title: Patient-controlled sedation with propofol/remifentanil versus propofol/alfentanil for patients undergoing outpatient colonoscopy, a randomized, controlled double-blind study.
abstract: BACKGROUND
  Many techniques are used for sedation of colonoscopies. Patient-controlled sedation (PCS) is utilizing many drugs or drug combinations.
  
  
  OBJECTIVE
  The aim of this study is to compare the safety and feasibility of propofol/remifentanil versus propofol/alfentanil given to sedate patients undergoing outpatient colonoscopies through a patient-controlled technique.
  
  
  METHODS
  Controlled randomized and double-blind study.
  
  
  METHODS
  A total of 80 patients were randomly divided into two groups; PA group received a combination of propofol/alfentanil and PR group received propofol/remifentanil combination. Patients were monitored for heart rate (HR), blood pressure (BP), oxygen saturation, and Ramsay sedation scale (RSS). Times of the following events were recorded; initiation of sedation, insertion and removal of the colonoscope, recovery and discharge. Five intervals were calculated; time to sedation, procedure time, postprocedure time, procedure room time, and postanesthesia care unit (PACU) time. Endoscopist and patient satisfaction scores were obtained.
  
  
  METHODS
  Unpaired Student's t-test was used to compare between the two groups. Paired Student's t-test was used to compare baseline readings with readings after 30 min of sedation in the same group when needed.
  
  
  RESULTS
  Both groups showed slowing of the HR and decrease in mean arterial BP. HR and mean arterial BP were significantly lower 5 and 10 min after initiation of sedation in PR group when compared with PA group. Both HR and mean arterial BP returned to presedation readings 30 min after initiation of sedation in PR group but not in PA group. No differences between the two groups concerning oxygen saturation, RSS, endoscopist and patient satisfaction scores. Postprocedure and PACU times were significantly prolonged in PA group.
  
  
  CONCLUSIONS
  PCS with either remifentanil/propofol or alfentanil/propofol for patients undergoing outpatient colonoscopy is safe and feasible. Remifentanil/proofol has more beneficial advantages in this setting secondary to its more rapid clearance.
authors.affiliation: Department of Anesthesia and Intensive Care, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Sherif S
authors.initials: SS
authors.lastname: Sultan
keywords: Alfentanil; colonoscopy; patient-controlled sedation; remifentanil