Safer colonoscopy with patient-controlled analgesia and sedation with propofol and alfentanil

Background: The aim of this study was to assess the efficacy of patient-con trolled analgesia and sedation with propofol/alfentanil for colonoscopy com pared with continuous drug infusion and conventional nurse-administered med ication. Methods: One hundred fifty patients undergoing colonoscopy on an outpatient basis were randomly assigned to 1 of 3 medication regimens. To maintain bl inding, all patients were connected to an infusion pump. Group 1 patients c ould self-administer boluses of 4.8 mg propofol and 125 mug alfentanil with out restriction. Group II patients received a continuous infusion with 0.04 8 mg/kg propofol and 0.12 mug/kg alfentanil per minute. Group III patients received intravenous premedication with 0.035 mg/kg midazolam and 0.35 mg/k g meperidine. Results: There were no differences between the groups with respect to pain (visual analogue scale) and procedure time. Patient-controlled analgesia an d sedation with propofol/alfentanil (group I) resulted in less of an increa se in the transcutaneous partial pressure of carbon dioxide (p = 0.0004) du ring colonoscopy and less of a decrease in mean arterial blood pressure (p = 0.0021) during recovery, as well as more complete recovery (p = 0.0019) a fter 45 minutes compared with conventional administration of midazolam/mepe ridine. Furthermore, patient-controlled analgesia and sedation yielded a hi gher degree of patient satisfaction than continuous infusion of propofol/al fentanil (p = 0.0033) or nurse-administered midazolam/meperidine (p = 0.009 4). Conclusions: Patient-controlled administration of propofol and alfentanil f or colonoscopy may provide a better margin of safety than conventional admi nistration of midazolam and meperidine and results in a higher level of pat ient satisfaction and shorter recovery.