Comparison of fentanyl and alfentanyl for outpatient anaesthesia

This study has been made to compare alfentanil and fentanyl in outpatient knee arthroscopy. Fifty patients of ASA I and II were included in the study. Patients were randomly divided into two groups (n=25). In alfentanil group, anaesthesia was induced with 30 ?g/kg alfentanil, 4 mg/kg Na thiopentone and 1.5 mg/kg succinylcholine. In fentanyl group 2 ?g/kg fentanyl, 4 mg/kg Na thiopentone and 1.5 mg/kg succinylcholine were used far induction. Anaesthesia was maintained by IPPV using 70% nitrous oxide in oxygen and added 1 ?g/kg/min alfentanil infusion in alfentanil group versus 0.1 ?g/kg/min fentanyl infusion in fentanyl group. During the operation systolic and diastolic arterial blood pressure, pulse rate and oxygen saturation were recorded. After discontinuation of nitrous oxide we recorded the time of eye opening and ability to answer verbal commands. Additionally each patient was evaluated at postoperative 1., 5., 10., 30., 40., 50. and 60th minutes with postanesthetic recovery room scores (PARRS). Trieger dot test was used to determine cognitive function (preoperative, postoperative 30, 45, 60, 90 and 120th minutes). In this study we could not find any difference between two drugs about systolic, diastolic and mean arterial pressure, pulse rate, oxygen saturation, side effects and early recovery time. But in alfentanil group, the results of psychomotor test which determines discharge time were more convincing. We concluded that; alfentanil is a more preferable agent for ambulatory surgery and provides adequate anaesthesia when combined with nitrous oxide and neuromuscular blocker.