Spinal, epidural or propofol anaesthesia for out-patient knee arthroscopy?

Background: We have compared three different methods of anaesthesia for out-patient knee arthroscopy in terms of peri operative conditions, postoperative pain, time taken and economy. Methods: 91 ASA I-II patients scheduled for elective knee arthroscopy were included. After premedication with diazepam 10 mg and naproxene 500 mg orally, they were randomly assigned into one of three groups: Group S (n=32) received spinal anaesthesia with lidocaine 50 mg/ml 1.5-2 mi in 7.5% glucose through a 27-G Quincke needle, Group E (n=29) received epi dural anaesthesia with mepivacaine 20 mg/ml and epinephrine 5 mu g/ml, 15-20 mi, and Group P (n=30) received propofol an aesthesia with a bolus induction of 2 mg/kg followed by infusion. Results: The time from start of anaesthesia until start of operation was significantly less in Group P than in the two other Groups: 7.4 +/- 5.4 min as compared to 23.0 +/- 4.8 min in Group S and 31.0 +/- 9.1 min in Group E (mean +/- SD, P<0.05). After end of surgery, the duration of the postoperative regional block was 75 +/- 28 min in Group S and 125 +/- 79 min in Group E (P<0.05). In Group S and Group E the postoperative pain was significantly :Less than in Group P at admission to the recovery unit and 60, 120 and 180 min later (P<0.05). The overall incidence of postoperative nausea or vomiting was less than 5% with no differences between the groups. One patient in Group E had block failure and one patient in Group S had a post-spinal headache. The perioperative costs of drugs and disposables were highest in Group P (30 USD) and lowest in Group S (6.5 USD). Conclusion: Propofol anaesthesia results in the shortest stay in the operation theatre but a higher degree of postoperative pain and a higher cost of drugs and disposables.