EPIDURAL ANAESTHESIA

SINGLE-SHOT FOR DAY-CASE KNEE ARTHROSCOPY USING A 50-50 MIXTURE OF LIGNOCAINE AND BUPIVACAINE

Abstract

Objectives: To compare the benefits and adverse effects of three different drug combinations when used for single-shot epidural anaesthesia for day-case arthroscopy. Design of Study: Prospective, random, double-blind study. Setting: A 250 bedded secondary care hospital. Period: From October 2005 to Feb 2007. Material and Methods: We studied 75 adult male patients, aged between 23 to 63 years, weight <100 kg, ASA physical status I or II undergoing elective knee arthroscopy as day-case procedure. Patients were randomly divided into three groups ( 25 patients in each group) and single-shot epidural anaesthesia was performed using a total of 20 ml epidural lignocaine 2% (Group 1) bupivacaine 0.5% (Group 2) or a mixture containing lignocaine 2% and bupivacaine 0.5%, 10 ml each (Group 3). Results: Time to achieve maximum height (in minutes) was similar in group-1 and group-3 (10±4 and 11±2), but it was significantly longer in group-2 (20±3). Block time was comparable in group-2 and 3 (130±25 and 118±37) but it was significantly shorter in group-1 (60±20). Post-operative discharge time was longest in the group-2, and comparable in group-1 and 3.The incidence of complications like bradycardia, hypotension, nausea and vomiting were more in group-2 and less in group-1 and group-3. Inadequate anaesthesia was more in group-1 and least in other two groups.
Four patients of group-1 needed rescue analgesia and two from same group needed general anaesthesia as compared to none in group-2 and group-3. In 4-point patient satisfaction scale, maximum patients from Group-3 rated it perfect while most patients from group-1 were not satisfied with the quality of anaesthesia. Conclusions: The results of our study show that a 50-50 mixture of lignocaine and bupivacaine with
fentanyl 50 μg when used for single-shot epidural anaesthesia for day case knee arthroscopy, provides better quality of analgesia, with fewer incidences of side effects and more patient satisfaction as compared to lignocaine or bupivacaine alone.