Epidural anaesthesia; single-shot for day-case knee arthroscopy using a 50-50 mixture of lignocaine and bupivacaine

ABSTRACT

To compare the benefits and adverse effects of three different drug combinations when used for single-shot epidural anaesthesia for day-case arthroscopy. Prospective, random, double-blind study. A 250 bedded secondary care hospital. From October 2005 to Feb 2007. 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]. 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 S.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. The results of our study show that a 50-50 mixture of lignocaine and bupivacaine with fentanyl 50 pg when used for single-shot epidural anaesthesia for day case knee arthroscopy, provides better quality of analgesia, with fewerincidences of side effects and more patient satisfaction as compared to lignocaine or bupivacaine alone