BACKGROUND: Knee arthroscopy is a commonly performed ambulatory surgical procedure. Both general and diverse types of regional anaesthesia have been used for these surgeries. Peripheral nerve blocks and spinal anaesthesia have many benefits in this outpatient setting and result in less post-operative resource use, better immediate post op analgesia and patient satisfaction. In recent years, peripheral nerve blocks have become increasingly popular but are still, less commonly used compared to spinal anaesthesia because of the increased time and expertise required for performing the blocks.

AIM: This study aims to compare the duration of analgesia caused by intrathecal bupivacaine with femoral 3-in-1 nerve block plus sciatic nerve block for orthopaedic knee surgeries and also to compare intra operative haemodynamics in these two groups of patients.

METHODS: After approval from Institutional Ethics Committee for this study, 60 patients in the age group of 15 – 55 years in ASA Gr I to III undergoing elective orthopaedic surgery of the knee were enrolled for the study. They were randomized into two groups. Group 1(n=30) or group FSB received femoral 3-in-l nerve block (15 ml with 0.5% Bupivacaine with 1/200,000 adrenaline), with Sciatic nerve block (30 ml of 0.5% Bupivacaine using nerve stimulator and USG guidance. Group II or group SA received 3.2 ml of 0.5% bupivacaine in the subarachnoid space after adequate preloading. All patients were monitored with pulse oximetry, NIBP, ECG Intraoperative sedation and analgesia were restricted to midazolam and fentanyl. The study compared the duration of analgesia in both the groups and the need of sedation/rescue analgesia from the time block was given. In the postoperative period, the patient was monitored for a period of 8 hours.

RESULTS: In comparison to Group 1(group FSB), patients in group 2(group SA) receiving nerve block had higher mean VAS scores and had incomplete anaesthesia for surgery requiring supplemental sedation for knee replacementbut had adequate anaesthesia for knee arthroscopy. 10% patients in the nerve block group required conversion of anaesthesia which was statistically significant (p=0.0237)

CONCLUSION: From the study, it was found that combined femoral- sciatic nerve block is an acceptable alternative for anaesthesia for knee arthroscopy but not for total knee replacement.

AUTHOR DETAILS
[a]- Dr. Anusha.k, Post Graduate, Anaesthesiology, Command Hospital, Air Force, Bangalore-560007
[b]-Col (Dr.) K. Prabhakaran, Professor, Dept. of. Anaesthesiology, Command Hospital, Air Force, Bangalore- 560007
[c]-Gp Capt. (Dr.) Sandeep Gupta, Associate Professor, Dept. of Orthopaedics, Command Hospital, Air Force, Bangalore-7