A comparative study of plain and hyperbaric solutions of 0.75% ropivacaine in spinal anaesthesia in elective lower abdominal and lower limb surgeries

Abstract

Background and objective: Spinal anaesthesia is the most common technique of regional anaesthesia used for lower abdominal and lower limb surgeries. Bupivacaine is the commonly administered drug. Ropivacaine, is an amino amide local anaesthetic, which has less cardiovascular and central nervous systems toxicity compared with bupivacaine. This study is undertaken to compare plain and hyperbaric solutions of ropivacaine in spinal anaesthesia. Methods: 80 patients of ASA I/II physical status undergoing elective lower abdominal and lower limb surgeries were randomised into 2 groups. Group C (n=40) patients received 3ml of 0.75% plain ropivacaine with 0.4 ml of normal saline and Group D (n=40) patients received 3 ml of 0.75% plain ropivacaine with 0.4 ml of 25% dextrose. Hemodynamic parameters, time of onset and duration of sensory and motor blockade, maximum height of block, total duration of sensory and motor blockade and time to mobilise were recorded. Results: Hemodynamic parameters were comparable between the two groups except at few intervals. Demographic data and duration of surgery were comparable. The onset of block to T10 in group C 10.1 ± 1.6 min, group D 4.6 ± 0.9 (p value <0.001), mean time to maximum block in group C 13.0 ± 2.7 min, group D 8.9 ± 0.9 (p value <0.001) were statistically significant. Mean duration of block at T10 in group C was 94.7± 24.7 min, group D 146.1 ± 31.9 (p value <0.001), duration of sensory regression in group C 291.6 ± 74.3 min, group D 239.9 ± 39.8 (p value <0.001), duration of motor regression in group C 225.4 ± 68.4 min, group D 186.0 ± 41.0 (p value 0.003) and time to mobilise in group C was 309.1 ± 76.3 min, group D 251.0 ± 41.1 min (p value <0.001) which were statistically significant. Conclusion: Hyperbaric ropivacaine has early and faster onset, spreads more to higher levels, has more denser block and is early to regress compared to plain ropivacaine.