Addition of intrathecal midazolam to bupivacaine produces better post-operative analgesia without prolonging recovery

Objective: The administration of midazolam by centroneuraxis route has been shown to produce segmental antinociception. This midazolam analgesia was f ound to enhance the effects of local anesthetics given in combination epidu rally without any adverse effects. The present study was designed to evalua te the post-operative analgesic effect of intrathecal midazolam-bupivacaine mixture in patients undergoing knee arthroscopy. Methods: Thirty healthy p atients scheduled for knee arthroscopy were divided into two groups to rece ive either midazolambupivacaine mixture (group M; n = 15) or bupivacaine al one (group B; n = 15) intrathecally. Level of sensory block, sedation score , assessment of pain using visual analogue score were recorded in both grou ps at regular time intervals. Time to block regression, recovery to ambulat ion and ability to void were recorded and noted before discharge. Results: A significantly higher VAS score was seen in group B patients as compared t o the score observed in group M patients before discharge (p < 0.05). All p atients received rescue analgesia in group B at a mean duration of 258 +/- 46.8 minutes whereas only one patient in group M required supplemental anal gesia within this period. Time to regression of sensory analgesia to L5-S1 level was longer in group M (267 +/- 67.38) as compared to group B (229.8 /- 41.4) (p < 0.05). Blood pressure, heart rate, oxygen saturation and seda tion score showed no differences between the groups. Neither motor block no r time to void were prolonged with the addition of midazolam to bupivacaine . Conclusion: The results suggest that addition of midazolam to bupivacaine intrathecally provided better post-operative analgesia without any adverse effects.