Effectiveness of addition of neostigmine or dexamethasone to local anaesthetic in providing perioperative analgesia for brachial plexus block: A prospective, randomized, double blinded, controlled study.

BACKGROUND: Various local anaesthetic agents are used for brachial plexus block.We compared effectiveness of addition of Dexamethasone versus Neostigmine to Lignocaine, adrenaline admixtures for Brachial plexus block in providing perioperative analgesia.

METHODS: Ninety patients were randomized in three groups and were received 24 ml of study drugs. The group A [Lignocaine with adrenaline (1.5%)], group B [Lignocaine with adrenaline (1.5%)] +500 microg Neostigmine, and group C (Lignocaine with adrenaline (1.5%) +4 mg Dexamethasone) for brachial plexus block through supraclavicular approach. The observed parameters were onset of analgesia, completion of sensory and motor blockade, Duration of analgesia, Surgeon's score, side effects, number of supplemental analgesics doses and Visual analogue scale (VAS) score for pain in 12 hour of post-operative period.

RESULTS: Mean onset of analgesia 4.6+/-1.1 , 4.4 +/-0.8 , 3.8+/-1.8 mins in group A,B and C respectively and the Mean onset of motor blockade were 7.7+/- 2.0, 7.0+/-1.8, 6.0 +/- 2.1 mins in group A,B and C respectively. Similarly Mean Complete sensory block in 10.6 +/-3, 10.4+/-2.5, and 8.9+/-2.2 mins and Mean complete motor block in 17.3+/-4.3, 17.2 +/-4.0 and 14.7+/-3.5 mins in group A, B and C respectively were achieved. Duration of analgesia was 176.5+/-53.5, 225.7+/-53.3 and 454.2+/-110.7 mins in group A, B and C respectively. Duration of analgesia in group C was statistically significant in comparison with other groups. The number of mean analgesic requirement by group C (0.9+/-0.4) was significantly (p-0.005) lower. The mean VAS was significantly lower in group C in 12 hours post-operatively.

CONCLUSION: The onsets of action, duration of analgesia were better in dexamethasone group and also need less number of rescue analgesics requirement.