[Neostigmine added to bupivacaine in axillary plexus block: which benefit?]

Recent study showed that neostigmine (500 microg) by intra-articular produces postoperative analgesia without adverse effect. The author's goal was to determine whether 500 microg of neostigmine added to bupivacaine in axillary plexus block could prolonged postoperative analgesia without increasing the incidence of side effects.

Ninety patients scheduled for orthopedic or plastic surgery with axillary plexus block were randomly assigned to one of 3 groups : group 1 (TGr n = 30) received saline solution (1 ml) in the axillary plexus, group 2 (NAGr n = 30) received 500 microg (1 ml) neostigmine in the axillary plexus and group 3.500 microg neostigmine subcutaneously (NSGr n = 30). We evaluated visual analog pain scores (VAS), the consumption of the ketoprofene, nausea and vomiting incidence during the first 24 h. ANOVA, Kruskall Wallis and Fisher tests were used for statistical analysis. A p value of <0.05 was considered significant.

The VAS score was lower in NAGr (21 +/- 18) vs NSGr (31 +/- 14) and control group TGr (45 +/- 2) (p < 0.05). The consumption of the ketoprofene is 127 +/- 65 mg in NAGr vs 150 +/- 53 mg in NSGr and 200 +/- 50 mg in group TGr (p = 0.02). Incidence of nausea and vomiting was 3.5% in NAGr vs 6.8% in NSGr and 0% for TGr.

Neostigmine combined to a mixture of lidocaine and bupivacaine prolongs postoperative analgesia after axillary plexus block.