Abstracts and Highlight Papers of the 33rd Annual European Society of Regional Anaesthesia & Pain Therapy (ESRA) Congress 2014

NEOSTIGMINE PROLONGS ANALGESIA IN PERIPHERAL NERVE BLOCK: A META-ANALYSIS. Background and aims: Background: Neostigmine- as an acetylcholinesterase inhibitor- can increase the acetylcholine receptors located on the dorsal horns inducing analgesia; the use of neostigmine as an adjuvant in locoregional anaesthesia showed a dose-dependent analgesic effect even if associated with nausea and vomiting. The intra-articular administration of neostigmine showed a significant analgesic effect; it is presumable that neostigmine can also be used as an adjuvant in the peripheral blocks.We performed a meta-analysis to assess the efficacy of peripherally administered neostigmine on the duration of analgesia and side-effects when supplemented to local anesthetics for peripheral nerve blocks. Objective:We performed a meta-analysis to assess the efficacy of peripherally administered neostigmine on the duration of analgesia and side-effects when added to local anesthetics for peripheral nerve blocks. Methods: Design: A meta-analysis of randomized-controlled human trials. Data sources: Google Scholar and PubMed were searched (updated May 25th, 2014). Authors and external experts were contacted. Eligibility criteria: Inclusion criteria for potentially relevant studies were: random allocation to treatment, comparison of neostigmine administered in peripheral nerve block versus placebo; experimental design with approval of Ethical Committee. Results: The use of neostigmine as adjuvant in the peripheral nerve block could prolong the duration of analgesia: + 47.88 min [CI: 21.86 –74.08 min] of analgesic effect, p for effect 0.0003; p for heterogeneity 0.69; I2=0%. The risk of nausea is not increased: 6/116 in neostigmine group vs 0/145 episodes in control arm; OR 5.34; 95% CI 0.89-31.89, p for effects 0.07, p for heterogeneity 1.00; I2= 0%). Conclusions: Peripherally administered neostigmine might prolong the duration of analgesia without increasing side effects, particularly nausea.