Efficacy of a nerve stimulator in regional analgesia; experience in a resident training programme

Forty interscalene brachial plexus regional blocks and twenty sciatic-femoral lower limb blocks were performed by 1st and 2nd year anaesthesia residents. Nerve trunk location was equally but randomly divided between use of a peripheral nerve stimulator and reliance on paraesthesiae. The stimulator group were sedated prior to nerve block while the non-stimulator group were similarly sedated after nerve block. There was no significant difference either in the number of needle insertions required for nerve location, or in the success rate, between stimulator and non-stimulator techniques. It is concluded that the stimulator is not a useful adjunct for nerve location, except in those patients who are unable to co-operate in eliciting paraesthesia. In such patients the stimulator permits a comparable success rate.