RESUMO
Commonly used methods of performing peripheral nerve blocks include elicitation of paresthesia and motor response to an electrical stimulus. The objective of this study was to compare the efficacy and reliability of these two methods in performing sciatic nerve block for lower limb surgery in elderly patients. Sixty patients, 60 - 90 years of age were randomly divided into two groups in this observer blinded study. In Group I Sciatic nerve block was established with a nerve locator and in group II paraesthesia elicitation technique was used. 20 ml of 0.5% bupivacine was administered in both groups. Haemodynamic parameters were recorded before and after the sciatic nerve block. We recorded the time of onset and extent of both sensory and motor blocks. The severity of pain was also noted in both groups. Statistically significant differences were seen in depth of sensory and motor blocks and degree of pain between groups [P < 0.05]. The time of onset of block was same in both groups and haemodynamics remained stable before and after the block. The use of nerve locator is more effective and successful in performing peripheral nerve blocks in comparison to paresthesia elicitation technique