A prospective randomised study to evaluate the influence of epidural volume extension on spinal block with hyperbaric levobupivacaine for lower limb surgeries

combined spinal epidural anesthesia is a  regional anesthesia technique preferred for lower limb surgeries due to its rapid onset through the spinal component and post operative pain relive through epidural component while avoiding the disadvantages of both. epidural volume extension is a modification of combined spinal epidural anesthesia where in normal saline is injected into the epidural space immedietly after the intrathecal dose as a part of CSEA so the injected volume of fluid in the epidural space causes compression of the CSF resulting in cephalad spread of local anesthetic present in the subarachnoid space. So in the present study  objective is to compare the onset and duration of sensory blockade , maximum level of sensory blockade achieved and onset and duration of motor blockade. And also to compare thr effect of hemodynamic changes like hypotension, bradycardia and other side effects like nausea, vomiting and shivering.