Combined spinal epidural anaesthesia technique for providing pain relief in orthopaedic procedures has gained popularity. This technique is done as a one-time procedure where first the epidural space is located and intrathecal administration of either a combination of local anaesthetic and opioid or each component separately is done, followed by catheter insertion in the epidural space. It combines the advantages of rapid onset and the reliability of blockade obtained spinally along with the flexibility given by epidural catheter avoiding the disadvantages of either.

The combined spinal epidural anaesthesia technique (CSE), first reported in caesarean section in 1984, has recently gained popularity. Combined Spinal and Epidural Anaesthesia (CSE) offers advantages over the epidural or spinal anaesthesia alone. CSE has the reliability of subarachnoid block as well as the flexibility of epidural block. Combined spinal epidural involves the use of a lower dose of spinal anaesthetic and allows flexibility of epidural reinforcement when required. The use of epidural or spinal anaesthesia during major hip surgeries has been linked to reduced risk of perioperative complications such a deep vein thrombosis, less deterioration of cerebral and pulmonary functions in patients who are at a higher risk of complications,early ambulation, superior pain relief, and thus higher patient satisfaction.

The epidural volume extension (EVE) technique is a modification of CSE in which the onset and level of block obtained by subarachnoid block is increased by a small volume of saline or local anesthetic administered through the epidural catheter.[3] The effect of EVE with saline in the enhancement of spinal block includes the volume effect

in which the theca is compressed by injected epidural saline, resulting in squeezing of CSF and more cephalic spread of subarachnoid local anesthetic. Injected saline extends the block height by a mechanical volume effect (time-dependent effect) and increases the regression time, thereby providing a longer duration of block with a smaller dose of hyperbaric bupivacaine given in subarachnoid space that may result in better hemodynamic stability and an early motor recovery.[4]The majority of hip orthopaedic surgery patients are elderly and have multiple coexisting medical problems. Ensuring hemodynamic stability in these patients requires selection of appropriate techniques of regional anaesthesia, focussing on maintaining a safe and desirable level of blockade while limiting extensive sympathectomy.

We hypothesize that EVE would achieve a higher level of the sensory block using a smaller volume of local anesthetic which otherwise would achieve a lower level of the block without EVE and may also reduce the incidence of hemodynamic side effects.

This study is aimed to evaluate the efficacy of block provided by extending the epidural volume with two different doses of normal saline for orthopaedic surgeries around hip joint using a low dose intrathecal hyperbaric bupivacaine.