The study aimed to investigate the impact of Epidural Volume Extension (EVE) on sensory block height following intrathecal injections with reduced doses of bupivacaine. It was designed as a randomized, controlled, double-blind trial involving 80 adult male patients with ASA status I or II scheduled for orthopedic lower limb surgery under combined spinal epidural anaesthesia. Patients were randomly assigned to receive either a reduced intrathecal dose of bupivacaine (5 or 8 mg) with or without EVE, based on group allocation. The study aimed to compare the maximum sensory level (Smax) achieved with and without EVE application across the two different intrathecal doses. Further research is warranted to better understand the relationship between intrathecal dose and EVE efficacy, considering various factors such as instillation technique, timing, and patient characteristics. Results: The study revealed that applying Epidural Volume Extension (EVE) alongside a 5 mg intrathecal bupivacaine dose significantly decreased the maximum sensory block height (Smax) compared to not using EVE However, there was no significant difference in Smax when EVE was applied alongside an 8 mg intrathecal bupivacaine dose compared to without it. Conclusion: Avoiding the application of Epidural Volume Extension (EVE) to 5 mg plain bupivacaine during a combined spinal epidural block in patients undergoing lower limb orthopedic surgery is advisable. This caution stems from the observation that implementing EVE alongside this particular dosage of bupivacaine could lead to a reduction in the maximum sensory level