Effect of Epidural Volume Extension with 10 mL versus No Saline on Combined Spinal Epidural Anaesthesia for Elective Lower Limb Surgeries: A Randomised Controlled Study

Introduction: Combined Spinal Epidural Anaesthesia (CSEA) is a regional anaesthetic technique that offers flexibility in prolonging anaesthesia and improving postoperative analgesia compared to spinal anaesthesia. Aim: To compare the effects of Epidural Volume Extension (EVE) with 0 mL and 10 mL of 0.9% normal saline on spinal anaesthesia in lower limb orthopaedic surgeries. Materials and Methods: A randomised controlled study was conducted at Deen Dayal Upadhyay Hospital, Delhi, India on 72 American Society of Anaesthesiologists (ASA) I and II patients undergoing elective orthopaedic surgeries under CSEA. Patients were assigned to two groups: S0 with 0 mL and S10 with10 mL of 0.9% normal saline on spinal anaesthesia using 12.5 mg (2.5 mL) of 0.5% hyperbaric bupivacaine in lower limb orthopaedic surgeries lasting less than three hours. Sensory block onset (pinprick method), motor block onset (Bromage scale), level of block, time to maximum sensory block, two-segment regression, and time to first epidural top-up were recorded. Haemodynamic parameters {Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), and SpO2 } were monitored preoperatively, intraoperatively and postoperatively. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 21.1, with p-value <0.05 considered significant. Results: Both groups, group S0 (N=36) and group S10 (N=36), were comparable in terms of age, gender, ASA grade and surgery duration. A significantly higher sensory block level was achieved in S10, (58.33% reached T4 vs. T8–T10 in S0 (p-value <0.001). Time to maximum sensory blockade was shorter in S10 (8.75±1.13 minutes vs. 10.17±3.85 minutes; p-value=0.042), while two-segment regression was longer (100.61±6.02 minutes vs. 76.72±7.66 minutes; p-value=0.001). Epidural topups were required in 83.33% of S0 patients vs. 16.67% in S10, with a longer mean time to top-up in S10 (147.5±4.97 minutes vs. 111.87±7.56 minutes; p-value <0.001). Haemodynamic parameters were similar across groups (p-value>0.05). Conclusion: EVE with 10 mL of 0.9% normal saline enhances sensory block level, prolongs two-segment regression time and reduces the need for epidural top-ups in CSEA for lower limb surgeries. This technique maintains haemodynamic stability, making it a safe and effective modification of CSEA. Compared to no volume extension, EVE improves intraoperative conditions and enhances postoperative analgesia.