Fixed-dose Hyperbaric Levobupivacaine versus Reconstituted Hyperbaric Levobupivacaine for Spinal Anaesthesia in Infra-umbilical Surgeries: A Double-blinded Randomised Clinical Study

Introduction: Spinal anaesthesia is a commonly used technique for infra-umbilical surgeries, with the choice of anaesthetic formulation playing a crucial role in efficacy and patient outcomes. Baricity or the density of the anaesthetic solution relative to cerebrospinal fluid, affects the spread and distribution of the drug, influencing the level and duration of anaesthesia. Fixeddose Combination (FDC) vials provide convenience and precise dosing, whereas reconstituted formulations allow for more personalised adjustments but require additional preparation. Aim: To compare the clinical effects of FDC hyperbaric levobupivacaine and reconstituted isobaric levobupivacaine in spinal anaesthesia. Materials and Methods: A randomised double-blind clinical study was conducted at the Department of Anaesthesiology, Teerthanker Mahaveer Medical College and Research Centre (TMMC&RC), Moradabad, Uttar Pradesh, India, enrolling 132 participants scheduled for infra-umbilical surgeries between November 2022 and April 2024. Participants were randomly allocated into two equal groups using a computer-generated randomisation table. Group F received a FDC of 0.5% hyperbaric levobupivacaine (15 mg/3 mL) with dextrose 80 mg/mL and 25 μg fentanyl, while Group R received a reconstituted mixture of 0.5% isobaric levobupivacaine (15 mg/3 mL) with dextrose 50 mg/mL and 25 μg fentanyl. All drugs were administered intrathecally under aseptic conditions. Haemodynamic variables were recorded at predefined intervals, and demographic characteristics {age, gender, Body Mass Index (BMI), American Society of Anaesthesiologists (ASA) grade} were compared between groups. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 17.0 with Independent t-tests and Chi-square tests, with p-value <0.05 considered statistically significant. Results: A total of 132 patients completed the study (66 per group). Baseline demographics differed in weight, height, BMI, and ASA grade (p-value <0.05). Sensory and motor block characteristics were comparable between groups (p-value >0.05). Group F required a significantly lower total analgesic dose (172±34.2 mg vs 193±37.3 mg; p-value=0.001) and showed lower VAS scores at 30 minutes, one hour, four hours, six hours, and eight hours (p-value <0.05). Haemodynamic variables, including Systolic Blood Pressure (SBP) and Mean Arterial Pressure (MAP), were more stable in group F at several intervals. Conclusion: Both fixed-dose hyperbaric levobupivacaine and reconstituted isobaric levobupivacaine provided effective spinal anaesthesia for infra-umbilical surgeries. While fixed-dose vials offer greater convenience and dosing accuracy, reconstituted formulations allow for personalised adjustments but require additional preparation. The choice between these formulations should be guided by surgical needs, patient characteristics, and cost considerations, ensuring optimal anaesthesia outcomes.