Comparison of Two Different Doses of Intrathecal Clonidine as Adjuvant to Hyperbaric Levobupivacaine for Spinal Anaesthesia in Femur Fracture Surgeries: A Randomised Triple-blind Clinical Study

Introduction: Femur fractures in elderly patients present unique challenges for anaesthetic management. Spinal anaesthesia with adjuvants has emerged as a preferred technique to enhance the quality of blockade while minimising local anaesthetic doses. Intrathecal clonidine, as an adjuvant to local anaesthetics, enhances the quality and duration of spinal anaesthesia. However, the optimal dose remains controversial due to dosedependent side-effects. Aim: To compare the efficacy and safety of two different doses of intrathecal clonidine (30 μg vs 50 μg) as an adjuvant to hyperbaric levobupivacaine for spinal anaesthesia in femur fracture surgeries. Materials and Methods: This randomised triple-blind clinical study was conducted at the Department of Anaesthesiology at Shrimati Bhikhiben Kanjibhai Shah (SBKS) Medical Institute and Research Centre, Sumandeep Vidyapeeth, Piparia, Vadodara, Gujarat, India, from January 2022 to December 2024 after institutional ethics committee approval. A total of 62 American Society of Anaesthesiologists (ASA) I-II patients aged 18- 65 years undergoing femur fracture surgeries were randomly allocated into two groups. Group LC30 (n=31) received 3 mL of 0.5% hyperbaric levobupivacaine with 30 μg clonidine and Group LC50 (n=31) received 3 mL of 0.5% hyperbaric levobupivacaine with 50 μg clonidine, both diluted to a total volume of 3.5 mL with normal saline. The onset and duration of sensory and motor blockade, along with the duration of absolute and effective analgesia, were assessed. Data analysis was performed using Jamovi software with independent t-tests for continuous variables and Chi-square tests for categorical variables. A p-value <0.05 was considered statistically significant. Results: Demographic parameters, including age, gender, ASA grade and baseline haemodynamics, were comparable between the groups. No significant difference was observed in the onset of sensory or motor blockade between the two groups. The duration of sensory and motor blockade was longer in Group LC50 (263.30±9.2 and 359.20±18.1 min, respectively) compared to Group LC30 (215.78±7.7 and 300.27±10.6 min, respectively). The durations of absolute and effective analgesia were also longer in Group LC50 (300.50±18.2 and 451.70±18.2 min, respectively) compared to Group LC30 (289.90±11.9 and 315.10±37.6 min, respectively), with rescue analgesia required more frequently in the LC30 group. However, the LC50 group demonstrated a higher incidence of bradycardia (32.3% vs 12.9%), hypotension (45.2% vs 19.4%) and greater sedation compared to the LC30 group. Sedation scores were significantly higher in the LC50 group throughout the perioperative period. Conclusion: Intrathecal clonidine 50 μg combined with hyperbaric levobupivacaine provides significantly prolonged sensory and motor blockade with extended postoperative analgesia compared to a 30 μg dose. However, the higher dose is associated with an increased incidence of haemodynamic side-effects, necessitating closer monitoring and prompt intervention.