Comparative Evaluation of Intravenous Dexmedetomidine and Clonidine on the Extent and Duration of Bupivacaine Spinal Anaesthesia: A Randomised Control Trial UC05-UC08
Dr. Amol Singam,
JNMC, Swanagi, Wardha, Maharashtra, India.
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Introduction: Several methods have been tried in recent years to alleviate post-operative pain, with partial or greater success. Alpha 2 adrenergic agonists have analgesic property when used as an adjuvant to regional anaesthesia. Clonidine is a partial a2-adrenoceptor agonist used intrathecally with a proven record of efficiency and safety. Dexmedetomidine is a selective a2-adrenoceptor agonist. Some studies have shown that intravenous dexmedetomidine is better than intravenous clonidine to provide better intraoperative analgesia during bupivacaine spinal anaesthesia.
Aim: To compare and evaluate the efficacy of intravenous dexmedetomidine with clonidine on the onset and duration of sensory and motor block following intrathecal bupivacaine.
Materials and Methods: In this randomised, double-blind clinical study, a total of 100 patients aged 20-60 years, American Society of Anaesthesiologists physical Status I or II scheduled for elective surgery under spinal anaesthesia were taken. These patients were randomly allocated to two equal groups of 50 with the help of a computer generated table of random numbers to receive the drugs after ethical approval. Group A received dexmedetomidine 0.5 Âµg/kg iv and Group B received clonidine 1 Âµg/kg iv. Time for the onset of sensory and motor blockade and duration of analgesia was noted. Haemodynamic changes, duration of post-operative analgesia and side-effects were also recorded. Data were analysed using chi-square test and the value of p<0.05 was considered statistically significant.
Results: Onset of sensory block was significantly shorter in Group A (2.60±1.12 minutes) as compared to Group B (3.45Â±1.50 minutes). Thus, dexmedetomidine has faster onset of sensory blockade than clonidine. Onset of motor blockade was significantly shorter in Group A (3.52±0.45 minutes) as compared to Group B (4.20±1.46 minutes). Thus, dexmedetomidine has faster onset of motor blockade than clonidine. Time for first analgesic request was 250.46±52.10 minutes in Group A and 180±50.28 minutes in Group B, thus post-operative analgesia was longer in Group A. The mean intraoperative RSS was higher in Group A, thus indicating that dexmedetomidine provides better sedation than clonidine.
Conclusion: Premedication with intravenous dexmedetomidine is better than intravenous clonidine to provide early onset of sensory analgesia, prolonged post-operative analgesia and adequate sedation.