COMPARATIVE STUDY OF CLONIDINE AND FENTANYLAS ADJUVANTS TO INTRATHECAL ROPIVACAINE TO ASSESS THE DURATION OF ANALGESIA IN LOWER LIMB SURGERIES.

Abstract

Objective: Ropivacaine has the benet of providing appropriate intraoperative anaesthesia and effective postoperative analgesia when used for lower limb procedures under spinal anaesthesia, but some patients still experience pain after the medication has taken its full course of action. Adjuvants added to local anaesthetics have the advantage of extending the sensory-motor block's duration and lowering the overall dose necessary.4 This study compared Clonidine and Fentanyl as adjuvants to intrathecal ropivacaine in enhancing the quality of anaesthesia by postponing the requirement for analgesics. Methods: 100 Patients who were undergoing lower limb surgeries were selected for the study and divided into two groups of 50 each. Patients were randomly allocated to one of the two groups using envelope method for blinding the investigator. GROUP A patients received 2.5ml 0.75% Ropivacaine(18.75mg) + Clonidine(60μg) 0.2ml, GROUP B patients received 2.5ml 0.75% ropivacaine(18.75mg) +Fentanyl (20mcg) 0.2ml. The following parameters were noted: Time of injection of subarachnoid block, Time of onset of sensory block at T10 level, Time of onset of motor block, Duration of motor block, Degree of sedation. Results and discussion: No difference in the onset of sensory and motor blockade between the two groups. There was statistically signicant prolongation in the duration of motor blockade in clonidine group 195.6 minutes when compared with fentanyl group 157.8 minutes (p < 0.001). Analgesic duration was signicantly higher in clonidine group 321.70 ± 48.93 min when compared with fentanyl group 273.60 min (p = < 0.001).The difference in haemodynamic parameters – heart rate, systolic & diastolic blood pressure, mean arterial pressure (except for systolic blood pressure at 150 minutes) were statistically insignicant between both the groups. Sedation was slightly higher in the fentanyl group when compared to clonidine group but was statistically insignicant. None of the patients required supplemental oxygen, analgesia, or anxiolysis intraoperatively. No signicant difference in the incidence of complications like bradycardia, hypotension, respiratory depression etc between the two groups. Conclusion: In our study subarachnoid block with 0.75% isobaric ropivacaine (2.5ml) for lower limb surgeries with addition of clonidine 60mcg as anaesthetic adjuvant has advantage over fentanyl 20 mcg, as it increases the duration of spinal anaesthesia and increases postoperative analgesic duration. No signicant complications were recorded in both study groups