Comparison of the Effects of Epidural Clonidine and Fentanyl on Spinal Anaesthesia in Lower Abdominal and Lower Limb Surgeries – A Randomised Controlled Study from Delhi, India

Abstract

BACKGROUND Addition of epidural adjuvants like opioids or α2-adrenoreceptor agonists can enhance the effectiveness of local anaesthetics for surgical procedures on lower abdomen, pelvis, and lower limbs, by intensifying the block and prolonging the duration of analgesia. We wanted to compare the duration of spinal blockade (sensory and motor) and the degree of analgesia between epidural clonidine and fentanyl before giving spinal anaesthesia. METHODS A prospective double blind randomized comparative study was conducted among 100 patients (18 - 65 years) scheduled for elective lower abdomen and lower limb surgeries. Patients were divided into two groups. For C group – clonidine 0.75ug / kg epidural given with spinal anaesthesia (5 % bupivacaine), in Group F fentanyl was given 1.5 ug / kg epidural with 5 % bupivacaine. The outcome measures were time of onset of sensory blockade, duration and level of sensory blockade, time to achieve highest blockade level, duration of motor blockade, vital parameters, and time of first rescue analgesia. All data was entered in MS excel and analysed. P value < 0.05 was considered significant. RESULTS The demographic data (age, gender) were comparable in both the groups. The preoperative blood pressure, pulse rate, SpO2 were comparable. Clonidine group had significantly lesser mean time of onset of sensory block and motor block (P < 0.001), higher duration of motor blockade (P < .0001) and higher time for first rescue analgesia (P < .0001) as compared to fentanyl group. The incidence of hypotension and bradycardia was more with clonidine group than with fentanyl group. CONCLUSIONS Clonidine 0.75 ug / kg is a better epidural adjuvant than fentanyl 1.5ug / kg when given by intrathecal route with 5 % bupivacaine in terms of mean time of onset and duration for both sensory and motor blockade. It also has better analgesic effect postoperatively. Whereas fentanyl is found to be safer in view of haemodynamic stability. KEY WORDS Clonidine, Fentanyl, Spinal Anaesthesia