Use of Intravenous Clonidine Vs Placebo for Prolonging Spinal Anaesthesia

Abstract

Use of intravenous clonidine for prolonging spinal anaesthesia with bupivacaine. Background: Several additives like clonidine are added to prolong spinal blockade. We considered using clonidine through intravenous route as it achieves peak plasma concentration more rapidly than oral or intrathecal routes. The aim was to study onset of analgesia and duration of sensory and motor blockade after spinal anaesthesia. Methods: Our study was a double blind prospective randomized controlled type of 100 patients. In clonidine group, intravenous 3 mcg/ kg of Clonidine diluted in 10ml of normal saline was administered after making the patient supine following the spinal blockade. In saline group, intravenous 10 ml of normal saline was administered. Patients were monitored until the sensory block regressed below L1 dermatome and knee flexion had recovered. Heart rate and mean arterial pressure were measured. Results: The mean duration of sensory blockade in clonidine group and saline groups were 206.20 and 136.20 minutes respectively. The motor blockade in clonidine group lasted for 157.60 and 129.60 minutes in saline group. The highest spinal level achieved was between T4 to T8 level and between T2 to T8 in clonidine and saline groups respectively. The incidence of bradycardia and hypotension was comparable. Conclusion: Intravenous clonidine significantly prolonged the duration of spinal blockade.