Comparison of clonidine and dexmedetomidine as adjuncts to intravenous regional anaesthesia

Abstract

Background and Aims:Intravenous regional anaesthesia (IVRA) provides reliable and rapid analgesia with good muscular relaxation of the extremity distal to the tourniquet, but tourniquet pain and absence of post-operative analgesia are major drawbacks. α2 agonists, clonidine and dexmedetomidine are known to potentiate peripheral nerve blocks. The aim of this study was to compare clonidine and dexmedetomidine as adjuvants to IVRA with respect to block characteristics, tourniquet pain and post-operative analgesia.Methods:A prospective, randomised, double-blind study was conducted on 60 adult patients of American Society of Anesthesiologists physical status grades I and II, in two groups of 30 each, to receive either clonidine 1 μg/kg or dexmedetomidine 1 μg/kg added to 40 ml 0.5% preservative-free lignocaine. Independent samples t-test was used for analysing demographic data, haemodynamic data and block characteristics and Mann-Whitney U-test for skewed data.Results:Sensorimotor block onset was significantly faster and recovery delayed with dexmedetomidine as compared to clonidine. Intra-operative visual analogue scale (VAS) at 10 min, 15 min and 40 min and post-operative VAS at 30 min and 2 h were significantly higher with clonidine. Fentanyl consumption and sedation were comparable. Duration of analgesia was significantly longer with dexmedetomidine. Haemodynamic parameters were comparable.Conclusions:Dexmedetomidine significantly facilitates onset, prolongs recovery of sensory as well as motor block and also prolongs duration of analgesia as compared to clonidine. Both decrease tourniquet pain satisfactorily and have comparable intra-operative fentanyl requirement . Patient satisfaction is better with dexmedetomidine.

The Study of Effect of Dexmedetomidine on the Characteristics of Bier’s Block (Intravenous Regional Anaesthesia) When Administered in Addition to Lidocaine for Forearm and Hand Surgeries

“…α-2 adrenergic receptor located at nerve endings may have a role in the analgesic effect of dexmedetomidine by preventing norepinephrine release. 10 The results were comparable with the study done by Pachore et al, 18 Shilpashri et al 20 and Balamurugan et al 21 In our study, the deflation of tourniquet was done in cyclic manner, which prevented sudden release of drug in systemic circulation and associated with lesser side effects. No patients in Group L had any side effects.…”

“…It thus prolongs the duration of sensory and motor blockade induced by local anaesthetics irrespective of the route of administration. 10 Mainly, two doses of dexmedetomidine have been used as an adjuvant in IVRA by many researchers in various studies, i.e. 0.5 mcg/kg and 1 mcg/kg, 17 but high doses of dexmedetomidine is associated with significant sedation postoperatively.…”

“…3/Issue 90/Nov. 10,2016 Page 4927 mins. The cuff deflation was performed in cyclic deflation technique.…”

“…8,9 Dexmedetomidine, a potent α-2 adrenoceptor agonist is approximately 8 times more selective towards the α-2 adrenoceptors than clonidine. 10 In addition to sympatholytic effects, dexmedetomidine has antihypertensive, anxiolytic, sedative/hypnotic and analgesic effects. It has been used clinically as an adjuvant to anaesthesia as an analgesic agent and also as a sedative in intensive care unit.…”

Dexmedetomidine as an adjuvant for intravenous regional anesthesia in upper limb surgeries

“…Onset of motor block was defined as time from the complete injection of drug to no voluntary movement of wrist and fingers was possible. [ 4 6 ] After complete sensory block was achieved, the distal cuff was inflated to 250 mmHg and the proximal cuff was deflated, and the surgery was allowed to start.…”