Addition of Dexmedetomidine to Low Dose Solution of Lidocaine for Intravenous Regional Anesthesia A Randomized Study

Abstract

Background and Aims: Intravenous Regional Anesthesia (IVRA) provides analgesia of distal part of limb by intravenous injection of local anesthesia in to the vein of the same limb, while the circulation to the limb is occluded by application of tourniquet. However, IVRAis limited by local anesthesia toxicity, tourniquet pain and absence of postoperative analgesia. Various additives to local anesthetics such as ketamine, clonidine, opiods, NSAIDs are used to address these issues. The aim of our study was to evaluate the effectiveness of Dexmedetomidine to low dose Lidocaine solution for IVRA.
Patients and Methods: A prospective, randomized double blind study was conducted on 60 patients divided in to two groups of thirty each; Group I patients received 40 ml of Lidocaine 0.25% while Group II patients received 40 ml of 0.25% of lidocaine mixed with I mcg/kg of dexmedetomidine. The motor and sensory block onset and recovery times were assessed. Tourniquet pain and sedation score were assessed intraoperatively and postoperatively.
Results: Sensory and motor block onset times were shorter and recovery times were prolonged in Dexmedetomidine group. The quality of anesthesia was better in the Dexmedetomidine group and the fentanyl dose required was also lower in the dexmedetomidine group. There was a significant difference in the postoperative analgesia time which was demonstrated by less use of intramuscular diclofenac in dexmedetomidine group.
Conclusions: A safe intravenous dose of lidocaine can be used for IVRA for superficial hand surgery, and the addition of I mcg /kg dexmedetomidine shortened the onset times for both sensory and motor blockade and improved the quality of anesthesia, with prolonged postoperative analgesia time. By adding dexmedetomidine we were able to reduce the dose of lidocaine to 0.25% concentration without compromising analgesia. JMS 2016; 19(1):21-25