Comparison of the efficacy of supraclavicular block with bupivacaine (0.5%) combined with dexmedetomidine, granisetron and magnesium sulphate in sensory and motor block and haemodynamic parameters of patients in upper-extremity orthopaedic surgery: A randomised clinical study

Abstract

Introduction: Peripheral nerve block leads to effective pain control. Peripheral nerve blocks are used both in general anaesthesia and as regional anaesthesia alone. The aim of this study was to compare the characteristics of the supraclavicular block with bupivacaine (0.5%) in combination with dexmedetomidine, granisetron and magnesium sulphate in upper-limb orthopaedic surgery. Materials and Methods: This double-blind clinical trial was carried out on 105 patients who were candidates for upper-limb orthopaedic surgery in Valiasr Hospital in Arak. The patients were divided into three equal groups (dexmedetomidine, granisetron and magnesium sulphate) using the block method for randomisation. Mean arterial pressure, heart rate and arterial oxygen saturation every 5 min until the end of the surgery, onset and duration of sensory and motor block, mean opioid consumption in 24 h and post-operative pain during recovery and 2 h after surgery at 4, 8, 12 and 24 h were recorded. Data were analysed by SPSS.22 software. Results: The lowest heart rate at all times and the lowest blood pressure from 40 min to the end of surgery were observed in the dexmedetomidine group (P < 0.05). The time to the onset of sensory block and the time to the onset of motor block were shorter in the magnesium sulphate and dexmedetomidine groups, respectively. Moreover, the duration of the sensory and motor block was longer in the dexmedetomidine group (P = 0.0001). In addition, pain and amount of opioid consumption were lower in the dexmedetomidine group (P = 0.0001). Conclusion: Magnesium sulphate caused earlier onset of sensory block, while dexmedetomidine increased the duration of sensory and motor block. In the dexmedetomidine group, haemodynamic changes were made in the form of a decrease in heart rate and blood pressure, which, of course, did not require special treatment. As such, magnesium sulphate as an adjuvant is recommended to be used in cases where there is a requirement for the rapid onset of sensory block. Meanwhile, dexmedetomidine should be used as an adjuvant for the rapid onset of motor block and increase of the duration of sensory and motor block when taking into account the patients' physical conditions and the anaesthesiologist's discretion.