Effect of Fentanyl and Dexmedetomidine as Additives to 0.5% Ropivacaine in Ultrasound Guided Supraclavicular Brachial Plexus Block for Elective Upper Limb Surgeries: A Randomised Clinical Trial

DOI: 10.7860/JCDR/2022/58281.16929 Original Article Anaesthesia Section Effect of Fentanyl and Dexmedetomidine as Additives to 0.5% Ropivacaine in Ultrasound Guided Supraclavicular Brachial Plexus Block for Elective Upper Limb Surgeries: A Randomised Clinical Trial M Umamaheshwar1, KM Shwetha2, Ramarao Bhogadi3 ABSTRACT Introduction: Supraclavicular brachial plexus block is a superior alternative to general anaesthesia for upper limb surgeries, and use of ultrasound makes it safe and efficient in implementation. Ropivacaine, having significantly higher threshold for cardiotoxicity and neurotoxicity and more potent blocker of A and C fibres, renders good sensory blockade and lesser motor. Hence, to overcome this, additives are added. Aim: To evaluate the block characteristics with addition of either fentanyl or dexmedetomidine to 0.5% ropivacaine for supraclavicular brachial block. Materials and Methods: This randomised double-blinded clinical trial, was conducted on 50 patients posted for upper limb surgeries under supraclavicular brachial plexus block were randomly allocated to either receive 30 mL of 0.5% ropivacaine with 50 µg fentanyl (Group RF) or 30 mL of 0.5% ropivacaine with 50 µg dexmedetomidine (Group RD). The time for onset of sensory block and motor block were noted. Intraoperative haemodynamic were monitored in all the patients. Postoperatively Visual Analog Scale (VAS) scoring for pain, the time for rescue analgesia and the duration of sensory and motor blockade were noted. Results: Both groups were comparable with respect to age, gender and American Society of Anaesthesiologists (ASA) grading. The onset of both sensory (p-value 0.008) and motor block (p-value 0.0005) was faster in Group RD compared to Group RF which was highly significant statistically. The duration of sensory (p-value 0.0005) and motor block (p-value 0.0005) was longer in Group RD compared to Group RF which was highly significant statistically. The requirement for rescue analgesia was lesser in Group RD since the mean VAS score was persistently low which was statistically significant (p-value <0.01) compared to Group RF. Conclusion: The blockade improved better with addition of dexmedetomidine than fentanyl to 0.5% ropivacaine. There were no increased incidence for side-effects. Keywords: Haemodynamics, Motor block, Side-effects INTRODUCTION Brachial plexus block is achieved commonly via interscalene, supraclavicular, infraclavicular, or axillary approach. Out of which, supraclavicular block is considered as “spinal of the arm” as it can anaesthetise the entire arm just distal to the shoulder. The use of ultrasound for supraclavicular brachial plexus block has improved the success rate of the block, as it decreases the incidence of pneumothorax and local anaesthetic systemic toxicity [1]. Regional anaesthesia has several advantages like excellent peri-operative analgesia, avoidance of airway instrumentation, avoidance of opioidrelated side-effects, decreased recovery time and improved patient satisfaction [2]. Regional anaesthesia techniques have been limited by three major factors like local anaesthetic agent’s slow onset time, short duration of action and limited duration of postoperative analgesia. Short acting and long acting local anaesthetic have been combined together to have a shorter onset of action and longer duration of action. Also, several adjuvants have been used with local anaesthetics during blocks. Alpha-2 agonists like clonidine, dexmedetomidine, opioids like fentanyl, tramadol and steroids like dexamethasone have been used to prolong neural blockade [3]. Various studies have concluded that the addition of perineural dexmedetomidine to local anaesthetics significantly shortened the onset of sensory and motor block, prolongs the duration of analgesia, and prolongs the time to first analgesic request with minimal side-effects [4-6]. Addition of fentanyl to local anaesthetics enhances postoperative analgesia, but the duration of this effect was very brief [7]. The present study 44 was conducted to compare the additives dexmedetomidine and fentanyl with ropivacaine in supraclavicular brachial plexus block. The block was performed under ultrasound guidance to achieve maximum success and better block characteristics. The primary outcome measures were the onset and time to complete sensory and motor block and the total duration of postoperative analgesia. Secondary objectives were the haemodynamic changes following the block, sedation (Ramsay sedation score), and any sideeffects of drugs used or complications related to block between the two groups. MATERIALS AND METHODS This randomised double-blinded clinical trial, was conducted between January 2018 to June 2019 in the Department of Anaesthesiology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India. The Institutional Ethics Committee had provided the clearance (VIEC/2017/APP/114). Sample size calculation: Based on the study by Cham S et al.,[4] the mean±SD of the onset of motor block of two groups was 3.06±0.25 and 3.26±0.45 minutes, respectively, considering confidence Interval of 95% and power of 80% with anticipated mean difference of 0.2 and assumed standard deviation of 0.25, the sample size was estimated employing the below-mentioned formula n=[2*{Z(1-α/2)+Z1-β}2*σ2]/d2 Zα/2=(α/2)th quantile of normal distribution Journal of Clinical and Diagnostic Research. 2022 Sep, Vol-16(9): UC44-UC47 www.jcdr.net M Umamaheshwar et al., Fentanyl and Dexmedetomidine as Additives to Ropivacaine in Supraclavicular Brachial Plexus Block Zβ=(β) thquantile of normal distribution (ulnar nerve), thumb opposition (median nerve), and flexion of elbow (musculocutaneous nerve) according to the modified Bromage scale on a 3-point scale as, D=difference in means σ2=population variance And the calculated sample size of each group was 25 in each group, total 50. Inclusion criteria: A total of 50 patients posted for upper limb surgeries under regional anaesthesia, belonging to American Society of Anaesthesiologists (ASA) grade I and II, aged between 18 and 60 years, weighing 50-70 kgs were included in the study. Exclusion criteria: Patients with known allergy to the study drug, those uncooperative for the block or any psychiatric illness history were excluded from the study. The patients satisfying the inclusion criteria were thoroughly evaluated, and written informed consent was obtained. Using the sealed envelope method, patients were randomly allocated into two groups [Table/Fig-1]: GROUP RF: 30 mL 0.5% ropivacaine+50 µg fentanyl Group RD: 30 mL 0.5%ropivacaine+50 µg Dexmedetomidine. • Score 1: Partial block, • Score 2: Almost complete block. • Score 3: Total block [4]. Time of onset of sensory block, defined as the time from completion of injection to the time sensory block began to be detected in the distribution of any one of the major nerves. Time of onset of motor block, defined as (...truncated)