Clinical Evaluation of Analgesic Efficacy and Safety of IV Nalbuphine versus IV Butorphanol in Patients Undergoing Tympanoplasty: A Randomised Clinical Study

Anaesthesia Section DOI: 10.7860/JCDR/2022/57414.16918 Original Article Clinical Evaluation of Analgesic Efficacy and Safety of IV Nalbuphine versus IV Butorphanol in Patients Undergoing Tympanoplasty: A Randomised Clinical Study Shruti Hazari1, Mankeerat Kaur2, Anjali Sathish3, Varsha Vyas4, Srinivas Gadde5, Jayshree Vaswani6 ABSTRACT Introduction: Middle Ear Surgeries (MESs) are generally performed using local anaesthesia under sedation. Butorphanol and nalbuphine both are well-known synthetic opioid with agonist-antagonist characteristics. However, no reports present a direct comparison of the analgesic efficacy of these two drugs. Aim: To evaluate analgesic efficacy of intravenous butorphanol versus intravenous nalbuphine during Monitored Anaesthesia Care (MAC) in patients undergoing tympanoplasty. Materials and Methods: This randomised clinical trial was conducted at the Department of Anaesthesiology, School of Medicine, D.Y. Patil Deemed to be University, Mumbai, Maharashtra India, from March 2018 to March 2021. Total 112 adult patients, undergoing tympanoplasty, were randomly allocated into two groups. Group N received 0.2 mg/kg nalbuphine intravenous (i.v.) and group B received i.v. 0.02 mg/kg butorphanol. The patients were then evaluated for analgesic efficacy, sedation, blood pressure, Mean Arterial Pressure (MAP), Heart Rate (HR), Respiratory Rate (RR), blood oxygen levels (SpO2), Visual Analogue Scale (VAS) Score, need for intraoperative rescue sedation/analgesia, duration of action and side-effects. Results: A significant difference was observed in the patients’ responses to needle prick, where only 8 (13.3%) subjects gave a vocal response in group N versus 22 (36.6%) in group B. A significant difference in the mean time of onset of pain amongst both the group was recorded (3.16±1.38 hours in group N and 2.63±1.19 hours in group B). A significant difference was also recorded in the mean VAS at 15th (p-value=0.012) and 30th min (p-value=0.017). Only 7 patients (11.6%) from group N, and 12 patients (20%) from group B required rescue agent (0.5 mcg/kg/hour dexmedetomidine injection and 75 mg diclofenac sodium injection intravenous). Conclusion: Both 0.2 mg/kg nalbuphine and 0.2 mg/kg butorphanolprovide satisfactory results in terms of analgesic efficacy, sedation, haemodynamic and respiratory parameters, albeit, nalbuphine can be coined to be superior in terms of response to pin prick and duration of action. Keywords: Anaesthesia, Blood pressure, Intravenous, Monitored anaesthesia care, Respiratory rate INTRODUCTION Monitored Anaesthesia Care (MAC) is qualified by American Society of Anaesthesiology (ASA) as a strategic procedure for undergoing local anaesthesia using analgesia alongwith sedation [1]. Various ear procedures can benefit from MAC, which provides appropriate sedation and analgesia without respiratory depression [2]. Owing to the number of advantages during the procedure, including minimal intraoperative bleeding, feasibility to test hearing, and maintaining facial nerve integrity makes local anaesthesia a popular choice for middle ear surgeries. Claustrophobia, drilling noise, and head and neck position manipulations are common causes of patient discomfort [3]. During procedures under MAC, anaesthetic drugs are administered with the objective of offering anxiolysis, sedation and analgesia ensuring rapid recovery without any adverse effects. Local anaesthetic and lengthy immobilisation during surgery necessitate the use of systemic painkillers, which are commonly used to alleviate discomfort. Sedative-hypnotic drugs are used to reduce anxiety and provide intraoperative amnesia thereby making procedures more bearable to the patients and allowing them to relax. Opioids, benzodiazepines, alpha-2 agonists and propofol, are commonly used anaesthetics for sedation and pain relief during middle ear surgery [4-8]. Butorphanol is a synthetic opioid with agonist-antagonist characteristics that is related to levorphanol chemically. It serves as a kappa receptor agonist and mu receptor antagonist that provides excellent analgesia while limiting respiratory depression. Butorphanol has a rapid onset of action (1-2 minutes) with elimination half-life of 2-3 hours. Butorphanol Journal of Clinical and Diagnostic Research. 2022 Sep, Vol-16(9): UC35-UC39 is metabolised by hydroxylation and N-dealkylation reactions to yield hydroxy butorphanol and norbutorphanol with no reported pharmacological consequence. Butorphanol was reported to exhibit some side-effects like nausea, vomiting, dysphoria and respiratory depression and was thus, supplemented with fentanyl 1-2 mcg/kg i.v. as part of balanced anaesthesia [9]. Nalbuphine is lipid soluble opioid with similar agonist-antagonist action as that of butorphanol albeit structurally related to oxymorphone [10]. Along with the rapid rate of clearance, it is reported to exhibit quick onset of action postintravenous injections i.e. 2-3 minutes in comparison to butorphanol (1-2 minutes). Nalbuphine is also less likely to cause side-effects such as excessive sedation, pruritis, urinary retention and respiratory depression. There have been plethora of reports comparing and differentiating the efficacies of various opioids but limited data is available to compare the analgesic efficacy of nalbuphine and butorphanol [11-13]. These reports reveal the superior analgesic efficacy of nalbuphine and butorphanol with better safety profile in separate studies when compared to different analgesic agents. Thus, the aim of the present study was to evaluate analgesic efficacy of intravenous butorphanol versus intravenous nalbuphine during MAC in patients undergoing tympanoplasty. The study primarily evaluated response to needle prick and onset of pain as a primary outcome. Further, the secondary parameters were haemodynamic changes, sedation, and adverse effects of intravenous butorphanol and nalbuphine administration. 35 Shruti Hazari et al., Comparative Study of Nalbuphine and Butorphanol in Tympanoplasty MATERIALS AND METHODS This randomised clinical trial was conducted at the Department of Anaesthesiology, School of Medicine, D.Y. Patil Deemed to be University, Mumbai, Maharashtra India, from March 2018 to March 2021. The Institutional Ethics Committee had approved the study (IEC Ref No: DYP/IEC/01-010/2019). The purpose, rationale of the study as well as role of the participants were explained to all the patients in the study while obtaining written informed consent, after which the patients were enrolled in the study. Further, an information sheet related to the project work was also given to all the participating patients. Sample size calculation: Medcalc version 12.0.3 was used for calculation of the sample size guided by: α error=5% (confidence level=95%), β error=5% (power of the test=95%). A total sample size of 54, divided into two equal groups, was found to be sufficient to conduct the study. Finally, a total of 120 (...truncated)