Comparison of the effects of midazolam, dexamethasone, ondansetron and propofol on the prevention and control of opioid-induced pruritus after spinal anaesthesia with bupivacaine combined with fentanyl in femoral fracture surgery

Introduction: The present study set out to compare the effects of midazolam, dexamethasone, ondansetron and propofol on the prevention and control of opioid-induced pruritus after spinal anaesthesia with bupivacaine and fentanyl as adjuvants in femoral fracture surgery. Materials and Methods: This double-blind clinical trial study was conducted on 136 patients who were scheduled for orthopaedic surgery in Valiasr Hospital of Arak. The patients were randomly divided into four groups (ondansetron, midazolam, dexamethasone and propofol) with a block randomisation pattern. Blood pressure, heart rate, oxygen saturation, the incidence of pruritus, nausea, vomiting and sedation level were monitored and recorded intraoperatively and postoperatively in recovery and every 2 h until 12 h postoperatively. Data were then analysed with SPSS 20. Results: From 10 min to 60 min, blood pressure was lower in the midazolam group, while it was lower in the propofol group from 60 min to 105 min. In general, blood pressure in the midazolam group was lower than that in the other groups (P = 0.001). Furthermore, pruritus was observed less in the midazolam group than in the other groups (P < 0.05). Sedation level was higher in the midazolam group than in the other groups (P < 0.05). Conclusion: Midazolam reduced pruritus and increased sedation in patients. On the other hand, a decrease in blood pressure was observed in the midazolam group, which did not require any special treatment. According to the results of the present study, after midazolam, propofol and dexamethasone, and finally ondansetron, respectively, were effective in controlling pruritus after spinal anaesthesia, but the efficacy and effectiveness of midazolam were higher than that in the other groups. As such, this drug is recommended to be used in such procedures. Of course, it should be mentioned that the final decision depends on the patients' physical conditions and the anaesthesiologist's discretion.