Effects of Ketamine, Fentanyl and Paracetamol on Pain Intensity and Hemodynamic Parameters after Deep Vitrectomy

Background & objectives: The aim of this study was to evaluate the effects of preventive administration of ketamine, fentanyl and paracetamol on pain intensity and hemodynamic parameters after deep vitrectomy. Methods: In this clinical trial, 80 candidates of deep vitrectomy surgery were randomly assigned into 4 groups (1-4) and received 0.5 mg / kg ketamine, 2 μg / kg fentanyl, 10 mg/kg of paracetamol and equivolume of normal saline respectively intravenous infusion during the last 15 minutes of surgery. Pain intensity and hemodynamic parameters were recorded and analyzed. Results: Pain intensity was significantly higher in placebo group during the first 4 hours after operation (p<0.01), but no significant differences were observed between the study groups at 8 and 24 hours after operation in this regard. There were no significant differences between the three intervention groups in terms of pain intensity during the study. Also there were no significant differences between the 4 study groups regarding to hemodynamic parameters. Conclusion: The use of each of the three intervention drugs significantly reduced the pain intensity compared to the control group without any hemodynamic derangement.