Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2026 02 22 1490 1490 Hamidreza Shetabi Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Laili Adinehmehr Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Navid Namakizadeh Esfahani Student Research Committee, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran. 2025 11 16 2025 12 25 Background: Cataract surgery requires proper sedation level and immobilization of the patient. This research sought to evaluate the impact of sublingual fentanyl versus sub-dissociative dose ketamine in achieving optimal conditions in cataract surgery. Methods: 90 participants were randomly assigned to two cohorts: sublingual fentanyl (SLF) or intravenous sub-dissociative dosage ketamine (SDK). In the SLF cohorts, fentanyl was administered sublingually at a dosage of 1.5 μg/kg and in the second cohort (SDK), ketamine was given intravenously with a dosage of 0.3 mg/kg. In both study cohorts, propofol was administered intravenously at a dosage of 0.4 mg/kg, followed by intermittent boluses of 0.1 mg/kg at 30-second intervals until desired level 4 sedation, according to the Ramsey Sedation Scale (RSS). The quality of sedation, hemodynamic parameters, patient and surgeon satisfaction, and complications were determined and compared between cohorts. Results: No notable disparency was found among the SLF and SDK cohorts regarding the quality of sedation during the operation and recovery (p > 0.05). The SDK cohort demonstrated superior pain control in comparison to the SLF cohort (p = 0.009) and required significantly less propofol (p = 0.047). Hemodynamic stability, including systolic (p<0.05) and diastolic (p<0.05) blood pressure, mean arterial pressure (p<0.05), and heart rate (p=0.02), was significantly better in the SDK cohort. However, no notable disparency were observed in SpO2 levels among the two cohorts (p>0.05). In the SDK cohort, both patient and surgeon satisfaction were found to be greater. (p=0.009 and p=0.048, respectively). Four participants in the SLF cohort and two in the SDK cohort experienced adverse events during surgery. However, during recovery, ten participants in the SDK cohort had complications, while none of the participants in the SLF cohort exhibited adverse reactions. Conclusion: The findings of this research suggest that SDK is a superior option for attaining optimal sedation, analgesia, and overall satisfaction for both patients and surgeons in the context of cataract surgery, particularly in comparison to SLF. https://aacc.tums.ac.ir/index.php/aacc/article/view/1490