The Small Dose of Ketamine Prevents the Hemodynamic Disturbance in Patients Who Underwent Phacoemulsification with Topical Anesthesia and Monitored Anesthesia Care

Background: Ketamine is the only anesthetic agent that leads to an increase of blood pressure and heart rate by activation of sympathetic nervous system. However, there is a controversy about this effect of ketamine especially if used in small dosage. We proposed to evaluate the hemodynamic effect of small dose of ketamine during Phacoemulsification. Methods: One hundred patients of ASA physical status I-III were chosen for this prospective, randomized, double-blind placebo-control study. Our patients were assigned randomly to two groups, ketamine group (n=50) and a control group (n=50). After premedication, 0.15 mg/kg ketamine was injected intravenously in ketamine group. After three minutes Phacoemulsification was begun under topical anesthesia. The hemodynamic variables were recorded during the procedure and compared between two groups. Results: The systolic, diastolic and mean blood pressure were statistically significantly higher in the ketamine group (p<0.001) during the procedure. The heart rate during operation was higher in the ketamine group compared to control group (p<0.001). 46 (92%) patients in the ketamine group and 38 (76%) patients in the control group were satisfied according to surgeons (p=0. 001). Nausea and vomiting occurred at similar rates in each group. Also, hallucination and other psychological events did not occur in either of the groups. Conclusion: We found that systolic, diastolic, mean arterial blood pressure in patients who received small dose of ketamine were higher during the operation.