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 IIII were chosen for this prospective, randomized, doubleblind placebocontrol 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.