The Effect of Intravenous Midazolam and Dexmedetomidine on Prevention of Cognitive Dysfunction after Cataract Surgery in the Elderly Patients under General Anesthesia Compared with the Control Group

  This study aimed to evaluate the effect of intravenous midazolam and dexmedetomidine on prevention of cognitive dysfunction after cataract surgery in the elderly patients under general anesthesia compared with the control group. In this clinical trial study, 150 patients underwent phacoemulsification surgery were selected and randomly divided into three equal groups. The three groups received 0.1 mg/kg midazolam, 1 mg/kg dexmedetomidine, and similar volume of normal saline, respectively before the surgery. The cognitive dysfunction scores were measured and compared using Mini-Mental Status Examination (MMSE) criteria before and after the surgery. The preoperative frequency of cognitive dysfunction was 6, 10, and 4 percent in midazolam, dexmedetomidine, and control groups, respectively (P = 0.47). 24 hours after the surgery, 14, 12, and 10 percent of the patients had cognitive dysfunction (P = 0.83); while one week after surgery, 8, 12, and 6 percent of patients had cognitive dysfunction in the three groups of midazolam, dexmedetomidine and control, respectively with no statistical difference between the three groups (P = 0.56). The effect of midazolam and dexmedetomidine was similar on prevention of the incidence of cognitive dysfunction, and it is possible to use the both drugs, if there is no contraception to use them.