Impact on Psychomotor Functions by Sedative Agents Used During Daycare Surgeries: A Randomized Controlled DoubleBlinded Study of Dexmedetomidine Versus Midazolam Fentanyl

Abstract

Background: Sedative agents are used during surgeries to reduce stress and anxiety and discomfort of the patient. An ideal sedation agent should provide a rapid onset of action and faster recovery. Almost all commonly used sedative agents in daycare surgeries affect the cognitive and psychomotor functions. The research question of this study was to find out which of the commonly used sedative agents- Dexmedetomidine or Midazolam-Fentanyl combination produces less impact on the psychomotor functions of the patients. Materials and Methods: Seventy two patients who were undergoing tympanoplasty under local anesthesia, were randomly divided into two equal groups - Group D (dexmedetomidine) and Group MF (midazolam and fentanyl) using a computer-based randomization scheme. Group D received dexmedetomidine till an adequate sedation score was achieved (Ramsay sedation scale =3). Group MF patients received midazolam and fentanyl till an adequate sedation score was achieved. Baseline psychomotor assessment and delirium assessment was done 30 minutes prior to the shifting of the patient to operation theatre. All the scores were compared at 30 minutes, 1 hour, 2 hours, 4 hours and 8 hours by using MMSE test and stroop color word interference test for psychomotor assessment and short-CAM & Short-CAM severity test for delirium assessment. Statistical analysis was done by applying paired t-test and repeated measure ANOVA for intra-group comparison and for intergroup comparison, independent t-test was applied. Results: There was a significant decline in MMSE score and stroop color word interference score at post-operative period as compared to the baseline values in both the groups up to 4 hours. No such significant difference was seen at 8 hours post-operative period. In both groups, more patients in MF group had mild cognitive dysfunction at 1 hour post-op period, as compared to patient in D group. None of the patients showed severe cognitive impairment. In Group MF, the total number of patients showing signs of delirium was more as compared to group D at Post-op 1 hour. But no signs of delirium were found in any patient in later readings. When presented, the severity of delirium was assessed by Short CAM severity test score. It was observed that all patients who had delirium had CAM severity score of 1 only. Conclusion: The present study concluded that drug dexmedetomidine causes less cognitive decline and less chances of producing post-op delirium as compared to midazolam-fentanyl combination when used for sedation at the time of surgery.