Effect of dexmedetomidine infusion of two different doses on cognitive function after surgery in elderly patients

Introduction: Postoperative cognitive dysfunction (POCD) is a significant social and financial problem occurring in a high percentage of cases in peoples over 60 years old. POCD is associated with additional costs due to hospital stays and increased need for institutionalization, rehabilitation, and home care. Dexmedetomidine (DEX) has been demonstrated to have a neuroprotectve effect. Methods: The present study was a randomized, case- controlled double-blind trial of 90 patients who had undergone surgerywith general anaesthesia (GA), The cognitive deficit of each patient was assessed using the Mini-Mental State Examination (MMSE). The 90 patients were randomly allocated into three groups: Group I: Patients receiving 0.25 mcg/kg/hr continuous infusion. Group II: Patients receiving 0.50 mcg/kg/hr continuous infusion. Group III: Normal saline group (control group). The SPSS Version 15.0 statistical Analysis Software was used for the statistical analyses. Results: Intragroup change in MMSE Score (from Baseline) at different time intervals (Paired ‘t’ test) p values shows that there is no significant changes in MMSE score at 24 hr and at 72 hr in group II patient.

Post-op Group I (<0.001), group II (0.013), group III (<0.001)

At 24 hr op Group I (0.009), group II (0.489), group III (<0.001)

At 72 hr op Group I (0.009), group II (1.000), group III (0.003)

Conclusion: The findings of the present study shows that DEX infusion 0.50 mcg/kg/hr after loading with 1 mcg/kg over 10 min may be an effective method for ameliorating postoperative cognitive impairment in elderly patients who have undergone surgery. Only a small number of patients were recruited. Therefore, larger studies should be performed, expanding the present study to a broader population.