[The effect of different methods of sedation on the cognitive functions of elderly patients during knee joint replacement.].

The aim of the study was to identify the safest drug for sedation during knee arthroplasty, with minimal impact on cognitive functions and hemodynamics in elderly patients. The prospective, controlled, randomized study included 78 patients diagnosed with primary and secondary gonarthrosis stage III-IV, elderly patients (75-90 years). Surgery - knee arthroplasty, anesthesia during surgery - combined spinal-epidural anesthesia. Randomization was performed into 2 groups - propofol was used as a sedative during the intraoperative period and dexmedetomidine was used as a sedative during the intraoperative period. The degree of sedation depth was assessed using the Ramsey sedation scale, to monitor the depth of drug-induced sleep, we used a bispectral index device - BIS monitoring. Cognitive status was assessed using the Hamilton Depression Scale at admission and on day 2 after surgery. Intraoperative hypotension was more common in the group of patients with propofol sedation, and intraoperative bradycardia was more common in the group of patients with dexmedetomidine sedation. BIS-monitored sedation with both propofol and dexmedetomidine with rates of 82-88% provides a level of 3-4 points of the Ramsey sedation scale and reduces the development of cognitive impairment according to the results of the Hamilton Depression Scale in patients with knee arthroplasty.