Pharmacological protection and recovery of cognitive functions in the elderly patients after abdominal surgical interventions

Abstract

Background. Postoperative cognitive dysfunction (POCD) is a predictor of the development of stable cognitive dysfunction and increases the risk of the dementia. Neuroprotective therapy acquires a significant practical value when preventing da­mage to neurons or correcting cognitive impairment. The purpose was to determine the influence of surgical intervention on cognitive functions, to evaluate the effectiveness of some methods of pharmacological prophylaxis and manage postoperative disorders of cognitive functions. Materials and methods. The study included 62 patients of both genders aged 55 to 75 years who underwent a planned abdominal surgery under ataralgesia. Patients were randomized into three groups: controls (19 people), the first research group (22 individuals who received thiocetam) and the second research group (21 people receiving meglumine sodium succinate). All patients underwent a set of standard perioperative clinical and laboratory examinations and intraoperative monitoring. Cognitive functions were investigated using the Raven’s Progressive Matrices. The survey was carried out at seven stages: 1) before surgery; 2) intraoperatively; 3) by the end of the surgery; 4) one day after surgery; 5) in 5 days; 6) in 14 days; 7) in 30 days. Results. Indicators of the somatic state of patients at all stages of the examination were in age reference limits, or their deviation did not have a clinical significance. Comparison of somatic state parameters in patients of investigated groups showed the absence of significant effects of meglumine sodium succinate and thiocetham on indicators of oxygen transport and cardiovascular system. Cognitive functions of controls on day 5 decreased by 22.2 % from baseline, indicating the development of postoperative cognitive dysfunction. However, on day 14, cognitive decline was only 3.87 % of the initial level, which indicated the absence of POCD. But on day 30, controls had a clear trend to repeated deterioration of cognitive functions. When applying meglumine sodium succinate, it was possible to prevent cognitive impairment below the POCD level on day 5 and re-deterioration on day 30. When using thiocetam, no reduction of cognitive functions was detected already on day 5, and at the next stages, their further gradual increase is found. In the control group, 89.5 % of patients (CER = 0.89) had cognitive impairment on day 5; on day 14, its manifestations remained in 36.8 % of cases (CER = 0.37), but on day 30, the number of patients with signs of cognitive dysfunction increased to 52.6 % (CER = 0.53). In the meglumine sodium succinate group, the frequency of POCD was 38.0 % (EER = 0.38), and in the thiocetam group — 22.7 % (EER = 0.23). The difference between the groups of meglumine sodium succinate and thiocetham on day 14 was more significant. Thus, the frequency of events in the thiocetham group was only 5 % (EER = 0.05), whereas in the meglumine sodium succinate group — 14 % (EER = 0.14). However, on day 30, the frequency of cognitive dysfunction in both groups was approximately the same and was by 88–89 % lower than in the control group. Conclusions. Elderly patients after abdominal surgery under general anesthesia using the method of ataralgesia reported a wave-like deterioration of cognitive functions with a primary decline in the first 5 days, a repeated decline on day 30 and partial recovery on day 14. The use of meglumine sodium succinate allows preventing cognitive impairment in the early and remote postoperative periods. Using thiocetam, a combination drug, not only prevents deterioration, but also improves cognitive functions in the elderly patients during both early and remote postoperative period.

Keywords

• postoperative cognitive dysfunction
• ataralgesia
• advanced age