Risk factors for post-operative cognitive dysfunction in neurosurgical patients

BACKGROUND: The impact of various risk factors on the development of post-operative cognitive dysfunction in neurosurgical patients requires research for decreasing the probability of developing this complication. AIM: To determine the effects of extra- and intraoperative risk factors on the development of post-operative cognitive dysfunction in neurosurgical patients after undergoing a vertebral column surgery with long-running anesthetic support. METHODS: The research was carried out among the neurosurgical patients with previous surgical intervention in the vertebral column, within the premises of the Neurosurgery Department of the State Budgetary Healthcare Institution of the Tyumen Oblast “Regional Clinical Hospital No. 2”. The evaluation included the cognitive functions before surgery and on Day 3 after the surgical intervention using the Montreal Cognitive Assessment (MoCA), along with a panel of Isaac tests and the Munsterberg test. The calculated coefficients were the Pearson’s and the point biserial correlation coefficients regarding the following intraoperative risk factors: type and duration of anesthetic management, medications used for anesthesia and muscle relaxation, as well as the type of surgery. Evaluations were also made for the interrelation between the development of post-operative cognitive dysfunction and the following extra-operational risk factors: the age, the body mass index, the number of education years, the presence of arterial hypertension or diabetes and smoking. RESULTS: A notable positive correlation was observed between the development of post-operative cognitive dysfunction and the age (r=0.53; p <0.01), moderate correlation with the body mass index (r=0.35; p <0.01) and with the presence of arterial hypertension (r=0.42; p <0.05). A moderate negative relation was observed for the number of education years and the development of post-operative cognitive dysfunction (r=-0.36; p <0.01). The relation of the presence of diabetes with post-operative cognitive dysfunction did not show significant correlation. Smoking and surgery duration show low level of interrelation, which does not allow to comprehensively interpret the obtained results as significant. The type of surgical intervention and the duration of anesthetic support did not correlate with the development of post-operative cognitive dysfunction (r <0.1; p <0.01). A moderate correlation was found for the anesthesia conducting using a drug combination of desflurane+fentanyl (r=0.31; p <0.05) along with the mild one when combining sevoflurane+fentanyl+ketamine (r=0.25; p <0.05). The usage of fentanyl together with sevoflurane (r=0.07), propofol (r=-0.1) and sodium oxybutyrate (r=0.05) does not lead to post-operative cognitive dysfunction (p <0.05). CONCLUSION: Elderly age, high body mass index, presence of arterial hypertension and low education level increase the risks of developing post-operative cognitive dysfunction. Using the desflurane+fentanyl and sevoflurane+fentanyl+ketamine combinations can also contribute to the occurrence of cognitive disorders.