With the increasing level of aging in The country, the proportion of elderly patients undergoing general anesthesia operation is also increasing every year [7]. As various bodily functions of elderly people decline to varying degrees with the increase of age, the risks they bear during surgery are significantly higher than those of other age groups [8]. Sternum reduction and fixation as a bone surgery with invasive surgical operation, mainly used for repair trauma fractures of the chest rib fracture, and need to be carried out under the premise of general anesthesia surgery, but because of the particularity of narcotic drugs and the vulnerability of the elderly, easy to cause cognitive dysfunction after surgery, inflammation aggravate or neurological disorders such as poor prognosis, It is usually manifested by impaired memory, aggravated anxiety, personality change, etc., which seriously threatens the prognosis and quality of life of elderly patients [9–10]. Therefore, it is of great significance to explore a general anesthesia method that can not only effectively maintain the depth and length of anesthesia sedation during surgery, but also reduce the stress response of the body, thus reducing the damage to neurological and cognitive functions, for improving the prognosis of elderly patients [11]. Is given priority to with red fentanyl and propofol TIVA and VICA has been widely used in clinical anesthesia way, two types of anesthetic sedative depth in consistency of clinical evaluation, but its influence on cognitive function after surgery for elderly patients with related research is still a few, so this research mainly by MoCA as a basis for the assessment of cognitive function, To analyze the effects of different anesthesia methods on cognitive function and oxidative stress response of elderly patients.
From the surgical indicators of the two groups, different anesthesia methods had no significant influence on the operation time, intraoperative blood loss and postoperative eye opening time, indicating that both TIVA and VICA had high intraoperative safety and would not cause postoperative adverse reactions easily caused by excessive intraoperative blood loss and prolonged surgery [12]. It was observed by MoCA scale that there was no difference in cognitive function between the two groups before surgery, but the MoCA score decreased after surgery due to the influence of general anesthesia operation, indicating that general anesthesia operation can affect the cognitive function of patients to varying degrees, but the MoCA score of TIVA group was higher than that of VICA group 1 day after surgery. Moreover, the cognitive function recovery on the second day after surgery was significantly higher than that on the first day after surgery (all P < 0.05), suggesting that TIVA can effectively reduce cognitive impairment and quickly restore postoperative cognitive function. After in-depth analysis of this result, we believe that both propofol and remifentanil are short-acting anesthetics with quick onset of action and short half-life, as well as fast metabolism and hydrolysis, so drug accumulation is not easy to occur, so the impact on neurological function is relatively small [13]. In VICA, sevoflurane is mainly inhaled as intraoperative anesthesia. Although it can exert the anesthetic effect from shallow to deep through the respiratory tract and has high intraoperative controllability, it can cause the dysfunction of the central cholinergic system to some extent, thus inhibiting the release of neurotransmitters and resulting in cognitive impairment [14].Zhiguo y[15] also showed that inhaled sevoflurane would affect the learning ability and memory of patients to varying degrees, and even affect the clearance of bronchial cilia, which further led to the occurrence of postoperative hypoxemia, resulting in cognitive impairment.
In addition, this study collected preoperative, intraoperative and postoperative each time point of oxidative stress related indexes were observed, the results show that at the beginning of operation two groups of Cor, N and NE levels are rising sharply, this is because the sternum reduction and fixation as a traumatic invasive surgery, will cause the body relatively strong stress reaction, Cor, N and NE are common stress hormones in clinical practice. Cor is one of the main indicators of adrenal corticosteroid secretion. When the body is traumatized, it is regulated by adrenalin secretion and secreted in large quantities, which directly reflects the stress level of the body. As a factor synthesized and secreted by adrenal medulla, E and NE can also reflect the stress state of the body and the damage degree of nerve function to a certain extent [16–17]. In this result, although the stress level of both groups increased sharply with the beginning of surgery, the stress response of TIVA group was significantly lower than that of VICA group, and the stress response at each time point after surgery was also lower than that of VICA group, indicating that TIVA can more effectively reduce the oxidative stress response of the body, thus further reducing the degree of neurological damage. While TIVA uses propofol for intraoperative anesthesia maintenance, which can further inhibit the generation of oxygen free radicals and enhance the antioxidant capacity of the body, thus inhibiting inflammatory response and reducing postoperative complications to a certain extent [18]. This conclusion was also confirmed in this study. Kaplan-meier curve showed that the number of adverse reactions occurred in TIVA group within 48 hours after surgery was significantly lower than that in VICA group, further confirming the clinical efficacy of TIVA.