Short-Term Memory And Attention After Total Intravenous Anesthesia A Prospective Clinical Observational Trials

Objective: Most patients have a period of memory deficit after general anesthesia,postoperative cognitive dysfunction,postoperative delirium patients also exist memory impairment;Working memory,long-term memory and attention are viewed as the vital elements of memory.This study is to explore the changes and recovery of the working memory,long-term memory and attention at different time points during the recovery period of total intravenous anesthesia by clinical observation.Methods: A total of 287 inpatients selected for elective surgery under general anesthesia(total intravenous anesthesia),excluded 26 cases for various reasons.A total of 261 patients were included in the study,mainly distributed in gastrointestinal surgery,hepatobiliary surgery,gynecology and urology.Participants were randomly assigned to each group and tested for working memory capacity,long-term memory capacity and attention network function.It was mainly divided into two groups: group L(208 cases),which was related to working memory capacity and long-term memory ability test;Group S(53 cases)was associated with attention network test.Group L: according to thedifferent time points of memory test,group L was again divided into four groups:preoperative(50 cases),postoperative 1 hour(54 cases),postoperative 6 hours(54 cases),and postoperative 24 hours(50 cases).Each group was independent of each other.Visual analogue scale(VAS)and sedation score(Ramsay)were performed for each group at 1h,6h and 24 h after surgery,and working memory capacity(DST scale)and long-term memory capacity(Snodgrass & Vanderwart standard picture method)were tested when VAS?3 and Ramsay was between 2 and 4.The preoperative group served as the control group in group L,and the subjects were hospitalized patients who met the inclusion requirements but had not yet received surgery.The test methods were consistent with those of the group 1,group 6 and group 24 hours after surgery.After the completion of task picture learning and memory for 24 hours,the number of task picture recall,recognition and forgetting in each group was followed up,and the memory of the events that occurred in PACU after anesthesia awakening was investigated.Group S:preoperative assessment of general status and cognitive function of enrolled patients was conducted.The cognitive function was assessed by Montreal cognitive scale(MOCA)test to exclude the patients with cognitive impairment.Patients with scores of no less than 26 points could receive attention network test(ANT).The main observation indicators were the working memory capacity(DST total score),long-term memory(task image memory results),attention network efficiency(ANT results).Results: There was no significant difference in age,gender,height,weight,education and previous history of general anesthesia in the L group(P> 0.05).Comparison among groups: the DST score and the immediate recall,free recall and recognition of task pictures of patients at different time points after general anesthesia decreased to different degrees compared with that before surgery,with the most significant reduction being 1hour after surgery(P<0.001).Moreover,the damage of free recall ability continued to be significant 6 hours after surgery,and basically recovered to the preoperative level 24 hours after surgery.In addition,the incidence of task picture amnesia was 25.5% in group L,and the incidence of PACU event amnesia was 17.1%.Group S: the patients tested with ANT after 24 h surgery,the attention network system of alerting,orienting,execution control compared with preoperative significantly reduced(P<0.05).However,the difference of average response time and accuracy was not statistically significant(P>0.05),indicating that the damage of attention network function could last for 24 h or even longer after general anesthesia.Conclusion: Working memory capacity and long-term memory capacity of patients at different time points during recovery from total intravenous anesthesia decreased to different degrees compared with that before surgery,with the most serious reduction being 1 hour after surgery.It can be basically restored to the preoperative level 6 hours and 24 hours after surgery.However,the attention network function of the patients was still significantly reduced 24 hours after surgery compared with that before.Therefore,the influence of total intravenous anesthesia on short-term memory of the patients mainly occurred within 6 hours after surgery,and the most serious was 1 hour after surgery,while the damage to attention capacity lasted for 24 hours after surgery,or even longer.