Vagus nerve is the main undertaker of the parasympathetic nervous system,participating in the regulation of inflammatory response and playing the role of organ function protection.Stimulation such as perioperative operation and anesthesia can often lead to a relative decrease in vagus nerve tension and in-crease in perioperative circulation,respiration,digestion,nerve,and other system-related complications.This article mainly reviews the effects of reduced vagal tone on perioperative multiple organ functions and va-gus nerve stimulation in organ function,aiming to provide new ideas for reducing various perioperative com-plications.

Objective To investigate the effectiveness and safety of acetaminophen combined with ketorolac tromethamine in pain management early after laparoscopic cholecystectomy(LC).Methods Ninety patients with LC under general anesthesia,42 males and 48 females,aged 18-78 years,BMI 18-28 kg/m2,ASA physical statusⅠorⅡ,were selected and randomly divided into two groups by random num-ber table method:the acetaminophen combined with ketorolac tromethamine group(group AK)and the nal-buphine group(group NA),45 patients in each group.Group AK received 500 mg(diluted to 50 ml)of acetaminophen injection and 30 mg of ketorolac tromethamine(diluted to 10 ml)injection pumped 15 mi-nutes before induction of anesthesia,and group NA received 50 ml of NS injection and 0.2 mg/kg of nalbu-phine(diluted to 10 ml)injection pumped at the same time.Postoperative pain was recorded 0.5,3,6,12,and 24 hours after surgery using VAS pain scores(the non-inferiority boundary Δ = 1.0 score).The sleep quality score on the night of surgery,the number of remedial analgesia cases within 24 hours after sur-gery,the Ramsay sedation score 0.5,3,and 6 hours after surgery,the occurrence of adverse reactions such as nausea and vomiting within 24 hours after surgery,and the overall satisfaction of patients were recorded.Results Compared with group NA,the VAS pain scores 0.5 hour after surgery was reduced in group AK(P＜0.05).The sleep quality score and overall satisfaction in group AK were significantly higher than those in group NA(P＜0.05).There were no significant differences in the rate of remedial analgesia,the score of Ramsay sedation at different time points and the incidence of nausea and vomiting within 24 hours after surgery between the two groups.Conclusion Acetaminophen combined with ketorolac tromethamine is not less effective than nalbuphine in relieving early postoperative pain after laparoscopic cholecystectomy without increasing the incidence of nausea and vomiting.Patients receiving acetaminophen combined with ketorolac tromethamine have higher sleep quality scores on the night of surgery and overall satisfaction.

Objective:To evaluate the relationship between the severity of preoperative brain injury and postoperative delirium (POD) in elderly patients using latent class analysis based on markers of brain injury.Methods:One hundred and thirty-one American Society of Anesthesiologists Physical Status classification Ⅰ-Ⅲ patients, aged 65-84 yr, with a body mass index of 18-28 kg/m 2, scheduled for elective unilateral total hip arthroplasty in our hospital, were selected. Cognitive function was assessed using the Mini-Mental State Examination before surgery. Arterial blood samples were collected before anesthesia to measure the plasma concentrations of brain-derived neurotrophic factor, inducible nitric oxide synthase, prostaglandin E2, central nervous system-specific protein (S100β), glial fibrillary acidic protein, neurofilament light chain, matrix metalloproteinase-9, fibroblast growth factor 23, complement 3, complement 3a, complement 5a and irisin using enzyme-linked immunosorbent assay. POD was evaluated using the Confusion Assessment Method within 3 days after operation, and the patients were divided into POD group and non-POD group. The patients were divided into different injury severity subtypes based on the levels of brain injury markers using latent class analysis, and logistic multivariate regression was used to analyze the independent risk factors for POD. Results:Compared with non-POD group, the concentrations of neurofilament light chain, glial fibrillary acidic protein, S100β and prostaglandin E2 were significantly different in POD group ( P<0.05). Using these four brain injury markers for latent class analysis, patients were divided into a high severity of brain injury group (91.51%) and a low severity of brain injury group (8.49%). The results of logistic multivariate regression analysis showed that subtypes of brain injury ( OR=8.31, 95% confidence interval [ CI] 1.77-38.90, P=0.007), age ( OR=1.14, 95% CI 1.03-1.24, P=0.007), and plasma irisin concentrations ( OR=0.99, 95% CI 0.98-0.99, P=0.027) were independent risk factors for POD. Conclusions:Higher severity of preoperative brain injury is an independent risk factor for POD in elderly patients.