Objective:In this study, we established a reliable surgical procedure of lung ischaemia-reperfusion(IR) injury in rats. The research progress of different lung IR injury models and application value was also discussed.Methods:Twenty-eight adult SD rats were randomly divided into SHAM group and lung IR injury group(IR group), 14 rats in each group. In IR group, rats underwent tracheotomy under general anesthesia and received mechanical ventilation. Chest was opened in supine position, and pulmonary hilum was blocked for 30 minutes then the occlusion was removed. Samples were harvested after reperfusion for 45minutes. Rats in SHAM group received surgery and exposure of the right pulmonary artery, and experienced the same amount of time before the chest closed. Arterial blood gas was extracted postoperatively. Gross view of the lungs and pathological changes were observed, and the dry/wet ratio(W/D) was determined. Protein level of pro-inflammatory factors, markers in oxidative stress pathway, and endothelial functional markers in lung were tested by western blot analysis.Results:In IR group, there was pink foamy secretion in the airway, and the lungs exhibited signs of edema and congestion. In IR group, the alveolitis score was significantly increased, the W/D ratio was also increased, p38MAPK and NF-κB signaling pathways were activated, and the expression of TNF-α was significantly increased, while the expression of eNOS was significantly decreased.Conclusion:Left hilum clamping and bilateral reperfusion injury in lung is a practical animal model, it is a simple, low-cost and repeatable animal model for further studies. No microsurgical instruments were required during the procedure. Lung IR injury is characterized by oxidative stress response, inflammatory response and endothelial cell dysfunction.

Objective:To evaluate the effect of stroke volume variation (SVV)-guided fluid therapy on perioperative haemodynamics and tissue perfusion in the patients with end-stage renal disease (ESRD) undergoing parathyroidectomy.Methods:One hundred and twenty-one patients of either sex, aged 18-64 yr, of American Society of Anesthesiologists Physical Status classification Ⅲ, with body mass index of 18-28 kg/m 2, with ESRD undergoing elective parathyroidectomy, who received haemodialysis treatment within 24 h before surgery, were enrolled in this study. The patients were divided into standard restrictive fluid therapy group (group SRT, n=61) and goal-directed fluid therapy group (group GDT, n=60) using a random number table method. Group SRT received restrictive fluid therapy, with a continuous infusion of 0.9% normal saline at a rate of 4 ml·kg -1·h -1. Group GDT received goal-directed fluid therapy guided by SVV, and when the SVV≥10% lasted for 5 min, the 0.9% normal saline 3 ml/kg was infused within 5 min until SVV<10%. Systolic blood pressure (SBP) was maintained at ≥90 mmHg or mean arterial pressure(MAP) at ≥65 mmHg throughout the perioperative period in both groups. The intraoperative volume of fluid infused, usage rate and consumption of intraoperative vasoactive drugs were recorded, and arterial blood lactate (Lac) level, MAP, heart rate, cardiac output, and inferior vena cava collapse index (IVC-CI) after removal of endotracheal tube at the end of surgery were measured. MAP was continuously recorded within 12 h after surgery, and MAP variability (CV MAP) was calculated. The occurrence of cardiovascular and cerebrovascular events within 30 days after operation was also recorded. Results:Compared with group SRT, the intraoperative volume of fluid infused was significantly increased, the usage rate of ephedrine and norepinephrine was decreased, the consumption of ephedrine was reduced, and the percentage of postoperative IVC-CI<50% and cardiac output were increased, the percentage of Lac≥2.0 mmol/L and CV MAP were decreased ( P<0.05), and no significant change was found in the incidence of cardiovascular and cerebrovascular events within 30 days after surgery in group GDT ( P>0.05). Conclusions:Compared with restrictive fluid therapy, SVV-guided fluid therapy can optimize the perioperative hemodynamics and tissue perfusion in the patients with ESRD undergoing parathyroidectomy.