The Effect Of Intraoperative Lung-protective Ventilation Strategy For Middle-aged And Elderly Patients With Abdominal Surgeries On The Postoperative Pulmonary Complications

Background:Non-appropriate ventilation mode can cause ventilation-related lung injury, resulting in pulmonary barotrauma, voluetrauma, atelectasis or biological trauma thus increasing risks of developing postoperative pulmonary complications. Therefore lowering the risks of postoperative pulmonary complications, one of the important factors of long hospitalization period, high cost and even death particularly on middle-aged and elderly patients, can effectively improve healing after surgery. Previous reports have no consistent views about the effect of intraoperative lung-protective ventilation strategy on improving postoperative pulmonary complications. Recently some researchers have found that lung-protective ventilation strategies(LPV) such as low tidal volumes(LVT), appropriate positive end-expiratory pressure(PEEP) and intermittent lung recruitment, compared to the traditional tidal volume ventilation strategy, can reduce patients’ postoperative pulmonary complications who have pre-unhealthy lung. The middle-aged and elderly patients have more postoperative pulmonary complications.However there are no reports making it sure that lung-protective ventilation strategy can reduce middle-aged and elderly patients’ postoperative pulmonary complicationsPurpose:To explore the effect that Lung-protective strategy has on postoperative pulmonary complications of middle-aged and elderly patients who have abdominal surgeries. We want to find out the appropriate ventilation mode for the middle-aged and the elderly.Methods:The trial took place at Zhongda hospital affiliated to southeast university, department of anesthesia, from November 2014 to march 2015, including in total 80 cases of patients between 55-85 years old that underwent abdominal laparotomy under general anesthesia and was approved by the ethics committee of Zhongda hospital, southeast university. All of patients were separated randomly into two groups, lung-protective ventilation group (tidal volume 6-8ml/kg predict body weight, PEEP and recruitment maneuvers) and non-protective ventilation group (tidal volume 10-12ml7kg predict body weight). The same anesthesia apparatus, methods for vital signs monitoring, were used during perioperative period on all patients. After anesthesia was induced, all patients underwent same airway management, hemodynamic management, fluid management and postoperative analgesia. Measurements of arterial blood gas were taken every hour from the beginning of anesthesia induction and venous blood serum was tested every two hours for inflammatory mediators (IL-8、TNF-α)till the end of operations. Arterial blood gas and venous blood serum were 24 hours postoperatively retested, furthermore patients were monitored for postoperative pulmonary complications during a week, records of both days of hospitalization (including general ward and ICU) and mortality within 30 days were taken.Results:In lung-protective ventilation group (LVT) and non-protective ventilation group (HVT), the difference of patients’ demographic data and the preoperative physical status was not statistically significant. Perioperative managements, including anesthesia induction and maintenance, intraoperative hemodynamic management, fluid management, postoperative pain management and so on are consistent, the difference between the two groups has no statistical significance. The results of blood routine examination and blood gas have no significant difference. The difference of IL-8 and TNF-abetween two groups are not statistically significant. The Seven days postoperatively, LVT group and HVT group the incidence rate of two groups of patients with fever were 40.0% and 33.3% respectively (P=0.424).The incidence of cough and expectoration were 63.3%and 46.7% respectively (P=0.27).The incidence of abnormal lung auscultation were 30.0% and 36.7% respectively (P=0.726).Two groups within 7 days after surgery in patients with pulmonary complications (PC) such as lung infection, the incidence of associated symptoms and signs has no statistical significance. In LVT group and HVT group, the postoperative hospital stay were 17.2±8.3 and 17.6±6.9 days (P= 0.882) respectively, the difference between the two groups have no statistical significance. The fatality rates of two groups within 30 days after surgery both are zero, no difference.Conclusion:Compared with the non-protective ventilation strategy, lung-protective ventilation strategy does not improve the postoperative pulmonary complications within 7 days, and shorten the patients’ postoperative hospital stay.