Effects on extravascular lung water of lung protective ventilation strategy applied on piglets with acute respiratory distress syndrome induced by paraquat / 中华劳动卫生职业病杂志

Objective: To study the effects on extravascular lung water of lung protective ventilation strategy applying on piglets with acute respiratory distress syndrome (ARDS) induced by paraquat (PQ) under pulse indicating continuous cardiac output (PiCCO) monitoring. Methods: The piglets models with ARDS induced by PQ were established in June 2020 and all of them were received mechanical ventilation and divided into three groups according to tidal volume (V(T)) : small V(T) group (6 ml/kg) , middle V(T) group (10 ml/kg) and large V(T) group (15 ml/kg) , there were 5 piglets in each group. The positive end expiratory pressure (PEEP) were all setup on 10 cmH(2)O. The indexes such as arterial blood gas analysis, oxygenation index (OI) , extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were monitored at time of before the model was established (baseline) , time of the model was established (t(0)) and 2 h (t(2)) , 4 h (t(4)) , 6 h (t(6)) after mechanical ventilation. Lung tissue were punctured at time of baseline, t(0) and t(6) to be stained by Hematoxylin-eosin (HE) staining and pulmonary pathology were observed under light microscopy. Results: The heart rate (HR) , mean arterial pressure (MAP) and partial pressure of carbon dioxide (PaCO(2)) of all groups were higher than the base value while the pH values, partial pressure of oxygen (PaO(2)) and OI were lower than the base value when the models were established (P<0.05) . After mechanical ventilation, the HR and MAP values of all groups at t(2), t(4) and t(6) were lower than t(0) while the PaCO(2) of t(4) and t(6) were all higher than t(0), the differences were statistically significant (P<0.05) . The PaO(2) and OI of all groups showed a trend of rising at first and then decreasing after mechanical ventilation. The MAP, PaO(2), PaCO(2) and OI of the middle V(T) group and large V(T) group were apparently lower than that of the small V(T) group at t(2), t(4) and t(6) (P<0.05) . The ELWI and PVPI at t(0) of all groups were higher than that of baseline (P<0.05) . The ELWI of the small V(T) group at t(6) were lower than t(0) of the same group and t(6) of the middle V(T) group and large V(T) group (P<0.05) . HE staining showed congestion and edema of alveolar tissue, swelling of capillaries, exudation of red blood cells and widening of alveolar septum in piglets after successful modeling. And further widening of alveolar septum and rupture of alveolar septum could be seen in the lung tissues of each group at t(6), and the injury was the slightest in the small V(T) group. Conclusion: The lung protective ventilation strategy can alleviate the extravascular lung water and ARDS induced by PQ and improve oxygenation.

Research progress of spontaneous respiration in mechanical ventilation of acute respiratory distress syndrome / 中华危重病急救医学

Mechanical ventilation is an important supportive treatment for acute respiratory distress syndrome (ARDS). However, improper mechanical ventilation can cause a "second hit" to the lung, that is, ventilator-induced lung injury (VILI), characterized by translocation of pulmonary inflammatory mediators into the bloodstream, aggravating systemic inflammatory response syndrome, and multiple organ failure. Although the current protective mechanical ventilation strategy plays an important role in supporting treatment, the mortality of ARDS with mechanical ventilation is still very high. Therefore, to explore the strategy of pulmonary protective ventilation has always been the key orientation of ARDS and has important clinical significance. This article reviews the application, advantages and disadvantages of assisted and non-assisted spontaneous respiration in ARDS patients undergoing mechanical ventilation, in order to provide a reference for research and development of new strategies for ARDS protective ventilation.

Effect of driving pressure-guided lung protective ventilation strategy on early postoperative pulmonary function in adults patients undergoing heart valve surgery: A randomized controlled study / 中国胸心血管外科临床杂志

@#Objective    To evaluate the effect of driving pressure-guided lung protective ventilation strategy on lung function in adult patients under elective cardiac surgery with cardiopulmonary bypass. Methods    In this randomized controlled trial, 106 patients scheduled for elective valve surgery via median sternal incision under cardiopulmonary bypass from July to October 2020 at West China Hospital of Sichuan University were included in final analysis. Patients were divided into two groups randomly. Both groups received volume-controlled ventilation. A protective ventilation group (a control group, n=53) underwent traditional lung protective ventilation strategy with positive end-expiratory pressure (PEEP) of 5 cm H2O and received conventional protective ventilation with tidal volume of 7 mL/kg of predicted body weight and PEEP of 5 cm H2O, and recruitment maneuver. An individualized PEEP group (a driving pressure group, n=53) received the same tidal volume and recruitment, but with individualized PEEP which produced the lowest driving pressure. The primary outcome was oxygen index (OI) after ICU admission in 30 minutes, and the secondary outcomes were the incidence of OI below 300 mm Hg, the severity of OI descending scale (the Berlin definition), the incidence of pulmonary complications at 7 days after surgery and surgeons’ satisfaction on ventilation. Results    There was a statistical difference in OI after ICU admission in 30 minutes between the two groups (273.5±75.5 mm Hg vs. 358.0±65.3 mm Hg, P=0.00). The driving pressure group had lower incidence of postoperative OI<300 mm Hg (16.9% vs. 49.0%, OR=0.21, 95%CI 0.08-0.52, P=0.00) and less severity of OI classification than the control group (P=0.00). The incidence of pulmonary complications at 7 days after surgery was comparable between the driving pressure group and the control group (28.3% vs. 33.9%, OR=0.76, 95%CI 0.33-1.75, P=0.48). The atelectasis rate was lower in the driving pressure group (1.0% vs. 15.0%, OR=0.10, 95%CI 0.01-0.89, P=0.01). Conclusion    Application of driving pressure-guided ventilation is associated with a higher OI and less lung injury after ICU admission compared with the conventional protective ventilation in patients having valve surgery.

Perioperative use of lung protective ventilation strategy on immune function in patients undergoing thoracoscopic radical resection of lung cancer / 临床麻醉学杂志

Objective To evaluate the lung protective ventilation strategy on immune function in patients undergoing radical resection of lung cancer.Methods Sixty patients undergoing thoracoscopic radical resection of lung cancer, 47 males and 13 females, aged 35-64 years, BMI 18-29 kg/m2, falling into ASA physical statusⅠ orⅡ, were randomly divided into 2 groups with 30 cases in each:conventional mechanical ventilation (group C), protective mechanical ventilation group (group P).Volume-controlled ventilation was performed in the 2 groups.Protective mechanical ventilation mode was setted up as follows:tidal volume (VT) 8 ml/kg and respiratory rate (RR) 12-14 breaths/min during two-lung ventilation (TLV) ;VT 6 ml/kg, PEEP 5 cm H2O and RR 14-16 breaths/min during one-lung ventilation (OLV).Before induction of anesthesia (T0), at the end of surgery (T1), 24 hafter surgery (T2), 72 hafter surgery (T3), blood samples were taken from the central venous for determination of peripheral T lymphocyte subsets CD3+, CD4+, CD8+ and NK cell.The CD4+/CD8+ratio was also calculated.Results Compared with T0, the percentage of CD3+, CD4+, NK cell and the CD4+/CD8+ratio was significantly decreased at T1 and T2 in both groups (P<0.05).Compared with group P, the percentage of CD3+, CD4+, NK cell and the CD4+/CD8+ratio was significantly lower in the group C at T1 and T2 (P<0.05).Compared with T0, there was no significant difference at T3 with respect of the percentage of CD3+, CD4+, NK cell and the CD4+/CD8+ratio in the group P while those parameters still lower at T3 in the group C (P<0.05).Conclusion Perioperative use of lung protective ventilation strategy could not only alleviate the immune suppression but also make the immune function recover faster in patients undergoing thoracoscopic elective radical resection of lung cancer.

Effect of intraoperative lung-protective mechanical ventilation on pulmonary oxygenation function and postoperative pulmonary complications after laparoscopic radical gastrectomy

This study aimed to observe the effects of lung-protective ventilation (LPV) on oxygenation index (OI) and postoperative pulmonary complications (PPCs) after laparoscopic radical gastrectomy in middle-aged and elderly patients. A total of 120 patients who were scheduled to undergo laparoscopic radical gastrectomy with an expected time of >3 h were randomly divided into conventional ventilation (CV group) with tidal volume (TV) of 10 mL/kg without positive end-expiratory pressure (PEEP), and lung-protective ventilation (PV group) with 7 mL/kg TV and personal level of PEEP with regular recruitment maneuver every 30 min. Measurements of OI, modified clinical pulmonary infection score (mCPIS), and PPCs were assessed during the perioperative period. Fifty-seven patients in the CV group and 58 in the PV group participated in the data analysis. Patients in the PV group showed better pulmonary dynamic compliance, OI, and peripheral capillary oxygen saturation during and after surgery. The mCPIS was significantly lower in the PV group than in the CV group after surgery. The incidence rate of PPCs was lower in the PV group than in the CV group and the difference was significant in patients whose ventilation time was longer than 6 h in both groups. LPV during laparoscopic radical gastrectomy significantly improved pulmonary oxygenation function and reduced postoperative mCPIS and the incidence of PPCs during the early period after surgery of middle-aged and elderly patients, especially patients whose mechanical ventilation time was longer than 6 h.

Application of lung protective ventilation strategy in radiofrequency ablation of atrial fibrillation / 实用医学杂志

Objective To observe the clinical significance of lung protective ventilation strategy in pa-tients with radiofrequency ablation of atrial fibrillation under general anesthesia through clinical controlled study. Methods Sixty patients undergoing radiofrequency catheter ablation were randomly divided into group L (n=30) and group C(n=30).Breathing parameters were set after tracheal intubation of general anesthesia.Arterial blood gas was collected.PETCO2and airway pressure were recorded during the operation.The operative time,ablation time,flu-oroscopy time and operation-related complications were recorded together with the surgeon satisfaction. Patients were followed up postoperatively for pulmonary complications. The length of patient′s hospital-stay was recorded. Results There was no significant difference in operation time, fluoroscopy time, ablation time and hospitalization days between the two groups (P>0.05). There was no significant difference in the occurrence and grade of PPCs between the two groups (P>0.05). There was significant difference in surgeon satisfaction between the two groups (P<0.01).Conclusion LPVS is suitable for ventilation management in radiofrequency ablation of atrial fibrillation.

Acute interstitial pneumonitis associated pediatric acute respiratory distress syndrome in 8 recipients after liver transplantation / 中华器官移植杂志

Objective To summarize the clinical course of acute interstitial pneumonitis (AIP) associated pediatric acute respiratory distress syndrome (PARDS) in 8 recipients after liver transplantation,and further discuss the potential risk factors and therapeutic highlights.Methods A total of 476 pediatric patients received liver transplantation in Tianjin First Center Hospital from January 2012 to September 2016.Among them,8 cases of AIP associated PARDS in ICU were recruited in this study.Medical data including clinical presentation,ICU management and outcomes were analyzed retrospectively.Results The onset time-window of AIP associated PARDS was (2.67 ± 0.77) months after liver transplantation,and the time interval between initial symptom and ICU administration was (6.75 ± 5.82) days.Five cases had the history of acute rejection therapy,and 5 cases had CMV and/or EBV viremia history.All 8 cases received mechanical ventilation,2 cases given nasal non-invasive ventilation and the rest 6 cases given invasive ventilation,3 of which were switched to high frequency oscillatory ventilation (HFOV) combined with inhaled nitric oxide.At the stage of hypoxic climax,the fraction of inspired oxygen (FiO2) was up-regulated to 1.0 to maintain the oxygenation index (OI) of (25.24 ± 5.94).Temporary replacement of immunosuppressants with intravenous glucocorticoids was implemented in all 8 cases without acute rejection episode.Of 8 cases,2 cases died from PARDS,1 case died from portal thrombosis associated hepatic failure,and the rest 5 cases survived.Conclusion AIP associated PARDS is a critical complication with high mortality in pediatric patients after liver transplantation.Excessively strong immunosuppression therapy at early post-transplant stage shows a risk factor for AIP.Lung protective ventilation strategy and HFOV are recommended to reduce ventilator induced lung injury in pediatric patients.Temporary intravenous glucocorticoids may reduce acute inflammatory reaction in PARDS patients without increasing the risk of acute rejection.

Clinical Observation of Lung Protective Ventilation Strategy in Gynecologic Laparoscopic Surgery / 实用妇产科杂志

Objective:By monitoring the lung compliance,oxygenation index(OI),CC16、IL-8 in plasma,observe whether the protective lung ventilation in patients undergoing gynecological laparoscopic surgery can improve the respiratoryw function and reduce lung injury.Methods:40 cases of ASA grade Ⅰ-Ⅱ were selected,and 40 patients were treated by elective laparoscopic radical resection of cervical cancer.The patients were divided into two groups according to the random number table method in 40 cases.Mechanical ventilation in general anesthesia,A group used traditional intermittent positive pressure ventilation mode,tidal volume is set to 10ml/KG (PBW);B group used lung protective ventilation strategy,tidal volume is set to 6ml/KG (PBW) + 5cmH2O PEEP + recruitment manoeuvres.For patients before pneumoperitoneum(T0),2 hours after pneumoperitoneum (T1),4 hours after pneumoperitoneum (T2)MAP,HR,CVP,RR and C were observed.In pneumoperitoneum (T0),2 hours after pneumoperitoneum(T1),4 hours after pneumoperitoneum (T2),2 hours after operation(T3),24 hours after surgery(T4) venous,IL-8,CC16 content detection.Results:Before pneumoperitoneum,two groups of patients with pulmonary compliancethe difference was statistically significant(P ＜0.05).Compared T1 、T2 with T0 in A group and B group,the pulmonary compliance all decreased and there existed significant deference(P＜0.05).Notably,A group decreased evidently(P＜0.05).T0,T1,T3,T4 time points in two groups of patients with oxygenation index,the difference was statistically significant (P ＜ 0.05).Two groups of patients with CC16,IL-8content in T1,T2,T3,T4 time point,the difference was statistically significant (P ＜ 0.05).Conclusions:Lung protective ventilation strategy can improve respiratory function in patients with gynecological laparoscopic surgery,and reduce the incidence of lung injury.

The clinical application of tracheal gas insufflation / 中国小儿急救医学

Tracheal gas insufflation is a non conventional respiratory support technology. It might avoid severe CO2 retention in lung protective ventilation strategy, reduce ventilator-associated lung injury, which was recommented recently. In this article,we made a brief introduction of the principle,classification and clinical applications of tracheal gas insufflation technique.

The strategy of pulmonary protective ventilation after cardiac arrest resuscitation in critical ill children and the follow-up study / 中华实用儿科临床杂志

Objective To investigate the strategy of cardiopulmonary resuscitation (CPR) after lung protective mechanical ventilation in critical children and follow-up study of the survivals 90 d after discharge.Methods Four hundred and eighty-nine cases of respiratory cardiac arrest which occurred for various reasons from January 2011 to June 2016 were analyzed in Pediatric Intensive Care Unit (PICU) in Guiyang Children's Hospital,in which mechanical ventilation was performed after CPR in 251 cases,death,or giving up treatment within 24 h in 83 cases,children surviving ＞ 24 h in 168 cases,118 cases were assigned into small tidal volume ventilation group,and 50 cases into conventional tidal volume ventilation group,and according to the tidal volume to adjust positive end expiratory pressure ventilation (PEEP),and the oxygen partial pressure [pa (O2)] and the oxygen index (OI),the change of the indexes of blood gas analysis,lactic acid clearance,and oxygenation were also observed.To observe the complications of mechanical ventilation,the situation of withdrawing machine as well as the outcome of the children.Follow-up was conducted for 90 d,including continuous respiratory symptoms,lung imaging examination after discharge and lung function,nervous system examination.Results (1) After mechanical ventilation treatment of 48 hours,compared with the levels of fractional inspired oxygen (FiO2) (0.42 ± 0.15 vs.0.43 ± 0.22),pa (O2) (8.25 ± 0.22 vs.8.27 ± 0.68),OI (5.33 ± 2.01 vs.6.59 ± 1.99) and lactic acid clearance(61.05 ± 1.87 vs.60.93 ± 2.71) between the routine tidal volume ventilation group and the lower tidal volume ventilation group,showing that the difference had no statistical significance (t =1.645,1.165,2.302,2.037,all P ＞ 0.05).(2) In small tidal volume group,the incidence of ventilator associated lung injury was significantly lower than that in the conventional tidal volume group,and the difference was statistically significant (x2 =5.873,P ＜ 0.05).(3) Comparing 2 groups of different tidal volume ventilation,the mortality of critical ill children had no statistically significant difference (x2 =1.063,P ＞ 0.05).(4) One hundred and twenty-seven cases of children survived and were discharged,and compared with their discharge,the follow-up of 62 cases after discharge for 30 d,90 d showed that all the children's lung function improved,tidal volume,inspiratory and expiratory time ratio(I/E),volume ratio of peak(VP/VE),time ratio of peak(TP/TE) and breathing rate(RR) were also improved,and there was significant difference (F =43.225,6.108,68.821,78.237,20.361,all P ＜ 0.05).(5) Neurological examination and children's brain function classification rating scale showed that some children had nerve dysfunction.Conclusions Small tidal volume ventilation in reducing the occurrence of ventilator associated lung injury is superior to the conventional tidal volume ventilation.To improve case fatality rate of the children with cardiac arrest resuscitation and oxygenation is not better than the conventional tidal volume group.Dynamic monitoring is helpful to adjust breathing mechanics indexes and parameters and ventilator.Through the follow-up most of the discharged children recovered well,but a few had recurrent respiratory infection and neurological sequelae.

Effect of lung protective ventilation strategy on oxygenation and pulmonary inflammatory response in dogs with severe smoke inhalation injury / 中国中西医结合急救杂志

Objective To observe the effect of lung protective ventilation strategy on oxygenation and pulmonary inflammatory response in dogs with severe smoke inhalation injury.Methods Twelve local healthy male dogs were selected and anesthetized underwent endotracheal intubation, the time controlled smoke was applied to replicate the model of severe smoke inhalation injury, and they were divided into two groups according to the random number table: conventional ventilation group (CV group) and protective ventilation group (PV group), each receiving corresponding ventilation mode for 8 hours respectively. The blood gas analyses were detected before injury, immediately after injury and at ventilation for 2, 4, 6, 8 hours. The contents of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) in serum were detected by the enzyme-linked immunosorbent assay (ELISA) at each time point. Animals were killed after 8-hour ventilation, and different parts of the lung tissues were obtained for pathological examinations of lung tissues and evaluation of injury scores. The levels of inflammatory factors as TNF-α and IL-10 in lung homogenates were measured by ELISA.Results The arterial partial pressure (PaO2) levels in CV and PV groups were significantly decreased after injury compared with those before injury [mmHg (1 mmHg = 0.133 kPa): 57±19 vs. 128±31, 58±15 vs. 126±22, bothP 0.05). At 6 hours ventilation, PaO2 level in PV group was significantly higher than that in CV group (mmHg: 121±11 vs. 105±11,P 0.05). The histopathological changes revealed that there were alveolar tissue edema and inflammatory cells infiltration in both groups, the degree of severity in CV group was more prominent and its pulmonary tissue injury score was higher than that in PV group (3.68±0.22 vs. 3.27±0.35, P < 0.05). The serum levels of TNF-α and IL-10 after smoke injury were significantly increased in CV and PV groups [TNF-α (μg/L): 4.32±1.13 vs. 0.35±0.11, 4.51±2.02 vs. 0.41±0.08; IL-10 (ng/L): 16.73±2.31 vs. 4.27±0.56, 18.39±3.15 vs. 4.03±1.07, allP < 0.01]. Compared with CV group, the levels of TNF-α were significantly lower at 6 hours and 8 hours of ventilation [6 hours (μg/L): 2.62±0.34 vs. 3.65±1.08, 8 hours (μg/L): 3.02±0.31 vs. 4.21±1.27, bothP < 0.05), while the contents of IL-10 were obviously increased in PV group [6 hours (ng/L): 21.07±2.95 vs. 16.11±3.02, 8 hours (ng/L): 23.57±2.69 vs. 18.28±3.21, bothP < 0.05]. The content of TNF-α in lung homogenate in CV group was significantly higher than that in PV group (μg/L: 5.85±2.57 vs. 3.08±1.17,P < 0.05), but the content of IL-10 in lung homogenate of CV group was markedly lower than that in CP group (ng/L: 19.64±3.16 vs. 24.05±2.09, P < 0.05).Conclusion Lung protective ventilation strategy can effectively improve oxygenation and pulmonary inflammatory response in dogs with severe smoke inhalation injury, thus the lung injury is alleviated and the strategy has protective effect on damaged lung tissues.