COVID-19 ARDS is characterized by higher extravascular lung water than non-COVID-19 ARDS: the PiCCOVID study.

BACKGROUND: In acute respiratory distress syndrome (ARDS), extravascular lung water index (EVLWi) and pulmonary vascular permeability index (PVPI) measured by transpulmonary thermodilution reflect the degree of lung injury. Whether EVLWi and PVPI are different between non-COVID-19 ARDS and the ARDS due to COVID-19 has never been reported. We aimed at comparing EVLWi, PVPI, respiratory mechanics and hemodynamics in patients with COVID-19 ARDS vs. ARDS of other origin. METHODS: Between March and October 2020, in an observational study conducted in intensive care units from three university hospitals, 60 patients with COVID-19-related ARDS monitored by transpulmonary thermodilution were compared to the 60 consecutive non-COVID-19 ARDS admitted immediately before the COVID-19 outbreak between December 2018 and February 2020. RESULTS: Driving pressure was similar between patients with COVID-19 and non-COVID-19 ARDS, at baseline as well as during the study period. Compared to patients without COVID-19, those with COVID-19 exhibited higher EVLWi, both at the baseline (17 (14-21) vs. 15 (11-19) mL/kg, respectively, p = 0.03) and at the time of its maximal value (24 (18-27) vs. 21 (15-24) mL/kg, respectively, p = 0.01). Similar results were observed for PVPI. In COVID-19 patients, the worst ratio between arterial oxygen partial pressure over oxygen inspired fraction was lower (81 (70-109) vs. 100 (80-124) mmHg, respectively, p = 0.02) and prone positioning and extracorporeal membrane oxygenation (ECMO) were more frequently used than in patients without COVID-19. COVID-19 patients had lower maximal lactate level and maximal norepinephrine dose than patients without COVID-19. Day-60 mortality was similar between groups (57% vs. 65%, respectively, p = 0.45). The maximal value of EVLWi and PVPI remained independently associated with outcome in the whole cohort. CONCLUSION: Compared to ARDS patients without COVID-19, patients with COVID-19 had similar lung mechanics, but higher EVLWi and PVPI values from the beginning of the disease. This was associated with worse oxygenation and with more requirement of prone positioning and ECMO. This is compatible with the specific lung inflammation and severe diffuse alveolar damage related to COVID-19. By contrast, patients with COVID-19 had fewer hemodynamic derangement. Eventually, mortality was similar between groups. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: ClinicalTrials.gov (NCT04337983). Registered 30 March 2020-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04337983 .

Early restrictive fluid resuscitation has no clinical advantage in experimental severe pediatric acute respiratory distress syndrome.

Intravenous fluids are widely used to treat circulatory deterioration in pediatric acute respiratory distress syndrome (PARDS). However, the accumulation of fluids in the first days of PARDS is associated with adverse outcome. As such, early fluid restriction may prove beneficial, yet the effects of such a fluid strategy on the cardiopulmonary physiology in PARDS are unclear. In this study, we compared the effect of a restrictive with a liberal fluid strategy on a hemodynamic response and the formation of pulmonary edema in an animal model of PARDS. Sixteen mechanically ventilated lambs (2-6 wk) received oleic acid infusion to induce PARDS and were randomized to a restrictive or liberal fluid strategy during a 6-h period of mechanical ventilation. Transpulmonary thermodilution determined extravascular lung water (EVLW) and cardiac output (CO). Postmortem lung wet-to-dry weight ratios were obtained by gravimetry. Restricting fluids significantly reduced fluid intake but increased the use of vasopressors among animals with PARDS. Arterial blood pressure was similar between groups, yet CO declined significantly in animals receiving restrictive fluids (P = 0.005). There was no difference in EVLW over time (P = 0.111) and lung wet-to-dry weight ratio [6.1, interquartile range (IQR) = 6.0-7.3 vs. 7.1, IQR = 6.6-9.4, restrictive vs. liberal, P = 0.725] between fluid strategies. Both fluid strategies stabilized blood pressure in this model, yet early fluid restriction abated CO. Early fluid restriction did not limit the formation of pulmonary edema; therefore, this study suggests that in the early phase of PARDS, a restrictive fluid strategy is not beneficial in terms of immediate cardiopulmonary effects.

Evaluation of the association between extravascular lung water and prognosis of sepsis: A protocol of systematic review.

BACKGROUND: The purpose of this study is to explore the association between extravascular lung water (EVLW) and prognosis of sepsis (PS). METHODS: We will carry out comprehensive literature search in electronic databases (PUBMED/MEDLINE, EMBASE, CENTRAL, WorldSciNet, PsycINFO, Allied and Complementary Medicine Database, CBM, and CNKI) and additional sources. All electronic databases will be searched from their initial to the present without language restrictions. Case-controlled studies reporting the association between EVLW and PS will be evaluated for inclusion. Outcomes of interest will include mortality rate, extravascular lung water index, pulmonary vascular permeability index, blood lactate clearance, oxygenation index, blood gas analysis, PaO2/FiO2, cardiac output index, global end diastolic volume index, intrathoracic blood volume index, systemic resistance index, acute physiology and chronic health scoring system II, and infection-related organ failure scoring system. Study quality will be evaluated using Newcastle-Ottawa Tool, and statistical analysis will be performed utilizing RevMan 5.4 software. RESULTS: This study will summarize the most recent evidence to investigate the association between EVLW and PS. CONCLUSIONS: The results of this study will provide an exhaustive view of the association between EVLW and PS. STUDY REGISTRATION OSF: osf.io/vhnxw.

Sodium-coupled neutral amino acid transporter SNAT2 counteracts cardiogenic pulmonary edema by driving alveolar fluid clearance.

The constant transport of ions across the alveolar epithelial barrier regulates alveolar fluid homeostasis. Dysregulation or inhibition of Na+ transport causes fluid accumulation in the distal airspaces resulting in impaired gas exchange and respiratory failure. Previous studies have primarily focused on the critical role of amiloride-sensitive epithelial sodium channel (ENaC) in alveolar fluid clearance (AFC), yet activation of ENaC failed to attenuate pulmonary edema in clinical trials. Since 40% of AFC is amiloride-insensitive, Na+ channels/transporters other than ENaC such as Na+-coupled neutral amino acid transporters (SNATs) may provide novel therapeutic targets. Here, we identified a key role for SNAT2 (SLC38A2) in AFC and pulmonary edema resolution. In isolated perfused mouse and rat lungs, pharmacological inhibition of SNATs by HgCl2 and α-methylaminoisobutyric acid (MeAIB) impaired AFC. Quantitative RT-PCR identified SNAT2 as the highest expressed System A transporter in pulmonary epithelial cells. Pharmacological inhibition or siRNA-mediated knockdown of SNAT2 reduced transport of l-alanine across pulmonary epithelial cells. Homozygous Slc38a2-/- mice were subviable and died shortly after birth with severe cyanosis. Isolated lungs of Slc38a2+/- mice developed higher wet-to-dry weight ratios (W/D) as compared to wild type (WT) in response to hydrostatic stress. Similarly, W/D ratios were increased in Slc38a2+/- mice as compared to controls in an acid-induced lung injury model. Our results identify SNAT2 as a functional transporter for Na+ and neutral amino acids in pulmonary epithelial cells with a relevant role in AFC and the resolution of lung edema. Activation of SNAT2 may provide a new therapeutic strategy to counteract and/or reverse pulmonary edema.

Changes of Extravascular Lung Water as an Independent Prognostic Factor for Early Developed ARDS in Severely Burned Patients.

An important feature of acute respiratory distress syndrome (ARDS) is fluid lost into the interstitium of lung combined with its compromised reabsorption, resulting in the elevation of extravascular lung water (EVLW). Although ARDS is known as an early, common, and life-threatening complication in major burns, the issue of whether or how the EVLW index (EVLWI) correlates with its prognosis has not been identified yet. In this retrospectively study, 121 severely burned adults with ARDS occurred in 2 weeks postburn were analyzed and divided into two groups: survivors (73 patients) and nonsurvivors (48 patients) according to the 28-day outcome after injury. Compared with nonsurvivors, survivors exhibited bigger EVLWI reduction in day 2 after ARDS onset (ΔEVLWI2), with no differences in ARDS timing and other EVLWI variables. ΔEVLWI2, rather than EVLWI on 2 days after ARDS onset, was identified as an independent prognostic factor even after adjusting other significant factors by Cox proportional hazard analysis. ROC curve analysis showed that ΔEVLWI2 [AUC = 0.723, 95% CI = (0.631-0.816), P < .001] was a relative predictor for survival on 28-day postburn, with a threshold of 1.9 ml/kg (63.0% sensitivity, 77.1% specificity). Kaplan-Meier survival curve analysis confirmed a significantly higher survival rate on 28-day postburn in patients with ΔEVLWI2 > 1.9 ml/kg (log-rank test: χ 2 =14.780, P < .001). Taken together, our study demonstrated that ΔEVLWI2 is an independent prognostic factor for early ARDS in severe burns. ΔEVLWI2 higher than 1.9 ml/kg might predict a higher survival rate in those patients.

Quantification of lung water in heart failure using cardiovascular magnetic resonance imaging.

BACKGROUND: Pulmonary edema is a cardinal feature of heart failure but no quantitative tests are available in clinical practice. The goals of this study were to develop a simple cardiovascular magnetic resonance (CMR) approach for lung water quantification, to correlate CMR derived lung water with intra-cardiac pressures and to determine its prognostic significance. METHODS: Lung water density (LWD, %) was measured using a widely available single-shot fast spin-echo acquisition in two study cohorts. Validation Cohort: LWD was compared to left ventricular end-diastolic pressure or pulmonary capillary wedge pressure in 19 patients with heart failure undergoing cardiac catheterization. Prospective Cohort: LWD was measured in 256 subjects, including 121 with heart failure, 82 at-risk for heart failure and 53 healthy controls. Clinical outcomes were evaluated up to 1 year. RESULTS: Within the validation cohort, CMR LWD correlated to invasively measured left-sided filling pressures (R = 0.8, p < 0.05). In the prospective cohort, mean LWD was 16.6 ± 2.1% in controls, 17.9 ± 3.0% in patients at-risk and 19.3 ± 5.4% in patients with heart failure, p < 0.001. In patients with or at-risk for heart failure, LWD >  20.8% (mean + 2 standard deviations of healthy controls) was an independent predictor of death, hospitalization or emergency department visit within 1 year, hazard ratio 2.4 (1.1-5.1, p = 0.03). CONCLUSIONS: In patients with heart failure, increased CMR-derived lung water is associated with increased intra-cardiac filling pressures, and predicts 1 year outcomes. LWD could be incorporated in standard CMR scans.

[Prognostic value of the dynamic changes in extra vascular lung water index and angiopoietin-2 in severe multiple trauma patients with acute respiratory distress syndrome].

OBJECTIVE: To observe the dynamic changes in extra vascular lung water index (EVLWI) and angiopoietin-2 (Ang-2) in severe multiple trauma patients with acute respiratory distress syndrome (ARDS), analyze the risk factor for short-term mortality, and to evaluate their prognostic values for prognosis. METHODS: A total of 54 severe multiple trauma patients with ARDS admitted to emergency intensive care unit (ICU) of the Affiliated Hospital of Guizhou Medical University from June 2014 to December 2018 were enrolled. The acute physiology and chronic health evaluation II (APACHE II), injury severity score (ISS) and oxygenation index (PaO2/FiO2), EVLWI [pulse-induced contour cardiac output (PiCCO) monitor] and plasma Ang-2 level [enzyme-linked immunosorbent assay (ELISA)] at 0 (immediately), 24, 48 and 72 hours after ICU admission, and the differences in PaO2/FiO2, EVLWI and Ang-2 between 0 hour and 72 hours (ΔPaO2/FiO2, ΔEVLWI, ΔAng-2) were calculated. The 28-day survival of patients was recorded, and the patients were divided into survival group and non-survival group. The differences in above mentioned parameters between the two groups were compared. Multivariate Logistic regression was used to analyze the independent risk factors associated with the prognosis. Receiver operating characteristic (ROC) curve was drawn to evaluate the prognostic values of ΔEVLWI and ΔAng-2 on the prognosis, and the Kaplan-Meier survival curve was plotted. RESULTS: 115 patients were enrolled in the final analysis, 72 survived in 28 days, 43 died, and the mortality rate was 37.4%. The APACHE II and ISS scores of the non-survival group were significantly higher than those of the survival group [APACHE II score: 25.7±2.7 vs. 20.6±2.2, ISS score: 22.1±3.1 vs. 18.1±2.1, both P < 0.05]. EVLWI and Ang-2 showed a gradual downwards tendency with the prolongation of the length of ICU stay in the survival group, but no significant change was found in the non-survival group. Parallel contour test showed that both P < 0.05, indicating that the curves between the two groups had different tendencies and were not parallel. The levels of EVLWI, Ang-2 and PaO2/FiO2 showed no statistical differences from 0 hour to 24 hours between the two groups, but EVLWI and Ang-2 in the non-survival group were significantly higher than those in the survival group from 48 hours on [EVLWI (mL/kg): 15.5±4.2 vs. 10.8±3.2, Ang-2 (ng/L): 352.7±51.2 vs. 237.9±42.8, both P < 0.05], and PaO2/FiO2 was significantly decreased [mmHg (1 mmHg = 0.133 kPa): 126.1±43.7 vs. 211.2±33.8, P < 0.05]. The ΔEVLWI and ΔAng-2 in the non-survival group were significantly lower than those in the survival group [ΔEVLWI (mL/kg): -0.9±6.1 vs. 3.1±6.4, ΔAng-2 (ng/L): -45.3±32.1 vs. 79.8±58.2, both P < 0.05], but ΔPaO2/FiO2 showed no significant difference as compared with the survival group (mmHg: 23.2±24.2 vs. -22.1±22.8, P > 0.05). Multivariate Logistic regression analysis demonstrated that ΔEVLWI [odds ratio (OR) = 2.811, 95% confidence interval (95%CI) = 1.232-3.161, P = 0.001], ΔAng-2 (OR = 2.204, 95%CI = 1.012-3.179, P = 0.001) and APACHE II (OR = 1.206, 95%CI = 1.102-1.683, P = 0.002) were independent risk factors for 28-day mortality of severe multiple trauma patients with ARDS. ROC curve analysis showed that the area under ROC curve (AUC) of ΔEVLWI for predicting 28-day prognosis of severe multiple trauma patients with ARDS was 0.832, which was higher than ΔAng-2 (AUC = 0.790) and APACHE II (AUC = 0.735). When the cut-off value of ΔEVLWI was 2.3 mL/kg, the sensitivity was 79.1%, and the specificity was 81.9%. Kaplan-Meier survival curve showed that the patients with ΔEVLWI > 2.3 mL/kg had a significantly higher 28-day cumulative survival rate as compared with the patients with ΔEVLWI ≤ 2.3 mL/kg (log-rank test: χ2 = 23.385, P = 0.000). CONCLUSIONS: ΔEVLWI and ΔAng-2 can be used as independent risk factors for 28-day mortality of severe multiple trauma patients with ARDS, and the predictive value of ΔEVLWI was better than Ang-2 and APACHE II. Dynamic observation of EVLWI could improve the accuracy of death forecasting for severe multiple trauma patients with ARDS.

The shape change index (SCI) of inferior vena cava (IVC) measuring by transabdominal ultrasound to predict the presence of septic shock in intensive care unit (ICU) patients.

OBJECTIVE: This study is designed as prospective and observational research of patients with sepsis. It was carried out in the intensive care unit (ICU). We investigated the shape change index (SCI) of inferior vena cava (IVC) measured with trans-abdominal ultrasound to detect the signs of septic shock. The aim of this research was to find the most effective tool in predicting shock in patients compared with that of other parameters such as brain natriuretic peptide (BNP), lactate, variation index of inferior vena cava IVC-VI, and extravascular lung water index (EVLWI). PATIENTS AND METHODS: We suppose that SCI can be used as the safest and most sensitive tool in the early recognition of septic dysfunction. The observational study was conducted in the Department of ICU, Shandong Provincial Hospital Affiliated to Shandong University from January 2016 to December 2017. SCI of IVC, serum lactate, BNP, IVC-VI, and EVLWI concentrations were measured in 30 sepsis patients. All studied biomarkers were analyzed and contrasted according to the score of the Sequential Organ Failure Assessment (SOFA). Pearson correlation analysis was analyzed to statistic the relationship between variables. RESULTS: We showed the correlation of BNP value, lactic acid value, IVC-VI, EVLWI, and SCI of IVC in sick patients suffering septic shock. Positive correlation was observed in the BNP value, lactic acid value, IVC-VI, EVLWI, and SCI of IVC (r=0.447, p=0.013; r=0.484, p=0.007; r=0.423, p=0.023; r=0.638, p<0.001; r=0.599, p<0.001; respectively). However, the SCI and EVLWI showed a stronger correlation with the SOFA than the others. SCI of IVC, as estimated by transabdominal ultrasound, was more accurate than the other commonly used non-invasive predictors. EVLWI, as an accurate and classical predictor, was an invasive predictor. SCI of IVC was faster, more convenient and safer than the other. CONCLUSIONS: SCI of IVC was faster, more convenient and safer than the other commonly used non-invasive predictors. Early recognition and diagnosis of sepsis may improve patient outcome.

Fluid restriction reduces pulmonary edema in a model of acute lung injury in mechanically ventilated rats.

Experimental acute lung injury models are often used to increase our knowledge on the acute respiratory distress syndrome (ARDS), however, existing animal models often do not take into account the impact of specific fluid strategies on the development of lung injury. In contrast, the current literature strongly suggests that fluid management strategies have a significant impact on clinical outcome of patients with ARDS. Thus, it is important to characterize the role of fluid management strategies in experimental models of lung injury. In this study we investigated the effect of two different fluid strategies on commonly used outcome variables in a short-term model of acute lung injury, in relation to age. Infant (2-3 weeks) and adult (3-4 months) Wistar rats received intratracheal instillations of lipopolysaccharide and 24 hours later were mechanically ventilated for 6 hours. During mechanical ventilation, rats from both age groups were randomized to either a standard or conservative intravenous fluid strategy. We found that the hemodynamic response in infant and adult rats was similar in both fluid strategies. Lung wet-to-dry ratios were lower in adult, but not in infant rats receiving the conservative fluid strategy as compared to the standard fluid strategy. There were age-related differences in markers of alveolar capillary barrier disruption and alveolar fluid clearance, yet these were unaffected by fluid strategy. Finally, we found significantly higher IL-1ß and TNF-α concentrations in the adult rats treated with the conservative as compared to the standard fluid regimen. In conclusion, the choice of fluid strategy in mechanically ventilated rats with experimental LPS-induced acute lung injury has a significant effect on pulmonary extravascular water, an important and well-recognized lung injury marker, and on the local pro-inflammatory cytokine profiles. We advocate the use of a more uniform, conservative, fluid strategy regimen in experimental models of acute lung injury.

Vitamin D to Prevent Lung Injury Following Esophagectomy-A Randomized, Placebo-Controlled Trial.

OBJECTIVES: Observational studies suggest an association between vitamin D deficiency and adverse outcomes of critical illness and identify it as a potential risk factor for the development of lung injury. To determine whether preoperative administration of oral high-dose cholecalciferol ameliorates early acute lung injury postoperatively in adults undergoing elective esophagectomy. DESIGN: A double-blind, randomized, placebo-controlled trial. SETTING: Three large U.K. university hospitals. PATIENTS: Seventy-nine adult patients undergoing elective esophagectomy were randomized. INTERVENTIONS: A single oral preoperative (3-14 d) dose of 7.5 mg (300,000 IU; 15 mL) cholecalciferol or matched placebo. MEASUREMENTS AND MAIN RESULTS: Primary outcome was change in extravascular lung water index at the end of esophagectomy. Secondary outcomes included PaO2:FIO2 ratio, development of lung injury, ventilator and organ-failure free days, 28 and 90 day survival, safety of cholecalciferol supplementation, plasma vitamin D status (25(OH)D, 1,25(OH)2D, and vitamin D-binding protein), pulmonary vascular permeability index, and extravascular lung water index day 1 postoperatively. An exploratory study measured biomarkers of alveolar-capillary inflammation and injury. Forty patients were randomized to cholecalciferol and 39 to placebo. There was no significant change in extravascular lung water index at the end of the operation between treatment groups (placebo median 1.0 [interquartile range, 0.4-1.8] vs cholecalciferol median 0.4 mL/kg [interquartile range, 0.4-1.2 mL/kg]; p = 0.059). Median pulmonary vascular permeability index values were significantly lower in the cholecalciferol treatment group (placebo 0.4 [interquartile range, 0-0.7] vs cholecalciferol 0.1 [interquartile range, -0.15 to -0.35]; p = 0.027). Cholecalciferol treatment effectively increased 25(OH)D concentrations, but surgery resulted in a decrease in 25(OH)D concentrations at day 3 in both arms. There was no difference in clinical outcomes. CONCLUSIONS: High-dose preoperative treatment with oral cholecalciferol was effective at increasing 25(OH)D concentrations and reduced changes in postoperative pulmonary vascular permeability index, but not extravascular lung water index.

A Simplified Ultrasound Comet Tail Grading Scoring to Assess Pulmonary Congestion in Patients with Heart Failure.

Ultrasound lung comets (ULCs) are a nonionizing bedside approach to assess extravascular lung water. We evaluated a protocol for grading ULC score to estimate pulmonary congestion in heart failure patients and investigated clinical and echocardiographic correlates of the ULC score. Ninety-three patients with congestive heart failure, admitted to the emergency department, underwent pulmonary ultrasound and echocardiography. A ULC score was obtained by summing the ULC scores of 7 zones of anterolateral chest scans. The results of ULC score were compared with echocardiographic results, the New York Heart Association (NYHA) functional classification, radiologic score, and N-terminal pro-b-type natriuretic peptide (NT-proBNP). Positive linear correlations were found between the 7-zone ULC score and the following: E/e', systolic pulmonary artery pressure, severity of mitral regurgitation, left ventricular global longitudinal strain, NYHA functional classification, radiologic score, and NT-proBNP. However, there was no significant correlation between ULC score and left ventricular ejection fraction, left ventricle diameter, left ventricular volume, or left atrial volume. A multivariate analysis identified the E/e', systolic pulmonary artery pressure, and radiologic score as the only independent variables associated with ULC score increase. The simplified 7-zone ULC score is a rapid and noninvasive method to assess lung congestion. Diastolic rather than systolic performance may be the most important determinant of the degree of lung congestion in patients with heart failure.

Cardiovascular Mechanisms of Extravascular Lung Water Accumulation in Divers.

This study assessed the relation between altered cardiac function and the development of interstitial pulmonary edema in scuba divers. Fifteen healthy men performed a 30-minute scuba dive in open sea. They were instructed to fin for 30 minutes and were wearing wet suits. Before and immediately after immersion, cardiac indexes and extravascular lung water were measured using echocardiography and lung ultrasound, respectively. The mean ultrasound lung comet score increased from 0 to 4.6 ± 3.4. The diameter of the inferior caval vein increased by 47 ± 5.2%, systolic pulmonary artery pressure by 105 ± 8.6%, left atrial volume by 18.0 ± 3.3%, and left ventricle end-diastolic volume by 10 ± 2.4% suggesting that both right and left ventricular (LV) filling pressures were elevated. Doppler studies showed an increased mitral E peak (+2.5 ± 0.3%) and E/A ratio (+22.5 ± 3.4%) with a decreased mitral A peak (-16.4 ± 2.7%), E peak deceleration time (-14.5 ± 2.4%) consistent with rapid early LV filling but without a change in LV stroke volume. There was an increase in right/left ventricle diameter ratio (+33.6 ± 4.8%) suggesting a relative increase in right-sided heart output compared with the left. Furthermore, the lung comet score correlated significantly with inferior caval vein diameter, systolic pulmonary artery pressure, right/left ventricle diameter ratio, and E-wave deceleration time. In conclusion, the altered right/left heart stroke volume balance could play an essential role in the development of immersion pulmonary edema. Our findings have important implications for the pathogenesis of cardiogenic pulmonary edema.

Increased Extravascular Lung Water and Plasma Biomarkers of Acute Lung Injury Precede Oxygenation Impairment in Primary Graft Dysfunction After Lung Transplantation.

BACKGROUND: After lung transplantation (LT), early prediction of grade 3 pulmonary graft dysfunction (PGD) remains a research gap for clinicians. We hypothesized that it could be improved using extravascular lung water (EVLWi) and plasma biomarkers of acute lung injury. METHODS: After institutional review board approval and informed consent, consecutive LT recipients were included. Transpulmonary thermodilution-based EVLWi, plasma concentrations of epithelial (soluble receptor for advanced glycation endproducts [sRAGE]) and endothelial biomarkers (soluble intercellular adhesion molecule-1 and endocan [full-length and cleaved p14 fragment]) were obtained before and after LT (0 [H0], 6, 12, 24, 48 and 72 hours after pulmonary artery unclamping). Grade 3 PGD was defined according to the International Society for Lung and Heart Transplantation definition, combining arterial oxygen partial pressure (PaO2)/inspired fraction of oxygen (FiO2) ratio and chest X-rays. Association of clinical risk factors, EVLWi and biomarkers with grade 3 PGD was analyzed under the Bayesian paradigm, using logistic model and areas under the receiver operating characteristic curves (AUCs). RESULTS: In 47 LT recipients, 10 developed grade 3 PGD, which was obvious at H6 in 8 cases. Clinical risk factors, soluble intercellular adhesion molecule-1 and endocan (both forms) were not associated with grade 3 PGD. Significant predictors of grade 3 PGD included (1) EVLWi (optimal cutoff, 13.7 mL/kg; AUC, 0.74; 95% confidence interval [CI], 0.48-0.99), (2) PaO2/FiO2 ratio (optimal cutoff, 236; AUC, 0.68; 95% CI, 0.52-0.84), and (3) sRAGE (optimal cutoff, 11 760 pg/mL; AUC, 0.66; 95% CI, 0.41-0.91) measured at H0. CONCLUSIONS: Immediate postreperfusion increases in EVLWi and sRAGE along with impaired PaO2/FiO2 ratios were early predictors of grade 3 PGD at or beyond 6 hours and may trigger early therapeutic interventions.

The differential effects of inspiratory, expiratory, and combined resistive breathing on healthy lung.

Combined resistive breathing (CRB) is the hallmark of obstructive airway disease pathophysiology. We have previously shown that severe inspiratory resistive breathing (IRB) induces acute lung injury in healthy rats. The role of expiratory resistance is unknown. The possibility of a load-dependent type of resistive breathing-induced lung injury also remains elusive. Our aim was to investigate the differential effects of IRB, expiratory resistive breathing (ERB), and CRB on healthy rat lung and establish the lowest loads required to induce injury. Anesthetized tracheostomized rats breathed through a two-way valve. Varying resistances were connected to the inspiratory, expiratory, or both ports, so that the peak inspiratory pressure (IRB) was 20%-40% or peak expiratory (ERB) was 40%-70% of maximum. CRB was assessed in inspiratory/expiratory pressures of 30%/50%, 40%/50%, and 40%/60% of maximum. Quietly breathing animals served as controls. At 6 hours, respiratory system mechanics were measured, and bronchoalveolar lavage was performed for measurement of cell and protein concentration. Lung tissue interleukin-6 and interleukin-1ß levels were estimated, and a lung injury histological score was determined. ERB produced significant, load-independent neutrophilia, without mechanical or permeability derangements. IRB 30% was the lowest inspiratory load that provoked lung injury. CRB increased tissue elasticity, bronchoalveolar lavage total cell, macrophage and neutrophil counts, protein and cytokine levels, and lung injury score in a dose-dependent manner. In conclusion, CRB load dependently deranges mechanics, increases permeability, and induces inflammation in healthy rats. ERB is a putative inflammatory stimulus for the lung.

[Not Available]. / Body composition changes assessed by bioelectrical impedance and their associations with functional class deterioration in stable heart failure patients.

BACKGROUND: Heart failure (HF) patients develop important changes in body composition, but only a small number of studies have evaluated the associations between these changes and functional class deterioration in a prospective manner. OBJECTIVE: The aim of this study was to evaluate whether changes in bioimpedance parameters were associated with NYHA functional class deterioration over six months. METHODS: A total of 275 chronic stable HF patients confirmed by echocardiography were recruited. Body composition measurements were obtained by whole body bioelectrical impedance with multiple frequency equipment (BodyStat QuadScan 4000). We evaluated functional class using the New York Heart Association (NYHA) classification at baseline and after six months. RESULTS: According to our results, 66 (24%) subjects exhibited functional class deterioration, while 209 improved or exhibited no change. A greater proportion of patients exhibited higher extracellular water (> 5%), and these patients developed hypervolemia, according to location on the resistance/reactance graph. A 5% decrease in resistance/height was associated with functional class deterioration with an OR of 1.42 (95% CI 1.01-2.0, p = 0.04). CONCLUSIONS: Body composition assessment through bioelectrical impedance exhibited a valuable performance as a marker of functional class deterioration in stable HF patients.

Impact of chronic systolic heart failure on lung structure-function relationships in large airways.

Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty-one HF (7F; age, 62 ± 11 years; ht. 175 ± 9 cm; wt. 91 ± 17 kg; LVEF, 28 ± 15%) and 29 controls (11F; age; 56 ± 11 years; ht. 174 ± 8 cm; wt. 77 ± 14 kg) completed the study. Subjects performed PFTs and a chest computed tomography (CT) scan before and after SABA CT measures of attenuation, skew, and kurtosis were obtained from areas of lung tissue to assess EVLW Airway luminal areas and wall thicknesses were also measured : CT tissue density suggested increased EVLW in HF without differences in the ratio of airway wall thickness to luminal area or luminal area to TLC (skew: 2.85 ± 1.08 vs. 2.11 ± 0.79, P < 0.01; Kurtosis: 15.5 ± 9.5 vs. 9.3 ± 5.5 P < 0.01; control vs. HF). PFTs were decreased in HF at baseline (% predicted FVC:101 ± 15% vs. 83 ± 18%, P < 0.01;FEV1:103 ± 15% vs. 82 ± 19%, P < 0.01;FEF25-75: 118 ± 36% vs. 86 ± 36%, P < 0.01; control vs. HF). Airway luminal areas, but not CT measures, were correlated with PFTs at baseline. The SABA cleared EVLW and decreased airway wall thickness but did not change luminal area. Patients with HF had evidence of increased EVLW, but not an expanded bronchial circulation. Airway caliber was maintained relative to controls, despite reductions in lung volume and flow rates. SABA improved lung function, primarily by reducing EVLW.

Effects of MIAVS on Early Postoperative ELWI and Respiratory Mechanics.

BACKGROUND: The effects of minimally invasive aortic valve surgery (MIAVS) on the early postoperative extravascular lung water index (ELWI) and respiratory mechanics have rarely been studied. MATERIAL/METHODS: A total of 90 patients were divided into 3 groups: a conventional full sternotomy (CS) group (n=30), an upper ministernotomy (US) group (n=30), and a right anterior thoracotomy (RT) group (n=30). Hemodynamic and respiratory mechanics parameters were recorded at perioperative time points, including before skin incision (T(-1)); at sternum closing (T0); and 4 h (T4), 8 h (T8), 12 h (T12), and 24 h (T24) after the operation. The ventilator support time, ICU length of stay, and postoperative hospitalization time, as well as the thoracic drainage volume and blood transfusion volume, were recorded. RESULTS: The ELWI and pulmonary vascular permeability index (PVPI) increased at T4, and the values were significantly lower in the US group than in the RT group and CS group (P<0.05). At T8, the ELWI and PVPI in the US group and RT group were significantly lower than in the CS group. At T12, there were no significant differences among the 3 groups. In addition, at T4 static lung compliance decreased, plateau airway pressure increased, and airway resistance changed non-significantly. There were no significant differences between the US group and the RT group, but both groups showed better results than the CS group did. CONCLUSIONS: The ELWI and PVPI may transiently increase after aortic valve surgery with cardiopulmonary bypass. Compared with the 12 h required to recover from a conventional sternotomy operation, it may only take 8 h to recover from MIAVS.

1,25-Dihydroxyvitamin D Enhances Alveolar Fluid Clearance by Upregulating the Expression of Epithelial Sodium Channels.

Vitamin D is implicated in the pathogenesis of asthma, acute lung injury, and other respiratory diseases. 1,25-Dihydroxyvitamin D (1,25(OH)2D3), the hormonal form of vitamin D, has been shown to reduce vascular permeability and ameliorate lung edema. Therefore, we speculate that 1,25(OH)2D3 may regulate alveolar Na(+) transport via targeting epithelial Na(+) channels (ENaC), a crucial pathway for alveolar fluid clearance. In vivo total alveolar fluid clearance was 39.4 ± 3.8% in 1,25(OH)2D3-treated mice, significantly greater than vehicle-treated controls (24.7 ± 1.9 %, n = 10, p < 0.05). 1,25(OH)2D3 increased amiloride-sensitive short-circuit currents in H441 monolayers, and whole-cell patch-clamp data confirmed that ENaC currents in single H441 cell were enhanced in 1,25(OH)2D3-treated cells. Western blot showed that the expression of α-ENaC was significantly elevated in 1,25(OH)2D3-treated mouse lungs and 1,25(OH)2D3-treated H441 cells. These observations suggest that vitamin D augments transalveolar fluid clearance, and vitamin D therapy may potentially be used to ameliorate pulmonary edema.

Effects of Early Continuous Venovenous Hemofiltration on E-Selectin, Hemodynamic Stability, and Ventilatory Function in Patients with Septic-Shock-Induced Acute Respiratory Distress Syndrome.

Objective. To investigate the effects of 72-hour early-initiated continuous venovenous hemofiltration (ECVVH) treatment in patients with septic-shock-induced acute respiratory distress syndrome (ARDS) (not acute kidney injury, AKI) with regard to serum E-selectin and measurements of lung function and hemodynamic stability. Methods. This prospective nonblinded single institutional randomized study involved 51 patients who were randomly assigned to receive or not receive ECVVH, an ECVVH group (n = 24) and a non-ECVVH group (n = 27). Besides standard therapies, patients in ECVVH group underwent CVVH for 72 h. Results. At 0 and 24 h after initiation of treatment, arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio, extravascular lung water index (EVLWI), and E-selectin level were not significantly different between groups (all P > 0.05). Compared to non-ECVVH group, PaO2/FiO2 is significantly higher and EVLWI and E-selectin level are significantly lower in ECVVH group (all P < 0.05) at 48 h and 72 h after initiation of treatment. The lengths of mechanical ventilation and stay in intensive care unit (ICU) were shorter in ECVVH group (all P < 0.05), but there was no difference in 28-day mortality between two groups. Conclusions. In patients with septic-shock-induced ARDS (not AKI), treatment with ECVVH in addition to standard therapies improves endothelial function, lung function, and hemodynamic stability and reduces the lengths of mechanical ventilation and stay in ICU.

The influence of high volume hemofiltration on extra vascular lung water and alveolar-arterial oxygen pressure difference in patients with severe sepsis.

OBJECTIVE: To explore the effects of high-volume hemofiltration (HVHF) on the plasma interleukin-6 (IL-6), pro-calcitonin (PCT), extra vascular lung water index (EVLWI) and alveolar-arterial oxygen exchange in patients with septic shock. PATIENTS AND METHODS: 97 cases intensive patients with septic shock were enrolled  from Department of Intensive Care Unit (ICU) of the Provincial Hospital affiliated to Shandong University between January 2011 and December 2014. According to the puting into practice of high-volume hemofiltration (HVHF) or not, all the patients were divided in two groups (NHVHF group, group A, n = 46 cases) and (HVHF group, group B, n = 51 cases). The plasma IL-6, PCT intrathoracic blood volume index (ITBVI), extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index(PVPI) was detected before treatment and after treatment 24h, 72h The Alveolar- arterial oxygen pressure difference P(A-a)DO2 was checked by arterial blood gas analysis (ABGA) at first and after treatment 24 hour, 72 hour, 7 day in two groups. The mortality at 28 day was compared between two groups. RESULTS: After 72h treatment, the plasma IL-6, PCT in group B has a significant decrease. After 72h treatment, the level ITBVI, EVLWI and PVPI in group B had a significant improvement. The levels of P(A-a)DO2 in HVHF group were reduced more significantly than N-HVHF group after 7 day. The EVLWI and P(A-a)DO2 had a significant positive correlation (correlation ratio = 0.712, 95% confident interval [0.617, 0.773], p = 0.001). The mortality at 28 day had a significant decrease between groups (15.22% vs. 34.15% χ2 = 4.242, p = 0.038). CONCLUSIONS: HVHF could decrease plasma inflammatory factors and EVLWI so that it could improve the levels of alveolar-arterial-oxygen exchange in patients with septic shock, so it could improve the survival rate of patients.