Higher Extravascular Lung Water Research Articles

Thrombin worsens extravascular lung water and outcomes of septic patients with acute respiratory distress syndrome: A case control study.

Endothelial cell (EC) activation may increase systemic vascular permeability, causing extravascular lung water (EVLW) in sepsis with acute respiratory distress syndrome (ARDS). However, the correlation between thrombin and EVLW in sepsis and ARDS has not yet been addressed. Patients with sepsis and ARDS were prospectively enrolled between 2014 and 2016, and EVLW and serum thrombin levels on days 1 and 3 were measured and compared between surviving and non-surviving patients. Additionally, morphological changes in human umbilical vein endothelial cells (HUVECs) in the serum of patients with high and low EVLW were evaluated. The levels of EVLW, endothelial cells, and thrombin may positively correlate with the survival of patients with severe sepsis and ARDS. Twenty-seven patients were enrolled, and baseline characteristics, including age, sex, Acute Physiology and Chronic Health Evaluation (APACHE) II, prior 24-h fluid balance, body mass index, and shock status, were similar between survivors and non-survivors; however, day 1 EVLW was higher in non-survivors (27.5 ± 8.4 vs 22 ± 6.5 mL/kg, P = .047). EVLW of survivors improved from day 1 to day 3 (22 ± 6.5 vs 11 ± 3.8 mL/kg, P < .001), but did not improve in non-survivors (27.5 ± 8.4 vs 28 ± 6.7 mL/kg, P = .086), which means that patients had significantly lower EVLW on day 3 than on day 1. Thrombin levels of survivors significantly improved (1.03 ± 0.55 vs 0.87 ± 0.25 U/mL, P = .04) but did not improve in non-survivors (1.97 ± 0.75 vs 2.2 ± 0.75 U/mL, P = .08) from day 1 to day 3. EVLW and thrombin levels were positively correlated (r2 = 0.71, P < .0001). In vitro, the morphology and junctions of HUVECs changed when the serum from patients with high EVLW was added. The intercellular distances among the control, high EVLW, and low EVLW groups were 5.25 ± 1.22, 21.33 ± 2.15, and 11.17 ± 1.64 µm, respectively (P < .05).

Intermittent Ex Vivo Lung Perfusion in a Porcine Model for Prolonged Lung Preservation.

Ex vivo lung perfusion expands the lung transplant donor pool and extends preservation time beyond cold static preservation. We hypothesized that repeated regular ex vivo lung perfusion would better maintain lung grafts. Ten pig lungs were randomized into 2 groups. The control underwent 16 h of cold ischemic time and 2 h of cellular ex vivo lung perfusion. The intermittent ex vivo lung perfusion group underwent cold ischemic time for 4 h, ex vivo lung perfusion (first) for 2 h, cold ischemic time for 10 h, and 2 h of ex vivo lung perfusion (second). Lungs were assessed, and transplant suitability was determined after 2 h of ex vivo lung perfusion. The second ex vivo lung perfusion was significantly associated with better oxygenation, limited extravascular water, higher adenosine triphosphate, reduced intraalveolar edema, and well-preserved mitochondria compared with the control, despite proinflammatory cytokine elevation. No significant difference was observed in the first and second perfusion regarding oxygenation and adenosine triphosphate, whereas the second was associated with lower dynamic compliance and higher extravascular lung water than the first. Transplant suitability was 100% for the first and 60% for the second ex vivo lung perfusion, and 0% for the control. The second ex vivo lung perfusion had a slight deterioration in graft function compared to the first. Intermittent ex vivo lung perfusion created a better condition for lung grafts than cold static preservation, despite cytokine elevation. These results suggested that intermittent ex vivo lung perfusion may help prolong lung preservation.

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

BackgroundIn 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.MethodsBetween 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.ResultsDriving 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.ConclusionCompared 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 registrationClinicalTrials.gov (NCT04337983). Registered 30 March 2020—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04337983.

Preliminary Exploration of Epidemiologic and Hemodynamic Characteristics of Restrictive Filling Diastolic Dysfunction Based on Echocardiography in Critically Ill Patients: A Retrospective Study

Objective To preliminarily describe the epidemiologic and hemodynamic characteristics of critically ill patients with restrictive filling diastolic dysfunction based on echocardiography. Setting A retrospective study. Methods Epidemiologic characteristics of patients with restrictive filling diastolic dysfunction in ICU were described; clinical and hemodynamic data were preliminarily summarized and compared between patients with and without restrictive filling diastolic dysfunction; most of the data were based on echocardiography. Results More than half of the patients in ICU had diastolic dysfunction and about 16% of them had restrictive filling pattern. The patients who had restrictive filling diastolic dysfunction were more likely to have wider diameter of IVC (2.18 ± 0.50 versus 1.92 ± 0.43, P = 0.037), higher extravascular lung water score (15.9 ± 9.2 versus 13.2 ± 9.1, P = 0.014), lower left ventricular ejection fraction (EF-S: 53.0 ± 16.3 versus 59.3 ± 12.5, P = 0.014), and lower percentage of normal LAP that was estimated by E/e′ (8.9% versus 90.0%, P = 0.001) when compared with those of patients without restrictive filling diastolic dysfunction. Conclusion Our results suggest that critically ill patients with restrictive filling diastolic dysfunction may experience rising volume status, increasing extravascular lung water ultrasonic score, reducing long-axis systolic dysfunction, and less possibility of normal left atrial pressure. Intensivists are advised to pay more attention to patients with diastolic dysfunction, especially the exquisite fluid management of patients with restrictive filling pattern due to the close relationship of restrictive filling diastolic dysfunction with volume status and extravascular lung water in our study.

Midterm Effects of Fluid Resuscitation Strategies in an Experimental Model of Lung Contusion and Hemorrhagic Shock

This study compared three different fluid resuscitation strategies in terms of respiratory tolerance and hemodynamic efficacy in a pig model of blunt chest trauma with lung contusion and controlled hemorrhagic shock. We hypothesized that the choice of fluid resuscitation strategy (type and amount of fluids) may impact differently contused lungs in terms of extravascular lung water (EVLW) 20 h after trauma. Anesthetized female pigs (n = 5/group) received five bolt shots to the right thoracic cage and allowed to hemorrhage for 30 min, with 25 to 30 mL/kg of blood loss. Pigs were randomly assigned to resuscitation groups that maintained a minimum mean arterial blood pressure of 70 mmHg with one of three methods: normal saline (NS), unrestricted normal saline; NOREPI, low-volume normal saline with norepinephrine; or HS-HES, hypertonic saline with hydroxyethyl starch. Control pigs were anesthetized, but received no injury or treatment. After 20 h, animals were killed to measure EVLW by gravimetry. Fluid loading was significantly different in each group. All three treatment groups had higher EVLW than controls. Moderate, bilateral pulmonary edema was observed in the NS and HS-HES groups. The three treatment groups showed similar reductions in oxygenation. Static pulmonary compliance was diminished in the NS and HS-HES groups, but compliance was similar in NOREPI and control groups. The NOREPI group had pathological lactate levels. This study demonstrated the impact of fluid resuscitation on contused lungs. Twenty hours after the trauma, all three resuscitation approaches showed modest clinical consequences, with moderate lung edema and reduced compliance in response to the infused volume.

The evaluation of the effect of body positioning on intra-abdominal pressure measurement and the effect of intra-abdominal pressure at different body positioning on organ function and prognosis in critically ill patients

PurposeCurrent literatures confirmed the widespread and frequent development of both intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) among the critically ill with a significant associated risk of organ failure and increased mortality. The 2004 International ACS Consensus Conference committee proposed that intra-abdominal pressure (IAP) be measured in complete supine position; however, the supine position of intensive care unit (ICU) patients (<30° of bed increase) presented a significant risk for ventilator-associated pneumonia. Therefore, the potential contribution of head of bed (HOB) position in elevating IAP should be considered. The purpose of this study was to evaluate the effect of body positioning on IAP measurement and the effect of IAP at different body positions on organ function and prognosis in critically ill patients. Materials and MethodsA prospective cohort study to investigate the effect of different patient positioning on IAP, organ function, and prognosis was conducted on 88 patients admitted to a medical-surgical ICU. On admission, patients' epidemiological data and risk factors for IAH were studied; daily mean IAPs, abdominal perfusion pressure, filtration gradient, Acute Physiology and Chronic Health Evaluation II score, sequential organ failure assessment score, and multiple organ dysfunction scores were registered; next, conventional hemodynamic variables, intrathoracic blood volume index, global end-diastolic volume index and extravascular lung water using the pulse contour cardiac output system were recorded. Intra-abdominal pressures were recorded through a bladder catheter every 4 hours on the first day. Intra-abdominal pressure was measured with the patient HOB increases from 0° to 45°. Mean arterial pressure was recorded simultaneously, whereas abdominal perfusion pressure and filtration gradient (FG) were also calculated simultaneously. ResultsThe main results of this study were the incidence of IAH (28.4%) and ACS (2.3%) in ICU patients; the significant and independent relationship between IAP and HOB increases. Considering the absolute numbers of IAP, the HOB of 10° and 20° showed slight differences, whereas that of 30° and 45° showed clinically significant differences; HOB elevation was associated with clinically significant decreases in abdominal perfusion pressure and FG; patients with IAH were prone to the development of shock and multiple organ dysfunction syndrome and exhibited significantly lower intrathoracic blood volume index and global end-diastolic volume index and higher extravascular lung water. ConclusionsThere is a significant and independent relationship between IAP and HOB positioning in critically ill patients, with the HOB of 30° and 45° showing significant difference. Abdominal perfusion pressure and FG are significantly decreased when the patient's HOB is elevated. The potential contribution of body position in elevating IAP should be considered in critically ill patients with the risk of IAH and ACS.

Measurement of cardiac output using the transpulmonary thermodilution method in the presence of high extravascular lung water in a pediatric animal model

Measurement of cardiac output using the transpulmonary thermodilution method in the presence of high extravascular lung water in a pediatric animal model

Measurement of cardiac output using the transpulmonary thermodilution method in the presence of high extravascular lung water in a pediatric animal model

Cardiac output (CO) can be measured using the transpulmonary thermodilution (TPTD) technique. TPTD is considered to be the gold standard in pediatric patients. We studied the influence of high levels of EVLW on the reliability of CO measurement using the TPTD technique in a pediatric animal model.

Thoracic intravascular and extravascular fluid volumes in cardiac surgical patients.

One possible mechanism of impaired oxygenation in cardiac surgery with extracorporeal circulation (ECC) is the accumulation of extravascular lung water (EVLW). Intrathoracic blood volume (ITBV) and pulmonary blood volume (PBV) also may increase after separation from ECC, which can influence both cardiac performance and pulmonary capillary fluid filtration. This study tested whether there were any relationships between lung fluid accumulation and pulmonary gas exchange during the perioperative period of cardiac surgery and ECC. Ten patients undergoing myocardial revascularization were studied. ITBV, PBV, and EVLW were determined from the mean transit times and decay times of the dye and thermal indicator curves obtained simultaneously in the descending aorta. Gas exchange was assessed by arterial and mixed venous partial pressure of oxygen (PO2) and carbon dioxide (PCO2), and calculation of alveolo-arterial PO2 gradient (PA-aO2) and venous admixture (QVA/QT). Recordings were made after induction of anesthesia, after sternotomy, 15 min after separation from ECC, and 4 and 20 h postoperatively. After induction of anesthesia, EVLW (6.0 +/- 1.0 ml/kg, mean +/- SD), PBV (3.6 +/- 1.3 ml/kg), and ITBV (18.4 +/- 2.7 ml/kg) were within normal ranges. Oxygenation was moderately impaired, as indicated by an increased PA-aO2 (144 +/- 46 mmHg) and QVA/QT (11 +/- 4%). After separation from ECC, EVLW had increased to 9.1 +/- 2.6 ml/kg, which was accompanied by an increase of ITBV (26.0 +/- 4.4 ml/kg) and PBV (5.6 +/- 1.9 ml/kg). PAa-O2 (396 +/- 116 mmHg) and QVA/QT (29 +/- 7%) also were increased. ITBV and PBV remained increased 4 and 20 h postoperatively, but EVLW decreased to presurgery values. No correlations were found between thoracic intravascular and extravascular fluid volumes and gas exchange. Cardiac surgery with the use of ECC induces alterations of thoracic intravascular and extravascular fluid volumes. Postoperatively, increased ITBV and PBV need not be associated with higher EVLW. Thus, sufficient mechanisms protecting against lung edema formation or providing resolution of EVLW probably are maintained after ECC. Since oxygenation is impaired during and after cardiac surgery, it is concluded that mechanisms other than or in addition to changes of ITBV, PBV, and EVLW predominantly influence gas exchange.

Fluid Balance during Pulmonary Edema: Is Fluid Gain a Marker or a Cause of Poor Outcome?

To evaluate the importance of fluid balance and changes in extravascular lung water (EVLW) on survival in the ICU and short-term outcome in patients with pulmonary edema.Retrospective analysis of data (sorting by survival and "treatment received") from a recent randomized controlled trial of fluid restriction in this population.Medical ICU of a university-affiliated, tertiary-care medical center.Eighty-nine patients (from the previously mentioned study) requiring pulmonary artery catheterization with abnormally high EVLW (greater than 7 ml/kg).When analyzed by survival, the survivors had no significant fluid gain or change in EVLW but decreased wedge pressure and body weight, compared to nonsurvivors. When analyzed by fluid balance, patients who gained less than 1 L of fluid by 36 hours into the study had a better rate of survival (74 percent) than the rest (50 percent; p less than 0.05). Also, the median duration of days on the ventilator, ICU days, and days of hospitalization was approximately half as long for each variable in the group with less than 1 L of fluid gain. Even accounting for baseline differences in the severity of illness, fluid balance was an independent predictor of survival (p less than 0.05). When analyzed by whether or not EVLW decreased by more than 15 percent between the first and last measurement, only patients with ARDS or sepsis had decreased days on the ventilator and ICU days.These data support the concept that positive fluid balance per se is at least partially responsible for poor outcome in patients with pulmonary edema and defend the strategy of attempting to achieve a negative fluid balance if tolerated hemodynamically.

Amiloride impairs lung water clearance in newborn guinea pigs

To determine whether epithelial ion transport is physiologically important for lung water clearance after birth, the sodium transport inhibitor amiloride or its vehicle saline was given intratracheally to newborn full-term guinea pigs before the first breath. Guinea pigs given saline intratracheally breathed normally and had arterial O2 saturations (SaO2) greater than 94%. In contrast, guinea pigs that had an estimated 10(-4) M intra-alveolar concentration of amiloride had chest wall retractions and 88 +/- 3.6% (SD) SaO2 (P less than 0.01). Extravascular lung water (EVLW) per gram of dry lung weight 4 h after birth was significantly greater in newborns that received amiloride (8.3 +/- 1.1, n = 5) than in those that received saline (5.6 +/- 0.9, n = 7, P less than 0.01). The degree of perivascular fluid cuffing at 25 cmH2O inflation was quantitatively similar in amiloride- and saline-treated animals. The effect of amiloride was dose dependent. Intratracheal amiloride did not affect EVLW in 9-day-old guinea pigs. This study demonstrates that intratracheal amiloride before the first breath results in respiratory distress, hypoxemia, and an abnormally high EVLW. Epithelial sodium transport contributes normal lung liquid clearance after birth.