Thoracic epidural analgesia in intensive care unit patients with acute pancreatitis: the EPIPAN multicenter randomized controlled trial.

BACKGROUND: Findings from preclinical studies and one pilot clinical trial suggest potential benefits of epidural analgesia in acute pancreatitis. We aimed to assess the efficacy of thoracic epidural analgesia, in addition to usual care, in improving clinical outcomes of intensive care unit patients with acute pancreatitis. METHODS: A multicenter, open-label, randomized, controlled trial including adult patients with a clinical diagnosis of acute pancreatitis upon admission to the intensive care unit. Participants were randomly assigned (1:1) to a strategy combining thoracic epidural analgesia and usual care (intervention group) or a strategy of usual care alone (control group). The primary outcome was the number of ventilator-free days from randomization until day 30. RESULTS: Between June 2014 and January 2019, 148 patients were enrolled, and 135 patients were included in the intention-to-treat analysis, with 65 patients randomly assigned to the intervention group and 70 to the control group. The number of ventilator-free days did not differ significantly between the intervention and control groups (median [interquartile range], 30 days [15-30] and 30 days [18-30], respectively; median absolute difference of - 0.0 days, 95% CI - 3.3 to 3.3; p = 0.59). Epidural analgesia was significantly associated with longer duration of invasive ventilation (median [interquartile range], 14 days [5-28] versus 6 days [2-13], p = 0.02). CONCLUSIONS: In a population of intensive care unit adults with acute pancreatitis and low requirement for intubation, this first multicenter randomized trial did not show the hypothesized benefit of epidural analgesia in addition to usual care. Safety of epidural analgesia in this setting requires further investigation. TRIAL REGISTRATION: ClinicalTrials.gov registration number NCT02126332 , April 30, 2014.

Design and Rationale of the Sevoflurane for Sedation in Acute Respiratory Distress Syndrome (SESAR) Randomized Controlled Trial.

Preclinical studies have shown that volatile anesthetics may have beneficial effects on injured lungs, and pilot clinical data support improved arterial oxygenation, attenuated inflammation, and decreased lung epithelial injury in patients with acute respiratory distress syndrome (ARDS) receiving inhaled sevoflurane compared to intravenous midazolam. Whether sevoflurane is effective in improving clinical outcomes among patients with ARDS is unknown, and the benefits and risks of inhaled sedation in ARDS require further evaluation. Here, we describe the SESAR (Sevoflurane for Sedation in ARDS) trial designed to address this question. SESAR is a two-arm, investigator-initiated, multicenter, prospective, randomized, stratified, parallel-group clinical trial with blinded outcome assessment designed to test the efficacy of sedation with sevoflurane compared to intravenous propofol in patients with moderate to severe ARDS. The primary outcome is the number of days alive and off the ventilator at 28 days, considering death as a competing event, and the key secondary outcome is 90 day survival. The planned enrollment is 700 adult participants at 37 French academic and non-academic centers. Safety and long-term outcomes will be evaluated, and biomarker measurements will help better understand mechanisms of action. The trial is funded by the French Ministry of Health, the European Society of Anaesthesiology, and Sedana Medical.

Changes in Plasma Soluble Receptor for Advanced Glycation End-Products Are Associated with Survival in Patients with Acute Respiratory Distress Syndrome.

The plasma soluble receptor for advanced glycation end-products (sRAGE) is a marker of lung epithelial injury with prognostic value when measured at baseline in acute respiratory distress syndrome (ARDS). However, whether changes in plasma sRAGE could inform prognosis in ARDS remains unknown. In this secondary analysis of the Lung Imaging for Ventilator Setting in ARDS (LIVE) multicenter randomized controlled trial, which evaluated a personalized ventilation strategy tailored to lung morphology, plasma sRAGE was measured upon study entry (baseline) and on days one, two, three, four and six. The association between changes in plasma sRAGE over time and 90-day survival was evaluated. Higher baseline plasma sRAGE (HR per-one log increment, 1.53; 95% CI, 1.16-2.03; p = 0.003) and an increase in sRAGE over time (HR for each one-log increment in plasma sRAGE per time unit, 1.01; 95% CI, 1.01-1.02; p < 10-3) were both associated with increased 90-day mortality. Each 100-unit increase in the plasma sRAGE level per unit of time increased the risk of death at day 90 by 1% in joint modeling. Plasma sRAGE increased over time when a strategy of maximal alveolar recruitment was applied in patients with focal ARDS. Current findings suggest that the rate of change in plasma sRAGE over time is associated with 90-day survival and could be helpful as a surrogate outcome in ARDS.

[Analytical validation of 13 biochemistry parameters (CEA, CA 19-9, amylase, lipase, sodium, potassium, chloride, creatinine, glucose, protein, albumin, LDH, triglycerides) in body fluids]. / Validation de méthodes des dosages de 13 paramètres biochimiques (ACE, CA 19-9, amylase, lipase, sodium, potassium, chlorure, créatinine, glucose, protéines, albumine, LDH, triglycérides) dans un panel de liquides biologiques.

The measurement performance of 13 biochemistry parameters (CEA, CA 19-9, amylase, lipase, sodium, potassium, chloride, creatinine, glucose, protein, albumin, LDH, triglycerides) was tested in a panel of biological fluids other than blood and urine (peritoneal, pleural, pancreatic fluids ...). Our protocol, based on a risk analysis, allowed us to justify our choices and compare the performance obtained with those of the serum or plasma matrix already validated. Thus, the coefficients of variation obtained in body fluids are comparable. The assessment of accuracy (spiking and dilution tests) shows the absence of bias, which is consistent with the absence of matrix effect. The linearity studied by dilution tests shows that the upper limits of the measurement interval communicated by the supplier are applicable to body fluids. The absence of contamination and stability have been also confirmed. All analytes are stable for 3 days at room temperature, 7 days between 2 and 8̊C, and 6 months at -20̊C; except LDH and lipase. For most analytes, at least one interference (hemolysis, icterus, lipemia) was found. Finally, a bibliographical study, confronted with the experience of prescribers, led us to define optimal thresholds to help interpret patients' results. In conclusion, this work has allowed us to validate analytical methods for body fluids testing after relying on their comparability to the blood matrix. We have also been able to adapt our practices and finally be accredited according to the standard NF IN ISO 15189.

Fetal fibronectin test for threatened preterm delivery 48h after admission: Cost-effectiveness study.

OBJECTIVE: The aim of this work was to assess the cost-effectiveness of the fetal fibronectin (fFN) test at 48 h after admission for threatened preterm delivery to promote early discharge. STUDY DESIGN: Before-and-after study to calculate the incremental cost-effectiveness ratio (ICER). Patients were enrolled 48 h after admission in a tertiary care centre for threatened preterm delivery between 24+0 and 34+6 weeks. fFN testing was performed. During the first period, physician was blinded to fFN test and discharge occurred after apparent reduced symptomatology at physician's discretion. During the second period, fFN test was revealed to physician and discharge was immediately proposed to negative test patients. The costs considered in this analysis were the direct medical costs from the hospital perspective: costs of hospitalisation, treatment, and imaging procedures. The efficacy criterion selected was the number of deliveries at 7 and at 14 days after admission for threatened preterm delivery. RESULTS: The study included 178 pregnant patient, 99 during the first period (July 2008-October 2009) and 79 during the second (March 2010-February 2012). The lengths of hospital stays were shorter during the second period, with more than 50% of women discharged home between 48 and 72 h (p < 0.0001) resulting in a cost-saving of 76 051 euros. The number of deliveries at 7 and at 14 days was similar between the two periods. CONCLUSION: The fFN test at 48 h after admission supported early discharge and was safe and cost-effective.

Driving pressure and acute respiratory distress syndrome in critically ill patients.

BACKGROUND AND OBJECTIVE: Elevated driving pressure (ΔP) may be associated with increased risk of acute respiratory distress syndrome (ARDS) in patients admitted via the emergency department and with post-operative pulmonary complications in surgical patients. This study investigated the association of higher ΔP with the onset of ARDS in a high-risk, intensive care unit (ICU) population. METHODS: This is a secondary analysis of a prospective multicentre observational study. Data for this ancillary study were obtained from intubated adult patients with at least one ARDS risk factor upon ICU admission enrolled in a previous multicentre observational study. Patients were followed up for the development of ARDS within 7 days (primary outcome). Univariate and multivariate analyses tested the association between ΔP (measured at ICU admission (baseline) or 24 h later (day 1)) and the development of ARDS. RESULTS: A total of 221 patients were included in this study, among whom 34 (15%) developed ARDS within 7 days. These patients had higher baseline ΔP than those who did not (mean ± SD: 12.5 ± 3.1 vs 9.8 ± 3.4 cm H2 O, respectively, P = 0.0001). The association between baseline ΔP and the risk of developing ARDS was robust to adjustment for baseline tidal volume, positive-end expiratory pressure, illness severity, serum lactate and sepsis, pneumonia, severe trauma and shock as primary ARDS risk factors (odds ratio: 1.20; 95% CI: 1.03-1.41; P = 0.02). The same results were found with day 1 ΔP. CONCLUSION: Among at-risk ICU patients, higher ΔP may identify those who are more likely to develop ARDS.

Serum soluble receptor for advanced glycation end-products during acute bronchiolitis in infant: Prospective study in 93 cases.

INTRODUCTION: Acute bronchiolitis is a major cause of acute respiratory distress in infants. The soluble receptor for advanced glycation end-products (sRAGE) is a biomarker of pulmonary damage processes, with a diagnostic and a prognostic value in acute respiratory distress syndrome (ARDS). The RAGE pathway is also implicated in the pathogenesis of other respiratory diseases like asthma, but the value of sRAGE levels in acute bronchiolitis remains under-investigated. MATERIAL AND METHODS: A prospective, observational, and analytical study was conducted at Clermont-Ferrand University Hospital. The main objective was to evaluate the correlation between serum sRAGE and clinical severity of bronchiolitis in hospitalized infants aged <1 year. We analyzed correlations between serum sRAGE and Wainwright score, short-term morbidity attributable to bronchiolitis, causal viruses and risk for recurrent wheezing at 1 year. RESULTS: The study included 93 infants. sRAGE levels were significantly lower in acute bronchiolitis patients (mean 1101 pg/mL) than in controls (2203 pg/mL, P < 0.001) but did not correlate with clinical severity. No correlation was found between serum sRAGE and severity score, respiratory viruses, and recurrent wheezing at 1 year. Serum sRAGE levels were negatively correlated with age (r = -0.45, P < 0.001). CONCLUSION: Serum sRAGE levels are decreased in acute bronchiolitis but not correlated with disease severity. sRAGE levels should be age-adjusted in infants. Serum sRAGE levels measured in the setting of acute bronchiolitis were not predictive of recurrent wheezing.

Clinical and Biological Predictors of Plasma Levels of Soluble RAGE in Critically Ill Patients: Secondary Analysis of a Prospective Multicenter Observational Study.

RATIONALE: Although soluble forms of the receptor for advanced glycation end products (RAGE) have been recently proposed as biomarkers in multiple acute or chronic diseases, few studies evaluated the influence of usual clinical and biological parameters, or of patient characteristics and comorbidities, on circulating levels of soluble RAGE in the intensive care unit (ICU) setting. OBJECTIVES: To determine, among clinical and biological parameters that are usually recorded upon ICU admission, which variables, if any, could be associated with plasma levels of soluble RAGE. METHODS: Data for this ancillary study were prospectively obtained from adult patients with at least one ARDS risk factor upon ICU admission enrolled in a large multicenter observational study. At ICU admission, plasma levels of total soluble RAGE (sRAGE) and endogenous secretory (es)RAGE were measured by duplicate ELISA and baseline patient characteristics, comorbidities, and usual clinical and biological indices were recorded. After univariate analyses, significant variables were used in multivariate, multidimensional analyses. MEASUREMENTS AND MAIN RESULTS: 294 patients were included in this ancillary study, among whom 62% were admitted for medical reasons, including septic shock (11%), coma (11%), and pneumonia (6%). Although some variables were associated with plasma levels of RAGE soluble forms in univariate analysis, multidimensional analyses showed no significant association between admission parameters and baseline plasma sRAGE or esRAGE. CONCLUSIONS: We found no obvious association between circulating levels of soluble RAGE and clinical and biological indices that are usually recorded upon ICU admission. This trial is registered with NCT02070536.

Receptor for advanced glycation end-products and ARDS prediction: a multicentre observational study.

Acute respiratory distress syndrome (ARDS) prediction remains challenging despite available clinical scores. To assess soluble receptor for advanced glycation end-products (sRAGE), a marker of lung epithelial injury, as a predictor of ARDS in a high-risk population, adult patients with at least one ARDS risk factor upon admission to participating intensive care units (ICUs) were enrolled in a multicentre, prospective study between June 2014 and January 2015. Plasma sRAGE and endogenous secretory RAGE (esRAGE) were measured at baseline (ICU admission) and 24 hours later (day one). Four AGER candidate single nucleotide polymorphisms (SNPs) were also assayed because of previous reports of functionality (rs1800625, rs1800624, rs3134940, and rs2070600). The primary outcome was ARDS development within seven days. Of 500 patients enrolled, 464 patients were analysed, and 59 developed ARDS by day seven. Higher baseline and day one plasma sRAGE, but not esRAGE, were independently associated with increased ARDS risk. AGER SNP rs2070600 (Ser/Ser) was associated with increased ARDS risk and higher plasma sRAGE in this cohort, although confirmatory studies are needed to assess the role of AGER SNPs in ARDS prediction. These findings suggest that among at-risk ICU patients, higher plasma sRAGE may identify those who are more likely to develop ARDS.

RAGE inhibition reduces acute lung injury in mice.

The receptor for advanced glycation end-products (RAGE) is involved in inflammatory response during acute respiratory distress syndrome (ARDS). Growing body of evidence support strategies of RAGE inhibition in experimental lung injury, but its modalities and effects remain underinvestigated. Anesthetised C57BL/6JRj mice were divided in four groups; three of them underwent orotracheal instillation of acid and were treated with anti-RAGE monoclonal antibody (mAb) or recombinant soluble RAGE (sRAGE), acting as a decoy receptor. The fourth group served as a control. Lung injury was assessed by the analysis of blood gases, alveolar permeability, histology, AFC, and cytokines. Lung expression and distribution epithelial channels ENaC, Na,K-ATPase, and aquaporin (AQP)-5 were assessed. Treatment with either anti-RAGE mAb or sRAGE improved lung injury, arterial oxygenation and decreased alveolar inflammation in acid-injured animals. Anti-RAGE therapies were associated with restored AFC and increased lung expression of AQP-5 in alveolar cell. Blocking RAGE had potential therapeutic effects in a translational mouse model of ARDS, possibly through a decrease in alveolar type 1 epithelial cell injury as shown by restored AFC and lung AQP-5 expression. Further mechanistic studies are warranted to describe intracellular pathways that may control such effects of RAGE on lung epithelial injury and repair.

Epidural analgesia in critically ill patients with acute pancreatitis: the multicentre randomised controlled EPIPAN study protocol.

BACKGROUND: Acute pancreatitis (AP) is associated with high morbidity and mortality in its most severe forms. Most patients with severe AP require intubation and invasive mechanical ventilation, frequently for more than 7 days, which is associated with the worst outcome. Recent increasing evidence from preclinical and clinical studies support the beneficial effects of epidural analgesia (EA) in AP, such as increased gut barrier function and splanchnic, pancreatic and renal perfusion, decreased liver damage and inflammatory response, and reduced mortality. Because recent studies suggest that EA might be a safe procedure in the critically ill, we sought to determine whether EA reduced AP-associated respiratory failure and other major clinical outcomes in patients with AP. METHODS AND ANALYSIS: The Epidural Analgesia for Pancreatitis (EPIPAN) trial is an investigator-initiated, prospective, multicentre, randomised controlled two-arm trial with assessor-blinded outcome assessment. The EPIPAN trial will randomise 148 patients with AP requiring admission to an intensive care unit (ICU) to receive EA (with patient-controlled epidural administration of ropivacaine and sufentanil) combined with standard care based on current recommendations on the treatment of AP (interventional group), or standard care alone (reference group). The primary outcome is the number of ventilator-free days at day 30. Secondary outcomes include main complications of AP (eg, organ failure and mortality, among others), levels of biological markers of systemic inflammation, epithelial lung injury, renal failure, and healthcare-associated costs. ETHICS AND DISSEMINATION: The study was approved by the appropriate ethics committee (CPP Sud-Est VI). Informed consent is required. If the combined application of EA and standard care proves superior to standard care alone in patients with AP in the ICU, the use of EA may become standard practice in experienced centres, thereby decreasing potential complications related to AP and its burden in critically ill patients. The results will be disseminated in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT02126332.

Rationale, study design and analysis plan of the lung imaging morphology for ventilator settings in acute respiratory distress syndrome study (LIVE study): Study protocol for a randomised controlled trial.

Different acute respiratory distress syndrome (ARDS) phenotypes may explain controversial results in clinical trials. Lung-morphology is one of the ARDS-phenotypes and physiological studies suggest different responses in terms of positive-end-expiratory-pressure (PEEP) and recruitment-manoeuvres (RM) according to loss of aeration. To evaluate whether tailored ventilator regimens may impact ARDS outcomes, our group has designed a randomised-clinical-trial of ventilator settings according to lung morphology in moderate-to-severe ARDS (LIVE study). METHOD: Patients will be enrolled within the first 12hours of ARDS onset. In both groups, volume-controlled ventilation with low tidal-volumes (Vt) will be used to target a plateau pressure≤30 cmH2O. In the control group, the PEEP level and inspired fraction of oxygen (FiO2) will be set using the ARDSNet table; a Vt of 6 mL/kg of predicted body weight (PBW) will be set and prone position (PP) will be applied. In the intervention arm, the ventilator will be set according to lung morphology (focal/non-focal) that will be assessed according to CT-scan±chest x-ray+lung echography. For focal ARDS patients, a Vt of 8 mL/kg PBW will be used along with low PEEP and PP. For non-focal ARDS patients, a Vt of 6 mL/kg PBW will be used with RM and PEEP to reach a plateau pressure≤30 cmH2O. The primary outcome is all-cause 90-day mortality and the secondary outcomes are: in-hospital mortality, mortality at day 28, 60, 180 and 365; ventilator-free days at day 30, quality of life at one year; ventilator-associated pneumonia rate; barotrauma; ICU and hospital length of stay. This RCT is registered on Clinicaltrials.gov under identifier NCT02149589.

Sevoflurane for Sedation in Acute Respiratory Distress Syndrome. A Randomized Controlled Pilot Study.

RATIONALE: Sevoflurane improves gas exchange, and reduces alveolar edema and inflammation in preclinical studies of lung injury, but its therapeutic effects have never been investigated in acute respiratory distress syndrome (ARDS). OBJECTIVES: To assess whether sevoflurane would improve gas exchange and inflammation in ARDS. METHODS: We did a parallel, open-label single-center randomized controlled trial at three intensive care units from a French university hospital between April 2014 and February 2016. Adult patients were randomized within 24 hours of moderate-to-severe ARDS onset to receive either intravenous midazolam or inhaled sevoflurane for 48 hours. The primary outcome was the PaO2/FiO2 ratio on Day 2. Secondary endpoints included alveolar and plasma levels of cytokines and soluble form of the receptor for advanced glycation end-products, and safety. Investigators who did the analyses were masked to group allocation. Analysis was by intention to treat. MEASUREMENTS AND MAIN RESULTS: Twenty-five patients were assigned to the sevoflurane group and 25 to the midazolam group. On Day 2, PaO2/FiO2 ratio was higher in the sevoflurane group than in the midazolam group (mean ± SD, 205 ± 56 vs. 166 ± 59, respectively; P = 0.04). There was a significant reduction over time in cytokines and soluble form of the receptor for advanced glycation end-products levels in the sevoflurane group, compared with the midazolam group, and no serious adverse event was observed with sevoflurane. CONCLUSIONS: In patients with ARDS, use of inhaled sevoflurane improved oxygenation and decreased levels of a marker of epithelial injury and of some inflammatory markers, compared with midazolam. Clinical trial registered with www.clinicaltrials.gov (NCT 02166853).

Elevated Plasma Levels of sRAGE Are Associated With Nonfocal CT-Based Lung Imaging in Patients With ARDS: A Prospective Multicenter Study.

BACKGROUND: During ARDS, CT can reveal two distinct lung imaging patterns, focal or nonfocal, with different responses to positive end-expiratory pressure, recruitment maneuvers, and prone position. Nevertheless, their association with plasma biomarkers and their distinct functional/pathobiological mechanisms are unknown. The objective of this study was to characterize focal and nonfocal patterns of lung CT-based imaging with plasma markers of lung injury. METHODS: A prospective multicenter cohort study involving 119 consecutive patients with ARDS. Plasma biomarkers (soluble form of the receptor for advanced glycation end product [sRAGE], plasminogen activator inhibitor-1, soluble intercellular adhesion molecule-1, and surfactant protein-D) were measured within 24 h of ARDS onset. Lung CT scan was performed within the first 48 h to assess lung morphology. RESULTS: Thirty-two (27%) and 87 (73%) patients had focal and nonfocal ARDS, respectively. Plasma levels of sRAGE were significantly higher in nonfocal ARDS, compared with focal ARDS. A cut-off of 1,188 pg/mL differentiated focal from nonfocal ARDS with a sensitivity of 94% and a specificity of 84%. Nonfocal patterns were associated with higher 28- and 90-day mortality than focal patterns (31% vs 12%, P = .038 and 46% vs 21%, P = .026, respectively). Plasma levels of plasminogen activator inhibitor-1 were significantly higher in nonfocal ARDS. There was no difference in other biomarkers. CONCLUSIONS: Plasma sRAGE is associated with a nonfocal ARDS. Such novel findings may suggest a role for RAGE pathway in an underlying endotype of impaired alveolar fluid clearance and stimulate future research on the association between ARDS phenotypes and therapeutic responses.

Net alveolar fluid clearance is associated with lung morphology phenotypes in acute respiratory distress syndrome.

BACKGROUND: The acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome that encompasses multiple phenotypes, e.g. with regards to lung morphology as assessed by computed tomography (CT). Focal or non-focal lung morphology may influence the response to positive end-expiratory pressure (PEEP), recruitment manoeuvres and prone position. Lung morphology has been hypothesized to be associated with alveolar fluid clearance (AFC), thus explaining various responses to such therapeutic interventions; however, this hypothesis has not been specifically studied in humans. METHODS: We measured net AFC rates in 30 patients with ARDS as a secondary data analysis of a prospective single-centre study. Net AFC rates were compared between patients with focal ARDS and those with non-focal ARDS, as assessed by lung CT-scans. RESULTS: Net AFC rates were significantly lower in patients with non-focal ARDS (n=23; median [interquartile range], 1.5 [0-5.5] %/h) as compared to those with focal ARDS (n=7; 10.3 [4.5-15] %/h) (P=0.01). The area under the receiver-operating characteristic curve when net AFC rates were used to differentiate the presence from absence of non-focal ARDS was 0.93 (95% confidence interval, 0.81-1). Tidal volumes and PEEP levels differed between focal and non-focal ARDS patients, but there was no difference in arterial oxygenation or in alveolar-capillary permeability. CONCLUSIONS: Non-focal lung morphology may be characterized by a functional endotype consistent with marked AFC impairment. Despite study limitations and the need for validating studies in larger cohorts, such novel findings may reinforce our understanding of the association between ARDS phenotypes and therapeutic responses.

Soluble Forms and Ligands of the Receptor for Advanced Glycation End-Products in Patients with Acute Respiratory Distress Syndrome: An Observational Prospective Study.

BACKGROUND: The main soluble form of the receptor for advanced glycation end-products (sRAGE) is elevated during acute respiratory distress syndrome (ARDS). However other RAGE isoforms and multiple ligands have been poorly reported in the clinical setting, and their respective contribution to RAGE activation during ARDS remains unclear. Our goal was therefore to describe main RAGE isoforms and ligands levels during ARDS. METHODS: 30 ARDS patients and 30 mechanically ventilated controls were prospectively included in this monocenter observational study. Arterial, superior vena cava and alveolar fluid levels of sRAGE, endogenous-secretory RAGE (esRAGE), high mobility group box-1 protein (HMGB1), S100A12 and advanced glycation end-products (AGEs) were measured in duplicate ELISA on day 0, day 3 and day 6. In patients with ARDS, baseline lung morphology was assessed with computed tomography. RESULTS: ARDS patients had higher arterial, central venous and alveolar levels of sRAGE, HMGB1 and S100A12, but lower levels of esRAGE and AGEs, than controls. Baseline arterial sRAGE, HMGB1 and S100A12 were correlated with nonfocal ARDS (AUC 0.79, 0.65 and 0.63, respectively). Baseline arterial sRAGE, esRAGE, S100A12 and AGEs were associated with severity as assessed by PaO2/FiO2. CONCLUSIONS: This is the first kinetics study of levels of RAGE main isoforms and ligands during ARDS. Elevated sRAGE, HMGB1 and S100A12, with decreased esRAGE and AGEs, were found to distinguish patients with ARDS from those without. Our findings should prompt future studies aimed at elucidating RAGE/HMGB1/S100A12 axis involvement in ARDS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01270295.

Association between intraoperative ventilator settings and plasma levels of soluble receptor for advanced glycation end-products in patients without pre-existing lung injury.

BACKGROUND AND OBJECTIVE: The soluble form of the receptor for advanced glycation end-products (sRAGE) is elevated and correlated with severity in patients with acute respiratory distress syndrome (ARDS). The impact of ventilator settings on plasma levels of sRAGE, in patients with or without pre-existing lung injury, remains under-investigated to date. Our objective was to assess the effects of a lung-protective ventilation strategy (combining low tidal volume, positive end-expiratory pressure and recruitment maneuvers), as compared with a non-protective approach (with high tidal volume and zero end-expiratory pressure), on plasma levels of sRAGE in patients without lung injury undergoing major abdominal surgery. METHODS: Plasma samples were obtained from 95 patients enrolled in a large randomized controlled trial of lung-protective ventilation for major abdominal surgery. Plasma levels of sRAGE were measured in duplicate with an enzyme-linked immunoassay on day 1, immediately after surgery, and on postoperative days 1, 3 and 7. RESULTS: Early postoperative plasma levels of sRAGE were significantly lower in the lung-protective ventilation group (n = 47) than in the non-protective ventilation group (n = 48) (mean (standard deviation), 1782 (836) vs 2171 (1678) pg/mL, respectively, P = 0.03). Intraoperative changes in plasma sRAGE were associated with postoperative hypoxemia and ARDS. CONCLUSIONS: A lung-protective ventilation strategy decreased plasma sRAGE in patients without lung injury undergoing major abdominal surgery compared with the patients with non-protective ventilation. This intraoperative decrease could reflect a lesser degree of epithelial injury.

Soluble Receptor for Advanced Glycation End-Products Predicts Impaired Alveolar Fluid Clearance in Acute Respiratory Distress Syndrome.

RATIONALE: Levels of the soluble form of the receptor for advanced glycation end-products (sRAGE) are elevated during acute respiratory distress syndrome (ARDS) and correlate with severity and prognosis. Alveolar fluid clearance (AFC) is necessary for the resolution of lung edema but is impaired in most patients with ARDS. No reliable marker of this process has been investigated to date. OBJECTIVES: To verify whether sRAGE could predict AFC during ARDS. METHODS: Anesthetized CD-1 mice underwent orotracheal instillation of hydrochloric acid. At specified time points, lung injury was assessed by analysis of blood gases, alveolar permeability, lung histology, AFC, and plasma/bronchoalveolar fluid measurements of proinflammatory cytokines and sRAGE. Plasma sRAGE and AFC rates were also prospectively assessed in 30 patients with ARDS. MEASUREMENTS AND MAIN RESULTS: The rate of AFC was inversely correlated with sRAGE levels in the plasma and the bronchoalveolar fluid of acid-injured mice (Spearman's ρ = -0.73 and -0.69, respectively; P < 10(-3)), and plasma sRAGE correlated with AFC in patients with ARDS (Spearman's ρ = -0.59; P < 10(-3)). Similarly, sRAGE levels were significantly associated with lung injury severity, and decreased over time in mice, whereas AFC was restored and lung injury resolved. CONCLUSIONS: Our results indicate that sRAGE levels could be a reliable predictor of impaired AFC during ARDS, and should stimulate further studies on the pathophysiologic implications of RAGE axis in the mechanisms leading to edema resolution. Clinical trial registered with www.clinicaltrials.gov (NCT 00811629).

Effects of a recruitment maneuver on plasma levels of soluble RAGE in patients with diffuse acute respiratory distress syndrome: a prospective randomized crossover study.

PURPOSE: The soluble form of the receptor for advanced glycation end-products (sRAGE) is a promising marker for epithelial dysfunction, but it has not been fully characterized as a biomarker of acute respiratory distress syndrome (ARDS). Whether sRAGE could inform on the response to ventilator settings has been poorly investigated, and whether a recruitment maneuver (RM) may influence plasma sRAGE remains unknown. METHODS: Twenty-four patients with moderate/severe, nonfocal ARDS were enrolled in this prospective monocentric crossover study and randomized into a "RM-SHAM" group when a 6-h-long RM sequence preceded a 6-h-long sham evaluation period, or a "SHAM-RM" group (inverted sequences). Protective ventilation was applied, and RM consisted of the application of 40 cmH2O airway pressure for 40 s. Arterial blood was sampled for gas analyses and sRAGE measurements, 5 min pre-RM (or 40-s-long sham period), 5, 30 min, 1, 4, and 6 h after the RM (or 40-s-long sham period). RESULTS: Mean PaO2/FiO2, tidal volume, PEEP, and plateau pressure were 125 mmHg, 6.8 ml/kg (ideal body weight), and 13 and 26 cmH2O, respectively. Median baseline plasma sRAGE levels were 3,232 pg/ml. RM induced a significant decrease in sRAGE (-1,598 ± 859 pg/ml) in 1 h (p = 0.043). At 4 and 6 h post-RM, sRAGE levels increased back toward baseline values. Pre-RM sRAGE was associated with RM-induced oxygenation improvement (AUC 0.84). CONCLUSIONS: We report the first kinetics study of plasma sRAGE after RM in ARDS. Our findings reinforce the value of plasma sRAGE as a biomarker of ARDS.

Predicting the severity of acute bronchiolitis in infants: should we use a clinical score or a biomarker?

Krebs von den Lungen 6 antigen (KL-6) has been shown to be a useful biomarker of the severity of Respiratory syncytial virus bronchiolitis. To assess the correlation between the clinical severity of acute bronchiolitis, serum KL-6, and the causative viruses, 222 infants with acute bronchiolitis presenting at the Pediatric Emergency Department of Estaing University Hospital, Clermont-Ferrand, France, were prospectively enrolled from October 2011 to May 2012. Disease severity was assessed with a score calculated from oxygen saturation, respiratory rate, and respiratory effort. A nasopharyngeal aspirate was collected to screen for a panel of 20 respiratory viruses. Serum was assessed and compared with a control group of 38 bronchiolitis-free infants. No significant difference in KL-6 levels was found between the children with bronchiolitis (mean 231 IU/mL ± 106) and those without (230 IU/mL ± 102), or between children who were hospitalized or not, or between the types of virus. No correlation was found between serum KL-6 levels and the disease severity score. The absence of Human Rhinovirus was a predictive factor for hospitalization (OR 3.4 [1.4-7.9]; P = 0.006). Older age and a higher oxygen saturation were protective factors (OR 0.65[0.55-0.77]; P < 0.0001 and OR 0.67 [0.54-0.85] P < 0.001, respectively). These results suggest that in infants presenting with bronchiolitis for the first time, clinical outcome depends more on the adaptive capacities of the host than on epithelial dysfunction intensity. Many of the features of bronchiolitis are affected by underlying disease and by treatment.