A Lifelike guided journey through the pathophysiology of pulmonary hypertension-from measured metabolites to the mechanism of action of drugs.

Introduction: Pulmonary hypertension (PH) is a pathological condition that affects approximately 1% of the population. The prognosis for many patients is poor, even after treatment. Our knowledge about the pathophysiological mechanisms that cause or are involved in the progression of PH is incomplete. Additionally, the mechanism of action of many drugs used to treat pulmonary hypertension, including sotatercept, requires elucidation. Methods: Using our graph-powered knowledge mining software Lifelike in combination with a very small patient metabolite data set, we demonstrate how we derive detailed mechanistic hypotheses on the mechanisms of PH pathophysiology and clinical drugs. Results: In PH patients, the concentration of hypoxanthine, 12(S)-HETE, glutamic acid, and sphingosine 1 phosphate is significantly higher, while the concentration of L-arginine and L-histidine is lower than in healthy controls. Using the graph-based data analysis, gene ontology, and semantic association capabilities of Lifelike, led us to connect the differentially expressed metabolites with G-protein signaling and SRC. Then, we associated SRC with IL6 signaling. Subsequently, we found associations that connect SRC, and IL6 to activin and BMP signaling. Lastly, we analyzed the mechanisms of action of several existing and novel pharmacological treatments for PH. Lifelike elucidated the interplay between G-protein, IL6, activin, and BMP signaling. Those pathways regulate hallmark pathophysiological processes of PH, including vasoconstriction, endothelial barrier function, cell proliferation, and apoptosis. Discussion: The results highlight the importance of SRC, ERK1, AKT, and MLC activity in PH. The molecular pathways affected by existing and novel treatments for PH also converge on these molecules. Importantly, sotatercept affects SRC, ERK1, AKT, and MLC simultaneously. The present study shows the power of mining knowledge graphs using Lifelike's diverse set of data analytics functionalities for developing knowledge-driven hypotheses on PH pathophysiological and drug mechanisms and their interactions. We believe that Lifelike and our presented approach will be valuable for future mechanistic studies of PH, other diseases, and drugs.

LASSO regression shows histidine and sphingosine 1 phosphate are linked to both sepsis mortality and endothelial damage.

Sepsis is a major cause of death worldwide, with a mortality rate that has remained stubbornly high. The current gold standard of risk stratifying sepsis patients provides limited mechanistic insight for therapeutic targeting. An improved ability to predict sepsis mortality and to understand the risk factors would allow better treatment targeting. Sepsis causes metabolic dysregulation in patients; therefore, metabolomics offers a promising tool to study sepsis. It is also known that that in sepsis endothelial cells affecting their function regarding blood clotting and vascular permeability. We integrated metabolomics data from patients admitted to an intensive care unit for sepsis, with commonly collected clinical features of their cases and two measures of endothelial function relevant to blood vessel function, platelet endothelial cell adhesion molecule and soluble thrombomodulin concentrations in plasma. We used least absolute shrinkage and selection operator penalized regression, and pathway enrichment analysis to identify features most able to predict 30-day survival. The features important to sepsis survival include carnitines, and amino acids. Endothelial proteins in plasma also predict 30-day mortality and the levels of these proteins also correlate with a somewhat overlapping set of metabolites. Overall metabolic dysregulation, particularly in endothelial cells, may be a contributory factor to sepsis response. By exploring sepsis metabolomics data in conjunction with clinical features and endothelial proteins we have gained a better understanding of sepsis risk factors.

Endothelial Cell Phenotypes Demonstrate Different Metabolic Patterns and Predict Mortality in Trauma Patients.

In trauma patients, shock-induced endotheliopathy (SHINE) is associated with a poor prognosis. We have previously identified four metabolic phenotypes in a small cohort of trauma patients (N = 20) and displayed the intracellular metabolic profile of the endothelial cell by integrating quantified plasma metabolomic profiles into a genome-scale metabolic model (iEC-GEM). A retrospective observational study of 99 trauma patients admitted to a Level 1 Trauma Center. Mass spectrometry was conducted on admission samples of plasma metabolites. Quantified metabolites were analyzed by computational network analysis of the iEC-GEM. Four plasma metabolic phenotypes (A-D) were identified, of which phenotype D was associated with an increased injury severity score (p < 0.001); 90% (91.6%) of the patients who died within 72 h possessed this phenotype. The inferred EC metabolic patterns were found to be different between phenotype A and D. Phenotype D was unable to maintain adequate redox homeostasis. We confirm that trauma patients presented four metabolic phenotypes at admission. Phenotype D was associated with increased mortality. Different EC metabolic patterns were identified between phenotypes A and D, and the inability to maintain adequate redox balance may be linked to the high mortality.

Thrombelastography (TEG® 6s) early amplitudes predict maximum amplitude in severely injured trauma patients.

Severely injured trauma patients are often coagulopathic and early hemostatic resuscitation is essential. Previous studies have revealed linear relationships between thrombelastography (TEG®) five- and ten-min amplitudes (A5 and A10), and maximum amplitude (MA), using TEG® 5000 technology. We aimed to investigate the performance of A5 and A10 in predicting low MA in severely injured trauma patients and identify optimal cut-off values for hemostatic intervention based on early amplitudes, using the cartridge-based TEG® 6s technology. Adult trauma patients with hemorrhagic shock were included in the iTACTIC randomized controlled trial at six European Level I trauma centers between 2016 and 2018. After admission, patients were randomized to hemostatic therapy guided by conventional coagulation tests (CCT) or viscoelastic hemostatic assays (VHA). Patients with available admission-TEG® 6s data were included in the analysis, regardless of treatment allocation. Low MA was defined as <55 mm for Kaolin TEG® and RapidTEG®, and <17 mm for TEG® functional fibrinogen (FF). One hundred eighty-seven patients were included. Median time to MA was 20 (Kaolin TEG®), 21 (RapidTEG®) and 12 (TEG® FF) min. For Kaolin TEG®, the optimal Youden index (YI) was at A5 < 36 mm (100/93% sensitivity/specificity) and A10 < 47 mm (100/96% sensitivity/specificity). RapidTEG® optimal YI was at A5 < 34 mm (98/92% sensitivity/specificity) and A10 < 45 mm (96/95% sensitivity/specificity). TEG® FF optimal YI was at A5 < 12 mm (97/93% sensitivity/specificity) and A10 < 15 mm (97/99% sensitivity/specificity). In summary, we found that TEG® 6s early amplitudes were sensitive and specific predictors of MA in severely injured trauma patients. Intervening on early amplitudes can save valuable time in hemostatic resuscitation.

Metabolic systems analysis identifies a novel mechanism contributing to shock in patients with endotheliopathy of trauma (EoT) involving thromboxane A2 and LTC4.

Purpose: Endotheliopathy of trauma (EoT), as defined by circulating levels of syndecan-1 ≥ 40 ng/mL, has been reported to be associated with significantly increased transfusion requirements and a doubled 30-day mortality. Increased shedding of the glycocalyx points toward the endothelial cell membrane composition as important for the clinical outcome being the rationale for this study. Results: The plasma metabolome of 95 severely injured trauma patients was investigated by mass spectrometry, and patients with EoT vs. non-EoT were compared by partial least square-discriminant analysis, identifying succinic acid as the top metabolite to differentiate EoT and non-EoT patients (VIP score = 3). EoT and non-EoT patients' metabolic flux profile was inferred by integrating the corresponding plasma metabolome data into a genome-scale metabolic network reconstruction analysis and performing a functional study of the metabolic capabilities of each group. Model predictions showed a decrease in cholesterol metabolism secondary to impaired mevalonate synthesis in EoT compared to non-EoT patients. Intracellular task analysis indicated decreased synthesis of thromboxanA2 and leukotrienes, as well as a lower carnitine palmitoyltransferase I activity in EoT compared to non-EoT patients. Sensitivity analysis also showed a significantly high dependence of eicosanoid-associated metabolic tasks on alpha-linolenic acid as unique to EoT patients. Conclusions: Model-driven analysis of the endothelial cells' metabolism identified potential novel targets as impaired thromboxane A2 and leukotriene synthesis in EoT patients when compared to non-EoT patients. Reduced thromboxane A2 and leukotriene availability in the microvasculature impairs vasoconstriction ability and may thus contribute to shock in EoT patients. These findings are supported by extensive scientific literature; however, further investigations are required on these findings.

Exploratory Investigation of the Plasma Proteome Associated with the Endotheliopathy of Trauma.

BACKGROUND: The endotheliopathy of trauma (EoT) is associated with increased mortality following injury. Herein, we describe the plasma proteome related to EoT in order to provide insight into the role of the endothelium within the systemic response to trauma. METHODS: 99 subjects requiring the highest level of trauma activation were included in the study. Enzyme-linked immunosorbent assays of endothelial and catecholamine biomarkers were performed on admission plasma samples, as well as untargeted proteome quantification utilizing high-performance liquid chromatography and tandem mass spectrometry. RESULTS: Plasma endothelial and catecholamine biomarker abundance was elevated in EoT. Patients with EoT (n = 62) had an increased incidence of death within 24 h at 21% compared to 3% for non-EoT (n = 37). Proteomic analysis revealed that 52 out of 290 proteins were differentially expressed between the EoT and non-EoT groups. These proteins are involved in endothelial activation, coagulation, inflammation, and oxidative stress, and include known damage-associated molecular patterns (DAMPs) and intracellular proteins specific to several organs. CONCLUSIONS: We report a proteomic profile of EoT suggestive of a surge of DAMPs and inflammation driving nonspecific activation of the endothelial, coagulation, and complement systems with subsequent end-organ damage and poor clinical outcome. These findings support the utility of EoT as an index of cellular injury and delineate protein candidates for therapeutic intervention.

Targeted plasma metabolomics in resuscitated comatose out-of-hospital cardiac arrest patients.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a leading cause of death. Even if successfully resuscitated, mortality remains high due to ischemic and reperfusion injury (I/R). The oxygen deprivation leads to a metabolic derangement amplified upon reperfusion resulting in an uncontrolled generation of reactive oxygen species in the mitochondria triggering cell death mechanisms. The understanding of I/R injury in humans following OHCA remains sparse, with no existing treatment to attenuate the reperfusion injury. AIM: To describe metabolic derangement in patients following resuscitated OHCA. METHODS: Plasma from consecutive resuscitated unconscious OHCA patients drawn at hospital admission were analyzed using ultra-performance-liquid-mass-spectrometry. Sixty-one metabolites were prespecified for quantification and studied. RESULTS: In total, 163 patients were included, of which 143 (88%) were men, and the median age was 62 years (53-68). All measured metabolites from the tricarboxylic acid (TCA) cycle were significantly higher in non-survivors vs. survivors (180-days survival). Hierarchical clustering identified four clusters (A-D) of patients with distinct metabolic profiles. Cluster A and B had higher levels of TCA metabolites, amino acids and acylcarnitine species compared to C and D. The mortality was significantly higher in cluster A and B (A:62% and B:59% vs. C:21 % and D:24%, p < 0.001). Cluster A and B had longer time to return of spontaneous circulation (A:33 min (21-43), B:27 min (24-35), C:18 min (13-28), and D:18 min (12-25), p < 0.001). CONCLUSION: Circulating levels of metabolites from the TCA cycle best described the variance between survivors and non-survivors. Four different metabolic phenotypes with significantly different mortality were identified.

Metabolic Response in Endothelial Cells to Catecholamine Stimulation Associated with Increased Vascular Permeability.

Disruption to endothelial cell homeostasis results in an extensive variety of human pathologies that are particularly relevant to major trauma. Circulating catecholamines, such as adrenaline and noradrenaline, activate endothelial adrenergic receptors triggering a potent response in endothelial function. The regulation of the endothelial cell metabolism is distinct and profoundly important to endothelium homeostasis. However, a precise catalogue of the metabolic alterations caused by sustained high catecholamine levels that results in endothelial dysfunction is still underexplored. Here, we uncover a set of up to 46 metabolites that exhibit a dose-response relationship to adrenaline-noradrenaline equimolar treatment. The identified metabolites align with the glutathione-ascorbate cycle and the nitric oxide biosynthesis pathway. Certain key metabolites, such as arginine and reduced glutathione, displayed a differential response to treatment in early (4 h) compared to late (24 h) stages of sustained stimulation, indicative of homeostatic metabolic feedback loops. Furthermore, we quantified an increase in the glucose consumption and aerobic respiration in endothelial cells upon catecholamine stimulation. Our results indicate that oxidative stress and nitric oxide metabolic pathways are downstream consequences of endothelial cell stimulation with sustained high levels of catecholamines. A precise understanding of the metabolic response in endothelial cells to pathological levels of catecholamines will facilitate the identification of more efficient clinical interventions in trauma patients.

Real-life experiences with goal-directed prohemostatic therapy with fibrinogen concentrate, prothrombin complex concentrate, and recombinant factor VIIa: a retrospective study of 287 consecutive patients.

The Danish Capital Region Blood Bank operates a 24/7 on-call service staffed with physicians specialized in hemostatic management to guide clinicians in hemostatic resuscitation, including administration of prohemostatic therapy (PHT). The outcome of patients who receive PHT as part of hemostatic resuscitation remains unanswered. The objective of this study was therefore to investigate clinical outcome of patients receiving PHT managed by the on-call service. We identified 287 patients who received PHT during 2015-16, of which 161 (59%) received fibrinogen concentrate (FC), 111 (39%) received prothrombin complex concentrate (PCC), and 15 (5%) received recombinant factor VIIa (rFVIIa) as the first product. Patients were critically ill with a 30-day mortality of 31%. Among FC recipients, cardiothoracic admission, non-trauma, and antithrombotics predicted survival. FC recipients had lower platelet count and thrombelastography clot strengths than the other PHT groups and within the group, these factors predicted mortality. The symptomatic thromboembolic event (TE) rate at 30 days was 5%. For PCC recipients, vitamin K antagonists predicted survival, while rivaroxaban predicted mortality. TE rate was 2%. We did not identify factors associated with survival in the small group of rFVIIa recipients. TE rate was 13%. In summary, trauma and coagulopathy predicted mortality in patients who received FC and our data suggest that optimization of PHT algorithms may be possible. Outcome of patients who received PCC was comparable to results reported elsewhere and its use may be safe in a setting as reported here. Recombinant FVIIa was rarely used but had the highest incidence of arterial thromboembolism.

Shock-Induced Endothelial Dysfunction is Present in Patients With Occult Hypoperfusion After Trauma.

BACKGROUND: Shock-induced endothelial dysfunction, evidenced by elevated soluble thrombomodulin (sTM) and syndecan-1 (Syn-1), is associated with poor outcomes after trauma. The association of endothelial dysfunction and overt shock has been demonstrated; it is unknown if hypoperfusion in the setting of normal vital signs (occult hypoperfusion [OH]) is associated with endothelial dysfunction. We hypothesized that sTM and Syn-1 would be elevated in patients with OH when compared to patients with normal perfusion. METHODS: A single-center study of patients requiring highest-level trauma activation (2012-2016) was performed. Trauma bay arrival plasma Syn-1 and sTM were measured by enzyme-linked immunosorbent assay. Shock was defined as systolic blood pressure (SBP) <90 mm Hg or heart rate (HR) ≥120 bpm. OH was defined as SBP ≥ 90, HR < 120, and base excess (BE) ≤-3. Normal perfusion was assigned to all others. Univariate and multivariable analyses were performed. RESULTS: Of 520 patients, 35% presented with OH and 26% with shock. Demographics were similar between groups. Patients with normal perfusion had the lowest Syn-1 and sTM, while patients with OH and shock had elevated levels. OH was associated with increased sTM by 0.97 ng/mL (95% CI 0.39-1.57, p = 0.001) and Syn-1 by 14.3 ng/mL (95% CI -1.5 to 30.2, p = 0.08). Furthermore, shock was associated with increased sTM by 0.64 (95% CI 0.02-1.30, p = 0.04) and with increased Syn-1 by 23.6 ng/mL (95% CI 6.2-41.1, p = 0.008). CONCLUSIONS: Arrival OH was associated with elevated sTM and Syn-1, indicating endothelial dysfunction. Treatments aiming to stabilize the endothelium may be beneficial for injured patients with evidence of hypoperfusion, regardless of vital signs.

Endothelial Dysfunction is Associated With Increased Incidence, Worsened Severity, and Prolonged Duration of Acute Kidney Injury After Severe Trauma.

INTRODUCTION: Nearly half of severely injured patients suffer acute kidney injury (AKI), but little is known about its pathogenesis or optimal management. We hypothesized that endothelial dysfunction, evidenced by elevated systemic soluble thrombomodulin (sTM) and syndecan-1, would be associated with higher incidence, worsened severity, and prolonged duration of AKI after severe trauma. METHODS: A single-center cohort study of severely injured patients surviving ≥24 h from 2012 to 2016 was performed. Arrival plasma sTM and syndecan-1 were measured by ELISA. Outcomes included 7-day AKI incidence, stage, and prolonged AKI ≥2 days. The Kidney Disease Improving Global Outcomes guidelines were used for AKI diagnosis and staging. Univariate and multivariable analyses were performed. RESULTS: Of 477 patients, 78% were male. Patients had a median age of 38 (interquartile ranges [IQR] 27-54) and injury severity score of 17 (IQR 10-26). AKI developed in 51% of patients. Those with AKI were older and displayed worse arrival physiology. Patients with AKI had higher plasma levels of syndecan-1 (median 34.9 ng/mL vs. 20.1 ng/mL) and sTM (6.5 ng/mL vs. 4.8 ng/mL). After adjustment, sTM and syndecan-1 were both associated with higher AKI incidence, worse AKI severity, and prolonged AKI duration. The strength and precision of the association of sTM and these outcomes were greater than those for syndecan-1. A sensitivity analysis excluding patients with AKI on arrival demonstrated the same relationship. CONCLUSIONS: Elevated sTM and syndecan-1, indicating endothelial dysfunction, were associated with higher incidence, worsened severity, and prolonged duration of AKI after severe trauma. Treatments that stabilize the endothelium hold promise for AKI treatment in severely injured patients.

Metabolic Systems Analysis of Shock-Induced Endotheliopathy (SHINE) in Trauma: A New Research Paradigm.

OBJECTIVE: Investigate the endothelial cell phenotype (s) that causes Shock-Induced Endotheliopathy in trauma. BACKGROUND: We have studied more than 2750 trauma patients and identified that patients with high circulating syndecan-1 (endothelial glycocalyx damage marker) in plasma have an increased mortality rate compared with patients with lower levels. Notably, we found that patients suffering from the same trauma severity could develop significantly different degrees of endothelial dysfunction as measured by syndecan-1. METHODS: Prospective observational study of 20 trauma patients admitted to a Level 1 Trauma Centre and 20 healthy controls. Admission plasma syndecan-1 level and mass spectrometry were measured and analyzed by computational network analysis of our genome-scale metabolic model of the microvascular endothelial cell function. RESULTS: Trauma patients had a significantly different endothelial metabolic profile compared with controls. Among the patients, 4 phenotypes were identified. Three phenotypes were independent of syndecan-1 levels. We developed genome-scale metabolic models representative of the observed phenotypes. Within these phenotypes, we observed differences in the cell fluxes from glucose and palmitate to produce Acetyl-CoA, and secretion of heparan sulfate proteoglycan (component of syndecan-1). CONCLUSIONS: We confirm that trauma patients have a significantly different metabolic profile compared with controls. A minimum of 4 shock-induced endotheliopathy phenotypes were identified, which were independent of syndecan-1level (except 1 phenotype) verifying that the endothelial response to trauma is heterogeneous and most likely driven by a genetic component. Moreover, we introduced a new research tool in trauma by using metabolic systems biology, laying the foundation for personalized medicine.

Absences of Endothelial Microvesicle Changes in the Presence of the Endotheliopathy of Trauma.

INTRODUCTION: Severe trauma is accompanied by endothelial glycocalyx disruption, which drives coagulopathy, increasing transfusion requirements and death. This syndrome has been termed endotheliopathy of trauma (EOT). Some have suggested EOT results from endothelial cellular damage and apoptosis. Endothelial microvesicles (EMVs) represent cellular damage. We hypothesized that EOT is associated with endothelial damage and apoptosis resulting in an increase in circulating EMVs. METHODS: Prospective, observational study enrolling severely injured patients. Twelve patients with EOT, based on elevated Syndecan-1 levels, were matched with 12 patients with lower levels, based on Injury Severity Score (ISS), abbreviated injury scale profile, and age. Thrombelastography and plasma levels of biomarkers indicative of cellular damage were measured from blood samples collected on admission. EMVs were determined by flow cytometry using varied monoclonal antibodies associated with endothelial cells. Significance was set at P < 0.05. RESULTS: Admission physiology and ISS (29 vs. 28) were similar between groups. Patients with EOT had higher Syndecan-1, 230 (158, 293) vs. 19 (14, 25) ng/mL, epinephrine, and soluble thrombomodulin levels. Based on thrombelastography, EOT had reductions in clot initiation, amplification, propagation and strength, and a greater frequency of transfusion, 92% vs. 33%. There were no differences in EMVs irrespective of the antibody used. Plasma norepinephrine, sE-selectin, sVE-cadherin, and histone-complexed DNA fragments levels were similar. CONCLUSION: In trauma patients presenting with EOT, endothelial cellular damage or apoptosis does not seem to occur based on the absence of an increase in EMVs and other biomarkers. Thus, this suggests endothelial glycocalyx disruption is the underlying primary cause of EOT.

Resuscitation of Endotheliopathy and Bleeding in Thoracic Aortic Dissections: The VIPER-OCTA Randomized Clinical Pilot Trial.

BACKGROUND: Thoracic aorta dissection is an acute critical condition associated with shock-induced endotheliopathy, coagulopathy, massive bleeding, and significant morbidity and mortality. Our aim was to compare the effect of coagulation support with solvent/detergent-treated pooled plasma (OctaplasLG) versus standard fresh frozen plasma (FFP) on glycocalyx and endothelial injury, bleeding, and transfusion requirements. METHODS: Investigator-initiated, single-center, blinded, randomized clinical pilot trial of adult patients undergoing emergency surgery for thoracic aorta dissection. Patients were randomized to receive OctaplasLG or standard FFP as coagulation factor replacement related to bleeding. The primary outcome was glycocalyx and endothelial injury. Other outcomes included bleeding, transfusions and prohemostatics at 24 hours, organ failure, length of stay in the intensive care unit and in the hospital, safety, and mortality at 30 and 90 days. RESULTS: Fifty-seven patients were included to obtain 44 evaluable on the primary outcome. The OctaplasLG group displayed significantly reduced damage to the endothelial glycocalyx (syndecan-1) and reduced endothelial tight junction injury (sVE-cadherin) compared to standard FFP. In the OctaplasLG group compared to the standard FFP, days on ventilator (1 day [interquartile range, 0-1] vs 2 days [1-3]; P = .013), bleeding during surgery (2150 [1600-3087] vs 2750 [2130-6875]; P = .046), 24-hour total transfusion and platelet transfusion volume (3975 mL [2640-6828 mL] vs 6220 mL [4210-10,245 mL]; P = .040, and 1400 mL [1050-2625 mL] vs 2450 mL [1400-3500 mL]; P = .027), and goal-directed use of prohemostatics (7/23 [30.4%] vs 13/21 [61.9%]; P = .036) were all significantly lower. Among the 57 patients randomized, 30-day mortality was 20.7% (6/29) in the OctaplasLG group and 25% (7/28) in the standard FFP group (P = .760). No safety concern was raised. CONCLUSIONS: In this randomized, clinical pilot trial of patients undergoing emergency surgery for thoracic aorta dissections, we found that OctaplasLG reduced glycocalyx and endothelial injury, reduced bleeding, transfusions, use of prohemostatics, and time on ventilator after surgery compared to standard FFP. An adequately powered multicenter trial is warranted to confirm the clinical importance of the findings.

Metabolic systems analysis of LPS induced endothelial dysfunction applied to sepsis patient stratification.

Endothelial dysfunction contributes to sepsis outcome. Metabolic phenotypes associated with endothelial dysfunction are not well characterised in part due to difficulties in assessing endothelial metabolism in situ. Here, we describe the construction of iEC2812, a genome scale metabolic reconstruction of endothelial cells and its application to describe metabolic changes that occur following endothelial dysfunction. Metabolic gene expression analysis of three endothelial subtypes using iEC2812 suggested their similar metabolism in culture. To mimic endothelial dysfunction, an in vitro sepsis endothelial cell culture model was established and the metabotypes associated with increased endothelial permeability and glycocalyx loss after inflammatory stimuli were quantitatively defined through metabolomics. These data and transcriptomic data were then used to parametrize iEC2812 and investigate the metabotypes of endothelial dysfunction. Glycan production and increased fatty acid metabolism accompany increased glycocalyx shedding and endothelial permeability after inflammatory stimulation. iEC2812 was then used to analyse sepsis patient plasma metabolome profiles and predict changes to endothelial derived biomarkers. These analyses revealed increased changes in glycan metabolism in sepsis non-survivors corresponding to metabolism of endothelial dysfunction in culture. The results show concordance between endothelial health and sepsis survival in particular between endothelial cell metabolism and the plasma metabolome in patients with sepsis.

Abnormalities of laboratory coagulation tests versus clinically evident coagulopathic bleeding: results from the prehospital resuscitation on helicopters study (PROHS).

BACKGROUND: Laboratory-based evidence of coagulopathy (LC) is observed in 25-35% of trauma patients, but clinically-evident coagulopathy (CC) is not well described. METHODS: Prospective observational study of adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers in 2015. Patients meeting predefined highest-risk criteria were divided into CC+ (predefined as surgeon-confirmed bleeding from uninjured sites or injured sites not controllable by sutures) or CC-. We used a mixed-effects, Poisson regression with robust error variance to test the hypothesis that abnormalities on rapid thrombelastography (r-TEG) and international normalized ratio (INR) were independently associated with CC+. RESULTS: Of 1,019 highest-risk patients, CC+ (n=41, 4%) were more severely injured (median ISS 32 vs 17), had evidence of LC on r-TEG and INR, received more transfused blood products at 4 hours (37 vs 0 units), and had greater 30-day mortality (59% vs 12%) than CC- (n=978, 96%). The overall incidence of LC was 39%. 30-day mortality was 22% vs 9% in those with and without LC. In two separate models, r-TEG K-time >2.5 min (RR 1.3, 95% CI 1.1-1.7), r-TEG mA <55 mm (RR 2.5, 95% CI 2.0-3.2), platelet count <150 x 109/L (RR 1.2, 95% CI 1.1-1.3), and INR >1.5 (RR 5.4, 95% CI 1.8-16.3) were independently associated with CC+. A combined regression model was not generated because too few patients underwent both r-TEG and INR. CONCLUSION: CC was rare compared to LC. CC was associated with poor outcomes and impairment of both clotting factor and platelet-mediated coagulation components.

Early haemorrhage control and management of trauma-induced coagulopathy: the importance of goal-directed therapy.

PURPOSE OF REVIEW: The aim of this study was to discuss the recent developments in trauma-induced coagulopathy and the evolvement of goal-directed therapy. RECENT FINDINGS: Mortality from major trauma continues to be a worldwide problem, and massive haemorrhage remains a major cause in 40% of potentially preventable trauma deaths. Development of trauma-induced coagulopathy challenges 25-35% of the patients further increasing trauma mortality. The pathophysiology of coagulopathy in trauma reflects at least two distinct mechanisms: Acute traumatic coagulopathy, consisting of endogenous heparinization, activation of the protein C pathway, hyperfibrinolysis and platelet dysfunction, and resuscitation associated coagulopathy. Clear fluid resuscitation with crystalloids and colloids is associated with dilutional coagulopathy and poor outcome in trauma. Haemostatic resuscitation is now the backbone of trauma resuscitation using a ratio-driven strategy aiming at 1:1:1 of red blood cells, plasma and platelets while applying goal-directed therapy early and repeatedly to control trauma-induced coagulopathy. SUMMARY: Trauma resuscitation should focus on early goal-directed therapy with use of viscoelastic haemostatic assays while initially applying a ratio 1:1:1 driven transfusion therapy (with red blood cells, plasma and platelets) in order to sustain normal haemostasis and control further bleeding.

Syndecan-1: A Quantitative Marker for the Endotheliopathy of Trauma.

BACKGROUND: Endothelial glycocalyx breakdown elicits syndecan-1 shedding and endotheliopathy of trauma (EoT). We hypothesized that a cutoff syndecan-1 level can identify patients with endothelial dysfunction who would have poorer outcomes. STUDY DESIGN: We conducted a prospective observational study. Trauma patients with the highest level of activation admitted from July 2011 through September 2013 were eligible. We recorded demographics, injury type/severity (Injury Severity Score), physiology and outcomes data, and quantified syndecan-1 and soluble thrombomodulin from plasma with ELISAs. With receiver operating characteristic curve analysis, we defined EoT+ as the syndecan-1 cutoff level that maximized the sum of sensitivity and specificity (Youden index) in predicting 24-hour in-hospital mortality. We stratified by this cutoff and compared both groups. Factors associated with 30-day in-hospital mortality were assessed with multivariable logistic regression (adjusted odds ratios and 95% CIs reported). RESULTS: From receiver operating characteristic curve analysis (area under the curve = 0.71; 95% CI 0.58 to 0.84), we defined EoT+ as syndecan-1 level ≥40 ng/mL (sensitivity = 0.62, specificity = 0.73). Of the 410 patients evaluated, 34% (n = 138) were EoT+ patients, who presented with higher Injury Severity Scores (p < 0.001) and blunt trauma frequency (p = 0.016) than EoT- patients. Although EoT+ patients had lower systolic blood pressure (median 119 vs 128 mmHg; p < 0.001), base excess and hemoglobin were similar between groups. The proportion of transfused (EoT+ 71.7% vs EoT- 36.4%; p < 0.001) and deceased EoT+ patients (EoT+ 24.6% vs EoT- 12.1%; p < 0.001) was higher. EoT+ was significantly associated with 30-day in-hospital mortality (adjusted odds ratio = 2.23; 95% CI 1.22 to 4.04). CONCLUSIONS: A syndecan-1 level ≥40 ng/mL identified patients with significantly worse outcomes, despite admission physiology similar to those without the condition.

Sympathoadrenal activation and endotheliopathy are drivers of hypocoagulability and hyperfibrinolysis in trauma: A prospective observational study of 404 severely injured patients.

BACKGROUND: One third of severely injured patients present with a laboratory-based diagnosis of coagulopathy. This study investigated clinical and biomarker profile of patients with rapid thrombelastography (rTEG) coagulopathy, hypothesizing that sympathoadrenal activation and endothelial damage were drivers of this condition. METHODS: Prospective observational study of 404 trauma patients admitted to a Level 1 US Trauma Center. Patients with admission rTEG and plasma measurements of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial activation/damage (syndecan-1, thrombomodulin, sE-selectin, sVE-cadherin, nucleosomes) were included. Demography, injury type/severity, physiology, treatment, and inhospital mortality were recorded. RESULTS: Patients had a median Injury Severity Score (ISS) of 17, 73% from blunt injury. One third (35%) of the patients had rTEG coagulopathy, which was associated with higher plasma adrenaline, syndecan-1, and nucleosomes (all <0.05), higher transfusion requirements and higher early (<24 hours, 9.3% vs. 2.5%) and late (28 days, 23.8% vs. 13.4%) mortality. By adjusted linear regression analyses, high plasma adrenaline, sVE-cadherin, and syndecan-1 (reflecting sympathoadrenal activation and endothelial cell junction and glycocalyx damage) along with male sex, high ISS, low platelet count and prehospital red blood cell transfusion were independently associated with hypocoagulable rTEG, whereas prehospital plasma and sE-selectin (reflecting endothelial activation) were independently associated with more hypercoagulable rTEG. CONCLUSION: In this cohort of severely injured trauma patients, rTEG coagulopathy was associated with sympathoadrenal activation, endotheliopathy, and excess mortality. High adrenaline and biomarkers reflecting endothelial cell junction and glycocalyx damage were independently associated with hypocoagulability and hyperfibrinolysis. These findings support that sympathoadrenal activation and endotheliopathy contribute to trauma-induced coagulopathy and warrants further studies of endothelial repair management. LEVEL OF EVIDENCE: Prognostic, Level III.

Traumatic Endotheliopathy: A Prospective Observational Study of 424 Severely Injured Patients.

OBJECTIVE: Investigate and confirm the association between sympathoadrenal activation, endotheliopathy and poor outcome in trauma patients. BACKGROUND: The association between sympathoadrenal activation, endotheliopathy, and poor outcome in trauma has only been demonstrated in smaller patient cohorts and animal models but needs confirmation in a large independent patient cohort. METHODS: Prospective observational study of 424 trauma patients admitted to a level 1 Trauma Center. Admission plasma levels of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial damage (syndecan-1, thrombomodulin, and sE-selectin) were measured and demography, injury type and severity, physiology, treatment, and mortality up till 28 days were recorded. RESULTS: Patients had a median ISS of 17 with 72% suffering from blunt injury. Adrenaline and noradrenaline correlated with syndecan-1 (r = 0.38, P < 0.001 and r = 0.23, P < 0.001, respectively) but adrenaline was the only independent predictor of syndecan-1 by multiple linear regression adjusted for age, injury severity score, Glascow Coma Scale, systolic blood pressure, base excess, platelet count, hemoglobin, prehospital plasma, and prehospital fluids (100 pg/mL higher adrenaline predicted 2.75 ng/mL higher syndecan-1, P < 0.001). By Cox analyses adjusted for age, sex, injury severity score, Glascow Coma Scale, base excess, platelet count and hemoglobin, adrenaline, and syndecan-1 were the only independent predictors of both <24-hours, 7-day and 28-day mortality (all P < 0.05). Furthermore, noradrenaline was an independent predictor of <24-hours mortality and thrombomodulin was an independent predictor of 7-day and 28-day mortality (all P < 0.05). CONCLUSIONS: We confirmed that sympathoadrenal activation was strongly and independently associated with endothelial glycocalyx and cell damage (ie, endotheliopathy) and furthermore that sympathoadrenal activation and endotheliopathy were independent predictors of mortality in trauma patients.