Intervening on the storage time of RBC units and its effects on adverse recipient outcomes using real-world data.

Randomized controlled trials (RCTs) have found no evidence that the storage time of transfused red blood cell (RBC) units affects recipient survival. However, inherent difficulties in conducting RBC transfusion RCTs have prompted critique of their design, analyses, and interpretation. Here, we address these issues by emulating hypothetical randomized trials using large real-world data to further clarify the adverse effects of storage time. We estimated the comparative effect of transfusing exclusively older vs fresher RBC units on the primary outcome of death, and the secondary composite end point of thromboembolic events, or death, using inverse probability weighting. Thresholds were defined as 1, 2, 3, and 4 weeks of storage. A large Danish blood transfusion database from the period 2008 to 2018 comprising >900 000 transfusion events defined the observational data. A total of 89 799 patients receiving >340 000 RBC transfusions during 28 days of follow-up met the eligibility criteria. Treatment with RBC units exclusively fresher than 1, 2, 3, and 4 weeks of storage was found to decrease the 28-day recipient mortality with 2.44 percentage points (pp) (0.86 pp, 4.02 pp), 1.93 pp (0.85 pp, 3.02 pp), 1.06 pp (-0.20 pp, 2.33 pp), and -0.26 pp (-1.78 pp, 1.25 pp) compared with transfusing exclusively older RBC units, respectively. The 28-day risk differences for the composite end point were similar. This study suggests that transfusing exclusively older RBC units stored for >1 or 2 weeks increases the 28-day recipient mortality and risk of thromboembolism or death compared with transfusing fresher RBC units.

Plasma as endothelial rescue in septic shock: A randomized, phase 2a pilot trial.

BACKGROUND: Septic shock is associated with high morbidity and mortality, the endothelium plays an important role. Crystalloids is standard of care to maintain intravascular volume. Plasma is associated with improved endothelial integrity and restoration of the glycocalyx layer. We evaluated the efficacy and safety aspects of cell-free and pathogen inactivated pooled plasma (OctaplasLG®) as resuscitation in septic shock patients. STUDY DESIGN AND METHODS: This randomized, investigator-initiated phase IIa trial ran at a Danish single center intensive care unit, from 2017 to 2019. Patients were 18 years of age or older with septic shock and randomized to fluid optimization with OctaplasLG® or Ringer-acetate in the first 24 h. The primary endpoints were changes in biomarkers indicative of endothelial activation, damage, and microvascular perfusion from baseline to 24 h. Safety events and mortality were assessed during 90 days. RESULTS: Forty-four patients were randomized, 20 to OctaplasLG versus 24 to Ringer-acetate. The median age was 69, and 55% were men. Median Sequential Organ Failure Assessment score was 13. Baseline differences favoring the Ringer-acetate group were observed. The OctaplasLG® group was resuscitated with 740 mL plasma and the Ringer-acetate group with 841 mL crystalloids. There was no significant change in the microvascular perfusion or five biomarkers except VEGFR1 change, which was higher in patients receiving OctaplasLG® 0.12(SD 0.37) versus Ringer-acetate -0.24 (SD 0.39), with mean difference 0.36 (95% CI, 0.13-0.59, p = .003) in favor of Ringer-acetate. DISCUSSION: This study found that fluid resuscitation with OctaplasLG® in critically ill septic shock patients is feasible. Baseline confounding prevented assessment of the potential effect of OctaplasLG®.

The effect of Mycobacterium tuberculosis treatment on thrombelastography-assessed haemostasis: a prospective cohort study.

BACKGROUND AND OBJECTIVE: Tuberculosis disease (TB) and tuberculosis infection (TBI) have been associated with increased risk of cardiovascular disease which may be connected to infection-related haemostatic changes. It is unknown if treatment of Mycobacterium tuberculosis influences haemostasis. Here, we assessed if TB or TBI treatment affects thrombelastography (TEG)-assessed haemostasis. METHODS: Individuals with TB or TBI were included from a TB outpatient clinic in Copenhagen, Denmark. Patients treated with antithrombotic medication or systemic immunosuppressants were excluded. TEG analysis was performed before and after TB/TBI treatment using the TEG®6s analyser to provide data on the reaction time of clot initiation (R) (min), the speed of clot formation (K) (min) and clot build-up (Angle) (°), maximum clot strength (MA) (mm), and clot breakdown/fibrinolysis (LY30) (%). Differences in TEG were assessed using paired t tests. RESULTS: We included eleven individuals with TB with median [interquartile range] [IQR] age 52 (Liu et al. in Medicine (United States) 95, 2016) years and mean (standard deviation) (SD) body mass index (BMI) 24.7 (6.3) kg/m2 as well as 15 individuals with TBI with median [IQR] age 49 (Wells et al. in Am J Respir Crit Care Med 204:583, 2021) years and BMI 26.0 (3.2) kg/m2. Treatment reduced MA for both TB (64.0 (6.3) vs. 57.9 (5.2) mm, p = 0.016) and TBI (61.3 (4.1) vs. 58.6 (5.0) mm, p = 0.023) whereas R, K, Angle and LY30 were unaffected. CONCLUSION: TEG analysis showed that treatments of TB and TBI were associated with reduced MA which may indicate the existence of cardiovascular benefits from therapy. TRIAL REGISTRATION: Registered at ClinicalTrials.gov 05 April 2021 with registration number NCT04830462.

Integrating Genome-Scale Metabolic Models with Patient Plasma Metabolome to Study Endothelial Metabolism In Situ.

Patient blood samples are invaluable in clinical omics databases, yet current methodologies often fail to fully uncover the molecular mechanisms driving patient pathology. While genome-scale metabolic models (GEMs) show promise in systems medicine by integrating various omics data, having only exometabolomic data remains a limiting factor. To address this gap, we introduce a comprehensive pipeline integrating GEMs with patient plasma metabolome. This pipeline constructs case-specific GEMs using literature-based and patient-specific metabolomic data. Novel computational methods, including adaptive sampling and an in-house developed algorithm for the rational exploration of the sampled space of solutions, enhance integration accuracy while improving computational performance. Model characterization involves task analysis in combination with clustering methods to identify critical cellular functions. The new pipeline was applied to a cohort of trauma patients to investigate shock-induced endotheliopathy using patient plasma metabolome data. By analyzing endothelial cell metabolism comprehensively, the pipeline identified critical therapeutic targets and biomarkers that can potentially contribute to the development of therapeutic strategies. Our study demonstrates the efficacy of integrating patient plasma metabolome data into computational models to analyze endothelial cell metabolism in disease contexts. This approach offers a deeper understanding of metabolic dysregulations and provides insights into diseases with metabolic components and potential treatments.

Major open abdominal surgery is associated with increased levels of endothelial damage and interleukin-6.

OBJECTIVE: To examine changes in biomarkers of endothelial glycocalyx shedding, endothelial damage, and surgical stress following major open abdominal surgery and the correlation to postoperative morbidity. INTRODUCTION: Major abdominal surgery is associated with high levels of postoperative morbidity. Two possible reasons are the surgical stress response and the impairment of the glycocalyx and endothelial cells. Further, the degree of these responses may correlate with postoperative morbidity and complications. METHODS: A secondary data analysis of prospectively collected data from two cohorts of patients undergoing open liver surgery, gastrectomy, esophagectomy, or Whipple procedure (n = 112). Hemodynamics and blood samples were collected at predefined timestamps and analyzed for biomarkers of glycocalyx shedding (Syndecan-1), endothelial activation (sVEGFR1), endothelial damage (sThrombomodulin (sTM)), and surgical stress (IL6). RESULTS: Major abdominal surgery led to increased levels of IL6 (0 to 85 pg/mL), Syndecan-1 (17.2 to 46.4 ng/mL), and sVEGFR1 (382.8 to 526.5 pg/mL), peaking at the end of the surgery. In contrast, sTM, did not increase during surgery, but increased significantly following surgery (5.9 to 6.9 ng/mL), peaking at 18 h following the end of surgery. Patients characterized with high postoperative morbidity had higher levels of IL6 (132 vs. 78 pg/mL, p = 0.007) and sVEGFR1 (563.1 vs. 509.4 pg/mL, p = 0.045) at the end of the surgery, and of sTM (8.2 vs. 6.4 ng/mL, p = 0.038) 18 h following surgery. CONCLUSION: Major abdominal surgery leads to significantly increased levels of biomarkers of endothelial glycocalyx shedding, endothelial damage, and surgical stress, with the highest levels seen in patients developing high postoperative morbidity.

Perioperative management of patients declining transfusions of blood components-National survey of anaesthesiologists, abdominal surgeons and obstetricians in Denmark.

Perioperative management of patients declining transfusions of blood products can be challenging both ethically and clinically. Jehovah's Witnesses (JW) decline treatment with blood products and have published a list of interventions they might accept as substitutes. No detailed documentation of available substitute interventions at Danish hospitals exists. Likewise, no national guidelines exist on how to optimise patients who refuse to receive treatment with blood products. The primary aim was to investigate which treatments are currently available to healthcare professionals in Denmark when treating patients who refuse transfusion of blood components. Additionally, we wanted to investigate how many departments have local guidelines for treatment for this group of patients. Based on our findings we would suggest potential improvements in the treatment of patients declining transfusion of blood components. Consultants from Danish departments of anaesthesiology, abdominal surgery and obstetrics were invited to participate in a nationwide cross-sectional online survey. The questionnaire explored available interventions offered perioperatively. Respondents were all on-call consultants. The questionnaire underwent content, face and technical validation during pilot testing. Ninety-six of 108 (89%) respondents from 55 departments completed the questionnaire. Thirty-five (36%) respondents reported having a departmental guideline mostly dealing with judicial aspects regarding patients declining transfusions with blood, and 34 (35%) would in collaboration with other professionals make an interdisciplinary strategy for patients declining transfusions with blood. For patients declining treatment with blood products in anticoagulant treatment, and hence with a greater risk of bleeding, reverting treatment is essential. Depending on the type of anticoagulant, between 31 (32%) and 59 (60%) of respondents reported locally available guidelines for reverting anticoagulant treatments. We found a considerable variation and limited availability of interventions to minimise blood loss in patients declining transfusion of blood components. This scarcity of local guidelines together with the considerable variation of available treatment documented in our survey could possibly be enhanced by a lack of national guidelines.

Novel subgroups in acute respiratory failure based on the trajectories of three endotheliopathy biomarkers: A cohort study.

Baseline levels of endotheliopathy are associated with worse respiratory outcomes and mortality in undifferentiated acute respiratory failure (ARF), but knowledge is lacking on the development of endotheliopathy over time in ARF. We, therefore, aimed to evaluate the prognostic significance of trajectories of endotheliopathy during the first days of ARF. We performed a secondary, exploratory analysis of a single-center prospective cohort including 459 patients requiring mechanical ventilation. Based on Days 1-3 Syndecan-1, soluble Thrombomodulin (sTM), and Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1), we divided patients into subgroups using latent class mixed modeling and correlated subgroups with clinical outcomes using Cox regression. Based on Syndecan-1 and sTM, respectively, we identified two subgroups. Based on PECAM-1, we identified three subgroups. Subgroups based on Syndecan-1 and sTM were identifiable from the baseline levels, but subgroups based on PECAM-1 were not. Patients with persistently high levels of both sTM and PECAM-1 were liberated from mechanical ventilation more slowly (Group high vs. Group low, sTM: hazard ratio [HR]: 0.66, 95% confidence interval [CI]: 0.50-0.88, p = .01, PECAM-1: HR: 0.59, 95% CI: 0.37-0.93, p = .02) and had higher 30-day mortality (sTM: HR: 1.90, 95% CI: 1.20-3.01, p = .01, PECAM-1: HR: 4.25, 95% CI: 1.99-9.07, p < .01). In ARF requiring mechanical ventilation, patients in subgroups with persistently high levels of sTM and PECAM-1 had lower rates of liberation from mechanical ventilation and higher 30-day mortality. However, patients with persistently high levels of sTM were identifiable based on the baseline level, and only the trajectory of PECAM-1 added information to that of the baseline level.

Prostacyclin in Intubated Patients with COVID-19 and Severe Endotheliopathy: A Multicenter, Randomized Clinical Trial.

Rationale: The mortality in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who require mechanical ventilation remains high, and endotheliopathy has been implicated. Objectives: To determine the effect of prostacyclin infusion in mechanically ventilated patients infected with SARS-CoV-2 with severe endotheliopathy. Methods: We conducted a multicenter, randomized clinical trial in adults infected with coronavirus disease (COVID-19) who required mechanical ventilation and had a plasma level of thrombomodulin >4 ng/ml; patients were randomized to 72-hour infusion of prostacyclin 1 ng/kg/min or placebo. Measurements and Main Results: The main outcome was the number of days alive and without mechanical ventilation within 28 days. Key secondary outcomes were 28-day mortality and serious adverse events within 7 days. Eighty patients were randomized (41 prostacyclin and 39 placebo). The median number of days alive without mechanical ventilation at 28 days was 16.0 days (SD, 12) versus 5.0 days (SD, 10) (difference of the medians, 10.96 days; 95% confidence interval [CI], -5 to 21; P = 0.07) in the prostacyclin and the placebo groups, respectively. The 28-day mortality was 21.9% versus 43.6% in the prostacyclin and the placebo groups, respectively (risk ratio, 0.50; 95% CI, 0.24 to 0.96; P = 0.06). The incidence of serious adverse events within 7 days was 2.4% versus 12.8% (risk ratio, 0.19; 95% CI, 0.001 to 1.11; P = 0.10) in the prostacyclin and the placebo groups, respectively. Conclusions: Prostacyclin was not associated with a significant reduction in the number of days alive and without mechanical ventilation within 28 days. The point estimates, however, favored the prostacyclin group in all analyses, including 28-day mortality, warranting further investigation in larger trials. Clinical trial registered with www.clinicaltrials.gov (NCT04420741); EudraCT Identifier: 2020-001296-33.

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.

Coagulopathy Underlying Rotational Thromboelastometry Derangements in Trauma Patients: A Prospective Observational Multicenter Study.

BACKGROUND: Viscoelastic hemostatic assays such as rotational thromboelastometry (ROTEM) are used to guide treatment of trauma induced coagulopathy. The authors hypothesized that ROTEM derangements reflect specific coagulation factor deficiencies after trauma. METHODS: This was a secondary analysis of a prospective cohort study in six European trauma centers in patients presenting with full trauma team activation. Patients with dilutional coagulopathy and patients on anticoagulants were excluded. Blood was drawn on arrival for measurement of ROTEM, coagulation factor levels, and markers of fibrinolysis. ROTEM cutoff values to define hypocoagulability were as follows: EXTEM clotting time greater than 80 s, EXTEM clot amplitude at 5 min less than 40 mm, EXTEM lysis index at 30 min less than 85%, FIBTEM clot amplitude at 5 min less than 10 mm, and FIBTEM lysis index at 30 min less than 85%. Based on these values, patients were divided into seven deranged ROTEM profiles and compared to the reference group (ROTEM values within reference range). The primary endpoint was coagulation factors levels and fibrinolysis. RESULTS: Of 1,828 patients, 732 (40%) had ROTEM derangements, most often consisting of a combined decrease in EXTEM and FIBTEM clot amplitude at 5 min, that was present in 217 (11.9%) patients. While an isolated EXTEM clotting time greater than 80 s had no impact on mortality, all other ROTEM derangements were associated with increased mortality. Also, coagulation factor levels in this group were similar to those of patients with a normal ROTEM. Of coagulation factors, a decrease was most apparent for fibrinogen (with a nadir of 0.78 g/l) and for factor V levels (with a nadir of 22.8%). In addition, increased fibrinolysis can be present when the lysis index at 30 min is normal but EXTEM and FIBTEM clot amplitude at 5 min is decreased. CONCLUSIONS: Coagulation factor levels and mortality in the group with an isolated clotting time prolongation are similar to those of patients with a normal ROTEM. Other ROTEM derangements are associated with mortality and reflect a depletion of fibrinogen and factor V. Increased fibrinolysis can be present when the lysis index after 30 min is normal.

Endotheliopathy is associated with slower liberation from mechanical ventilation: a cohort study.

BACKGROUND: Endotheliopathy is suggested as pivotal pathophysiology of sepsis and trauma-associated organ failure, but its role in acute respiratory failure is not yet determined. We investigated if endotheliopathy biomarkers at ICU admission are associated with illness severity and clinical outcomes in patients with acute respiratory failure requiring mechanical ventilation. METHODS: We conducted a prospective single-center cohort study including 459 mechanically ventilated adults at ICU admission. Plasma levels of three endotheliopathy biomarkers were measured at ICU admission: Syndecan-1, soluble Thrombomodulin (sTM), and Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1). The primary outcome was the rate of liberation from mechanical ventilation, which is presented together with the rate of the competing risk of death while still on mechanical ventilation. Secondary outcomes were PaO2/FiO2-ratios on admission and on last measurement in patients dying within five days, and 30-day all-cause mortality. The primary outcome and 30-day all-cause mortality were analyzed using Cox regression, controlled for gender, age, chronic obstructive pulmonary disease, septic shock, heart failure, PaO2/FiO2-ratio at admission, respiratory infection, acute kidney injury, and bilirubin. PaO2/FiO2-ratios were analyzed using linear regression, controlled for age, chronic obstructive pulmonary disease, respiratory infection, and shock. RESULTS: Patients with high sTM were liberated from mechanical ventilation at a lower rate (adjusted hazard ratio (HR) 0.71, for an increase from the 25th to the 75th percentile, 95% confidence interval (CI) 0.54-0.93, p = 0.01). Patients with high PECAM-1 were liberated from mechanical ventilation at a lower rate, but only during the first 5 days (adjusted HR 0.72, for an increase from the 25th to the 75th percentile, 95% CI 0.58-0.9, p < 0.01). High levels of Syndecan-1 and PECAM-1 were associated with a higher rate of death while still on mechanical ventilation. sTM and PECAM-1 were negatively associated with PaO2/FiO2-ratio at ICU admission and no biomarker was associated with last measured PaO2/FiO2-ratio. High levels of all biomarkers were associated with higher 30-day all-cause mortality. CONCLUSION: In acute respiratory failure, endotheliopathy biomarkers are associated with lower rates of liberation from mechanical ventilation, hypoxemia at ICU admission, and 30-day all-cause mortality.

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.

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.

Evaluation of the systemic inflammatory response, endothelial cell dysfunction, and postoperative morbidity in patients, receiving perioperative corticosteroid, developing severe mesenteric traction syndrome - an exploratory study.

OBJECTIVE: To determine whether a severe mesenteric traction syndrome (MTS) leads to increased surgical stress, endothelial dysfunction, and postoperative morbidity in a cohort in which all patients received a single dose of methylprednisolone. INTRODUCTION: Preoperatively administered corticosteroids lower the incidence of severe MTS and may also attenuate surgical stress and endothelial damage associated with the development of severe MTS, ultimately lowering the postoperative morbidity. METHODS: This exploratory study analyzed prospectively collected data from 45 patients all receiving 125 mg methylprednisolone. No control group was included. The severity of MTS was graded intraoperatively, and postoperative morbidity was assessed blinded. Blood samples for plasma prostacyclin (PGI2), IL6 and endothelial damage (Syndecan-1, sVEGRF1 and sThrombomodulin) biomarkers were obtained at predefined time points. RESULTS: Patients undergoing either open liver surgery (n = 23) or Whipple's procedure (n = 22) were included. No differences were found in postoperative morbidity between patients developing and not developing severe MTS. Surgery led to significantly increased plasma levels of biomarkers indicative of surgical stress and endothelial damage. Further, patients developing severe MTS had increased levels of PGI2 (p = 0.05) and lower systemic vascular resistance (p < 0.05) 15 min into surgery. However, when comparing the biomarkers of surgical stress, endothelial damage no differences between patients with and without severe MTS were identified. CONCLUSION: This exploratory study found that surgery was associated with a pro-inflammatory response and damage to the endothelium. However, no differences were found between patients developing severe MTS and patients developing moderate/no MTS in biomarkers of surgical stress, endothelial damage, or postoperative morbidity. Corticosteroids may therefore attenuate the endothelial damage in patients developing severe MTS. However, as this was an exploratory study, these findings must be confirmed in future randomized controlled studies.

Review of PEEK implants and biomechanical and immunological responses to a zirconium phosphate nano-coated PEEK, a blasted PEEK, and a turned titanium implant surface.

PURPOSE: To investigate the biomechanical and immunological reactions to coated and non-coated blasted PEEK implants in vivo after 12 weeks and review the associated literature. METHODS: Two osteotomy sites were performed in each proximal tibia of 10 lop-eared rabbits (n= 4 per rabbit). Each rabbit received a randomly placed (1) blasted zirconium phosphate nano-coated PEEK- (nano-ZrP), (2) blasted PEEK- (PEEK) and (3) titanium implant (Ti) and an empty sham site. At 12 weeks, removal torque of all implants and biological investigation with qPCR was performed. The implant surfaces were analyzed prior to insertion with interferometry, SEM and XPS. RESULTS: The interferometry analysis showed that there was no difference in roughness for the uncoated PEEK compared to the ZrP coated PEEK implants. The titanium implants were considerably smoother (Sa= 0.23 µm) than the uncoated Sa= 1.11 µm) and ZrP coated PEEK implants (Sa= 1.12 µm). SEM analysis on the PEEK implants corroborated the interferometry results; no difference in structure between the uncoated vs. the ZrP coated PEEK was visible on the micrometer level. At higher magnifications, the ZrP coating was visible in the SEM as a thin, porous network. All tested implants displayed osseointegration with the highest RTQ for nano-ZrP (18.4 Ncm) followed by PEEK (14.5 Ncm) and Ti (11.5 Ncm). All implants activated the immune system, with elevated macrophage and M2 macrophage qPCR markers at 12 weeks compared to the sham site. CLINICAL SIGNIFICANCE: Nano-ZrP coating improves osseointegration of blasted PEEK implants at 12 weeks of follow-up. Osseointegration of titanium, PEEK and nano-ZrP PEEK is not a normal bone healing process, but rather a shield-off mechanism that appears to be regulated by the innate immune system.

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.

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.

Shock-Driven Endotheliopathy in Trauma Patients Is Associated with Leucocyte Derived Extracellular Vesicles.

Endotheliopathy following trauma is associated with poor outcome, but the underlying mechanisms are unknown. This study hypothesized that an increased extracellular vesicle (EV) concentration is associated with endotheliopathy after trauma and that red blood cell (RBC) transfusion could further enhance endotheliopathy. In this post hoc sub study of a multicentre observational trial, 75 trauma patients were stratified into three groups based on injury severity score or shock. In patient plasma obtained at hospital admission and after transfusion of four RBC transfusions, markers for endotheliopathy were measured and EVs were labelled with anti CD41 (platelet EVs), anti CD235a (red blood cell EVs), anti CD45 (leucocyte EVs), anti CD144 (endothelial EVs) or anti CD62e (activated endothelial EVs) and EV concentrations were measured with flow cytometry. Statistical analysis was performed by a Kruskall Wallis test with Bonferroni correction or Wilcoxon rank test for paired data. In patients with shock, syndecan-1 and von Willebrand Factor (vWF) were increased compared to patients without shock. Additionally, patients with shock had increased red blood cell EV and leucocyte EV concentrations compared to patients without shock. Endotheliopathy markers correlated with leucocyte EVs (ρ = 0.263, p = 0.023), but not with EVs derived from other cells. Injury severity score had no relation with EV release. RBC transfusion increased circulating red blood cell EVs but did not impact endotheliopathy. In conclusion, shock is (weakly) associated with EVs from leucocytes, suggesting an immune driven pathway mediated (at least in part) by shock.

The wound healing effect of local leukocyte platelet-rich plasma after total hip arthroplasty: A randomized controlled trial.

Rapid wound closure is important after arthroplasty procedures to prevent postoperative complications. Platelets are rich in growth factors and leukocytes contribute to innate immunity. We hypothesized that topical leukocyte platelet-rich plasma (L-PRP) derived from the blood of patients would be beneficial to wound healing. In this randomized controlled trial, patients subjected to elective total hip arthroplasty (THA) were assigned by concealed allocation either L-PRP application onto the sutured fascia or no application (control) after the THA intervention. In addition, all patients received 1.5 g protein/kg, 5 g L-arginine, 500 mg vitamin C and 44 mg zinc daily over the 4-week postoperative period to obtain optimal nutrition. The primary endpoint was complete healing of the skin incision. The secondary endpoints were blood transfusions, length of hospital stay, pain and wound infections. Sixteen patients in the L-PRP group and 17 patients in the control group completed the trial. L-PRP treatment accelerated complete wound healing after 3 weeks (seven in the L-PRP group vs. zero in the control group, p = 0.003) and after 4 weeks (12 in the L-PRP group vs. six in the control group, p = 0.037). No postoperative superficial wound infections occurred within 4 weeks, and there were no significant differences in the other secondary outcomes. L-PRP generated in 10 sex-matched healthy volunteers revealed increased concentrations of platelets (5.8-fold) and leukocytes (2.3-fold) compared with those in whole blood. Furthermore, the concentration of keratinocyte mitogen epidermal growth factor in L-PRP (380 ± 130 pg/ml, mean ± SD) was higher (p < 0.001) than that in serum (130 ± 26 pg/ml). In conclusion, a single intraoperative local application of L-PRP promoted wound healing after THA, possibly mediated by EGF receptor agonists.

Efficacy and safety of iloprost in trauma patients with haemorrhagic shock-induced endotheliopathy-Protocol for the multicentre randomized, placebo-controlled, blinded, investigator-initiated shine-trauma trial.

BACKGROUND: Traumatic injury accounts for 800 000 deaths in the European Union annually. The main causes of deaths in trauma patients are exsanguination and multiple organ failure (MOF). We have studied >1000 trauma patients and identified shock-induced endotheliopathy (SHINE), the pathophysiological mechanism responsible for MOF and high mortality. Pilot studies indicate that low-dose iloprost (1 ng/kg/min) improves endothelial functionality in critically ill patients suggesting this intervention may improve patient outcome in traumatic SHINE. MATERIAL AND METHODS: This is a multicentre, randomized, blinded clinical investigator-initiated phase 2B trial in trauma patients with haemorrhagic shock-induced endotheliopathy. Patients are randomized 1:1 to 72 hours infusion of iloprost 1 ng/kg/min or Placebo (equal volume of saline). A total of 220 trauma patients will be included. The primary endpoint is the number of intensive care unit (ICU)-free days, within 28 days of admission. Secondary endpoints include 28- and 90-day all-cause mortality, hospital length of stay, vasopressor-free days in the intensive care unit (ICU) within 28 days, ventilator-free days in the ICU within 28 days, renal replacement-free days in the ICU within 28 days, number of serious adverse reactions and serious adverse events within the first 4 days of admission. DISCUSSION: This trial will test the safety and efficacy of administration of iloprost vs placebo for 72 hours in trauma patients with haemorrhagic shock-induced endotheliopathy. Trial endpoints focus on the potential effect of iloprost to reduce the need for ICU stay secondary to mitigation of organ failure. TRIAL REGISTRATION: SHINE-TRAUMA trial-EudraCT no. 2019-000936-24-Clinicaltrials.gov: NCT03903939 Ethics Committee no. H-19014482.