Jakob Stensballe

Background: Thrombocytopenia is frequent in adult intensive care unit (ICU) patients and may contribute to adverse outcomes, including bleeding, morbidity and mortality. To reduce the risk of bleeding, platelet transfusions are commonly used, yet transfusion thresholds vary, and the evidence base is very limited. Randomised clinical trials investigating platelet transfusion strategies in ICU patients are therefore a high research priority. With this survey, we aim to assess ICU doctors' willingness to randomise adult ICU patients to restrictive versus liberal platelet transfusion thresholds across clinically relevant scenarios in a future randomised trial. Methods: We will conduct an international, web‐based survey targeting ICU doctors within an established research network. The survey includes questions on respondent characteristics and willingness to enrol patients with an indication for platelet transfusion across a range of transfusion thresholds in different clinical scenarios, including non‐bleeding patients, those undergoing invasive procedures, and those with bleeding. The survey has been pilot‐tested and refined twice before distribution. We will summarise results using descriptive statistics and conduct stratified analyses by country and ICU type. Conclusions: This international survey will assess ICU doctors' willingness to randomise adult ICU patients to restrictive versus liberal platelet transfusion strategies across multiple clinical scenarios.

Background: Informed consent is a fundamental part of clinical research involving human participants. However, in certain emergency medical situations, participants are unable to provide prospective informed consent before inclusion, or the urgency of the situation deems it non‐futile to await consent before the intervention. This has led to the introduction of legal guardians who can provide proxy consent initially, where the legal guardian, next‐of‐kin, and the participant themselves later can give or withdraw consent regarding continued follow‐up. Prior to the initiation of an emergency trial in Denmark, it has been accepted and approved by national or regional research ethics committees, as well as The Danish Medicines Agency if it is a drug study. Objective: The objective of this systematic review is to first identify all conducted emergency trials in Denmark and then contact the researchers of those trials through a national survey. This will serve as the basis for providing a systematic evaluation of the consent procedures and how they are utilized in emergency setting trials in Denmark through both quantitative and qualitative data. Methods: This protocol describes a two‐phase study, consisting of a systematic review identifying all emergency trials in Denmark throughout the different iterations of legislation, and a national survey regarding the use of proxy consent in the trials identified in the systematic review. An information specialist will generate the search string to identify all relevant trials by searching relevant databases. These trials will have data extracted, and the corresponding authors of the trials will be contacted and invited to conduct a survey. This survey will contain quantitative questions about the amount of included participants and to what extent consent was either denied or not obtained. Furthermore, an anonymized section of the questionnaire will investigate qualitatively the opinions, suggestions, and beliefs of the emergency researchers regarding the consent procedures.

Background: Trauma hemorrhage induces a coagulopathy with a high associated mortality rate. The Implementing Treatment Algorithms for the Correction of Trauma Induced Coagulopathy (ITACTIC) randomized trial tested two goal-directed treatment algorithms for coagulation management: one guided by conventional coagulation tests and one by viscoelastic hemostatic assays (viscoelastic). The lack of a difference in 28-day mortality led the authors to hypothesize that coagulopathic patients received insufficient treatment to correct coagulopathy. Methods: During ITACTIC, two sites were coenrolling patients into an ongoing prospective observational study, which included serial blood sampling at the same intervals as in ITACTIC. The subgroup in both studies had conventional and viscoelastic test results for each patient available for analysis. A goal-directed treatment was defined as one triggered by an ITACTIC algorithm. Coagulopathy was defined as rotational thromboelastometry EXTEM A5 less than 40 mm. The primary outcome was correction of coagulopathy by the 12th unit of erythrocyte transfusion during resuscitation. Results: Full viscoelastic and conventional coagulation test results were available for 133 patients. Of these patients, 71% were coagulopathic on admission, and 16% developed a coagulopathy during resuscitation. ITACTIC viscoelastic hemostatic assay group patients were more likely to receive goal-directed treatment than the standard group (76% vs. 47%; odds ratio, 3.73; 95% CI, 1.64 to 8.49; P = 0.002). However, only 54% of patients received goal-directed treatment, and only 20% corrected their coagulopathy (vs. 0% with empiric treatment alone; not significant). Median time to first goal-directed treatment was 68 (53 to 88) min for viscoelastic and 110 (77 to 123) min for standard (P = 0.005). Conclusions: In ITACTIC, many bleeding trauma patients did not receive an indicated goal-directed treatment. Interventions arrived late during resuscitation and were only partially effective at correcting coagulopathy. Editor’s Perspective: What We Already Know about This Topic: What This Article Tells Us That Is New:

BACKGROUND: In the Study of Tranexamic Acid During Air and Ground Prehospital Transport (STAAMP) Trial, prehospital tranexamic acid (TXA) was associated with lower mortality in specific patient subgroups. The underlying mechanisms responsible for a TXA benefit remain incompletely characterized. We hypothesized that TXA may mitigate endothelial injury and sought to assess whether TXA was associated with decreased endothelial or tissue damage markers among all patients enrolled in the STAAMP Trial. METHODS: We collected blood samples from STAAMP Trial patients and measured markers of endothelial function and tissue damage including syndecan-1, soluble thrombomodulin (sTM), and platelet endothelial cell adhesion molecule-1 at hospital admission (0 hours) and 12 hours, 24 hours, and 72 hours after admission. We compared these marker values for patients in each treatment group during the first 72 hours, and modeled the relationship between TXA and marker concentration using regression analysis to control for potential confounding factors. RESULTS: We analyzed samples from 766 patients: 383 placebo, 130 abbreviated dosing, 119 standard dosing, and 130 repeat dosing. Lower levels of syndecan-1, TM, and platelet endothelial cell adhesion molecule measured within the first 72 hours of hospital admission were associated with survival at 30 days (p < 0.001). At hospital admission, syndecan-1 was lower in the TXA group (28.30 [20.05, 42.75] vs. 33.50 [23.00, 54.00] p = 0.001) even after controlling for patient, injury, and prehospital factors (p = 0.001). For every 1 g increase in TXA administered over the first 8 hours of prehospital transport and hospital admission, there was a 4-ng/mL decrease in syndecan-1 at 12 hours controlling for patient, injury, and treatment factors (p = 0.03). CONCLUSION: Prehospital TXA was associated with decreased syndecan-1 at hospital admission. Syndecan-1 measured 12 hours after admission was inversely related to the dose of TXA received. Early prehospital and in-hospital TXA may decrease endothelial glycocalyx damage or upregulate vascular repair mechanisms in a dose-dependent fashion. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

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.

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.

Objectives: To investigate the effect of continuous infusion of the potential endothelial cytoprotective agent prostacyclin (Iloprost) 1 ng/kg/min vs. placebo for 72 hours on pulmonary endotheliopathy in mechanically ventilated COVID-19 patients. Trial design: A multicenter, randomized (1:1, active: placebo), blinded, parallel group exploratory trial Participants: Inclusion criteria are: Adult patients (>18 years); Confirmed COVID-19 infection; Need for mechanical interventions; Endothelial biomarker soluble thrombomodulin >4ng/ml. Exclusion criteria: Withdrawal from active therapy; Pregnancy (non-pregnancy confirmed by patient being postmenopausal (age 60 or above) or having a negative urine- or plasma-hCG); Known hypersensitivity to iloprost or to any of the other ingredients; Previously included in this trial or a prostacyclin trial within 30 days; Consent cannot be obtained; Life-threatening bleeding defined by the treating physician; Known severe heart failure (NYHA class IV); Suspected acute coronary syndrome The study is conducted at five intensive care units in the Capital Region of Denmark at Rigshospitalet, Herlev Hospital, Hvidovre Hospital, Bispebjerg Hospital, Nordsjællands Hospital. Intervention and comparator: The patients are randomized to 72-hours continuous infusion of either prostacyclin (Iloprost/Ilomedin) at a dose of 1 ng/kg/min or Placebo (normal saline). Main outcomes: Primary endpoint: Days alive without mechanical ventilation in the intensive care units within 28 days Randomisation: The randomisation sequence is performed in permuted blocks of variable sizes stratified for trial site using centralised, concealed allocation. The randomisation sequence is generated 1:1 (active/placebo) using the online randomisation software ‘Sealed Envelope’ (https://www.sealedenvelope.com/). Once generated the randomisation sequence is formatted and uploaded into Research Electronic Data Capture system (REDCap) to facilitate centralised, web-based allocation according to local written instruction. Blinding (masking): The following are blinded: all clinicians, patients, investigators, and those assessing the outcomes including the statisticians. Numbers to be randomised (sample size): Forty patients are planned to be randomized to each group, with a total sample size of 80 patients. Trial Status: Protocol version 1.4 dated May 25, 2020. Recruitment is ongoing. The recruitment was started June 15, 2020 and the anticipated finish of recruitment is February 28, 2021 with 90 days follow up hereafter. Trial registration: Trial registration at clinicaltrialregisters.eu; EudraCT no. 2020-001296-33 on 3 April 2020 and at ClinicalTrials.gov Identifier: NCT04420741 on 9 June 2020 Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1).In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.