The Role of Plasma Transfusion in Massive Bleeding: Protecting the Endothelial Glycocalyx?

The Crucial Triad: Endothelial Glycocalyx, Oxidative Stress, and Inflammation in Cardiac Surgery-Exploring the Molecular Connections

Since its introduction, the number of heart surgeries has risen continuously. It is a high-risk procedure, usually involving cardiopulmonary bypass, which is associated with an inflammatory reaction that can lead to perioperative and postoperative organ dysfunction. The extent of complications following cardiac surgery has been the focus of interest for several years because of their impact on patient outcomes. Recently, numerous scientific efforts have been made to uncover the complex mechanisms of interaction between inflammation, oxidative stress, and endothelial dysfunction that occur after cardiac surgery. Numerous factors, such as surgical and anesthetic techniques, hypervolemia and hypovolemia, hypothermia, and various drugs used during cardiac surgery trigger the development of systemic inflammatory response and the release of oxidative species. They affect the endothelium, especially endothelial glycocalyx (EG), a thin surface endothelial layer responsible for vascular hemostasis, its permeability and the interaction between leukocytes and endothelium. This review highlights the current knowledge of the molecular mechanisms involved in endothelial dysfunction, particularly in the degradation of EG. In addition, the major inflammatory events and oxidative stress responses that occur in cardiac surgery, their interaction with EG, and the clinical implications of these events have been summarized and discussed in detail. A better understanding of the complex molecular mechanisms underlying cardiac surgery, leading to endothelial dysfunction, is needed to improve patient management during and after surgery and to develop effective strategies to prevent adverse outcomes that complicate recovery.

Comparing the effects of various fluid resuscitative strategies on Glycocalyx damage in a canine hemorrhage model

Hemorrhagic shock and subsequent resuscitation can cause significant dysregulation of critical systems, including the vascular endothelium. Following hemorrhage, the endothelial lining (glycocalyx) can shed, causing release of glycocalyx components, endothelial activation, and systemic inflammation. A canine model of hemorrhagic shock was used to evaluate five resuscitation fluids, including Lactated Ringers+Hetastarch, Whole Blood (WB), Fresh Frozen Plasma+packed Red Blood Cells (FFP+pRBC), and two hemoglobin-based oxygen carrier (HBOC) fluids, for their impact on glycocalyx shedding. Under anesthesia, purpose-bred adult canines were instrumented and subjected to a controlled hemorrhage with blood being drawn until a mean arterial pressure of <50 mmHg was reached or 40 % of the estimated blood volume was removed. Canines were left in shock for 45 mins before being resuscitated with one of the resuscitation fluids over 30 mins. Following resuscitation, the dogs were monitored up to 2 weeks. Following an additional 3-4 weeks for washout, the canines repeated the protocol, undergoing each resuscitation fluid individually. Blood samples were collected during each round at various timepoints for serum isolation, which was used for detection of glycocalyx biomarker. Comparison of baseline and post-hemorrhage alone showed a significant reduction in serum protein (p<0.0001), heparan sulfate (p<0.001), and syndecan-1 (p<0.0001) concentrations, and a significant increase in hyaluronan (p<0.0001) concentration. Intercomparisons of resuscitation fluids indicated minimal differences in glycocalyx markers over time. Comparisons within each fluid showed dynamic responses in glycocalyx biomarkers over time. Relative to individual baselines, syndecan-1 was significantly reduced after resuscitation in most cases (p<0.0001), excluding WB and FFP+pRBC. In all cases, VE-cadherin was significantly elevated at 24 hr compared to baseline (p<0.001). Hyaluronan was significantly elevated by 3 hr in all cases (p<0.01), except for HBOC fluids. Total glycosaminoglycans were significantly reduced only at 3 hr (p<0.001) for non-HBOC fluids. Similarly, heparan sulfate was significantly reduced with all fluids between resuscitation and 24 hr (p<0.01), except WB. The temporal changes in canine glycocalyx biomarkers were atypical of hemorrhage response in other species. This suggests that the hemorrhage lacked severity and/or typical glycocalyx biomarkers do not reflect the canine endothelium compared to other species. Further research is needed to characterize the canine endothelium and the response to resuscitation fluids.

Insights into the Molecular Mechanism of Endothelial Glycocalyx Dysfunction during Heart Surgery

The endothelial glycocalyx (EGC) is a layer of proteoglycans (associated with glycosaminoglycans) and glycoproteins, which adsorbs plasma proteins on the luminal surface of endothelial cells. Its main function is to participate in separating the circulating blood from the inner layers of the vessels and the surrounding tissues. Physiologically, the EGC stimulates mechanotransduction, the endothelial charge, thrombocyte adhesion, leukocyte tissue recruitment, and molecule extravasation. Hence, severe impairment of the EGC has been implicated in various pathological conditions, including sepsis, diabetes, chronic kidney disease, inflammatory disorders, hypernatremia, hypervolemia, atherosclerosis, and ischemia/reperfusion injury. Moreover, alterations in EGC have been associated with altered responses to therapeutic interventions in conditions such as cardiovascular diseases. Investigation into the function of the glycocalyx has expanded knowledge about vascular disorders and indicated the need to consider new approaches in the treatment of severe endothelial dysfunction. This review aims to present the current understanding of the molecular mechanisms underlying cardiovascular diseases and to elucidate the impact of heart surgery on EGC dysfunction.

Mechanism matters: mortality and endothelial cell damage marker differences between blunt and penetrating traumatic injuries across three prehospital clinical trials

Injury mechanism is an important consideration when conducting clinical trials in trauma. Mechanisms of injury may be associated with differences in mortality risk and immune response to injury, impacting the potential success of the trial. We sought to characterize clinical and endothelial cell damage marker differences across blunt and penetrating injured patients enrolled in three large, prehospital randomized trials which focused on hemorrhagic shock. In this secondary analysis, patients with systolic blood pressure < 70 or systolic blood pressure < 90 and heart rate > 108 were included. In addition, patients with both blunt and penetrating injuries were excluded. The primary outcome was 30-day mortality. Mortality was characterized using Kaplan-Meier and Cox proportional-hazards models. Generalized linear models were used to compare biomarkers. Chi squared tests and Wilcoxon rank-sum were used to compare secondary outcomes. We characterized data of 696 enrolled patients that met all secondary analysis inclusion criteria. Blunt injured patients had significantly greater 24-h (18.6% vs. 10.7%, log rank p = 0.048) and 30-day mortality rates (29.7% vs. 14.0%, log rank p = 0.001) relative to penetrating injured patients with a different time course. After adjusting for confounders, blunt mechanism of injury was independently predictive of mortality at 30-days (HR 1.84, 95% CI 1.06-3.20, p = 0.029), but not 24-h (HR 1.65, 95% CI 0.86-3.18, p = 0.133). Elevated admission levels of endothelial cell damage markers, VEGF, syndecan-1, TM, S100A10, suPAR and HcDNA were associated with blunt mechanism of injury. Although there was no difference in multiple organ failure (MOF) rates across injury mechanism (48.4% vs. 42.98%, p = 0.275), blunt injured patients had higher Denver MOF score (p < 0.01). The significant increase in 30-day mortality and endothelial cell damage markers in blunt injury relative to penetrating injured patients highlights the importance of considering mechanism of injury within the inclusion and exclusion criteria of future clinical trials.

Use of Therapeutic Apheresis methods in ICU

Apheresis is a modern medical approach in which plasma or cellular components are separated from the whole blood. Apheresis can be either diagnostic or therapeutic. Diagnostic apheresis is typically applied in hematology and cancer research. Therapeutic Apheresis (TA) includes a broad spectrum of extracorporeal treatments applied in various medical specialties, including Intensive Care Unit (ICU). Considering the complexity of the pathophysiologic characteristics of various clinical entities and in particular sepsis, apheresis methods are becoming increasingly applicable. Therapeutic Plasma Exchange (TPE) is the most common used method in ICU. It is considered as first line therapy for Thrombotic Thrombocytopenic Purpura (TTP) and Guillain Barre Syndrome, while the current data for sepsis are scarce. Over the last decades, technologic evolution has led to increasing application of new and more selective methods based on adsorptive techniques. In this review we will describe the current data of characteristics of different techniques, safety and clinical impact of apheresis methods used in ICUs.

Lung Protection After Severe Thermal Burns With Adenosine, Lidocaine, and Magnesium (ALM) Resuscitation and Importance of Shams in a Rat Model

The management of severe burns remains a complex challenge. Adenosine, lidocaine, and magnesium (ALM) resuscitation therapy has been shown to protect against hemorrhagic shock and traumatic injury. The aim of the present study was to investigate the early protective effects of small-volume ALM fluid resuscitation in a rat model of 30% total body surface area (TBSA) thermal injury. Male Sprague-Dawley rats (320-340 g; n = 25) were randomly assigned to: 1) Sham (surgical instrumentation and saline infusion, without burn, n = 5), 2) Saline resuscitation group (n = 10), or 3) ALM resuscitation group (n = 10). Treatments were initiated 15-min after burn trauma, including 0.7 mL/kg 3% NaCl ± ALM bolus and 0.25-0.5 mL/kg/h 0.9% NaCl ± ALM drip, with animals monitored to 8.25-hr post-burn. Hemodynamics, cardiac function, blood chemistry, hematology, endothelial injury markers and histopathology were assessed. Survival was 100% for Shams and 90% for both ALM and Saline groups. Shams underwent significant physiological, immune and hematological changes over time as a result of surgical traums. ALM significantly reduced malondialdehyde levels in the lungs compared to Saline (P = .023), and showed minimal alveolar destruction and inflammatory cell infiltration (P < .001). ALM also improved cardiac function and oxygen delivery (21%, P = .418 vs Saline), reduced gut injury (P < .001 vs Saline), and increased plasma adiponectin (P < .001 vs baseline). Circulating levels of the acute phase protein alpha 1-acid glycoprotein (AGP) increased 1.6-times (P < .001), which may have impacted ALM's therapeutic efficacy. We conclude that small-volume ALM therapy significantly reduced lung oxidative stress and preserved alveolar integrity following severe burn trauma. Further studies are required to assess higher ALM doses with longer monitoring periods.

Evaluation of the treatment options for COVID-19 patients using generalized hesitant fuzzy- multi criteria decision making techniques

The breakout of the pandemic COVID-19 has affected numerous countries and territories worldwide. As COVID-19 specific medicines yet to be invented, at present the treatment is case specific, hence identification and evaluation of different prevalent treatment options based on various criteria and attributes are very important not only from the point of view of present pandemic but also for futuristic pandemic preparedness. The present study focuses on identifying, evaluation and ranking of treatment options using Multi Criteria Decision Making (MCDM). In this regard, the existing literature, doctors and scientist were interviewed to know the current treatment options in vogue and the scale of their importance with respect to the criteria. The criteria taken are side effect, regime cost, treatment duration, plasma stability, plasma turnover, time of suppression, ease of application, drug-drug interaction, compliance, fever, pneumonia, intensive care, organ failure, macrophage activation syndrome, hemophagocytic syndrome, pregnancy, kidney problem, age. This study extended Hesitant Fuzzy Set (HFS) to Generalized Hesitant Fuzzy Sets (GHFS). Generalized Hesitant Pentagonal Fuzzy Number (GHPFN) is developed. The properties of GHPFN are demonstrated. Two types of GHPFN has been described. The GHPFN (2nd type) along with MCDM tool Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) has been applied to rank the treatment options. The result of the study ranked 'Hydroxychloroquine' as the first alternative followed by, 'Plasma Exchange', 'Tocilizumab', 'Remdesivir' and 'Favipravir'. To check the robustness and steadiness of the proposed methodology, comparative analysis and sensitivity analysis has been conducted.

Endothelial Dysfunction in Patients Undergoing Cardiac Surgery: A Narrative Review and Clinical Implications

Cardiac surgery is one of the highest-risk procedures, usually involving cardiopulmonary bypass and commonly inducing endothelial injury that contributes to the development of perioperative and postoperative organ dysfunction. Substantial scientific efforts are being made to unravel the complex interaction of biomolecules involved in endothelial dysfunction to find new therapeutic targets and biomarkers and to develop therapeutic strategies to protect and restore the endothelium. This review highlights the current state-of-the-art knowledge on the structure and function of the endothelial glycocalyx and mechanisms of endothelial glycocalyx shedding in cardiac surgery. Particular emphasis is placed on potential strategies to protect and restore the endothelial glycocalyx in cardiac surgery. In addition, we have summarized and elaborated the latest evidence on conventional and potential biomarkers of endothelial dysfunction to provide a comprehensive synthesis of crucial mechanisms of endothelial dysfunction in patients undergoing cardiac surgery, and to highlight their clinical implications.

The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition

BACKGROUND

Severe trauma represents a major global public health burden and the management of post-traumatic bleeding continues to challenge healthcare systems around the world. Post-traumatic bleeding and associated traumatic coagulopathy remain leading causes of potentially preventable multiorgan failure and death if not diagnosed and managed in an appropriate and timely manner. This sixth edition of the European guideline on the management of major bleeding and coagulopathy following traumatic injury aims to advise clinicians who care for the bleeding trauma patient during the initial diagnostic and therapeutic phases of patient management.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma included representatives from six European professional societies and convened to assess and update the previous version of this guideline using a structured, evidence-based consensus approach. Structured literature searches covered the period since the last edition of the guideline, but considered evidence cited previously. The format of this edition has been adjusted to reflect the trend towards concise guideline documents that cite only the highest-quality studies and most relevant literature rather than attempting to provide a comprehensive literature review to accompany each recommendation.

RESULTS

This guideline comprises 39 clinical practice recommendations that follow an approximate temporal path for management of the bleeding trauma patient, with recommendations grouped behind key decision points. While approximately one-third of patients who have experienced severe trauma arrive in hospital in a coagulopathic state, a systematic diagnostic and therapeutic approach has been shown to reduce the number of preventable deaths attributable to traumatic injury.

CONCLUSION

A multidisciplinary approach and adherence to evidence-based guidelines are pillars of best practice in the management of severely injured trauma patients. Further improvement in outcomes will be achieved by optimising and standardising trauma care in line with the available evidence across Europe and beyond.

Balanced hemostatic resuscitation for bleeding pediatric trauma patients: A nationwide quantitative analysis of outcomes

BACKGROUND

The administration of balanced component therapy has been associated with improvements in outcomes in adult trauma. There is little to no specific data to guide transfusion ratios in children. The aim of our study is to compare outcomes among different transfusion strategies in pediatric trauma patients.

METHODS

We conducted a (2014-2016) retrospective analysis of the Trauma Quality Improvement Program. We selected all pediatric (age < 18) trauma patients who received at least one unit of packed red blood cells (PRBC) and fresh frozen plasma (FFP) within 4 h of admission. Patients were stratified based on their FFP:PRBC transfusion ratio in the first 4 h into: 1:1, 1:2, 1:3, and 1:3+. Primary outcomes were 24-mortality, in-hospital mortality. Secondary outcomes were complications and 24 h PRBC transfusion requirements. Multivariable logistic regression analysis was performed.

RESULTS

A total of 1,233 patients were identified of which 637 received transfusion ratio of 1:1, 365 1:2, 116 1:3, and 115 1:3+. Mean age was 11 ± 6y, 70% were male, ISS was 27 [20-38], and 62% sustained penetrating injuries. Patients in the 1:1 group had the lowest 24 h mortality (14% vs. 18% vs. 22% vs. 24%; p = 0.01) and in-hospital mortality (32% vs. 36% vs. 40% vs. 44%; p = 0.01). No difference was found between the groups in terms of complications (22% vs. 21% vs. 23% vs. 22%; p = 0.96) such as acute respiratory distress syndrome (3.3% vs. 3.6% vs. 0.9% vs. 0%; p = 0.10), and acute kidney injury (3% vs. 2.2% vs. 0.9% vs. 0.9%; p = 0.46). Additionally the 1:1 group had the lowest PRBC transfusion requirements (3[2-7] vs. 5[2-10] vs. 6[3-8] vs. 6[4-10]; p < 0.01). On regression analysis a progressive increase in the mortality adjusted odds ratio was observed as the FFP:PRBC transfusion ratio decreased.

CONCLUSION

FFP:PRBC ratios closest to 1 were associated with increased survival in children. The resuscitation of pediatric patients should target a 1:1 ratio of FFP:PRBC. Further studies are needed for the development of massive transfusion protocols for this age group.

LEVEL OF EVIDENCE

Level IV STUDY TYPE: Therapeutic/Care Management.

High Dimensional Multiomics Reveals Unique Characteristics of Early Plasma Administration in Polytrauma Patients With TBI

OBJECTIVES

The authors sought to identify causal factors that explain the selective benefit of prehospital administration of thawed plasma (TP) in traumatic brain injury (TBI) patients using mediation analysis of a multiomic database.

BACKGROUND

The Prehospital Air Medical Plasma (PAMPer) Trial showed that patients with TBI and a pronounced systemic response to injury [defined as endotype 2 (E2)], have a survival benefit from prehospital administration of TP. An interrogation of high dimensional proteomics, lipidomics and metabolomics previously demonstrated unique patterns in circulating biomarkers in patients receiving prehospital TP, suggesting that a deeper analysis could reveal causal features specific to TBI patients.

METHODS

A novel proteomic database (SomaLogic Inc., aptamer-based assay, 7K platform) was generated using admission blood samples from a subset of patients (n=149) from the PAMPer Trial. This proteomic dataset was combined with previously reported metabolomic and lipidomic datasets from these same patients. A 2-step analysis was performed to identify factors that promote survival in E2-TBI patients who had received early TP. First, features were selected using both linear and multivariate-latent-factor regression analyses. Then, the selected features were entered into the causal mediation analysis.

RESULTS

Causal mediation analysis of observable features identified 16 proteins and 41 lipids with a high proportion of mediated effect (>50%) to explain the survival benefit of early TP in E2-TBI patients. The multivariate latent-factor regression analyses also uncovered 5 latent clusters of features with a proportion effect >30%, many in common with the observable features. Among the observable and latent features were protease inhibitors known to inhibit activated protein C and block fibrinolysis (SERPINA5 and CPB2), a clotting factor (factor XI), as well as proteins involved in lipid transport and metabolism (APOE3 and sPLA(2)-XIIA).

CONCLUSIONS

These findings suggest that severely injured patients with TBI process exogenous plasma differently than those without TBI. The beneficial effects of early TP in E2-TBI patients may be the result of improved blood clotting and the effect of brain protective factors independent of coagulation.

Non-coagulopathic hemothorax in a dog: A case report

An 8-year-old, female-spayed, Blue Heeler presented with suspected non-coagulopathic spontaneous, hemothorax with neoplasia as the most likely differential as coagulation parameters were normal and no obvious history of trauma was reported. Computed tomography scan was crucial for diagnosis of a traumatic partial vascular avulsion injury that was successfully managed supportively.

Endothelial Glycocalyx Degradation in Critical Illness and Injury

The endothelial glycocalyx is a gel-like layer on the luminal side of blood vessels that is composed of glycosaminoglycans and the proteins that tether them to the plasma membrane. Interest in its properties and function has grown, particularly in the last decade, as its importance to endothelial barrier function has come to light. Endothelial glycocalyx studies have revealed that many critical illnesses result in its degradation or removal, contributing to endothelial dysfunction and barrier break-down. Loss of the endothelial glycocalyx facilitates the direct access of immune cells and deleterious agents (e.g., proteases and reactive oxygen species) to the endothelium, that can then further endothelial cell injury and dysfunction leading to complications such as edema, and thrombosis. Here, we briefly describe the endothelial glycocalyx and the primary components thought to be directly responsible for its degradation. We review recent literature relevant to glycocalyx damage in several critical illnesses (sepsis, COVID-19, trauma and diabetes) that share inflammation as a common denominator with actions by several common agents (hyaluronidases, proteases, reactive oxygen species, etc.). Finally, we briefly cover strategies and therapies that show promise in protecting or helping to rebuild the endothelial glycocalyx such as steroids, protease inhibitors, anticoagulants and resuscitation strategies.

After 9,000 Laparotomies for Blunt Trauma, Resuscitation Is Becoming More Balanced and Time to Intervention Shorter: Evidence in Action

INTRODUCTION

Several advancements in hemorrhage control have been advocated for in the past decade, including balanced transfusions and earlier times to intervention. The aim of this study is to examine the effect of these advancements on outcomes of blunt trauma patients undergoing emergency laparotomy.

METHODS

This is a 5-year (2013-2017) analysis of the Trauma Quality Improvement Program. Adult (age ≥ 18 years) blunt trauma patients with early (≤4 hours) PRBC and FFP transfusions and an emergency (≤4 hours) laparotomy for hemorrhage control were identified. Time-trend analysis of 24-hour mortality, PRBC/FFP ratio, and time to laparotomy was performed over the study period. The association between mortality and PRBC/FFP ratio, patient demographics, injury characteristics, transfusion volumes, and ACS verification level was examined by hierarchical regression analysis adjusting for inter-year variability.

RESULTS

A total of 9,773 blunt trauma patients with emergency laparotomy were identified. Mean age was 44 ± 18 years, 67.5% were male, and median ISS was 34 [24-43]. Mean SBP at presentation was 73 ± 28 mm Hg, and median transfusion requirements were PRBC 9 [5-17] and FFP 6 [3-12]. During the 5-year analysis, time to laparotomy decreased from 1.87 hours to 1.37 hours (p < 0.001), PRBC/FFP ratio at 4 hours decreased from 1.93 to 1.71 (p < 0.001), and 24-hour mortality decreased from 23.0% to 19.3% (p = 0.014). (Figure) On multivariate analysis, decreased PRBC/FFP ratio was independently associated with decreased 24-hour mortality (OR 0.88; p < 0.001) and in-hospital mortality (OR 0.89; p < 0.001).

CONCLUSION

Resuscitation is becoming more balanced and time to emergency laparotomy shorter in blunt trauma patients, with a significant improvement in mortality. Future efforts should be directed towards incorporating transfusion practices and timely surgical interventions as markers of trauma center quality.

LEVEL OF EVIDENCE

Level III.

Targeting repair of the vascular endothelium and glycocalyx after traumatic injury with plasma and platelet resuscitation

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Endothelial glycocalyx shedding is a key instigator of the endotheliopathy of trauma.

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Plasma and platelet transfusions preserve vascular integrity in pre-clinical models.

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However, platelets may be less effective than plasma in preserving the glycocalyx.

Severely injured patients with hemorrhagic shock can develop endothelial dysfunction, systemic inflammation, and coagulation disturbances collectively known as the endotheliopathy of trauma (EOT). Shedding of the endothelial glycocalyx occurs early after injury, contributes to breakdown of the vascular barrier, and plays a critical role in the pathogenesis of multiple organ dysfunction, leading to poor outcomes in trauma patients. In this review we discuss (i) the pathophysiology of endothelial glycocalyx and vascular barrier breakdown following hemorrhagic shock and trauma, and (ii) the role of plasma and platelet transfusion in maintaining the glycocalyx and vascular endothelial integrity.

Prehospital Plasma Transfusion: What Does the Literature Show?

Background

Early initiation of blood products transfusion after injury has been associated with improved patient outcomes following traumatic injury. The ability to transfuse patients' plasma in the prehospital setting provides a prime opportunity to begin resuscitation with blood products earlier and with a more balanced plasma: RBC ratio than what has traditionally been done. Published studies on the use of prehospital plasma show a complex relationship between its use and improved survival.

Summary

Examination of the literature shows that there may be a mortality benefit from the use of prehospital plasma, but that it may be limited to certain subgroups of trauma patients. The likelihood of realizing these survival benefits appears to be predicted by several factors including the type of injury, length of transport time, presence of traumatic brain injury, and total number of blood products transfused, whether the patient required only a few products or a massive transfusion. When taken as a whole the evidence appears to show that prehospital plasma may have a mortality benefit that is most clearly demonstrated in patients with blunt injuries, moderate transfusion requirements, traumatic brain injury, and/or transport time greater than 20 min, as well as those who demonstrate a certain cytokine expression profile.

Key Messages

The evidence suggests that a targeted use of prehospital plasma will most likely maximize the benefits from the use of this limited resource. It is also possible that prehospital plasma may best be provided through whole blood as survival benefits were greatest in patients who received both prehospital plasma and RBCs.

Fibrinogen inhibits microRNA-19b, a novel mechanism for repair of haemorrhagic shock-induced endothelial cell dysfunction

BACKGROUND

The benefits of plasma as an adjunct to the treatment of haemorrhagic shock are well established; however, the mechanism by which plasma modulates the endotheliopathy of trauma remains unclear. Our recent data demonstrated a novel role of microRNA-19b in post-haemorrhagic shock endothelial dysfunction via targeting of syndecan-1. Additionally, fibrinogen, as a key component of plasma or an isolated haemostatic protein, protects the endothelium by stabilizing syndecan-1. We therefore hypothesized that fibrinogen would inhibit microRNA-19b to mitigate the endotheliopathy of trauma in a murine model of haemorrhagic shock.

MATERIALS AND METHODS

C57BL/6J mice were subjected to haemorrhagic shock (mean arterial pressure 35±5 mmHg for 90 minutes) followed by resuscitation with lactated Ringer's, fresh frozen plasma, fibrinogen or no resuscitation. MicroRNA-19b and syndecan-1 mRNA were measured in lung tissue by qRT-PCR. Lungs were stained for histopathologic injury, and broncheoalveolar lavage was collected for protein as a permeability indicator.

RESULTS

Pulmonary microRNA-19b was increased after haemorrhagic shock and lactated Ringers, but reduced to sham levels by plasma and fibrinogen. Conversely, pulmonary syndecan-1 mRNA was downregulated by haemorrhagic shock and lactated Ringers, but returned to sham levels by plasma and fibrinogen. Plasma and fibrinogen-based resuscitation reduced lung injury compared to haemorrhagic shock and lactated Ringers while fibrinogen also reduced broncheoalveolar lavage protein.

DISCUSSION

We have demonstrated a novel mechanism by which fibrinogen, a key component of plasma and haemostatic agent, inhibits miR-19b, possibly by mitigating the endotheliopathy of trauma. Complete demonstration of the mechanism of fibrinogen inhibition of endotheliopathy via microRNA, however, remains to be elucidated. These findings support the early and empiric use of fibrinogen in post-haemorrhagic shock resuscitation.

Volume Resuscitation in the Acutely Hemorrhaging Patient: Historic Use to Current Applications

Acute hemorrhage in small animals results from traumatic and non-traumatic causes. This review seeks to describe current understanding of the resuscitation of the acutely hemorrhaging small animal (dog and cat) veterinary patient through evaluation of pre-clinical canine models of hemorrhage and resuscitation, clinical research in dogs and cats, and selected extrapolation from human medicine. The physiologic dose and response to whole blood loss in the canine patient is repeatable both in anesthetized and awake animals and is primarily characterized clinically by increased heart rate, decreased systolic blood pressure, and increased shock index and biochemically by increased lactate and lower base excess. Previously, initial resuscitation in these patients included immediate volume support with crystalloid and/or colloid, regardless of total volume, with a target to replace lost vascular volume and bring blood pressure back to normal. Newer research now supports prioritizing hemorrhage control in conjunction with judicious crystalloid administration followed by early consideration for administration of platelets, plasma and red blood during the resuscitation phase. This approach minimizes blood loss, ameliorates coagulopathy, restores oxygen delivery and correct changes in the glycocalyx. There are many hurdles in the application of this approach in clinical veterinary medicine including the speed with which the bleeding source is controlled and the rapid availability of blood component therapy. Recommendations regarding the clinical approach to volume resuscitation in the acutely hemorrhaging veterinary patient are made based on the canine pre-clinical, veterinary clinical and human literature reviewed.

Never-frozen liquid plasma transfusion in civilian trauma: a nationwide propensity-matched analysis

BACKGROUND

Never-frozen liquid plasma (LQP) was found to reduce component waste, decrease health care expenses, and have a superior hemostatic profile compared with fresh frozen plasma (FFP). Although transfusing LQP in hemorrhaging patients has become more common, its clinical effectiveness remains to be explored. This study aims to examine outcomes of trauma patients transfused with LQP compared with thawed FFP.

METHODS

Adult (≥18 years) trauma patients receiving early (≤4 hours) plasma transfusions were identified in the Trauma Quality Improvement Program 2017. Patients were stratified into those receiving LQP versus FFP. Propensity-score matching in a 1:2 ratio was performed. Primary outcome measures were mortality and time to first plasma unit transfusion. Secondary outcome measures were major complications and hospital length of stay.

RESULTS

A total of 107 adult trauma patients receiving LQP were matched to 214 patients receiving FFP. Mean age was 48 ± 19 years, 73% were male, and median Injury Severity Score was 27 [23-41]. A total of 42% of patients were in shock, 22% had penetrating injuries, and 31% required surgical intervention for hemorrhage control. Patients received a median of 4 [2-6] units of PRBC, 2 [1,3] units of LQP or FFP, and 1 [0-1] unit of platelets. The median time to the first LQP unit transfused was significantly shorter compared with the first FFP unit transfused (54 [28-79] minutes vs. 98 [59-133] minutes; p < 0.001). Rates of 24-hour mortality (2.8% vs. 3.7%; p = 0.664) and in-hospital mortality (16.8% vs. 20.1%; p = 0.481) were not different between the LQP and FFP groups. Similarly, there was no difference in major complications (15.9% vs. 21.5%; p = 0.233) and hospital length of stay (12 [6-21] vs. 12 [6-23] days; p = 0.826).

CONCLUSION

Never-frozen liquid plasma is safe and effective in resuscitating trauma patients. Never-frozen liquid plasma has the potential to expand our transfusion armamentarium given its longer storage time and immediate availability.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Use of serum hyaluronic acid as a biomarker of endothelial glycocalyx degradation in dogs with septic peritonitis

OBJECTIVE

To describe daily changes in serum concentrations of hyaluronic acid (HA), a biomarker of endothelial glycocalyx degradation, in dogs with septic peritonitis and to determine whether relationships exist among serum concentrations of HA and biomarkers of inflammation and patient fluid status.

ANIMALS

8 client-owned dogs.

PROCEDURES

Serum samples that had been collected for a previous study and stored at -80°C were used. Blood samples were collected at admission and daily thereafter during hospitalization and were analyzed for concentrations of HA and interleukins 6, 8, and 10. Patient data including acute patient physiologic and laboratory evaluation score, type and amount of fluids administered daily, and daily CBC and lactate concentration results were recorded. To determine the significant predictors of HA concentration, a general linear mixed model for repeated measures was developed.

RESULTS

All dogs survived to discharge. Concentrations of HA ranged from 18 to 1,050 ng/mL (interquartile [25th to 75th percentile] range, 49 to 119 ng/mL) throughout hospitalization. Interleukin-6 concentration was a significant predictor of HA concentration as was total administered daily fluid volume when accounting for interleukin-6 concentration. When fluid volume was analyzed independent of inflammatory status, fluid volume was not a significant predictor. Concentrations of HA did not significantly change over time but tended to increase on day 2 or 3 of hospitalization.

CONCLUSIONS AND CLINICAL RELEVANCE

Results supported the theory that inflammation is associated with endothelial glycocalyx degradation. Dogs recovering from septic peritonitis may become more susceptible to further endothelial glycocalyx damage as increasing fluid volumes are administered.

Resuscitative Strategies to Modulate the Endotheliopathy of Trauma: From Cell to Patient

Clinical data has supported the early use of plasma in high ratios of plasma to red cells to patients in hemorrhagic shock. The benefit from plasma seems to extend beyond its hemostatic effects to include protection to the post-shock dysfunctional endothelium. Resuscitation of the endothelium by plasma and one of its major constituents, fibrinogen, involves cell surface stabilization of syndecan-1, a transmembrane proteoglycan and the protein backbone of the endothelial glycocalyx. The pathogenic role of miRNA-19b to the endothelium is explored along with the PAK-1-mediated intracellular pathway that may link syndecan-1 to cytoskeletal protection. Additionally, clinical studies using fibrinogen and cyroprecipitate to aid in hemostasis of the bleeding patient are reviewed and new data to suggest a role for plasma and its byproducts to treat the dysfunctional endothelium associated with nonbleeding diseases is presented.

Post-expiry stability of freeze-dried plasma under field conditions - Can shelf life be extended?

BACKGROUND

This prospective study evaluated the effect of routine, uncontrolled, Israeli field storage conditions on the safety and efficacy of Lyo-Plas N Freeze-Dried Plasma (FDP) at the end of the manufacturer's shelf life, and up to 24 months post expiry. Clotting factors V, VIII and XI, proteins S, C, fibrinogen, PTT, ATIII, VWF, and INR as well as TEG, DDM, residual moisture, pH, and sterility of FDP returned from field units after uncontrolled storage were evaluated.

STUDY DESIGN AND METHODS

Parameters measured at the end of manufacturer shelf life, as well as 6, 12, 18, and 24 months after expiry, were compared to those of freshly supplied FDP doses.

RESULTS

Changes were found when comparing freshly supplied FDP to all field-stored groups in INR, PT, PTT, pH, fibrinogen, and factor VIII. A significant change was also seen in Factor XI in the 12, 18, and 24 months post-expiry samples, Factor V and R in the 24 months post-expiry samples, MA in the 12, 24 months post-expiry group, and Protein C in the 18 months post-expiry group. An increase in the residual moisture from 0.90% in freshly supplied FDP to 1.35% in 24 months post-expiry FDP.; all p < .05. No growth was found in sterility analysis.

CONCLUSION

Despite uncontrolled field storage conditions, the findings demonstrate that the safety and efficacy of FDP units, stored in uncontrolled conditions are only slightly affected, even beyond their expiration date. This information allows consideration of possibly extending the shelf life.

Therapeutic application of recombinant human ADAMTS-13 improves shock reversal and coagulation status in a trauma hemorrhage and transfusion rat model

INTRODUCTION

In hemorrhaging trauma patients, the endothelium is activated, resulting in excessive endothelial synthesis of von Willebrand Factor (vWF), which may enhance micro-thrombi formation, resulting in obstruction of the microcirculation and endothelial injury, aggravating bleeding, as well as contributing to organ failure. Under normal conditions, vWF is cleaved by the metalloprotease ADAMTS-13. After trauma, ADAMTS-13 levels are reduced.

OBJECTIVES

To assess whether recombinant human ADAMTS-13 inhibits endothelial injury and organ failure in a rat trauma-transfusion model.

METHODS

Blood products were prepared from syngeneic rat blood according to blood bank standards. Polytrauma was induced in rats by crush injury to the intestines and liver and by fracture of the femur. The rats were hemorrhaged until a mean arterial pressure (MAP) of 40 mmHg was reached. Rats were randomized to receive transfusion of RBCs, FFPs, and platelets in a 1:1:1 ratio to achieve a MAP of 70 mmHg, with or without the addition of ADAMTS-13 (50 μg/kg). Blood samples were assessed for biochemistry and rotational thromboelastometry (ROTEM). Syndecan-1 and VE-cadherin levels were measured as a reflection of endothelial integrity. The amount of leakage of dextran-FITC from the vascular system to the parenchyma in lungs was quantified. To assess inflammation, IL-6 and IL-8 levels were determined. Organ damage was assessed by histopathology.

RESULTS

All rats were severely shocked, with no significant differences in shock parameters between groups. Rats treated with ADAMTS-13 showed signs of a more effective shock reversal (higher blood pressure, lower lactate levels) compared to controls. Also, ROTEM parameters of clot formation in rats receiving ADAMTS-13 improved compared to controls, which was mainly platelet-dependent. Syndecan-1 levels relative to baseline trended to be lower in ADAMTS-13 treated rats compared to controls (107 vs 149%, p = 0.08). ADAMTS-13 reduced albuminuria (1.7 vs 4.4 g/L, p < 0.01) and organ-specific inflammation (pulmonary IL-6 243 vs 369 pg/mL, p = 0.08; splenic IL-6 253 vs 307, p = 0.03) compared to controls, but did not improve histopathological scores.

CONCLUSIONS

The use of ADAMTS-13 in a rat trauma-transfusion model improves parameters of shock, platelet-driven coagulation, endothelial damage, and organ inflammation. These results suggest that ADAMTS-13 is important in mediating outcome of trauma. Whether ADAMTS-13 can be used as a therapeutic adjunct to treat bleeding trauma patients remains to be determined.

An Assessment of Research Priorities to Dampen the Pendulum Swing of Burn Resuscitation

On June 17 to 18, 2019, the American Burn Association, in conjunction with Underwriters Laboratories, convened a group of experts on burn resuscitation in Washington, DC. The goal of the meeting was to identify and discuss novel research and strategies to optimize the process of burn resuscitation. Patients who sustain a large thermal injury (involving >20% of the total body surface area [TBSA]) face a sequence of challenges, beginning with burn shock. Over the last century, research has helped elucidate much of the underlying pathophysiology of burn shock, which places multiple organ systems at risk of damage or dysfunction. These studies advanced the understanding of the need for fluids for resuscitation. The resultant practice of judicious and timely infusion of crystalloids has improved mortality after major thermal injury. However, much remains unclear about how to further improve and customize resuscitation practice to limit the morbidities associated with edema and volume overload. Herein, we review the history and pathophysiology of shock following thermal injury, and propose some of the priorities for resuscitation research. Recommendations include: studying the utility of alternative endpoints to resuscitation, reexamining plasma as a primary or adjunctive resuscitation fluid, and applying information about inflammation and endotheliopathy to target the underlying causes of burn shock. Undoubtedly, these future research efforts will require a concerted effort from the burn and research communities.

Convalescent Plasma Therapy for Management of COVID-19: Perspectives and Deployment in the Current Global Pandemic

The world is striving against the severe crisis of the COVID-19 pandemic. Healthcare professionals are struggling to treat their patients based on nonspecific therapies. Amidst this uncertainty, convalescent plasma therapy (CPT) has appeared to be an interim adjuvant therapy for severely ill patients of COVID-19 until long-term clinical trial treatment options are available. Considering the transfusion-related hazards, especially lung injuries and microbial transmission, where sensitivity is not ensured, rigorous trials should be conducted to determine this therapy's efficacy. Moreover, the ratio of recovered cases to plasma donors is not satisfying, which questioning this therapy's availability and accessibility. Although some countries are making the treatment free, the attributable cost mandates a justification for its suitability and sustainability. Our article aimed to review the published facts and findings of CPT's effectiveness in lowering the mortality rate of COVID-19. This pandemic showed that healthcare systems worldwide need core reform. A unified global collaboration must align and coordinate to face the current pandemic and enhance world readiness for future outbreaks based on health equity and equality.

Association of Prehospital Plasma With Survival in Patients With Traumatic Brain Injury: A Secondary Analysis of the PAMPer Cluster Randomized Clinical Trial

IMPORTANCE

Prehospital plasma administration improves survival in injured patients at risk for hemorrhagic shock and transported by air ambulance. Traumatic brain injury (TBI) is a leading cause of death following trauma, but few early interventions improve outcomes.

OBJECTIVE

To assess the association between prehospital plasma and survival in patients with TBI.

DESIGN, SETTING, AND PARTICIPANTS

The Prehospital Air Medical Plasma (PAMPer) trial was a pragmatic, multicenter, phase 3, cluster randomized clinical trial involving injured patients who were at risk for hemorrhagic shock during air medical transport to a trauma center. The trial was conducted at 6 US sites with 9 level-I trauma centers (comprising 27 helicopter emergency services bases). The original trial analyzed 501 patients, including 230 patients who were randomized to receive plasma and 271 randomized to standard care resuscitation. This secondary analysis of a predefined subgroup included patients with TBI. Data analysis was performed from October 2019 to February 2020.

INTERVENTIONS

Patients were randomized to receive standard care fluid resuscitation or 2 units of thawed plasma.

MAIN OUTCOMES AND MEASURES

The primary outcome was mortality at 30 days. Patients with TBI were prespecified as a subgroup for secondary analysis and for measurement of markers of brain injury. The 30-day survival benefit of prehospital plasma in subgroups with and without TBI as diagnosed by computed tomography was characterized using Kaplan-Meier survival analysis and Cox proportional hazard regression.

RESULTS

In total, 166 patients had TBI (median [interquartile range] age, 43.00 [25.00-59.75] years; 125 men [75.3%]). When compared with the 92 patients who received standard care, the 74 patients with TBI who received prehospital plasma had improved 30-day survival even after adjustment for multiple confounders and assessment of the degree of brain injury with clinical variables and biomarkers (hazard ratio [HR], 0.55; 95% CI, 0.33-0.94; P = .03). Receipt of prehospital plasma was associated with improved survival among patients with TBI with a prehospital Glasgow Coma Scale score of less than 8 (HR, 0.56; 95% CI, 0.35-0.91) and those with polytrauma (HR, 0.50; 95% CI, 0.28-0.89). Patients with TBI transported from the scene of injury had improved survival following prehospital plasma administration (HR, 0.45; 95% CI, 0.26-0.80; P = .005), whereas patients who were transferred from an outside hospital showed no difference in survival for the plasma intervention (HR, 1.00; 95% CI, 0.33-3.00; P = .99).

CONCLUSIONS AND RELEVANCE

These findings are exploratory, but they suggest that receipt of prehospital plasma is associated with improved survival in patients with computed tomography-positive TBI. The prehospital setting may be a critical period to intervene in the care of patients with TBI. Future studies are needed to confirm the clinical benefits of early plasma resuscitation following TBI and concomitant polytrauma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01818427.

The Glycocalyx and Its Role in Vascular Physiology and Vascular Related Diseases

Purpose

In 2007 the two senior authors wrote a review on the structure and function of the endothelial glycocalyx layer (Weinbaum in Annu Rev Biomed Eng 9:121–167, 2007). Since then there has been an explosion of interest in this hydrated gel-like structure that coats the luminal surface of endothelial cells that line our vasculature due to its important functions in (A) basic vascular physiology and (B) vascular related diseases. This review will highlight the major advances that have occurred since our 2007 paper.

Methods

A literature search mainly focusing on the role of the glycocalyx in the two major areas described above was performed using electronic databases.

Results

In part (A) of this review, the new formulation of the century old Starling principle, now referred to as the Michel–Weinbaum glycoclayx model or revised Starling hypothesis, is described including new subtleties and physiological ramifications. New insights into mechanotransduction and release of nitric oxide due to fluid shear stress sensed by the glycocalyx are elaborated. Major advances in understanding the organization and function of glycocalyx components, and new techniques for measuring both its thickness and spatio-chemical organization based on super resolution, stochastic optical reconstruction microscopy (STORM) are presented. As discussed in part (B) of this review, it is now recognized that artery wall stiffness associated with hypertension and aging induces glycocalyx degradation, endothelial dysfunction and vascular disease. In addition to atherosclerosis and cardiovascular diseases, the glycocalyx plays an important role in lifestyle related diseases (e.g., diabetes) and cancer. Infectious diseases including sepsis, Dengue, Zika and Corona viruses, and malaria also involve the glycocalyx. Because of increasing recognition of the role of the glycocalyx in a wide range of diseases, there has been a vigorous search for methods to protect the glycocalyx from degradation or to enhance its synthesis in disease environments.

Conclusion

As we have seen in this review, many important developments in our basic understanding of GCX structure, function and role in diseases have been described since the 2007 paper. The future is wide open for continued GCX research.

SARS-CoV-2 Bound Human Serum Albumin and Systemic Septic Shock

The emergence of the COVID-19 virus and the subsequent pandemic have driven a great deal of research activity. The effects of COVID-19 are caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is the underlying actions of SARs-CoV-2 virions on the endothelial glycocalyx that we consider here. One of the key factors in COVID-19 infection is its almost unique age-related profile, with a doubling in mortality every 10 years after the age of 50. The endothelial glycocalyx layer is essential in maintaining normal fluid homeostasis, but is fragile and prone to pathophysiological damage. It is physiologically significant in capillary microcirculation and in fluid distribution to the tissues. Human serum albumin (HSA), the most abundant protein in plasma, is created in the liver which also maintains its concentration, but this reduces by 10-15% after 50 years of age. HSA transports hormones, free fatty acids and maintains oncotic pressure, but SARS-CoV-2 virions bind competitively to HSA diminishing its normal transport function. Furthermore, hypoalbuminemia is frequently observed in patients with such conditions as diabetes, hypertension, and chronic heart failure, i.e., those most vulnerable to SARS-CoV-2 infection. Hypoalbuminemia, coagulopathy, and vascular disease have been linked in COVID-19 and have been shown to predict outcome independent of age and morbidity. Hypoalbuminemia is also known factor in sepsis and Acute respiratory distress syndrome (ARDS) occurs when fluids build-up in the alveoli and it is associated with sepsis, whose mechanism is systemic, being associated with the fluid and logistic mechanisms of the circulation. Glycocalyx damage is associated with changes plasma protein concentration, particularly HSA and blockage of albumin transport can produce the systemic symptoms seen in SARS-CoV-2 infection and sepsis. We therefore conclude that albumin binding to SARS-CoV-2 virions may inhibit the formation of the endothelial glycocalyx by inhibition of albumin transport binding sites. We postulate that albumin therapy to replace bound albumin might alleviate some of the symptoms leading to sepsis and that clinical trials to test this postulation should be initiated as a matter of urgency.

The therapeutic efficacy of adjunct therapeutic plasma exchange for septic shock with multiple organ failure: a single-center experience

Background

Sepsis remains a common condition with high mortality when multiple organ failure develops. The evidence for therapeutic plasma exchange (TPE) in this setting is promising but inconclusive. Our study aims to evaluate the efficacy of adjunct TPE for septic shock with multiple organ failure compared to standard therapy alone.

Methods

A retrospective, observational chart review was performed, evaluating outcomes of patients with catecholamine-resistant septic shock and multiple organ failure in intensive care units at a tertiary care hospital in Winston-Salem, NC, from August 2015 to March 2019. Adult patients with catecholamine-resistant septic shock (≥ 2 vasopressors) and evidence of multiple organ failure were included. Patients who received adjunct TPE were identified and compared to patients who received standard care alone. A propensity score using age, gender, chronic co-morbidities (HTN, DM, CKD, COPD), APACHE II score, SOFA score, lactate level, and number of vasopressors was used to match patients, resulting in 40 patients in each arm.

Results

The mean baseline APACHE II and SOFA scores were 32.5 and 14.3 in TPE patients versus 32.7 and 13.8 in control patients, respectively. The 28-day mortality rate was 40% in the TPE group versus 65% in the standard care group (p = 0.043). Improvements in baseline SOFA scores at 48 h were greater in the TPE group compared to standard care alone (p = 0.001), and patients receiving adjunct TPE had a more favorable fluid balance at 48 h (p = 0.01). Patients receiving adjunct TPE had longer ICU and hospital lengths of stay (p = 0.003 and p = 0.006, respectively).

Conclusions

Our retrospective, observational study in adult patients with septic shock and multiple organ failure demonstrated improved 28-day survival with adjunct TPE compared to standard care alone. Hemodynamics, organ dysfunction, and fluid balance all improved with adjunct TPE, while lengths of stay were increased in survivors. The study design does not allow for a generalized statement of support for TPE in all cases of sepsis with multiple organ failure but offers valuable information for a prospective, randomized clinical trial.

Pre-hospital blood transfusion - an ESA survey of European practice

Background

Blood products are a lifesaving commodity in the treatment of major trauma.

Although there is little evidence for use of pre-hospital blood products (PHBP) in seriously injured patients, an increasing number of emergency medical services have started using PHBP for treatment of major haemorrhage.

The primary aim of this survey was to establish the degree of prehospital blood product use throughout Europe and discover main indications. The secondary aim was to evaluate opinions about PHBP and also the experience and the personal views of its users.

Methods

The subcommittee for Critical Emergency Medicine of the European Society of Anaesthesiology (ESA) held an online survey of European Helicopter Emergency Services (HEMS) and all French Services d’Aide Médicale Urgente (SAMU) regions. It contained 13 questions both open and multiple-choice about the frequency transfusions are carried out, the PHBP used and the perceived benefit. The survey was distributed to the corresponding HEMS leads in 14 European countries.

Results

In total there were 172 valid responses; overall 48% of all respondents have prehospital access to packed red cells, 22% to fresh plasma and 14% use lyophilised plasma. Besides blood product administration, 94% of all services use tranexamic acid. Sixty five percent of all replies came from French and from German services (37 and 28% respectively). PHBP were mainly used for trauma related emergencies. France has the highest uptake of use of blood products at 89%, whereas the rate in Germany was far lower at 6%.

Fifty five percent of the service leads felt that PHBP are beneficial, and even lifesaving in individual cases despite being needed infrequently.

Conclusions

We found remarkable dissimilarities in practice between the different European countries. Even if there is not an absolute consensus amongst providers on the benefit of PHBP, the majority feel they are beneficial. The difference in practice is possibly related to the perceived lack of evidence on prehospital blood transfusion. We suggest to include the use of PHBP in trauma registries in order to consolidate the existing evidence.

Can Endothelial Glycocalyx Be a Major Morphological Substrate in Pre-Eclampsia?

Today pre-eclampsia (PE) is considered as a disease of various theories; still all of them agree that endothelial dysfunction is the leading pathogenic factor. Endothelial dysfunction is a sequence of permanent immune activation, resulting in the change of both the phenotype and the functions of an endothelial cell and of the extracellular layer associated with the cell membrane—endothelial glycocalyx (eGC). Numerous studies demonstrate that eGC mediates and regulates the key functions of endothelial cells including regulation of vascular tone and thromboresistance; and these functions are disrupted during PE. Taking into account that eGC and its components undergo alterations under pathological conditions leading to endothelial activation, it is supposed that eGC plays a certain role in pathogenesis of PE. Envisaging the eGC damage as a key factor of PE, might be a new approach to prevention, treatment, and rehabilitation of patients with PE. This approach could include the development of drugs protecting eGC and promoting regeneration of this structure. Since the issue of PE is far from being solved, any effort in this direction might be valuable.

Prehospital plasma is associated with distinct biomarker expression following injury

BACKGROUNDPrehospital plasma improves survival in severely injured patients transported by air ambulance. We hypothesized that prehospital plasma would be associated with a reduction in immune imbalance and endothelial damage.METHODSWe sampled blood from 405 trauma patients enrolled in the Prehospital Air Medical Plasma (PAMPer) trial upon hospital admission (0 hours) and 24 hours post admission across 6 U.S. sites. We assayed samples for 21 inflammatory mediators and 7 markers associated with endothelial function and damage. We performed hierarchical clustering analysis (HCA) of these biomarkers of the immune response and endothelial injury. Regression analysis was used to control for differences across study and to assess any association with prehospital plasma resuscitation.RESULTSHCA distinguished two patient clusters with different injury patterns and outcomes. Patients in cluster A had greater injury severity and incidence of blunt trauma, traumatic brain injury, and mortality. Cluster A patients that received prehospital plasma showed improved 30-day survival. Prehospital plasma did not improve survival in cluster B patients. In an adjusted analysis of the most seriously injured patients, prehospital plasma was associated with an increase in adiponectin, IL-1β, IL-17A, IL-23, and IL-17E upon admission, and a reduction in syndecan-1, TM, VEGF, IL-6, IP-10, MCP-1, and TNF-α, and an increase in IL-33, IL-21, IL-23, and IL-17E 24 hours later.CONCLUSIONPrehospital plasma may ameliorate immune dysfunction and the endotheliopathy of trauma. These effects of plasma may contribute to improved survival in injured patients.TRIAL REGISTRATIONNCT01818427.FUNDINGDepartment of Defense; National Institutes of Health, U.S. Army.

Incidence and Prognostic Value of Acute Coagulopathy After Extensive Severe Burns

Acute burn-induced coagulopathy (ABIC) occurs after severe burns. However, the incidence, prognostic value, and clinical significance of ABIC after an extensive severe burn remain inconclusive due to wide variances in burn severity and coagulation profile evaluation timings in previous studies. This retrospective study explored the incidence and clinical and prognostic significance of early phase ABIC in 129 adult patients with extensive burns (&gt;50% total body surface area [TBSA]) admitted to the burn centers of two hospitals within 10 hours postburn injury during 2009–2017. Demographics (age and sex) and clinical data (burn severity, vital signs, prehospital fluid replacement volume, hemodynamic parameters, coagulation profile, blood gas, and blood biochemical indicators) were collected upon admission. The incidence of ABIC in patients with severe burns and its relationship with their survival and clinical significance were analyzed. The average postburn interval was 5.7 ± 2.7 hours, and the incidence of ABIC was 31% (40/129). A logistic regression analysis identified ABIC as an independent predictor of 4-week severe mortality due to severe burn. The incidence of ABIC was significantly associated with the total burn area, lactic acid levels upon admission, and postburn admission interval, but not with the prehospital fluid replacement volume. In conclusion, approximately 30% of patients with severe burns developed ABIC within 10 hours postburn, and this condition strongly predicts 4-week mortality. Although burn severity and tissue ischemia/hypoxia are main risk factors for ABIC, the pathogenesis is not fully understood and should be explored in future studies.

Endothelial Glycocalyx

The endothelial glycocalyx (EG) is the most luminal layer of the blood vessel, growing on and within the vascular wall. Shedding of the EG plays a central role in many critical illnesses. Degradation of the EG is associated with increased morbidity and mortality. Certain illnesses and iatrogenic interventions can cause degradation of the EG. It is not known whether restitution of the EG promotes the survival of the patient. First trials that focus on the reorganization and/or restitution of the EG seem promising. Nevertheless, the step "from bench to bedside" is still a big one.

Endothelial glycocalyx in acute care surgery - what anaesthesiologists need to know for clinical practice

The endothelial glycocalyx (EG) is the thin sugar-based lining on the apical surface of endothelial cells. It has been linked to the physiological functioning of the microcirculation and has been found to be damaged in critical illness and after acute care surgery. This review aims to describe the role of EG in severely injured patients undergoing surgery, discuss specific situations (e.G. major trauma, hemorrhagic shock, trauma induced coagulopathy) as well as specific interventions commonly applied in these patients (e.g. fluid therapy, transfusion) and specific drugs related to perioperative medicine with regard to their impact on EG.EG in acute care surgery is exposed to damage due to tissue trauma, inflammation, oxidative stress and inadequate fluid therapy. Even though some interventions (transfusion of plasma, human serum albumin, hydrocortisone, sevoflurane) are described as potentially EG protective there is still no specific treatment for EG protection and recovery in clinical medicine.The most important principle to be adopted in routine clinical practice at present is to acknowledge the fragile structure of the EG and avoid further damage which is potentially related to worsened clinical outcome.

Plasma for burn shock resuscitation: is it time to go back to the future?

Patients with burn shock can be challenging to resuscitate. Burn shock produces a variety of physiologic derangements: Patients are hypovolemic from volume loss, have a increased systemic vascular resistance, and may have a depressed cardiac output depending on the extent of the thermal injury. Additionally, the burn wound produces a significant inflammatory cascade of events that contributes to the shock state. Fluid resuscitation is foundational for the initial treatment of burn shock. Typical resuscitation is with intravenous lactated Ringer's in accordance with well-established formulas based on burn wound size. In the past century, as therapies to treat thermal injuries were being developed, plasma was the fluid used for burn resuscitation; in fact, plasma was used in World War II and throughout the 1950s and 1960s. Plasma was abandoned because of infectious risks and complications. Despite huge strides in transfusion medicine and the increased safety of blood products, plasma has never been readopted for burn resuscitation. Over the past 15 years, there has been a paradigm shift in trauma resuscitation: Less crystalloid and more blood products are used; this strategy has demonstrated improved outcomes. Plasma is a physiologic fluid that stabilizes the endothelium. The endotheliopathy of trauma has been described and is mitigated by transfusion strategies with a 1:1 ratio of RBCs to plasma. Thermal injury also results in endothelial dysfunction: the endotheliopathy of burns. Plasma is likely a better resuscitation fluid for patients with significant burn wounds because of its capability to restore intravascular volume status and treat the endotheliopathy of burns.

Resuscitation Fluid Choices to Preserve the Endothelial Glycocalyx

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.