Acute coagulopathy and early deaths post major trauma

The Effect of Extracorporeal Membrane Oxygenation in Patients With Multiple Orthopaedic Injuries

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) plays a vital role in providing life support for patients with reversible cardiac or respiratory failure. Given the high rate of complications and difficulties associated with caring for ECMO patients, the goal of this study was to compare outcomes of orthopaedic surgery in polytrauma patients who received ECMO with similar patients who have not. This will help elucidate the timing and type of fixation that should be considered in patients on ECMO.

METHODS

A retrospective cohort was collected from the electronic medical record of two level I trauma centers over an 8-year period (2015 to 2022) using Current Procedural Terminology codes. Patients were matched with a similar counterpart not requiring ECMO based on sex, age, American Society of Anesthesiologists score, body mass index, injury severity score, and fracture characteristics. Outcomes measured included length of stay, number of revisions, time to definitive fixation, infection, amputation, revision surgery to promote bone healing, implant failure, bleeding requiring return to the operating room, and mortality.

RESULTS

Thirty-two patients comprised our ECMO cohort with a patient-matched control group. The ECMO cohort had an increased length of stay (40 versus 17.5 days, P = 0.001), number of amputations (7 versus 0, P = 0.011), and mortality rate (19% versus 0%, P = 0.024). When comparing patients placed on ECMO before definitive fixation and after definitive fixation, the group placed on ECMO before definitive fixation had significantly longer time to definitive fixation than the group placed on ECMO after fixation (14 versus 2.0 days, P < 0.001).

CONCLUSION

ECMO is a lifesaving measure for trauma patients with cardiopulmonary issues but can complicate fracture care. Although it is not associated with an increase in revision surgery rates, ECMO was associated with prolonged hospital stay and delays in definitive fracture surgery when initiated before definitive fixation.

LEVEL OF EVIDENCE

III.

Pre-hospital freeze-dried plasma for critical bleeding after trauma: A pilot randomized controlled trial

OBJECTIVES

Transfusion of a high ratio of plasma to packed red blood cells (PRBCs), to treat or prevent acute traumatic coagulopathy, has been associated with survival after major trauma. However, the effect of prehospital plasma on patient outcomes has been inconsistent. The aim of this pilot trial was to assess the feasibility of transfusing freeze-dried plasma with red blood cells (RBCs) using a randomized controlled design in an Australian aeromedical prehospital setting.

METHODS

Patients attended by helicopter emergency medical service (HEMS) paramedics with suspected critical bleeding after trauma managed with prehospital RBCs were randomized to receive 2 units of freeze-dried plasma (Lyoplas N-w) or standard care (no plasma). The primary outcome was the proportion of eligible patients enrolled and provided the intervention. Secondary outcomes included preliminary data on effectiveness, including mortality censored at 24 h and at hospital discharge, and adverse events.

RESULTS

During the study period of June 1 to October 31, 2022, there were 25 eligible patients, of whom 20 (80%) were enrolled in the trial and 19 (76%) received the allocated intervention. Median time from randomization to hospital arrival was 92.5 min (IQR 68-101.5 min). Mortality may have been lower in the freeze-dried plasma group at 24 h (RR 0.24, 95% CI 0.03-1.73) and at hospital discharge (RR 0.73, 95% CI 0.24-2.27). No serious adverse events related to the trial interventions were reported.

CONCLUSIONS

This first reported experience of freeze-dried plasma use in Australia suggests prehospital administration is feasible. Given longer prehospital times typically associated with HEMS attendance, there is potential clinical benefit from this intervention and rationale for a definitive trial.

Team Approach: The Unstable Trauma Patient

» A multidisciplinary, integrated, and synergistic team approach to the unstable polytrauma patient is critical to optimize outcomes, minimize morbidity, and reduce mortality.» The use of Advanced Trauma Life Support protocols helps standardize the assessment and avoid missing critical injuries» Effective and open dialog with consulting specialists is paramount for effective team-based care.» Orthopaedic surgeons should play an important role in the rapid assessment of potentially life-threatening and/or limb-threatening injuries including pelvic ring disruption, open fractures with substantial blood loss, and dysvascular limbs.

A cost-aware framework for the development of AI models for healthcare applications

Accurate artificial intelligence (AI) for disease diagnosis could lower healthcare workloads. However, when time or financial resources for gathering input data are limited, as in emergency and critical-care medicine, developing accurate AI models, which typically require inputs for many clinical variables, may be impractical. Here we report a model-agnostic cost-aware AI (CoAI) framework for the development of predictive models that optimize the trade-off between prediction performance and feature cost. By using three datasets, each including thousands of patients, we show that relative to clinical risk scores, CoAI substantially reduces the cost and improves the accuracy of predicting acute traumatic coagulopathy in a pre-hospital setting, mortality in intensive-care patients and mortality in outpatient settings. We also show that CoAI outperforms state-of-the-art cost-aware prediction strategies in terms of predictive performance, model cost, training time and robustness to feature-cost perturbations. CoAI uses axiomatic feature-attribution methods for the estimation of feature importance and decouples feature selection from model training, thus allowing for a faster and more flexible adaptation of AI models to new feature costs and prediction budgets.

Novel tool (BIS) heralds the need for blood transfusion and/or failure of non-operative management in pediatric blunt liver and spleen injuries

BACKGROUND

Non-operative management (NOM) is the standard of care for the majority of children with blunt liver and spleen injuries (BLSI). The shock index pediatric age-adjusted (SIPA) was previously shown to predict the need for blood transfusions in pediatric trauma patients with BLSI. We combined SIPA with base deficit (BD) and International Normalized Ratio (INR) to create the BIS score. We hypothesized that the BIS score would predict the need for blood transfusions and/or failure of NOM in pediatric trauma patients with BLSI.

METHODS

Patients (≤ 18 years) who presented to our Level I pediatric trauma center with BLSI from 2009 to 2019 were identified. BIS scores were calculated by giving 1 point for each of the following: base deficit ≤ -8.8, INR ≥ 1.5, or elevated SIPA. Receiver operating characteristic curves (ROC) were generated for BIS scores ≥ 1, ≥ 2, and ≥ 3. Area under the curve (AUC), sensitivity, and specificity of each score were calculated for ability to predict need for blood transfusions and/or failure of NOM.

RESULTS

Of 477 children included, 19.9% required a blood transfusion and 6.7% failed NOM. A BIS score ≥ 1 was the best predictor of the need for blood transfusions with an AUC of 0.81 and a sensitivity of 96.0%. A BIS score ≥ 1 was also the best predictor of failure of NOM with an AUC of 0.72 and a sensitivity of 97.0%.

CONCLUSION

The BIS score is a highly sensitive tool that identifies pediatric patients with BLSI at risk for blood transfusions and/or failure of NOM.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective comparative study.

Brain-Derived Extracellular Vesicles Induce Vasoconstriction and Reduce Cerebral Blood Flow in Mice

Traumatic brain injury (TBI) impairs cerebrovascular autoregulation and reduces cerebral blood flow (CBF), leading to ischemic secondary injuries. We have shown that injured brains release brain-derived extracellular vesicles (BDEVs) into circulation, where they cause a systemic hypercoagulable state that rapidly turns into consumptive coagulopathy. BDEVs induce endothelial injury and permeability, leading to the hypothesis that they contribute to TBI-induced cerebrovascular dysregulation. In a study designed to test this hypothesis, we detected circulating BDEVs in C57BL/6J mice subjected to severe TBI, reaching peak levels of 3x104/µl at 3 hours post injury (71.2±21.5% of total annexin V-binding EVs). We further showed in an adaptive transfer model that 41.7±5.8% of non-injured mice died within 6 hours after being infused with 3x104/µl of BDEVs. BDEVs transmigrated through the vessel walls, induced rapid vasoconstriction by inducing calcium influx in vascular smooth muscle cells, and reduced CBF by 93.8±5.6% within 30 minutes after infusion. The CBF suppression was persistent in mice that eventually died but it recovered quickly in surviving mice. It was prevented by the calcium channel blocker nimodipine. When being separated, neither protein nor phospholipid components from the lethal number of BDEVs induced vasoconstriction, reduced CBF, and caused death. These results demonstrate a novel vasoconstrictive activity of BDEVs that depends on the structure of BDEVs and contributes to TBI-induced disseminated cerebral ischemia and sudden death.

Anticoagulation targeting membrane-bound anionic phospholipids improves outcomes of traumatic brain injury in mice

Severe traumatic brain injury (TBI) often causes an acute systemic hypercoagulable state that rapidly develops into consumptive coagulopathy. We have recently demonstrated that TBI-induced coagulopathy (TBI-IC) is initiated and disseminated by brain-derived extracellular vesicles (BDEVs) and propagated by extracellular vesicles (EVs) from endothelial cells and platelets. Here, we present results from a study designed to test the hypothesis that anticoagulation targeting anionic phospholipid-expressing EVs prevents TBI-IC and improves the outcomes of mice subjected to severe TBI. We evaluated the effects of a fusion protein (ANV-6L15) for improving the outcomes of TBI in mouse models combined with in vitro experiments. ANV-6L15 combines the phosphatidylserine (PS)-binding annexin V (ANV) with a peptide anticoagulant modified to preferentially target extrinsic coagulation. We found that ANV-6L15 reduced intracranial hematoma by 70.2%, improved neurological function, and reduced death by 56.8% in mice subjected to fluid percussion injury at 1.9 atm. It protected the TBI mice by preventing vascular leakage, tissue edema, and the TBI-induced hypercoagulable state. We further showed that the extrinsic tenase complex was formed on the surfaces of circulating EVs, with the highest level found on BDEVs. The phospholipidomic analysis detected the highest levels of PS on BDEVs, as compared with EVs from endothelial cells and platelets (79.1, 15.2, and 3.5 nM/mg of protein, respectively). These findings demonstrate that TBI-IC results from a trauma-induced hypercoagulable state and may be treated by anticoagulation targeting on the anionic phospholipid-expressing membrane of EVs from the brain and other cells.

ECMO (extra corporeal membrane oxygenation) in major trauma: A 10 year single centre experience

Aim To review the indications, complications and outcomes of extracorporeal membrane oxygenation (ECMO) in major trauma patients. Methods Single centre, retrospective, cohort study. Results Over a ten year period, from 13,420 major trauma patients, 11 were identified from our institutional trauma registry as having received ECMO. These patients were predominantly younger (mean 39 +/- 17 years), male (91%) and severely traumatised (median ISS 50, IQR 34 - 54). Veno-venous (VV) ECMO was used predominantly (n = 7, 64%), to treat hypoxic respiratory failure (mean PaO2/FiO2 ratio 69.7 +/- 38.6), secondary to traumatic lung injury. Veno-arterial (VA) ECMO was used less frequently, primarily to treat massive pulmonary embolism following trauma. Major bleeding complications occurred in four patients, however only one patient died from haemorrhage. Heparin free (2/11), delayed (3/11) or low dose heparin (2/11) therapy was frequently utilised. The median time from injury to ECMO initiation was 1 day (IQR 0.5 - 5.5) and median ECMO duration 9 days (IQR 6.5 - 10.5). ECMO was initiated <72 hours in 6 patients, with survival to discharge 67%, compared to 20% in those initiated >72 hours. Overall survival to discharge was 45%, and was higher with VV ECMO (64%), than other configurations (25%). Conclusion ECMO was rarely used in major trauma, the most common indication being severe hypoxaemic respiratory failure secondary to lung injury. In this severely injured cohort, overall survival was poor but better in VV compared to VA and better if initiated early (<72 hours), compared to late.

The Role of DAMPS in Burns and Hemorrhagic Shock Immune Response: Pathophysiology and Clinical Issues. Review

Severe or major burns induce a pathophysiological, immune, and inflammatory response that can persist for a long time and affect morbidity and mortality. Severe burns are followed by a "hypermetabolic response", an inflammatory process that can be extensive and become uncontrolled, leading to a generalized catabolic state and delayed healing. Catabolism causes the upregulation of inflammatory cells and innate immune markers in various organs, which may lead to multiorgan failure and death. Burns activate immune cells and cytokine production regulated by damage-associated molecular patterns (DAMPs). Trauma has similar injury-related immune responses, whereby DAMPs are massively released in musculoskeletal injuries and elicit widespread systemic inflammation. Hemorrhagic shock is the main cause of death in trauma. It is hypovolemic, and the consequence of volume loss and the speed of blood loss manifest immediately after injury. In burns, the shock becomes evident within the first 24 h and is hypovolemic-distributive due to the severely compromised regulation of tissue perfusion and oxygen delivery caused by capillary leakage, whereby fluids shift from the intravascular to the interstitial space. In this review, we compare the pathophysiological responses to burns and trauma including their associated clinical patterns.

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Protocol for a multicentre prehospital randomised controlled trial investigating tranexamic acid in severe trauma: the PATCH-Trauma trial

INTRODUCTION

Haemorrhage causes most preventable prehospital trauma deaths and about a third of in-hospital trauma deaths. Tranexamic acid (TXA), administered soon after hospital arrival in certain trauma systems, is an effective therapy in preventing or managing acute traumatic coagulopathy. However, delayed administration of TXA appears to be ineffective or harmful. The effectiveness of prehospital TXA, incidence of thrombotic complications, benefit versus risk in advanced trauma systems and the mechanism of benefit remain uncertain.

METHODS AND ANALYSIS

The Pre-hospital Anti-fibrinolytics for Traumatic Coagulopathy and Haemorrhage (The PATCH-Trauma study) is comparing TXA, initiated prehospital and continued in hospital over 8 hours, with placebo in patients with severe trauma at risk of acute traumatic coagulopathy. We present the trial protocol and an overview of the statistical analysis plan. There will be 1316 patients recruited by prehospital clinicians in Australia, New Zealand and Germany. The primary outcome will be the eight-level Glasgow Outcome Scale Extended (GOSE) at 6 months after injury, dichotomised to favourable (GOSE 5-8) and unfavourable (GOSE 1-4) outcomes, analysed using an intention-to-treat (ITT) approach. Secondary outcomes will include mortality at hospital discharge and at 6 months, blood product usage, quality of life and the incidence of predefined adverse events.

ETHICS AND DISSEMINATION

The study was approved by The Alfred Hospital Research and Ethics Committee in Victoria and also approved in New South Wales, Queensland, South Australia, Tasmania and the Northern Territory. In New Zealand, Northern A Health and Disability Ethics Committee provided approval. In Germany, Witten/Herdecke University has provided ethics approval. The PATCH-Trauma study aims to provide definitive evidence of the effectiveness of prehospital TXA, when used in conjunction with current advanced trauma care, in improving outcomes after severe injury.

TRIAL REGISTRATION NUMBER

NCT02187120.

Conformation-dependent blockage of activated VWF improves outcomes of traumatic brain injury in mice

Traumatic brain injury-induced coagulopathy (TBI-IC) causes life-threatening secondary intracranial bleeding. Its pathogenesis differs mechanistically from that of coagulopathy arising from extracranial injuries and hemorrhagic shock, but it remains poorly understood. We report results of a study designed to test the hypothesis that von Willebrand factor (VWF) released during acute TBI is intrinsically hyperadhesive because its platelet-binding A1-domain is exposed and contributes to TBI-induced vascular leakage and consumptive coagulopathy. This hyperadhesive VWF can be selectively blocked by a VWF A2-domain protein to prevent TBI-IC and to improve neurological function with a minimal risk of bleeding. We demonstrated that A2 given through intraperitoneal injection or IV infusion reduced TBI-induced death by >50% and significantly improved the neurological function of C57BL/6J male mice subjected to severe lateral fluid percussion injury. A2 protected the endothelium from extracellular vesicle-induced injury, reducing TBI-induced platelet activation and microvesiculation, and preventing a TBI-induced hypercoagulable state. A2 achieved this therapeutic efficacy by specifically blocking the A1 domain exposed on the hyperadhesive VWF released during acute TBI. These results suggest that VWF plays a causal role in the development of TBI-IC and is a therapeutic target for this life-threatening complication of TBI.

Polytrauma management - What is new and what is true in 2020 ?

This is a review of changes in the practice of treating polytrauma managemtent within the years prior to 2020. It focuses on five different topics, 1. The development of an evidence based definition of Polytrauma, 2. Resuscitation Associated Coagulopathy (RAC), 3. neutrophil guided initial resuscitation, 4. perioperative Scoring to evaluate patients at risk, and 5. evolution of fracture fixation strategies according to protocols^1,2 (Early total care, ETC, damage control orthopedics, DCO, early appropriate care, EAC, safe definitive surgery, SDS).

Diverse activities of von Willebrand factor in traumatic brain injury and associated coagulopathy

Traumatic brain injury (TBI) is a leading cause of death and disability. Patients with isolated TBI lose a limited amount of blood to primary injury, but they often develop secondary coagulopathy, resulting in delayed or recurrent intracranial and intracerebral hematoma. TBI-induced coagulopathy is closely associated with poor outcomes for these patients, including death. This secondary coagulopathy is consumptive in nature, involving not only brain-derived molecules, coagulation factors, and platelets, but also endothelial cells in a complex process now called blood failture. A key question is how a localized injury to the brain is rapidly disseminated to affect systemic hemostasis that is not directly affected the way it is in trauma to the body and limbs, especially with hemorrhagic shock. Increasing evidence suggests that the adhesive ligand von Willebrand factor (VWF), which is synthesized in and released from endothelial cells, plays a paradoxical role in both facilitating local hemostasis at the site of injury and also propagating TBI-induced endotheliopathy and coagulopathy systemically. This review discusses recent progress in understanding these diverse activities of VWF and the knowledge gaps in defining their roles in TBI and associated coagulopathy.

New Uses for Thromboelastography and Other Forms of Viscoelastic Monitoring in the Emergency Department: A Narrative Review

Patients frequently visit the emergency department with conditions that place them at risk of worse outcomes when accompanied by coagulopathy. Routine tests of coagulation-prothrombin time, partial thromboplastin time, platelets, and fibrinogen-have shortcomings that limit their use in providing emergency care. One alternative is to investigate coagulation disturbance with viscoelastic monitoring (VEM), a coagulation test that measures the timing and strength of blood clot development in real time. VEM is widely used and studied in cardiac surgery, liver transplant surgery, anesthesia, and trauma. In this article, we review the technique of VEM and the biologic rationale of using it in addition to routine tests of coagulation in emergency clinical situations. Then, we review the evidence (or lack thereof) for using VEM in the diagnosis and treatment of specific conditions. Finally, we describe the limitations of the test and future directions for clinical use and research in emergency medicine.

Current perspective on fibrinogen concentrate in critical bleeding

INTRODUCTION

. Massive hemorrhage continues to be a treatable cause of death. Its management varies from prefixed ratio-driven administration of blood components to goal-directed therapy based on point-of-care testing and administration of coagulation factor concentrates.

AREAS COVERED

. We review the current role of fibrinogen concentrate (FC) for the management of massive hemorrhage, either administered without coagulation testing in life-threatening hemorrhage, or within an algorithm based on viscoelastic hemostatic assays and plasma fibrinogen level. We identified relevant guidelines, meta-analyzes, randomized controlled trials, and observational studies that included indications, dosage, and adverse effects of FC, especially thromboembolic events.

EXPERT OPINION

. Moderate- to high-grade evidence supports the use of FC for the treatment of severe hemorrhage in trauma and cardiac surgery; a lower grade of evidence is available for its use in postpartum hemorrhage and end-stage liver disease. Pre-emptive FC administration in non-bleeding patients is not recommended. FC should be administered early, in a goal-directed manner, guided by early amplitude of clot firmness parameters (A5- or A10-FIBTEM) or hypofibrinogenemia. Further investigation is required into the early use of FC, as well as its potential advantages over cryoprecipitate, and whether or not its administration at high doses leads to a greater risk of adverse events.

Mortality and Complication Rates in Adult Trauma Patients Receiving Tranexamic Acid: A Single-center Experience in the Post-CRASH-2 Era

OBJECTIVES

The CRASH-2 trial demonstrated that tranexamic acid (TXA) in adults with significant traumatic hemorrhage safely reduces mortality. Given that the CRASH-2 trial did not include U.S. sites, our objective was to evaluate patient characteristics, TXA dosing strategies, and the incidence of mortality and adverse events in adult trauma patients receiving TXA at a U.S. Level I trauma center in the post-CRASH-2 era.

METHODS

We conducted a retrospective study that included patients aged 18 years or older who received TXA after an acute injury from July 2014 to June 2017. We excluded patients who received TXA orally, patients who received TXA for elective surgical procedures or nontrauma indications, patients who received it 8 hours or longer after the time of injury, and patients with cardiac arrest at time of emergency department arrival. Trained abstractors collected data from the trauma registry and hospital electronic medical records. Our primary outcome measures were in-hospital death and acute thromboembolic events within 28 days from injury.

RESULTS

We included 273 patients with a mean (±SD) age of 43.8 (±18.7)  years. The mean (±SD) time of administration of TXA from time of injury was 1.55 (±1.2)  hours with 229 patients (83.9%) receiving TXA within 3 hours. The overall mortality within 28 days from injury was 12.8% (95% confidence interval [CI] = 8.9% to 16.7%), which was similar compared to that in the CRASH-2 trial (14.5%, 95% CI = 13.9% to 15.2%). The incidence of acute thromboembolic events was 6.6% (95% CI = 3.7% to 9.5%), which was higher than that in the CRASH-2 trial (2.0%, 95% CI = 1.73% to 2.27%). Patients in our cohort also received surgery (64.8% vs. 47.9%) and blood transfusions (74.0% vs. 50.4%) more frequently than those in the CRASH-2 cohort.

CONCLUSIONS

Adult trauma patients receiving TXA had similar incidences of death but higher incidences of thromboembolic events compared to the CRASH-2 trial. Variation in patient characteristics, injury severity, TXA dosing, and surgery and transfusion rates could explain these observed differences. Further research is necessary to provide additional insight into the incidence and risk factors of thromboembolic events in TXA use.

Trauma Coagulopathy and Its Outcomes

Background and Objectives: Trauma coagulopathy begins at the moment of trauma. This study investigated whether coagulopathy upon arrival in the emergency room (ER) is correlated with increased hemotransfusion requirement, more hemodynamic instability, more severe anatomical damage, a greater need for hospitalization, and hospitalization in the intensive care unit (ICU). We also analyzed whether trauma coagulopathy is correlated with unfavorable indices, such as acidemia, lactate increase, and base excess (BE) increase. Material and Methods: We conducted a prospective, monocentric, observational study of all patients (n = 503) referred to the Department of Emergency and Acceptance, IRCCS Fondazione Policlinico San Matteo, Pavia, for major trauma from 1 January 2018 to 30 January 2019. Results: Of the 503 patients, 204 had trauma coagulopathy (group 1), whereas 299 patients (group 2) did not. Group 1 had a higher hemotransfusion rate than group 2. In group 1, 15% of patients showed hemodynamic instability compared with only 8% of group 2. The shock index (SI) distribution was worse in group 1 than in group 2. Group 1 was more often hypotensive, tachycardic, and with low oxygen saturation, and had a more severe injury severity score than group 2. In addition, 47% of group 1 had three or more body districts involved compared with 23% of group 2. The hospitalization rate was higher in group 1 than in group 2 (76% vs. 58%). The length of hospitalization was >10 days for 45% of group 1 compared with 28% of group 2. The hospitalization rate in the ICU was higher in group 1 than in group 2 (22% vs. 14.8%). The average duration of ICU hospitalization was longer in group 1 than in group 2 (12.5 vs. 9.78 days). Mortality was higher in group 1 than in group 2 (3.92% vs. 0.98%). Group 1 more often had acidemia and high lactates than group 2. Group 1 also more often had BE <−6. Conclusions: Trauma coagulopathy patients, upon arrival in the ER, have greater hemotransfusion (p = 0.016) requirements and need hospitalization (p = 0.032) more frequently than patients without trauma coagulopathy. Trauma coagulopathy seems to be more present in patients with a higher injury severity score (ISS) (p = 0.000) and a greater number of anatomical districts involved (p = 0.000). Head trauma (p = 0.000) and abdominal trauma (p = 0.057) seem related to the development of trauma coagulopathy. Males seem more exposed than females in developing trauma coagulopathy (p = 0.018). Upon arrival in the ER, the presence of tachycardia or alteration of SI and its derivatives can allow early detection of patients with trauma coagulopathy.

Thromboelastography Reaction-Time Thresholds for Optimal Prediction of Coagulation Factor Deficiency in Trauma

BACKGROUND

Coagulopathy is common in multitrauma patients and repletion of procoagulant factor deficiency with fresh frozen plasma (FFP) improves hemostasis. Optimal kaolin-thromboelastography thresholds for FFP transfusion in trauma patients have not been well established.

STUDY DESIGN

Adult trauma patients with an Injury Severity Score ≥15 were included in this retrospective observational cohort study. The primary end point was area under the receiver operating characteristic curve (AUROC) for reaction time (R-time) to detect procoagulant factor deficiency, as reflected by an elevated international normalized ratio (INR) or aPTT. Test characteristics for the optimal R-time threshold calculated in our study were compared against thresholds recommended by the American College of Surgeons for FFP transfusion.

RESULTS

Six hundred and ninety-four pairs of thromboelastography and conventional coagulation tests were performed in 550 patients, with 144 patients having additional pairs of tests after the first hour. The R-time was able to detect procoagulant factor deficiency (INR ≥1.5 AUROC 0.80; 95% CI, 0.75 to 0.85; aPTT ≥40 seconds AUROC 0.85; 95% 0.80 to 0.89) and severe procoagulant factor deficiency (INR ≥2.0 AUROC 0.82; 95% CI, 0.73 to 0.99; aPTT ≥60 seconds AUROC 0.89; 95% CI, 0.81 to 0.98) with good accuracy. Optimal thresholds to maximize sensitivity and specificity were 3.9 minutes for detection of INR ≥1.5, 4.1 minutes for detection of aPTT ≥40 seconds, 4.3 minutes for detection of INR ≥2.0, and 4.3 for detection of aPTT ≥60 seconds. Currently recommended R-time thresholds for FFP transfusion had 100% specificity for detecting procoagulant factor deficiency, but low sensitivity (3% to 7%).

CONCLUSIONS

R-time can detect procoagulant factor deficiency in multitrauma patients with good accuracy, but currently recommended R-time thresholds are highly specific and not sensitive. Use of low-sensitivity thresholds might result in undertreatment of many patients with procoagulant factor deficiency.

Viscoelastic Signals for Optimal Resuscitation in Trauma: Kaolin Thrombelastography Cutoffs for Diagnosing Hypofibrinogenemia (VISOR Study)

BACKGROUND

Acute traumatic coagulopathy is common in trauma patients. Prompt diagnosis of hypofibrinogenemia allows for early treatment with cryoprecipitate or fibrinogen concentrate. At present, optimal cutoffs for diagnosing hypofibrinogenemia with kaolin thrombelastography (TEG) have not been established. We hypothesized that kaolin kaolin-TEG parameters, such as kinetic time (K-time), α-angle, and maximum amplitude (MA), would accurately diagnose hypofibrinogenemia (fibrinogen <200 mg/dL) and severe hypofibrinogenemia (fibrinogen <100 mg/dL).

METHODS

Adult trauma patients (injury severity score >15) presenting to our trauma center between October 2015 and October 2017 were identified retrospectively. All patients had a traditional plasma fibrinogen measurement and kaolin-TEG performed within 15 minutes of each other and within 1 hour of admission. Some patients had additional measurements after. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether K-time, α-angle, and MA could diagnose hypofibrinogenemia and severe hypofibrinogenemia. Area under the ROC curve (AUROC) was calculated for each TEG parameter with a bootstrapped 99% confidence interval (CI). Further, ROC analysis was used to estimate ideal cutoffs for diagnosing hypofibrinogenemia and severe hypofibrinogenemia by maximizing sensitivity and specificity. In addition, likelihood ratios were also calculated for different TEG variable cutoffs to diagnose hypofibrinogenemia and severe hypofibrinogenemia.

RESULTS

Seven hundred twenty-two pairs of TEGs and traditional plasma fibrinogen measurements were performed in 623 patients with 99 patients having additional pairs of tests after the first hour. MA (AUROC = 0.84) and K-time (AUROC = 0.83) better diagnosed hypofibrinogenemia than α-angle (AUROC = 0.8; P = .03 and P < .001 for AUROC comparisons, respectively). AUROCs statistically improved for each parameter when severe hypofibrinogenemia was modeled as the outcome (P < .001). No differences were found between parameters for diagnosing severe hypofibrinogenemia (P > .05 for all comparisons). The estimated optimal cutoffs for diagnosing hypofibrinogenemia were 1.5 minutes for K-time (95% CI, 1.4-1.6), 70.0° for α-angle (95% CI, 69.8-71.0), and 60.9 mm for MA (95% CI, 59.2-61.8). The estimated optimal cutoffs for diagnosing severe hypofibrinogenemia were 2.4 minutes for K-time (95% CI, 1.7-2.8), 60.6° for α-angle (95% CI, 57.2-67.3), and 51.2 mm for MA (95% CI, 49.0-56.2). Currently recommended K-time and α-angle cutoffs from the American College of Surgeons had low sensitivity for diagnosing hypofibrinogenemia (3%-29%), but sensitivity improved to 74% when using optimal cutoffs.

CONCLUSIONS

Kaolin-TEG parameters can accurately diagnose hypofibrinogenemia and severe hypofibrinogenemia in trauma patients. Currently recommended cutoffs for the treatment of hypofibrinogenemia are skewed toward high specificity and low sensitivity. Many patients are likely to be undertreated for hypofibrinogenemia using current national guidelines.

Decision-making criteria for damage control surgery in Japan

Controversy still remains regarding the optimal criteria for selecting damage control surgery (DCS). Our objective was to propose an indication for implementing DCS for abdominal trauma requiring emergency laparotomy. This was a multicenter, retrospective, observational study that used data from the Japan Trauma Data Bank. Patients who underwent emergency laparotomy were included. We compared the patients regarding the performance of DCS. Of the 4447 patients included in the study, 532 patients were in the DCS group and 3915 patients were in the non-DCS group. Logistic regression analysis revealed that body temperature, level of consciousness (Glasgow Coma Scale), and type of injury (blunt or penetrating) were independent predictors of DCS. Using these predictors, we created the Damage Control Indication Detecting score. The score showed a positive correlation with mortality. The score was obtained as 5 of 9 points in total, revealing mortality of 30.8%, sensitivity of 64.8%, and specificity of 70.0%. The area under the curve for the receiver operating characteristic curve was 0.715. This score can help surgeons determine when to perform DCS. However, more than 95% of trauma cases in Japan involve blunt injuries, suggesting that the results of our study may not be applicable internationally.

Current state of transfusion in traumatic brain injury and associated coagulopathy

Traumatic brain injury (TBI)-induced coagulopathy has long been recognized as a significant risk for poor outcomes in patients with TBI, but its pathogenesis remains poorly understood. As a result, current treatment options for the condition are limited and ineffective. The lack of information is most significant for the impact of blood transfusions on patients with isolated TBI and in the absence of confounding influences from trauma to the body and limbs and the resultant hemorrhagic shock. Here we discuss recent progress in understanding the pathogenesis of TBI-induced coagulopathy and the current state of blood transfusions for patients with TBI and associated coagulopathy.

Blunt Abdominal Trauma in a European Trauma Setting: Need for Complex or Non-Complex Skills in Emergency Laparotomy

BACKGROUND AND AIMS

Blunt abdominal trauma can lead to substantial organ injury and hemorrhage necessitating open abdominal surgery. Currently, the trend in surgeon training is shifting away from general surgery and the surgical treatment of blunt abdominal trauma patients is often done by sub-specialized surgeons. The aim of this study was to identify what emergency procedures are needed after blunt abdominal trauma and whether they can be performed with the skill set of a general surgeon.

MATERIALS AND METHODS

The records of blunt abdominal trauma patients requiring emergency laparotomy (n = 100) over the period 2006-2016 (Helsinki University Hospital Trauma Registry) were reviewed. The organ injuries and the complexity of the procedures were evaluated.

RESULTS

A total of 89 patients (no need for complex skills, NCS) were treated with the skill set of general surgeons while 11 patients required complex skills. Complex skills patients were more severely injured (New Injury Severity Score 56.4 vs 35.9, p < 0.001) and had a lower systolic blood pressure (mean: 89 vs 112, p = 0.044) and higher mean shock index (heart rate/systolic blood pressure: 1.43 vs 0.95, p = 0.012) on admission compared with NCS patients. The top three NCS procedures were splenectomy (n = 33), bowel repair (n = 31), and urinary bladder repair (n = 16). In patients requiring a complex procedure (CS), the bleeding site was the liver (n = 7) or a major blood vessel (n = 4).

CONCLUSION

The majority of patients requiring emergency laparotomy can be managed with the skills of a general surgeon. Non-responder blunt abdominal trauma patients with positive ultrasound are highly likely to require complex skills. The future training of surgeons should concentrate on NCS procedures while at the same time recognizing those injuries requiring complex skills.

Soluble GPVI is elevated in injured patients: shedding is mediated by fibrin activation of GPVI

Soluble glycoprotein VI (sGPVI) is shed from the platelet surface and is a marker of platelet activation in thrombotic conditions. We assessed sGPVI levels together with patient and clinical parameters in acute and chronic inflammatory conditions, including patients with thermal injury and inflammatory bowel disease and patients admitted to the intensive care unit (ICU) for elective cardiac surgery, trauma, acute brain injury, or prolonged ventilation. Plasma sGPVI was measured by enzyme-linked immunosorbent assay and was elevated on day 14 after thermal injury, and was higher in patients who developed sepsis. sGPVI levels were associated with sepsis, and the value for predicting sepsis was increased in combination with platelet count and Abbreviated Burn Severity Index. sGPVI levels positively correlated with levels of D-dimer (a fibrin degradation product) in ICU patients and patients with thermal injury. sGPVI levels in ICU patients at admission were significantly associated with 28- and 90-day mortality independent of platelet count. sGPVI levels in patients with thermal injury were associated with 28-day mortality at days 1, 14, and 21 when adjusting for platelet count. In both cohorts, sGPVI associations with mortality were stronger than D-dimer levels. Mechanistically, release of GPVI was triggered by exposure of platelets to polymerized fibrin, but not by engagement of G protein-coupled receptors by thrombin, adenosine 5'-diphosphate, or thromboxane mimetics. Enhanced fibrin production in these patients may therefore contribute to the observed elevated sGPVI levels. sGPVI is an important platelet-specific marker for platelet activation that predicts sepsis progression and mortality in injured patients.

Thromboelastography-Guided Therapy of Hemorrhagic Complications after Craniopharyngioma Resection: Case-Based Update

PURPOSE

Thromboelastography (TEG) is a point-of-care test that evaluates the entire hemostatic process. The use of TEG is expanding in multiple pediatric surgical disciplines. However, there is very little literature regarding its application in pediatric neurosurgical patients.

METHODS

The authors provide a case-based update and literature review regarding potential applications of TEG to pediatric neurosurgical patients.

RESULTS

The authors describe a 12-year-old female who experienced a number of complications after a craniopharyngioma resection. The patient suffered multiple new intraventricular hemorrhages with removal of external ventricular drains. Standard coagulopathy tests did not reveal any abnormalities. However, an abnormal TEG value suggested primary hyperfibrinolysis, which led to a change in medical management. The patient did not suffer any further bleeding episodes after the change in treatment.

CONCLUSIONS

The authors discuss a case where TEG influenced patient management and identified a problem despite normal values of standard laboratory tests. Neurosurgeons should be aware of the potential benefits for TEG testing in pediatric patients.

Impact of initial temporary abdominal closure in damage control surgery: a retrospective analysis

Background

Damage control surgery has revolutionized trauma surgery. Use of damage control surgery allows for resuscitation and reversal of coagulopathy at the risk of loss of abdominal domain and intra-abdominal complications. Temporary abdominal closure is possible with multiple techniques, the choice of which may affect ability to achieve primary fascial closure and further complication.

Methods

A retrospective analysis of all trauma patients requiring damage control laparotomy upon admission to an ACS-verified level one trauma center from 2011 to 2016 was performed. Demographic and clinical data including ability and time to attain primary fascial closure, as well as complication rates, were recorded. The primary outcome measure was ability to achieve primary fascial closure during initial hospitalization.

Results

Two hundred and thirty-nine patients met criteria for inclusion. Primary skin closure (57.7%), ABThera™ VAC system (ABT) (15.1%), Bogota bag (BB) (25.1%), or a modified Barker's vacuum-packing (BVP) (2.1%) were used in the initial laparotomy. Patients receiving skin-only closure had significantly higher rates of primary fascial closure and lower hospital mortality, but also significantly lower mean lactate, base deficit, and requirement for massive transfusion. Between ABT or BB, use of ABT was associated with increased rates of fascial closure. Multivariate regression revealed primary skin closure to be significantly associated with primary fascial closure while BB was associated with failure to achieve fascial closure.

Conclusions

Primary skin closure is a viable option in the initial management of the open abdomen, although these patients demonstrated less injury burden in our study. Use of vacuum-assisted dressings continues to be the preferred method for temporary abdominal closure in damage control surgery for trauma.

Coagulopathy induced by traumatic brain injury: systemic manifestation of a localized injury

Traumatic brain injury (TBI)-induced coagulopathy is a common and well-recognized risk for poor clinical outcomes, but its pathogenesis remains poorly understood, and treatment options are limited and ineffective. We discuss the recent progress and knowledge gaps in understanding this lethal complication of TBI. We focus on (1) the disruption of the brain-blood barrier to disseminate brain injury systemically by releasing brain-derived molecules into the circulation and (2) TBI-induced hypercoagulable and hyperfibrinolytic states that result in persistent and delayed intracranial hemorrhage and systemic bleeding.

A transfusion prescription template and other human factor interventions to improve balanced transfusion delivery in major haemorrhage due to trauma

OBJECTIVES

The aim of this study is to improve practice in the management of major haemorrhage, particularly in red cell to plasma transfusion ratios.

BACKGROUND

A review of the management of major haemorrhage in trauma in Newcastle Hospitals Trust in 2012-2013 showed good mortality outcomes but found that red cell : plasma transfusion ratios could be improved. Human factors techniques transferable from industry and the military were identified, and a package of interventions was implemented, including an intensive multidisciplinary team training programme and a new major haemorrhage prescription template.

METHODS/MATERIALS

We reviewed the management of all 243 adult trauma patients admitted with major haemorrhage to the Emergency Department in the Newcastle Hospitals Trust in the 4-year period from April 2012. We analysed clinical details, blood components transfused and patient outcomes and used Trauma Audit and Research Network data to correlate with injury severity and predicted survival.

RESULTS

Mean transfusion ratios of red cells to plasma improved from 1·5 : 1 and 1·6 : 1 in the first 2 years to 1·1 : 1 in the 2 years following implementation of the new measures. There was a statistically significant improvement in the delivery of a balanced transfusion, defined as a red cell : plasma ratio of <1·3 : 1 following the changes.

CONCLUSION

Simple changes to procedures, specifically implementation of a new major haemorrhage prescription template and multidisciplinary team training, have resulted in marked improvement in the ratio of red cells to plasma transfused to trauma patients with major haemorrhage or requiring emergency blood. The package of changes could be easily replicated in other health-care settings.

Lactadherin promotes microvesicle clearance to prevent coagulopathy and improves survival of severe TBI mice

Coagulopathy is common in patients with traumatic brain injury (TBI) and predicts poor clinical outcomes. We have shown that brain-derived extracellular microvesicles, including extracellular mitochondria, play a key role in the development of TBI-induced coagulopathy. Here, we further show in mouse models that the apoptotic cell-scavenging factor lactadherin, given at a single dose of 400 μg/kg 30 minutes before (preconditioning) or 30 minutes after cerebral fluid percussion injury, prevented coagulopathy as defined by clotting time, fibrinolysis, intravascular fibrin deposition, and microvascular bleeding of the lungs. Lactadherin also reduced cerebral edema, improved neurological function, and increased survival. It achieved these protective effects by enhancing the clearance of circulating microvesicles through phosphatidylserine-mediated phagocytosis. Together, these results identify the scavenging system for apoptotic cells as a potential therapeutic target to prevent TBI-induced coagulopathy and improve the outcome of TBI.

Development of Novel Criteria of the "Lethal Triad" as an Indicator of Decision Making in Current Trauma Care: A Retrospective Multicenter Observational Study in Japan

OBJECTIVES

To evaluate the utility of the conventional lethal triad in current trauma care practice and to develop novel criteria as indicators of treatment strategy.

DESIGN

Retrospective observational study.

SETTINGS

Fifteen acute critical care medical centers in Japan.

PATIENTS

In total, 796 consecutive trauma patients who were admitted to emergency departments with an injury severity score of greater than or equal to 16 from January 2012 to December 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All data were retrospectively collected, including laboratory data on arrival. Sensitivities to predict trauma death within 28 days of prothrombin time international normalized ratio greater than 1.50, pH less than 7.2, and body temperature less than 35°C were 15.7%, 17.5%, and 15.9%, respectively, and corresponding specificities of these were 96.4%, 96.6%, and 93.6%, respectively. The best predictors associated with hemostatic disorder and acidosis were fibrin/fibrinogen degradation product and base excess (the cutoff values were 88.8 µg/mL and -3.05 mmol/L). The optimal cutoff value of hypothermia was 36.0°C. The impact of the fibrin/fibrinogen degradation product and base excess abnormality on the outcome were approximately three- and two-folds compared with those of hypothermia. Using these variables, if the patient had a hemostatic disorder alone or a combined disorder with acidosis and hypothermia, the sensitivity and specificity were 80.7% and 66.8%.

CONCLUSIONS

Because of the low sensitivity and high specificity, conventional criteria were unsuitable as prognostic indicators. Our revised criteria are assumed to be useful for predicting trauma death and have the potential to be the objective indicators for activating the damage control strategy in early trauma care.

A recommended early goal-directed management guideline for the prevention of hypothermia-related transfusion, morbidity, and mortality in severely injured trauma patients

Hypothermia is present in up to two-thirds of patients with severe injury, although it is often disregarded during the initial resuscitation. Studies have revealed that hypothermia is associated with mortality in a large percentage of trauma cases when the patient's temperature is below 32 °C. Risk factors include the severity of injury, wet clothing, low transport unit temperature, use of anesthesia, and prolonged surgery. Fortunately, associated coagulation disorders have been shown to completely resolve with aggressive warming. Selected passive and active warming techniques can be applied in damage control resuscitation. While treatment guidelines exist for acidosis and bleeding, there is no evidence-based approach to managing hypothermia in trauma patients. We synthesized a goal-directed algorithm for warming the severely injured patient that can be directly incorporated into current Advanced Trauma Life Support guidelines. This involves the early use of warming blankets and removal of wet clothing in the prehospital phase followed by aggressive rewarming on arrival at the hospital if the patient's injuries require damage control therapy. Future research in hypothermia management should concentrate on applying this treatment algorithm and should evaluate its influence on patient outcomes. This treatment strategy may help to reduce blood loss and improve morbidity and mortality in this population of patients.

Tranexamic acid: from trauma to routine perioperative use

PURPOSE OF REVIEW

Optimizing hemostasis with antifibrinolytics is becoming a common surgical practice. Large clinical studies have demonstrated efficacy and safety of tranexamic acid (TXA) in the trauma population to reduce blood loss and transfusions. Its use in patients without pre-existing coagulopathies is debated, as thromboembolic events are a concern. In this review, perioperative administration of TXA is examined in nontrauma surgical populations. Additionally, risk of thromboembolism, dosing regimens, and timing of dosing are assessed.

RECENT FINDINGS

Perioperative use of TXA is associated with reduced blood loss and transfusions. Thromboembolic effects do not appear to be increased. However, optimal dosing and timing of TXA administration is still under investigation for nontrauma surgical populations.

SUMMARY

As part of a perioperative blood management programme, TXA can be used to help reduce blood loss and mitigate exposure to blood transfusion.

Is there a role for antifibrinolytics in pelvic and acetabular fracture surgery?

BACKGROUND

Pelvic and acetabular fractures are rare, complex injuries associated with significant morbidity. Fixation of these injuries requires major orthopaedic surgery which in itself is associated with substantial blood loss owing to the extensile operative approach and prolonged operating time required to address the complex fracture anatomy. In order to reduce morbidity, a multifactor approach to blood conservation must be adopted.

CURRENT ROLE OF ANTIFIBRINOLYTICS IN ORTHOPAEDIC SURGERY

The use of antifibrinolytics to reduce operative blood loss is well documented in many surgical specialties, including orthopaedic surgery. Elective spinal surgery and joint arthroplasty have benefited from the introduction of antifibrinolytics; however, their role in trauma and fracture surgery is not fully defined. Pelvic and acetabular fracture surgery would benefit from further investigation on the benefit and safety of these agents.

CONCLUSION

Routine use cannot be recommended at this time but agents may be considered on a case-specific basis.

Admission fibrinogen levels in severe trauma patients: A comparison of elderly and younger patients

INTRODUCTION

Acute coagulopathy of trauma has been much discussed recently. However, the changes in coagulation markers after trauma in the elderly are unknown. Furthermore, the baseline fibrinogen level is high in elderly patients, and the question remains as to whether fibrinogen levels also decrease early and the degree of decrease in elderly trauma patients. The purpose of this study was to compare coagulation markers including the fibrinogen level on admission in younger and elderly severe trauma patients.

METHODS

A cohort of severe trauma patients (Injury Severity Score (ISS) ≥16), admitted from January 2011 to June 2014, with coagulation markers including the fibrinogen level on admission available, was reviewed retrospectively. The patients were divided into a younger (16-64 years old) and an older (≥65 years old) group based upon their age at presentation. Activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen, and D-dimer were compared between the younger and older groups.

RESULTS

There were 251 patients who met the inclusion criteria for this analysis. The younger group included 117 patients and the older group included 134 patients. The median aPTT (26.3 vs 27.5s, P=0.001) and median D-dimer levels (18.8 vs 40.2 μg/dL, P=0.006) were significantly higher in the older group. However, the fibrinogen level (205 vs 248 mg/dL, P<0.001) was significantly higher in the older group. The regression lines of fibrinogen and age in non-massive transfusion and massive transfusion cases are given by Y=1.03 X+185 (r=0.24, r(2)=0.06, P<0.001) and Y=0.86 X+134 (r=0.25, r(2)=0.06, P=0.09) respectively, and the fibrinogen levels tended to increase with older age in severe trauma patients.

CONCLUSIONS

The fibrinogen level did not show a low value as it can in younger patients in elderly patients. Therefore, the fibrinogen level is difficult to use as an early indicator of acute blood loss with haemorrhage in elderly severe trauma patients, as it can be used in younger patients. Thus, it is necessary to keep in mind that the fibrinogen level increases by approximately 1mg/dL when the age increases by 1 year and to carefully observe the fibrinogen level even if the admission level is not low.

Emergency General Surgery: Defining Burden of Disease in the State of Maryland

Acute care surgery services continue expanding to provide emergency general surgery (EGS) care. The aim of this study is to define the characteristics of the EGS population in Maryland. Retrospective review of the Health Services Cost Review Commission database from 2009 to 2013 was performed. American Association for the Surgery of Trauma-defined EGS ICD-9 codes were used to define the EGS population. Data collected included patient demographics, admission origin [emergency department (ED) versus non-ED], length of stay (LOS), mortality, and disposition. There were 3,157,646 encounters. In all, 817,942 (26%) were EGS encounters, with 76 per cent admitted via an ED. The median age of ED patients that died was 74 years versus 61 years for those that lived ( P < 0.001). Twenty one per cent of ED admitted patients had a LOS > 7 days. Of 78,065 non-ED admitted patients, the median age of those that died was 68 years versus 59 years for those that lived ( P < 0.001). Twenty eight per cent of non-ED admits had LOS > 7 days. In both ED and non-ED patients, there was a bimodal distribution of death, with most patients dying at LOS ≤ 2 or LOS > 7 days. In this study, EGS diagnoses are present in 26 per cent of inpatient encounters in Maryland. The EGS population is elderly with prolonged LOS and a bimodal distribution of death.

The traditional vs "1:1:1" approach debate on massive transfusion in trauma should not be treated as a dichotomy

Traditional transfusion guidelines suggest that fresh frozen plasma (FFP) should be given based on laboratory or clinical evidence of coagulopathy or acute loss of 1 blood volume. This approach tends to result in a significant lag time between the first units of erythrocytes and FFP in trauma requiring massive transfusion. In severe trauma, observational studies have found an association between increased survival and aggressive use of FFP and platelets such that FFP:platelet:erythrocyte ratio approaches 1:1:1 to 2 from the first units of erythrocytes given. There are considerable concerns over either approach, and no randomized controlled trials have been published comparing the 2 approaches. Nowadays, trauma clinicans are incorporating the strenghts of both approaches and are no longer treating them as a dichotomy. Specifically, "1:1:1" proponents have devised 1:1:1 activation criteria to minimize unnecessary FFP and platelet transfusion and are prepared to deactivate the protocol as soon as patient is stabilized. Similarly, 1:1:1 skeptics are more mindful of the need to be proactive about trauma coagulopathy and the inherent delays in FFP administration in trauma patients.

Evolving beyond the vicious triad: Differential mediation of traumatic coagulopathy by injury, shock, and resuscitation

BACKGROUND

A subset of trauma patients with critical injury present with coagulopathy, portending markedly worse outcomes. Clinical practice is evolving to treat the classical risk factors of hypothermia, hemodilution, and acidosis; however, coagulopathy persists even in the absence of these factors. We sought to determine the relative importance of injury- and shock-specific factors compared with resuscitation-associated factors in coagulopathy after trauma.

METHODS

Comprehensive demographic data, laboratory data, and outcomes data were prospectively collected from seven trauma centers over 8 years (November 2003 to August 2011) as part of the Inflammation and the Host Response to Injury Large-Scale Collaborative Program. A total of 1,537 critically injured patients with blunt trauma and hemorrhagic shock were analyzed to evaluate predictors of admission coagulopathy (international normalized ratio [INR] ≥ 1.3), multiorgan failure, and mortality.

RESULTS

Of 1,537 patients, 578 (37.6%) had admission INR of 1.3 or greater. Coagulopathic patients had more severe injury, more severe base deficit and lactate levels, as well as lower admission temperature, lower pH, and higher prehospital crystalloid volume (all p < 0.001). Coagulopathic patients required more blood products and mechanical ventilation and had higher rates of nosocomial infection, multiorgan failure, and mortality (all p < 0.02). Injury severity, temperature, and acidosis (all p < 0.02) independently predicted coagulopathy in multivariate analysis, with a significant interaction between lactate and prehospital crystalloid. In Cox regression models, however, coagulopathy itself remained an independent predictor of both multiorgan failure and mortality (p < 0.02) even when adjusted for injury severity, shock, and elements of the vicious triad.

CONCLUSION

Most patients with coagulopathy after trauma have mixed risk factors; however, coagulopathy has deleterious effects independent of injury severity, shock, and the vicious triad. Better understanding of the biochemical mechanisms of acute traumatic coagulopathy may facilitate biochemically targeted resuscitation strategies and improve outcomes.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level II.

Massive transfusion prediction with inclusion of the pre-hospital Shock Index

BACKGROUND

Detecting occult bleeding can be challenging and may delay resuscitation. The Shock Index (SI) defined as heart rate divided by systolic blood pressure has attracted attention. Prediction models using combinations of pre-hospital SI (phSI) and the trauma centre SI (tcSI) values may be effective in identifying patients requiring massive blood transfusions (MT).

AIM

To explore whether combinations of the phSI and the tcSI augment MT prediction.

METHODS

The scores were retrospectively developed using all major trauma patients that presented to The Alfred Hospital between 2006 and 2012. The first PH and TC observations were used. To avoid exclusion of the 'sickest' patients, the SI was imputed to 2 where SBP was missing, but HR was present. We developed 4 models. (i) 'Dichotomised', defined as positive when both phSI and tcSI were ≥1. (ii) 'Formulaic', defined by logistic regression analysis. (iii) 'Combination', defined pragmatically based on the logistic regression. (iv) 'Trending', defined as: tcSI minus phSI.

RESULTS

There were 6990 major trauma patients and 360 (5.2%) received MT. There were 1371 cases with either phSI or tcSI missing and were thus excluded from the analysis. The 'Dichotomised' had higher positive predictive value than the tcSI with a further 5 per 100 patients identified. The 'Formulaic' model, defined as: log Odds (MT)=2.16×tcSI+0.89×phSI-5.42, and the 'Combination' model, defined as: phSI×0.5+tcSI, performed equally (AUROC 0.83 versus 0.83, χ(2)=0.86, p=0.35). The 'Formulaic' performed marginally, but statistically significantly, more accurate than the tcSI alone (AUROC 0.83 versus 0.82, χ(2)=6.89, p<0.01). An 'Upward Trending' SI was observed in 1758 patients, revealing a 4.6-fold univariate association with MT (OR 4.55; 95%CI 2.64-7.83), and an AUROC of 0.79 (95%CI 0.74-0.83). The 'Downward Trending' SI was protective against MT (OR 0.44; 95%CI 0.34-0.57).

CONCLUSION

The initial pre-hospital SI is associated with MT. However, this relationship did not clinically augment MT decision when combined with the in-hospital SI. The simplicity of the SI makes it a favourable option to explore further. Computer-assisted technology in data capturing, analysis and prognostication presents avenues for further research.

Optimal fluid resuscitation in trauma: type, timing, and total

PURPOSE OF REVIEW

This review article explores the recent literature regarding the optimal type and amount of intravenous fluids for the trauma patient from the time of injury through their ICU stay. It discusses damage control principles as well as targeted resuscitation utilizing new technology.

RECENT FINDINGS

In the prehospital arena, intravenous fluids have been associated with worse patient outcomes due to increased coagulopathy and time to definitive care. Once in the trauma bay, damage control resuscitation principles apply to the severely injured patient. Large volume crystalloid infusion increases mortality. The best patient outcomes have been found with transfusion of blood products in a ratio that closely mimics whole blood. Thrombelastography is a useful adjunct in resuscitation and can help guide the judicious use of blood products. New technology can help providers ascertain when a patient is appropriately resuscitated by determining adequate global and regional perfusion.

SUMMARY

During the resuscitation of the acutely injured patient, crystalloids should be limited in favor of blood components. Damage control principles apply until definitive hemostasis is obtained, at which point the focus should change to targeted resuscitation using traditional global endpoints of resuscitation in conjunction with determinants of regional perfusion.

Brain-derived microparticles induce systemic coagulation in a murine model of traumatic brain injury

Traumatic brain injury (TBI) is associated with coagulopathy, although it often lacks 2 key risk factors: severe bleeding and significant fluid resuscitation associated with hemorrhagic shock. The pathogenesis of TBI-associated coagulopathy remains poorly understood. We tested the hypothesis that brain-derived microparticles (BDMPs) released from an injured brain induce a hypercoagulable state that rapidly turns into consumptive coagulopathy. Here, we report that mice subjected to fluid percussion injury (1.9 ± 0.1 atm) developed a BDMP-dependent hypercoagulable state, with peak levels of plasma glial cell and neuronal BDMPs reaching 17 496 ± 4833/μL and 18 388 ± 3657/μL 3 hours after TBI, respectively. Uninjured mice injected with BDMPs developed a dose-dependent hyper-turned hypocoagulable state measured by a progressively prolonged clotting time, fibrinogen depletion, and microvascular fibrin deposition in multiple organs. The BDMPs were 50 to 300 nm with intact membranes, expressing neuronal or glial cell markers and procoagulant phosphatidylserine and tissue factor. Their procoagulant activity was greater than platelet microparticles and was dose-dependently blocked by lactadherin. Microparticles were produced from injured hippocampal cells, transmigrated through the disrupted endothelial barrier in a platelet-dependent manner, and activated platelets. These data define a novel mechanism of TBI-associated coagulopathy in mice, identify early predictive markers, and provide alternative therapeutic targets.

"After-hours" staffing of trauma centres and outcomes among patients presenting with acute traumatic coagulopathy

OBJECTIVE

To examine the effect of the "after-hours" (18:00-07:00) model of trauma care on a high-risk subgroup - patients presenting with acute traumatic coagulopathy (ATC).

DESIGN, PARTICIPANTS AND SETTING

Retrospective analysis of data from the Alfred Trauma Registry for patients with ATC presenting between 1 January 2006 and 31 December 2011.

MAIN OUTCOME MEASURE

Mortality at hospital discharge, adjusted for potential confounders, describing the association between after-hours presentation and mortality.

RESULTS

There were 398 patients with ATC identified during the study period, of whom 197 (49.5%) presented after hours. Mortality among patients presenting after hours was 43.1%, significantly higher than among those presenting in hours (33.1%; P = 0.04). Following adjustment for possible confounding variables of age, presenting Glasgow Coma Scale score, urgent surgery or angiography and initial base deficit, after-hours presentation was significantly associated with higher mortality at hospital discharge (adjusted odds ratio, 1.77; 95% CI, 1.10-2.87).

CONCLUSION

The after-hours model of care was associated with worse outcomes among some of the most critically ill trauma patients. Standardising patient reception at major trauma centres to ensure a consistent level of care across all hours of the day may improve outcomes among patients who have had a severe injury.

The quest for a universal definition of polytrauma: a trauma registry-based validation study

BACKGROUND

A pilot validation recommended defining polytrauma as patients with an Abbreviated Injury Scale (AIS) score greater than 2 in at least two Injury Severity Score (ISS) body regions (2 × AIS score > 2). This study aimed to validate this definition on larger data set. We hypothesized that patients defined by the 2 × AIS score > 2 cutoff have worse outcomes and use more resources than those without 2 × AIS score > 2 and that this would therefore be a better definition of polytrauma.

METHODS

Patients injured between 2009 and 2011, with complete documentation of AIS by New South Wales Trauma Registry and 16 years and older were selected. Age and sex were obtained in addition to outcomes of ISS, hospital length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, and mortality. We compared demographic characteristics and outcomes between patients with ISS greater than 15 who did and did not meet the 2 × AIS score > 2 definition. We then undertook regression analyses (logistic regression for binary outcomes [ICU admission and death] and linear regression for hospital and ICU LOS) to compare outcomes for patients with and without 2 × AIS score > 2, adjusting for sex and age categories.

RESULTS

In the adjusted analyses, patients with 2 × AIS score > 2 had twice the odds of being admitted to the ICU compared with those without 2 × AIS score > 2 (odds ratio, 2.5; 95% confidence interval [CI], 2.2-2.8) and 1.7 times the odds of dying (95% CI, 1.4-2.0; p < 0.001 for both models). Patients with 2 × AIS score > 2 also had a mean difference of 1.5 days longer stay in the hospital compared with those without 2 × AIS score > 2 (95% CI, 1.4-1.7) and 1.6 days longer ICU stay (95% CI, 1.4-1.8; p < 0.001 for all models).

CONCLUSION

Patients with 2 × AIS score > 2 had higher mortality, more frequent ICU admissions, and longer hospital and ICU stay than those without 2 × AIS score > 2 and represents a superior definition to the definitions for polytrauma currently in use.

LEVEL OF EVIDENCE

Diagnostic test/ criteria, level III.

Tranexamic acid for trauma: filling the 'GAP' in evidence

Following findings of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial, tranexamic acid (TxA) use post trauma is becoming widespread. However, issues of generalisability, applicability and predictability beyond the context of study sites remain unresolved. Internal and external validity of the CRASH-2 trial are currently lacking and therefore incorporation of TxA into routine trauma resuscitation guidelines appears premature. The Pre-hospital Antifibrinolytics for Traumatic Coagulopathy and Haemorrhage (PATCH)-Trauma study is a National Health and Medical Research Council-funded randomised controlled trial of early administration of TxA in severely injured patients likely to have acute traumatic coagulopathy. The study population chosen has high mortality and morbidity and is potentially most likely to benefit from TxA's known mechanisms of action. This and further trials involving appropriate sample populations are required before evidence based guidelines on TxA use during trauma resuscitation can be developed.

Resuscitative goals and new strategies in severe trauma patient resuscitation

Traumatic injuries represent a major health problem all over the world. In recent years we have witnessed profound changes in the paradigm of severe trauma patient resuscitation, new concepts regarding acute coagulopathy in trauma have been proposed, and there has been an expansion of specific commercial products related to hemostasis, among other aspects. New strategies in severe trauma management include the early identification of those injuries that are life threatening and require surgical hemostasis, tolerance of moderate hypotension, rational intravascular volume replacement, prevention of hypothermia, correction of acidosis, optimization of oxygen carriers, and identification of those factors required by the patient (fresh frozen plasma, platelets, tranexamic acid, fibrinogen, cryoprecipitates and prothrombin complex). However, despite such advances, further evidence is required to improve survival rates in severe trauma patients.