Resuscitation speed affects brain injury in a large animal model of traumatic brain injury and shock

Background: Optimal fluid resuscitation strategy following combined traumatic brain injury (TBI) and hemorrhagic shock (HS) remain controversial and the effect of resuscitation infusion speed on outcome is not well known. We have previously reported that bolus infusion of fresh frozen plasma (FFP) protects the brain compared with bolus infusion of 0.9% normal saline (NS). We now hypothesize reducing resuscitation infusion speed through a stepwise infusion speed increment protocol using either FFP or NS would provide neuroprotection compared with a high speed resuscitation protocol. Methods: 23 Yorkshire swine underwent a protocol of computer controlled TBI and 40% hemorrhage. Animals were left in shock (mean arterial pressure of 35 mmHg) for two hours prior to resuscitation with bolus FFP (n = 5, 50 ml/min) or stepwise infusion speed increment FFP (n = 6), bolus NS (n = 5, 165 ml/min) or stepwise infusion speed increment NS (n = 7). Hemodynamic variables over a 6-hour observation phase were recorded. Following euthanasia, brains were harvested and lesion size as well as brain swelling was measured. Results: Bolus FFP resuscitation resulted in greater brain swelling (22.36 ± 1.03% vs. 15.58 ± 2.52%, p = 0.04), but similar lesion size compared with stepwise resuscitation. This was associated with a lower cardiac output (CO: 4.81 ± 1.50 l/min vs. 5.45 ± 1.14 l/min, p = 0.03). In the NS groups, bolus infusion resulted in both increased brain swelling (37.24 ± 1.63% vs. 26.74 ± 1.33%, p = 0.05) as well as lesion size (3285.44 ± 130.81 mm3 vs. 2509.41 ± 297.44 mm3, p = 0.04). This was also associated with decreased cardiac output (NS: 4.37 ± 0.12 l/min vs. 6.35 ± 0.10 l/min, p < 0.01). Conclusions: In this clinically relevant model of combined TBI and HS, stepwise resuscitation protected the brain compared with bolus resuscitation

Thrombelastography and tromboelastometry in assessing coagulopathy in trauma

Death due to trauma is the leading cause of lost life years worldwide, with haemorrhage being responsible for 30-40% of trauma mortality and accounting for almost 50% of the deaths the initial 24 h. On admission, 25-35% of trauma patients present with coagulopathy, which is associated with a several-fold increase in morbidity and mortality. The recent introduction of haemostatic control resuscitation along with emerging understanding of acute post-traumatic coagulability, are important means to improve therapy and outcome in exsanguinating trauma patients. This change in therapy has emphasized the urgent need for adequate haemostatic assays to monitor traumatic coagulopathy and guide therapy. Based on the cell-based model of haemostasis, there is emerging consensus that plasma-based routine coagulation tests (RCoT), like prothrombin time (PT) and activated partial thromboplastin time (APTT), are inappropriate for monitoring coagulopathy and guide therapy in trauma. The necessity to analyze whole blood to accurately identify relevant coagulopathies, has led to a revival of the interest in viscoelastic haemostatic assays (VHA) such as Thromboelastography (TEG®) and Rotation Thromboelastometry (ROTEM®). Clinical studies including about 5000 surgical and/or trauma patients have reported on the benefit of using the VHA as compared to plasma-based assays, to identify coagulopathy and guide therapy

The volume-expanding effects of autologous liquid stored plasma following hemorrhage.

Background: Plasma use has increased since studies have suggested that early treatment with blood components in trauma with severe hemorrhage may improve outcome. Plasma is also commonly used to correct coagulation disturbances in non-bleeding patients. Little is known about the effects of plasma transfusion on plasma volume. We report a prospective interventional study in which the plasma volume-expanding effect of autologous plasma was investigated after a controlled hemorrhage. Methods: Plasma obtained by plasmapheresis from nine healthy regular blood donors was stored at 2-6°C. Five weeks after donation the subjects were bled of 600 ml and then transfused with 600 ml of autologous plasma. Plasma volume was estimated using (125)I-albumin before and after bleeding, and immediately after plasma transfusion. Plasma volume changes were then estimated by measuring changes in hematocrit during the following 3-h period. Results: Estimated plasma volume after bleeding was 3170 ± 320 ml and 3690 ± 380 ml (mean ± standard deviation) immediately following the transfusion of plasma (p 0.05). This increase in plasma volume corresponds to 86 ± 13% of the infused volume. Three hours after transfusion, plasma volume was still 3680 ± 410 ml. Conclusions: Stored liquid plasma has a plasma volume expanding effect up to 86% of its infused volume with a duration of at least 3 h

Effect of acute hypobaric hypoxia on the endothelial glycocalyx and digital reactive hyperemia in humans

Introduction: Hypoxia is associated with increased capillary permeability. This study tested whether acute hypobaric hypoxia involves degradation of the endothelial glycocalyx. Methods: We exposed 12 subjects to acute hypobaric hypoxia (equivalent to 4,500 m for 2-4 hours) and measured venous blood concentrations of biomarkers reflecting endothelial and glycocalyx degradation (catecholamines, syndecan-1, soluble CD40 ligand, protein C, soluble thrombomodulin, tissue-type plasminogen activators, histone-complexed DNA fragments and nitrite/nitrate). Endothelial function was assessed by the hyperemic response to brachial artery occlusion by peripheral arterial tonometry. Results: Compared with normoxic baseline levels, hypoxia increased concentrations of syndecan-1 from 22 (95% confidence interval: 17-27) to 25 (19-30) ng/ml (p < 0.02) and protein C from 76 (70-83) % to 81 (74-88) % (p < 0.02). Nitrite/nitrate decreased from 23 (18-27) μM at baseline to 19 (14-24) μM and 18 (14-21) μM in hypoxia and recovery, respectively (p < 0.05). Other biomarkers remained unchanged. The post-occlusion/pre-occlusion ratio (reactive hyperemia index, RHI) decreased from 1.80 (1.52–2.07) in normoxia to 1.62 (1.28–1.96) after 2 to 4 hours of hypobaric hypoxia and thereafter increased to 2.43 (1.99-2.86) during normoxic recovery (p < 0.01). Conclusions: The increase in syndecan-1 and protein C suggests that acute hypobaric hypoxia produces minor degree of glycocalyx degradation and overall cellular damage. After hypoxia RHI rebounded to higher than baseline levels suggesting improved endothelial functionality

Successful pulmonary administration of activated recombinant factor VII in diffuse alveolar hemorrhage

INTRODUCTION: Diffuse alveolar hemorrhage (DAH) is a serious pulmonary complication seen in patients with autoimmune disorders and patients treated with chemotherapy or after hematopoietic stem cell transplantation. The clinical management of DAH is complex and the condition has a high mortality rate. Tissue factor is expressed in the lung alveoli during inflammation and therefore pulmonary administration of human recombinant activated factor VIIa (rFVIIa) could be a rational treatment option. METHODS: Six patients with acute, bronchoscopically confirmed DAH from a single intensive care unit university hospital center were included in the study of acute DAH in critically ill patients. The patients were treated with intrapulmonary administration of 50 μg/kg rFVIIa in 50 ml of sodium chloride by bronchoalveolar lavage (BAL) with 25 ml in each of the main bronchi, which was repeated after 24 hours in case of treatment failure. RESULTS: An excellent response, defined as complete and sustained hemostasis after a single dose of rFVIIa, was seen in three patients. A good response, meaning that sustained hemostasis was achieved by a repeated rFVIIa administration, was seen in the remaining three patients. In one of these patients, the BAL treatment was repeated twice; in another patient, the second dose of rFVIIa was administered by nebulizer after extubation after the initial BAL. The hemostatic effect was statistically significant (p = 0.031). The oxygenation capacity, as reflected by the PaO(2)/FiO(2 )(arterial oxygen pressure/inspiratory fractional oxygen content) ratio, increased significantly (p = 0.024) in all six patients following the local rFVIIa therapy. CONCLUSION: Symptomatic therapy of DAH after intrapulmonary administration of one or more doses of rFVIIa was found to have a good to excellent hemostatic effect in six consecutive patients with DAH. The intrapulmonary administration of rFVIIa seemed to have a high benefit-to-risk ratio. Larger series should confirm the safety of this approach

Reduced clot strength upon admission, evaluated by thrombelastography (TEG), in trauma patients is independently associated with increased 30-day mortality

<p>Abstract</p> <p>Introduction</p> <p>Exsanguination due to uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. About one third of trauma patients present with coagulopathy on admission, which is associated with increased mortality and will aggravate bleeding in a traumatized patient. Thrombelastographic (TEG) clot strength has previously been shown to predict outcome in critically ill patients. The aim of the present study was to investigate this relation in the trauma setting.</p> <p>Methods</p> <p>A retrospective study of trauma patients with an injury severity qualifying them for inclusion in the European Trauma Audit and Research Network (TARN) and a TEG analysis performed upon arrival at the trauma centre.</p> <p>Results</p> <p>Eighty-nine patients were included. The mean Injury Severity Score (ISS) was 21 with a 30-day mortality of 17%. Patients with a reduced clot strength (maximal amplitude < 50 mm) evaluated by TEG, presented with a higher ISS 27 (95% CI, 20-34) vs. 19 (95% CI, 17-22), p = 0.006 than the rest of the cohort. Clot strength correlated with the amount of packed red blood cells (p = 0.01), fresh frozen plasma (p = 0.04) and platelet concentrates (p = 0.03) transfused during the first 24 hours of admission. Patients with low clot strength demonstrated increased 30-day mortality (47% vs. 10%, p < 0.001). By logistic regression analysis reduced clot strength was an independent predictor of increased mortality after adjusting for age and ISS.</p> <p>Conclusion</p> <p>Low clot strength upon admission is independently associated with increased 30-day mortality in trauma patients and it could be speculated that targeted interventions based on the result of the TEG analysis may improve patient outcome. Prospective randomized trials investigating this potential are highly warranted.</p

Thrombelastography and biomarker profiles in acute coagulopathy of trauma: a prospective study

<p>Abstract</p> <p>Background</p> <p>Severe injury induces an acute coagulopathy associated with increased mortality. This study compared the Thrombelastography (TEG) and biomarker profiles upon admission in trauma patients.</p> <p>Methods</p> <p>Prospective observational study of 80 trauma patients admitted to a Level I Trauma Centre. Data on demography, biochemistry including standard coagulation tests, hematology, transfusions, Injury Severity Score (ISS) and TEG were recorded. Retrospective analysis of thawed plasma/serum for biomarkers reflecting tissue injury (histone-complexed DNA fragments), sympathoadrenal activation (adrenaline, noradrenaline), coagulation activation/inhibition and fibrinolysis (sCD40L, protein C, activated Protein C, tissue-type plasminogen activator, plasminogen activator inhibitor-1, D-dimer, prothrombinfragment 1+2, plasmin/α₂-antiplasmin complex, thrombin/antithrombin complex, tissue factor pathway inhibitor, antithrombin, von willebrand factor, factor XIII). Comparison of patients stratified according to ISS/TEG maximum clot strength. Linear regression analysis of variables associated with clot strength.</p> <p>Results</p> <p>Trauma patients had normal (86%), hypercoagulable (11%) or hypocoagulable (1%) TEG clot strength; one had primary hyperfibrinolysis. Hypercoagulable patients had higher age, fibrinogen and platelet count (all p < 0.05), none had increased activated partial thromboplastin time (APTT) or international normalized ratio (INR) and none required massive transfusion (> 10 red blood cells the initial 24 h). Patients with normal or hypercoagulable TEG clot strength had comparable biomarker profiles, but the few patients with hypocoagulable TEG clot strength and/or hyperfibrinolysis had very different biomarker profiles.</p> <p>Increasing ISS was associated with higher levels of catecholamines, histone-complexed DNA fragments, sCD40L, activated protein C and D-dimer and reduced levels of non-activated protein C, antithrombin, fibrinogen and factor XIII (all p < 0.05). Fibrinogen and platelet count were associated independently with clot strength in patients with ISS ≤ 26 whereas only fibrinogen was associated independently with clot strength in patients with ISS > 26. In patients with ISS > 26, adrenaline and sCD40L were independently negatively associated with clot strength.</p> <p>Conclusions</p> <p>Trauma patients displayed different coagulopathies by TEG and variables independently associated with clot strength changed with ISS. In the highest ISS group, adrenaline and sCD40L were independently negatively associated with clot strength indicating that these may contribute to acute coagulopathy.</p

Blood product ratio in acute traumatic coagulopathy - effect on mortality in a Scandinavian level 1 trauma centre

BACKGROUND: Trauma is the leading cause of loss of life expectancy worldwide. In the most seriously injured patients, coagulopathy is often present on admission. Therefore, transfusion strategies to increase the ratio of plasma (FFP) and platelets (PLT) to red blood cells (RBC), simulating whole blood, have been introduced. Several studies report that higher ratios improve survival in massively bleeding patients. Here, the aim was to investigate the potential effect of increased FFP and PLT to RBC on mortality in trauma patients. METHODS: In a retrospective before and after study, all trauma patients primarily admitted to a level-one Trauma Centre, receiving blood transfusion, in 2001-3 (n = 97) and 2005-7 (n = 156), were included. In 2001-3, FFP and PLT were administered in accordance with the American Society of Anesthesiologists (ASA) guidelines whereas in 2005-7, Hemostatic Control Resuscitation (HCR) entailing pre-emptive use of FFP and PLT in transfusion packages during uncontrolled haemorrhage and thereafter guided by thrombelastograph (TEG) analysis was employed. The effect of transfusion therapy and coagulopathy on mortality was investigated. RESULTS: Patients included in the early and late period had comparable demography, injury severity score (ISS), admission hematology and coagulopathy (27% vs. 34% had APTT above normal). There was a significant change in blood transfusion practice with shorter time interval from admission to first transfusion (median time 3 min vs.28 min in massive bleeders, p < 0.001), transfusion of higher ratios of FFP:RBC, PLT:RBC and PLT:FFP in the HCR group but 30-day mortality remained comparable in the two periods. In the 2005-7 period, higher age, ISS and Activated Partial Thromboplastin Time (APTT) above normal were independent predictors of mortality whereas no association was fund between blood product ratios and mortality. CONCLUSION: Aggressive administration of FFP and PLT did not influence mortality in the present trauma population

Evaluation of the TEG(® )platelet mapping™ assay in blood donors

BACKGROUND: Monitoring of antiplatelet therapy in patients at cardiovascular risk is difficult because existing platelet function tests are too sophisticated for clinical routine. The whole blood TEG(® )Platelet Mapping™ assay measures clot strength as maximal amplitude (MA) and enables for quantification of platelet function, including the contribution of the adenosine diphosphate (ADP) and thromboxane A2 (TxA2) receptors to clot formation. METHODS: In 43 healthy blood donors, the analytical (CV(a)) and inter-individual variability (CV(g)) of the TEG(® )Platelet Mapping™ assay were determined together with platelet receptor inhibition in response to arachidonic acid (AA) and ADP. RESULTS: The CV(a )of the assay for maximal platelet contribution to clot strength (MA(Thrombin)) was 3.5%, for the fibrin contribution to clot strength (MA(Fibrin)) 5.2%, for MA(AA )4.5% and for MA(ADP )it was 6.6%. The MA(Thrombin )CV(g )was 2.8%, MA(Fibrin )4.7%, MA(AA )6.6% and for MA(ADP )it was 26.2%. Females had a higher MA(Thrombin )compared to males (62.8 vs. 58.4 mm, p = 0.005). The platelet TxA2 receptor inhibition was 1.2% (range 0–10%) and lower than for the ADP receptor (18.6% (0–58%); p < 0.0001). CONCLUSION: The high variability in ADP receptor inhibition may explain both the differences in response to ADP receptor inhibitor therapy and why major bleeding sometimes develops during surgery in patients not treated with ADP receptor inhibitors. An analytical variation of ~5 % for the TEG(® )enables, however, for routine monitoring of the variability in ADP receptor inhibition and of antiplatelet therapy