Impact of fibrinogen levels on outcomes after acute injury in patients requiring a massive transfusion

Early hypocoagulable state in traumatic brain injury patients: incidence, predisposing factors, and outcomes in a retrospective cohort study

Coagulopathy development in traumatic brain injury (TBI) is among the significant complications that can negatively affect the clinical course and outcome of TBI patients. Timely identification of this complication is of utmost importance in the acute clinical setting. We reviewed TBI patients admitted to our trauma center from 2015 to 2021. Demographic data, mechanism of injury, findings on admission, imaging studies, procedures during hospitalization, and functional outcomes were gathered. INR with a cutoff of 1.3, platelet count less than 100 × 10⁹/L, or partial thromboplastin time greater than 40s were utilized as the markers of coagulopathy. A total of 4002 patients were included. Coagulopathy occurred in 38.1% of the patients. Age of the patients (Odds Ratio (OR) = 0.993, 95% Confidence Interval (CI) = 0.986-0.999, p = 0.028), systolic blood pressure (OR = 0.993, 95% CI = 0.989-0.998, p = 0.005), fibrinogen level (OR = 0.998, 95% CI = 0.996-0.999, p < 0.001), and hemoglobin level (OR = 0.886, 95% CI = 0.839-0.936, p < 0.001) were independently associated with coagulopathy. Furthermore, coagulopathy was independently associated with higher mortality rates and longer ICU stays. Coagulopathy had the most substantial effect on mortality of TBI patients (OR = 2.6, 95% CI = 2.1-3.3, p < 0.001), compared to other admission clinical characteristics independently associated with mortality such as fixed pupillary light reflex (OR = 1.8, 95% CI = 1.5-2.4, p < 0.001), GCS (OR = 0.91, 95% CI = 0.88-0.94, p < 0.001), and hemoglobin level (OR = 0.93, 95% CI = 0.88-0.98, p = 0.004). Early coagulopathy in TBI patients can lead to higher mortality rates. Future studies are needed to prove that early detection and correction of coagulopathy and modifiable risk factors may help improve outcomes of TBI patients.

Empiric Cryoprecipitate Transfusion in Patients with Severe Hemorrhage: Results from the US Experience in the International CRYOSTAT-2 Trial

BACKGROUND

Hypofibrinogenemia has been shown to predict massive transfusion and is associated with higher mortality in severely injured patients. However, the role of empiric fibrinogen replacement in bleeding trauma patients remains controversial. We sought to determine the effect of empiric cryoprecipitate as an adjunct to a balanced transfusion strategy (1:1:1).

STUDY DESIGN

This study is a subanalysis of patients treated at the single US trauma center in a multicenter randomized controlled trial. Trauma patients (more than 15 years) were eligible if they had evidence of active hemorrhage requiring emergent surgery or interventional radiology, massive transfusion protocol (MTP) activation, and received at least 1 unit of blood. Transfer patients, those with injuries incompatible with life, or those injured more than 3 hours earlier were excluded. Patients were randomized to standard MTP (STANDARD) or MTP plus 3 pools of cryoprecipitate (CRYO). Primary outcomes included all-cause mortality at 28 days. Secondary outcomes were transfusion requirements, intraoperative and postoperative coagulation laboratory values, and quality-of-life measures (Glasgow outcome score-extended).

RESULTS

Forty-nine patients (23 in the CRYO group and 26 in the STANDARD group) were enrolled between May 2021 and October 2021. Time to randomization was similar between groups (14 vs 24 minutes, p = 0.676). Median time to cryoprecipitate was 41 minutes (interquartile range 37 to 48). There were no differences in demographics, arrival physiology, laboratory values, or injury severity. Intraoperative and ICU thrombelastography values, including functional fibrinogen, were similar between groups. There was no benefit to CRYO with respect to post-emergency department transfusions (intraoperative and ICU through 24 hours), complications, Glasgow outcome score, or mortality.

CONCLUSIONS

In this study of severely injured, bleeding trauma patients, empiric cryoprecipitate did not improve survival or reduce transfusion requirements. Cryoprecipitate should continue as an "on-demand" addition to a balanced transfusion strategy, guided by laboratory values and should not be given empirically.

Optimal dose of cryoprecipitate in massive transfusion following trauma

BACKGROUND

While cryoprecipitate (Cryo) is commonly included in massive transfusion protocols for hemorrhagic shock, the optimal dose of Cryo transfusion remains unknown. We evaluated the optimal red blood cell (RBC) to RBC to Cryo ratio during resuscitation in massively transfused trauma patients.

METHODS

Adult patients in the American College of Surgeon Trauma Quality Improvement Program (2013-2019) receiving massive transfusion (≥4 U of RBCs, ≥1 U of fresh frozen plasma, and ≥1 U of platelets within 4 hours) were included. A unit of Cryo was defined as a pooled unit of 100 mL. The RBC:Cryo ratio was calculated for blood products transfused within 4 hours of presentation. The association between RBC:Cryo and 24-hour mortality was analyzed with multivariable logistic regression adjusting for the volume of RBC, plasma and platelet transfusions, global and regional injury severity, and other relevant variables.

RESULTS

The study cohort included 12,916 patients. Among those who received Cryo (n = 5,511 [42.7%]), the median RBC and Cryo transfusion volume within 4 hours was 11 U (interquartile range, 7-19 U) and 2 U (interquartile range, 1-3 U), respectively. Compared with no Cryo administration, only RBC:Cryo ratios ≤8:1 were associated with a significant survival benefit, while lower doses of Cryo (RBC:Cryo >8:1) were not associated with decreased 24-hour mortality. Compared with the maximum dose of Cryo administration (RBC:Cryo, 1:1-2:1), there was no difference in 24-hour mortality up to RBC:Cryo of 7:1 to 8:1, whereas lower doses of Cryo (RBC:Cryo, >8:1) were associated with significantly increased 24-hour mortality.

CONCLUSION

One pooled unit of Cryo (100 mL) per 7 to 8 U of RBCs could be the optimal dose of Cryo in trauma resuscitation that provides a significant survival benefit while avoiding unnecessary blood product transfusions.

LEVEL OF EVIDENCE

Prognostic and Epidemiologic; Level IV.

Association between lung contusion volume and acute changes in fibrinogen levels: A single-center observational study

Aim

Organ tissue damage, including the lungs, may lead to acute coagulopathy. This study aimed to evaluate the association between lung contusion volume and serum fibrinogen level during the acute phase of trauma.

Methods

We conducted an observational study using electronic medical records at a tertiary-care center between January 2015 and December 2018. We included patients with lung contusions on hospital arrival. We used three-dimensional computed tomography to calculate lung contusion volumes. The primary outcome was the lowest fibrinogen level measured within 24 h of hospital arrival. We evaluated the association between lung contusion volume and outcome with multivariable linear regression analysis. Also, we calculated the sensitivity and specificity of lung contusion volume in patients with a serum fibrinogen level of ≤150 mg/dL.

Results

We identified 124 eligible patients. Their median age was 43.5 years, and 101 were male (81.5%). The median lung contusion volume was 10.9%. The median lowest fibrinogen level within 24 h from arrival was 188.0 mg/dL. After adjustment, lung contusion volume had a statistically significant association with the lowest fibrinogen level within 24 h from arrival (coefficient -1.6, 95% confidence interval -3.16 to -0.07). When a lung contusion volume of 20% was used as the cutoff, the sensitivity and specificity to identify fibrinogen depletion were 0.27 and 0.95, respectively.

Conclusion

Lung contusion volume was associated with the lowest fibrinogen level measured within 24 h from hospital arrival. Measuring lung contusion volume may help to identify patients with a progression of fibrinogen depletion.

Preoperative fibrinogen level and blood transfusions in liver transplantation: A systematic review

BACKGROUND

Orthotopic liver transplantation (OLT) is a major surgery often associated with significant bleeding. We conducted a systematic review to explore the association between preoperative fibrinogen level and intraoperative blood products transfusion, blood loss and clinical outcomes in patients undergoing OLT.

METHODS

We included observational studies conducted in patients undergoing an OLT mostly for end-stage liver disease that reported an association between the preoperative fibrinogen level and our outcomes of interest. Our primary outcome was the intraoperative red blood cell (RBC) transfusion requirements. Our secondary outcomes were intraoperative blood loss, intraoperative transfusion of any blood product, postoperative RBC transfusion, postoperative thrombotic or hemorrhagic complications, and mortality. We used a standardized search strategy. We reported our results mostly descriptively but conducted meta-analyses using random-effect models when judged feasible.

RESULTS

We selected 24 cohort studies reporting at least one of our outcomes. We found that a high preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, and lower blood loss. We also found a lower overall survival in patients with a higher fibrinogen level (pooled hazard ratio [95% CI] of 1.50 [1.23 to 1.84]; 5 studies, n = 1012, I2 = 48%). Only one study formally explored a fibrinogen level threshold effect. Overall, reporting was heterogeneous, and risk of bias was variable mostly because of uncontrolled confounding.

CONCLUSION

A higher preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, lower blood loss, and higher mortality. Further studies may help clarify observed associations and inform guidelines.

Early and Empirical High-Dose Cryoprecipitate for Hemorrhage After Traumatic Injury: The CRYOSTAT-2 Randomized Clinical Trial

Importance

Critical bleeding is associated with a high mortality rate in patients with trauma. Hemorrhage is exacerbated by a complex derangement of coagulation, including an acute fibrinogen deficiency. Management is fibrinogen replacement with cryoprecipitate transfusions or fibrinogen concentrate, usually administered relatively late during hemorrhage.

Objective

To assess whether survival could be improved by administering an early and empirical high dose of cryoprecipitate to all patients with trauma and bleeding that required activation of a major hemorrhage protocol.

Design, Setting, and Participants

CRYOSTAT-2 was an interventional, randomized, open-label, parallel-group controlled, international, multicenter study. Patients were enrolled at 26 UK and US major trauma centers from August 2017 to November 2021. Eligible patients were injured adults requiring activation of the hospital's major hemorrhage protocol with evidence of active hemorrhage, systolic blood pressure less than 90 mm Hg at any time, and receiving at least 1 U of a blood component transfusion.

Intervention

Patients were randomly assigned (in a 1:1 ratio) to receive standard care, which was the local major hemorrhage protocol (reviewed for guideline adherence), or cryoprecipitate, in which 3 pools of cryoprecipitate (6-g fibrinogen equivalent) were to be administered in addition to standard care within 90 minutes of randomization and 3 hours of injury.

Main Outcomes and Measures

The primary outcome was all-cause mortality at 28 days in the intention-to-treat population.

Results

Among 1604 eligible patients, 799 were randomized to the cryoprecipitate group and 805 to the standard care group. Missing primary outcome data occurred in 73 patients (principally due to withdrawal of consent) and 1531 (95%) were included in the primary analysis population. The median (IQR) age of participants was 39 (26-55) years, 1251 (79%) were men, median (IQR) Injury Severity Score was 29 (18-43), 36% had penetrating injury, and 33% had systolic blood pressure less than 90 mm Hg at hospital arrival. All-cause 28-day mortality in the intention-to-treat population was 26.1% in the standard care group vs 25.3% in the cryoprecipitate group (odds ratio, 0.96 [95% CI, 0.75-1.23]; P = .74). There was no difference in safety outcomes or incidence of thrombotic events in the standard care vs cryoprecipitate group (12.9% vs 12.7%).

Conclusions and Relevance

Among patients with trauma and bleeding who required activation of a major hemorrhage protocol, the addition of early and empirical high-dose cryoprecipitate to standard care did not improve all cause 28-day mortality.

Trial Registration

ClinicalTrials.gov Identifier: NCT04704869; ISRCTN Identifier: ISRCTN14998314.

Hypofibrinogenemia following injury in 186 children and adolescents: identification of the phenotype, current outcomes, and potential for intervention

Objectives

Recent studies evaluating fibrinogen replacement in trauma, along with newly available fibrinogen-based products, has led to an increase in debate on where products such as cryoprecipitate belong in our resuscitation strategies. We set out to define the phenotype and outcomes of those with hypofibrinogenemia and evaluate whether fibrinogen replacement should have a role in the initial administration of massive transfusion.

Methods

All patients <18 years of age presenting to our trauma center 11/17-4/21 were reviewed. We then evaluated all patients who received emergency-release and massive transfusion protocol (MTP) products. Patients were defined as hypofibrinogenemic (HYPOFIB) if admission fibrinogen <150 or rapid thrombelastography (r-TEG) angle <60 degrees. Our analysis sought to define risk factors for presenting with HYPOFIB, the impact on outcomes, and whether early replacement improved mortality.

Results

4169 patients were entered into the trauma registry, with 926 level 1 trauma activations, of which 186 patients received emergency-release blood products during this time; 1%, 3%, and 10% were HYPOFIB, respectively. Of the 186 patients of interest, 18 were HYPOFIB and 168 were non-HYPOFIB. The HYPOFIB patients were significantly younger, had lower field and arrival Glasgow Coma Scale, had higher head Abbreviated Injury Scale, arrived with worse global coagulopathy, and died from brain injury. Non-HYPOFIB patients were more likely to have (+)focused assessment for the sonography of trauma on arrival, sustained severe abdominal injuries, and die from hemorrhage. 12% of patients who received early cryoprecipitate (0-2 hours) had higher mortality by univariate analysis (55% vs 31%, p=0.045), but no difference on multivariate analysis (OR 0.36, 95% CI 0.07 to 1.81, p=0.221). Those receiving early cryoprecipitate who survived after pediatric intensive care unit (PICU) admission had lower PICU fibrinogen and r-TEG alpha-angle values.

Conclusion

In pediatric trauma, patients with hypofibrinogenemia on admission are most likely younger and to have sustained severe brain injury, with an associated mortality of over 80%. Given the absence of bleeding-related deaths in HYPOFIB patients, this study does not provide evidence for the empiric use of cryoprecipitate in the initial administration of a massive transfusion protocol.

Level of Evidence

Level III - Therapeutic/Care Management.

Severe Trauma-Induced Coagulopathy: Molecular Mechanisms Underlying Critical Illness

Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies.

Shock Index for Early Detection of Low Plasma Fibrinogen in Trauma: A Prospective Observational Cohort Pilot Study

Shock index (a ratio between heart rate and systolic blood pressure) predicts transfusion requirements and the need for haemostatic resuscitation in severe trauma patients. In the present study, we aimed to determine whether prehospital and on-admission shock index values can be used to predict low plasma fibrinogen in trauma patients. Between January 2016 and February 2017, trauma patients admitted from the helicopter emergency medical service into two large trauma centres in the Czech Republic were prospectively assessed for demographic, laboratory and trauma-associated variables and shock index at scene, during transport and at admission to the emergency department. Hypofibrinogenemia defined as fibrinogen plasma level of 1.5 g·L^-l was deemed as a cut-off for further analysis. Three hundred and twenty-two patients were screened for eligibility. Of these, 264 (83%) were included for further analysis. The hypofibrinogenemia was predicted by the worst prehospital shock index with the area under the receiver operating characteristics curve (AUROC) of 0.79 (95% CI 0.64-0.91) and by the admission shock index with AUROC of 0.79 (95% CI 0.66-0.91). For predicting hypofibrinogenemia, the prehospital shock index ≥ 1 has 0.5 sensitivity (95% CI 0.19-0.81), 0.88 specificity (95% CI 0.83-0.92) and a negative predictive value of 0.98 (0.96-0.99). The shock index may help to identify trauma patients at risk of hypofibrinogenemia early in the prehospital course.

Association between Fibrinogen-to-Albumin Ratio and Prognosis in Patients Admitted to an Intensive Care Unit

The objective of this study was to investigate the usefulness of fibrinogen-to-albumin ratio (FAR) as a prognostic marker in patients admitted to an intensive care unit (ICU) compared with Sequential Organ Failure Assessment (SOFA) score, a widely used prognostic scoring system. An inverse probability weighting (IPW) was used to control for selection bias and confounding factors. After IPW adjustment, the high FAR group showed significantly higher risk of 1-year compared with low FAR group (36.4% vs. 12.4%, adjust hazard ratio = 1.72; 95% confidence interval (CI): 1.59-1.86; p < 0.001). In the receiver-operating characteristic curve analysis associated with the prediction of 1-year mortality, there was no significant difference between the area under the curve of FAR on ICU admission (C-statistic: 0.684, 95% CI: 0.673-0.694) and that of SOFA score on ICU admission (C-statistic: 0.679, 95% CI: 0.669-0.688) (p = 0.532). In this study, FAR and SOFA score at ICU admission were associated with 1-year mortality in patients admitted to an ICU. Especially, FAR was easier to obtain in critically ill patients than SOFA score. Therefore, FAR is feasible and might help predict long-term mortality in these patients.

Raising the bar on fibrinogen: a retrospective assessment of critical hypofibrinogenemia in severely injured trauma patients

Objectives

Fibrinogen depletion may occur at higher levels than historically referenced. We evaluated hypofibrinogenemia and associated mortality and multiple organ failure (MOF) after severe injury.

Methods

Retrospective investigation including 417 adult patients with Injury Severity Score (ISS) >15. Demographics and injury characteristics were collected. Fibrinogen within 30 minutes of admission was described: <150 mg/dL, 150 mg/dL to 200 mg/dL and >200 mg/dL. Primary outcome: 28-day mortality. Secondary outcomes: 28-day MOF and blood product transfusion. Multivariable logistic regression model evaluated association of fibrinogen categories on risk of death, after controlling for confounding variables. Results presented as OR and 95% CIs.

Results

Fibrinogen <150 mg/dL: 4.8%, 150 mg/dL to 200 mg/dL: 18.2%, >200 mg/dL: 77.0%. 28-day mortality: 15.6%. Patients with <150 mg/dL fibrinogen had over fourfold increased 28-day mortality risk (OR: 4.9, 95% CI 1.53 to 15.7) after adjusting for age, ISS and admission Glasgow Coma Scale. Patients with lower fibrinogen were more likely to develop MOF (p=0.04) and receive larger red blood cell transfusion volumes at 3 hours and 24 hours (p<0.01).

Conclusions

Fibrinogen <150 mg/dL is significantly associated with increased 28-day mortality. Patients with fibrinogen <150 mg/dL were more likely to develop MOF and required increased administration of blood products. The optimal threshold for critically low fibrinogen, the association with MOF and subsequent fibrinogen replacement requires further investigation.

Level of evidence

Level III.

Diagnostic Tests for Hypofibrinogenemia Resulting from Green Pit Viper (Trimeresurus albolabris) Envenomation: A Simulated In Vitro Study

INTRODUCTION

The green pit viper (GPV) Trimeresurus albolabris is found in Southeast Asia. Its venom has a thrombin-like activity that can cause hypofibrinogenemia. Fibrinogen measurement is not always available. We aimed to establish a more available diagnostic tool indicating hypofibrinogenemia caused by GPV envenomation.

METHODS

This was an in vitro study, in which healthy subjects aged 20 to 45 y were enrolled. There were 2 experiments. In Experiment 1, blood samples from 1 subject had varying amounts of T albolabris venom added to determine its effect on the fibrinogen level (FL). In Experiment 2, 3 sets of blood samples were obtained from another 25 subjects. The 2 venom doses established in Experiment 1 were used on 2 sets of the samples to simulate severe (FL <1.0 g·L-1) and mild hypofibrinogenemia (FL 1.0-1.7 g·L-1). The third set of samples was venom-free. All samples were used for platelet counts, prothrombin time (PT)/international normalized ratio (INR)/activated partial thromboplastin time (aPTT), and 2 bedside clotting tests. Diagnostic parameters were calculated against the target FL of <1.0 g·L-1 and <1.7 g·L-1.

RESULTS

Twenty-five subjects were enrolled in Experiment 2. On referencing normal cutoff values (platelet count >150,000 cells/mm3, venous clotting time <15 min, normal 20-min whole blood clotting time, INR <1.2, aPTT <30), we found abnormalities of 5, 0, 0, 3, and 22%, respectively. The highest correlation with hypofibrinogenemia was provided by PT/INR. For an FL of <1.0 g·L-1, PT and INR revealed the highest areas under the receiver operating characteristic curve, 0.76 (95% CI, 0.55-0.97) and 0.76 (95% CI, 0.57-0.97), respectively. The highest accuracy and the highest sensitivity were provided by PT/INR.

CONCLUSIONS

PT/INR could be used as a diagnostic test for severe hypofibrinogenemia in GPV envenomation because of its high accuracy and area under the receiver operating characteristic curve.

Transfusion management in the trauma patient

PURPOSE OF REVIEW

Transfusion of blood products is lifesaving in the trauma ICU. Intensivists must be familiar with contemporary literature to develop the optimal transfusion strategy for each patient.

RECENT FINDINGS

A balanced ratio of red-blood cells to plasma and platelets is associated with improved mortality and has therefore become the standard of care for resuscitation. There is a dose-dependent relationship between units of product transfused and infections. Liquid and freeze-dried plasma are alternatives to fresh frozen plasma that can be administered immediately and may improve coagulation parameters more rapidly, though higher quality research is needed. Trauma induced coagulopathy can occur despite a balanced transfusion, and administration of prothrombin complex concentrate and cryoprecipitate may have a role in preventing this. In addition to balanced ratios, viscoelastic guidance is being increasingly utilized to individualize component transfusion. Alternatively, whole blood can be used, which has become the standard in military practice and is gaining popularity at civilian centers.

SUMMARY

Hemorrhagic shock is the leading cause of death in trauma. Improved resuscitation strategy has been one of the most important contemporary advancements in trauma care and continues to be a key area of clinical research.

Hyperfibrinolysis drives mechanical instabilities in a simulated model of trauma induced coagulopathy

INTRODUCTION

Trauma induced coagulopathy (TIC) is common after severe trauma, increasing transfusion requirements and mortality among patients. TIC has several phenotypes, with primary hyperfibrinolysis being among the most lethal. We aimed to investigate the contribution of hypercoagulation, hemodilution, and fibrinolytic activation to the hyperfibrinolytic phenotype of TIC, by examining fibrin formation in a plasma-based model of TIC. We hypothesized that instabilities arising from TIC will be due primarily to increased fibrinolytic activation rather than hemodilution or tissue factor (TF) induced hypercoagulation.

METHODS

The influence of TF, hemodilution, fibrinogen consumption, tissue plasminogen activator (tPA), and the antifibrinolytic tranexamic acid (TXA) on plasma clot formation and structure were examined using rheometry, optical properties, and confocal microscopy. These were then compared to plasma samples from trauma patients at risk of developing TIC.

RESULTS

Combining TF-induced clot formation, 15 % hemodilution, fibrinogen consumption, and tPA-induced fibrinolysis, the clot characteristics and hyperfibrinolysis were consistent with primary hyperfibrinolysis. TF primarily increased fibrin polymerization rates and reduced fiber length. Hemodilution decreased clot optical density but had no significant effect on mechanical clot stiffness. TPA addition induced primary clot lysis as observed mechanically and optically. TXA restored mechanical clot formation but did not restore clot structure to control levels. Patients at risk of TIC showed increased clot formation, and lysis like that of our simulated model.

CONCLUSIONS

This simulated TIC plasma model demonstrated that fibrinolytic activation is a primary driver of instability during TIC and that clot mechanics can be restored, but clot structure remains altered with TXA treatment.

Cryoprecipitate transfusion in trauma patients attenuates hyperfibrinolysis and restores normal clot structure and stability: Results from a laboratory sub-study of the FEISTY trial

BACKGROUND

Fibrinogen is the first coagulation protein to reach critical levels during traumatic haemorrhage. This laboratory study compares paired plasma samples pre- and post-fibrinogen replacement from the Fibrinogen Early In Severe Trauma studY (FEISTY; NCT02745041). FEISTY is the first randomised controlled trial to compare the time to administration of cryoprecipitate (cryo) and fibrinogen concentrate (Fg-C; Riastap) in trauma patients. This study will determine differences in clot strength and fibrinolytic stability within individuals and between treatment arms.

METHODS

Clot lysis, plasmin generation, atomic force microscopy and confocal microscopy were utilised to investigate clot strength and structure in FEISTY patient plasma.

RESULTS

Fibrinogen concentration was significantly increased post-transfusion in both groups. The rate of plasmin generation was reduced 1.5-fold post-transfusion of cryo but remained unchanged with Fg-C transfusion. Plasminogen activator inhibitor 1 activity and antigen levels and Factor XIII antigen were increased post-treatment with cryo, but not Fg-C. Confocal microscopy analysis of fibrin clots revealed that cryo transfusion restored fibrin structure similar to those observed in control clots. In contrast, clots remained porous with stunted fibres after infusion with Fg-C. Cryo but not Fg-C treatment increased individual fibre toughness and stiffness.

CONCLUSIONS

In summary, our data indicate that cryo transfusion restores key fibrinolytic regulators and limits plasmin generation to form stronger clots in an ex vivo laboratory study. This is the first study to investigate differences in clot stability and structure between cryo and Fg-C and demonstrates that the additional factors in cryo allow formation of a stronger and more stable clot.

Impact of Pelvic Fracture Sites on Fibrinogen Depletion in Patients with Blunt Trauma: A Single-Center Cohort Study

Background: We aimed to examine the association of pelvic fracture sites with the minimum fibrinogen level within 24 h after hospital arrival. Methods: We conducted a single-center cohort study using health records review. We included patients with pelvic fractures transported by ambulance to a tertiary-care hospital from January 2012 to December 2018 and excluded those transported from other hospitals or aged younger than 16 years. The pelvic fracture was diagnosed and confirmed by trauma surgeons and/or radiologists. We classified the fracture sites of the pelvis as ilium, pubis, ischium, acetabulum, sacrum, sacroiliac joint diastasis, and pubic symphysis diastasis, and each side was counted separately except for pubic symphysis diastasis. We performed linear regression analysis to evaluate the association between pelvic fracture sites and the minimum fibrinogen level within 24 h of arrival. Results: We analyzed 120 pelvic fracture patients. Their mean age was 47.3 years, and 69 (57.5%) patients were men. The median Injury Severity Score was 24, and in-hospital mortality was 10.8%. The mean minimum fibrinogen level within 24 h of arrival was 171.4 mg/dL. Among pelvic fracture sites, only sacrum fracture was statistically significantly associated with the minimum fibrinogen level within 24 h of arrival (estimate, −34.5; 95% CI, −58.6 to −10.4; p = 0.005). Conclusions: Fracture of the sacrum in patients with pelvic fracture was associated with lower minimum fibrinogen levels within 24 h of hospital arrival and the requirement of blood transfusion.

Fibrinogen Supplementation for the Trauma Patient: Should You Choose Fibrinogen Concentrate Over Cryoprecipitate?

INTRODUCTION

Trauma-induced coagulopathy is frequently associated with hypofibrinogenemia. Cryoprecipitate (Cryo), and fibrinogen concentrate (FC) are both potential means of fibrinogen supplementation. The aim of this study was to compare the outcomes of traumatic hemorrhagic patients who received fibrinogen supplementation using FC versus Cryo.

METHODS

We performed a 2-year (2016-2017) retrospective cohort analysis of the American College of Surgeons (ACS) Trauma Quality Improvement Program database. All adult trauma patients (≥18 years) who received FC or Cryo as an adjunct to resuscitation were included. Patients with bleeding disorders, chronic liver disease, and those on preinjury anticoagulants were excluded. Patients were stratified into those who received FC, and those who received Cryo. Propensity score matching (1:2) was performed. Outcome measures were transfusion requirements, major complications, hospital, and ICU lengths of stay (LOS), and mortality.

RESULTS

A matched cohort of 255 patients who received fibrinogen supplementation (85 in FC, 170 in Cryo) was analyzed. Overall, the mean age was 41 ± 19 years, 74% were male, 74% were white and median ISS was 26 [22-30]. Compared to the Cryo group, the FC group required less units of packed red blood cells (pRBC), fresh frozen plasma (FFP), and platelets, and had shorter in-hospital and ICU LOS. There were no significant differences between the two groups in terms of major in-hospital complications and mortality.

CONCLUSIONS

Fibrinogen supplementation in the form of FC for the traumatic hemorrhagic patient is associated with improved outcomes and reduced transfusion requirements as compared to Cryo. Further studies are required to evaluate the optimal method of fibrinogen supplementation in the resuscitation of trauma patients.

LEVEL OF EVIDENCE

III Therapeutic/Care Management.

A point-of-care microfluidic channel-based device for rapid and direct detection of fibrinogen in whole blood

Hemorrhage is the leading cause of preventable death in civilian and battlefield traumatic injuries. Patients with severe traumatic hemorrhagic shock are more likely to be deficient in fibrinogen than those with other coagulation factors, and hypofibrinogenemia is an independent risk factor for mortality. Thus, rapid detection of fibrinogen levels is of great importance in these patients during damage control resuscitation. Plasma is used as an analyte in fibrinogen detection, which restricts the use of existing devices in emergencies. To meet the needs of on-site detection, we developed a point-of-care microfluidic channel-based device for direct measurement of fibrinogen concentration in whole blood. In our method, thrombin is dispersed on a reaction strip to initiate conversion of fibrinogen to fibrin. The permeability of the resulting blood clots depends on the fibrinogen level. A hydrophobic plastic protection flake between the reaction strip and a wicking strip is then removed to allow flow of unclotted blood. The rate of blood flow along the wicking strip was inversely related to the fibrinogen concentration. The whole process could be completed in as fast as 5 minutes for a whole blood sample size of 150 μL, and yielded accurate results ranging from 0 to 4 g L^-1, which were unaffected by Ca²⁺, blood lipids, hematocrit, warfarin and tissue plasminogen activators (tPAs). Results using clinical whole blood samples were also highly consistent with those using an automatic coagulation analyzer, yielding a Pearson correlation coefficient of up to 0.919. This approach has potential for allowing rapid diagnosis of fibrinogen concentration in critically ill bleeding patients in different settings, thus helping to judge the suitability of fibrinogen replacement therapy (FRT) in cases of emergency bleeding and in patients at risk of thrombosis due to hyperfibrinogenemia.

Role of Fibrinogen in Trauma-Induced Coagulopathy

BACKGROUND

Fibrinogen is the first coagulation factor to decrease after massive hemorrhage. European massive transfusion guidelines recommend early repletion of fibrinogen; however, this practice has not been widely adopted in the US. We hypothesize that hypofibrinogenemia is common at hospital arrival and is an integral component of trauma-induced coagulopathy.

STUDY DESIGN

This study entailed review of a prospective observational database of adults meeting the highest-level activation criteria at an urban level 1 trauma center from 2014 through 2020. Resuscitation was initiated with 2:1 red blood cell (RBC) to fresh frozen plasma (FFP) ratios and continued subsequently with goal-directed thrombelastography. Hypofibrinogenemia was defined as fibrinogen below 150 mg/dL. Massive transfusion (MT) was defined as more than 10 units RBC or death after receiving at least 1 unit RBC over the first 6 hours of admission.

RESULTS

Of 476 trauma activation patients, 70 (15%) were hypofibrinogenemic on admission, median age was 34 years, 78% were male, median New Injury Severity Score (NISS) was 25, and 72 patients died (15%). Admission fibrinogen level was an independent risk factor for MT (odds ratio [OR] 0.991, 95% CI 0.987-0.996]. After controlling for confounders, NISS (OR 1.034, 95% CI 1.017-1.052), systolic blood pressure (OR 0.991, 95% CI 0.983-0.998), thrombelastography angle (OR 0.925, 95% CI 0.896-0.954), and hyperfibrinolysis (OR 2.530, 95% CI 1.160-5.517) were associated with hypofibrinogenemia. Early cryoprecipitate administration resulted in the fastest correction of hypofibrinogenemia.

CONCLUSION

Hypofibrinogenemia is common after severe injury and predicts MT. Cryoprecipitate transfusion results in the most expeditious correction. Earlier administration of cryoprecipitate should be considered in MT protocols.

Transfusion strategies in bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

Purpose

To develop evidence-based clinical practice recommendations regarding transfusion practices and transfusion in bleeding critically ill adults.

Methods

A taskforce involving 15 international experts and 2 methodologists used the GRADE approach to guideline development. The taskforce addressed three main topics: transfusion support in massively and non-massively bleeding critically ill patients (transfusion ratios, blood products, and point of care testing) and the use of tranexamic acid. The panel developed and answered structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

Results

The taskforce generated 26 clinical practice recommendations (2 strong recommendations, 13 conditional recommendations, 11 no recommendation), and identified 10 PICOs with insufficient evidence to make a recommendation.

Conclusions

This clinical practice guideline provides evidence-based recommendations for the management of massively and non-massively bleeding critically ill adult patients and identifies areas where further research is needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06531-x.

Evaluation of trauma-induced coagulopathy in the fibrinogen in the initial resuscitation of severe trauma trial

BACKGROUND

Coagulopathic bleeding is frequently present after major trauma. However, trauma-induced coagulopathy (TIC) remains incompletely understood. This laboratory analysis of blood samples derived from our completed trial on fibrinogen in the initial resuscitation of severe trauma (FiiRST) was conducted to evaluate TIC and associated responses to fibrinogen replacement.

STUDY DESIGN AND METHODS

We conducted a retrospective evaluation of TIC in 45 FiiRST trial patients based on rotational thromboelastometry (ROTEM), international normalized ratio (INR), and biomarkers for hemostasis and endotheliopathy. Whole blood was analyzed by ROTEM. Plasma was analyzed for INR and biomarkers.

RESULTS

Overall, 19.0% and 30.0% of the FiiRST trial patients were coagulopathic on admission defined by EXTEM maximum clot firmness out of the range of 40-71 mm and INR >1.2, respectively. The FiiRST patients showed lower fibrinogen, factor II and V levels, protein C and antiplasmin activities, higher activated protein C, tissue plasminogen activator, d-dimer, and thrombomodulin concentrations at admission than healthy controls. Most of the biomarkers changed their activities during 48-h hospitalization, but were at abnormal levels even 48-h after admission. The fibrinogen treatment reduced hypofibrinogenemia and increased factor XIII level, but had no significant effects on other biomarkers levels. Limited development of endotheliopathy was indicated by syndean-1, thrombomodulin, and sE-selectin.

CONCLUSIONS

About 19%-30% of the trauma patients in the FiiRST trial were coagulopathic on hospital admission depending on the definition of TIC. Analyses of the TIC biomarkers demonstrated that hemostasis would not return to normal after 48-h hospitalization, and fibrinogen replacement improved hypofibrinogenemia.

Fibrinogen in traumatic haemorrhage

PURPOSE OF REVIEW

Recent advances in the understanding of the pathophysiological processes associated with traumatic haemorrhage and trauma-induced coagulopathy (TIC) have resulted in improved outcomes for seriously injured trauma patients. However, a significant number of trauma patients still die from haemorrhage. This article reviews the role of fibrinogen in normal haemostasis, the effect of trauma and TIC on fibrinogen levels and current evidence for fibrinogen replacement in the management of traumatic haemorrhage.

RECENT FINDINGS

Fibrinogen is usually the first factor to reach critically low levels in traumatic haemorrhage and hypofibrinogenaemia after severe trauma is associated with increased risk of massive transfusion and death. It is postulated that the early replacement of fibrinogen in severely injured trauma patients can improve outcomes. There is, however, a paucity of evidence to support this, and in addition, there is little evidence to support or refute the effects of cryoprecipitate or fibrinogen concentrate for fibrinogen replacement.

SUMMARY

The important role fibrinogen plays in haemostasis and effective clot formation is clear. A number of pilot trials have investigated different strategies for fibrinogen replacement in severe trauma. These trials have formed the basis of several large-scale phase III trials, which, cumulatively will provide a firm evidence base to harmonise worldwide clinical management of severely injured trauma patients with major haemorrhage.

Cryoprecipitate attenuates the endotheliopathy of trauma in mice subjected to hemorrhagic shock and trauma

BACKGROUND

Plasma has been shown to mitigate the endotheliopathy of trauma. Protection of the endothelium may be due in part to fibrinogen and other plasma-derived proteins found in cryoprecipitate; however, the exact mechanisms remain unknown. Clinical trials are underway investigating early cryoprecipitate administration in trauma. In this study, we hypothesize that cryoprecipitate will inhibit endothelial cell (EC) permeability in vitro and will replicate the ability of plasma to attenuate pulmonary vascular permeability and inflammation induced by hemorrhagic shock and trauma (HS/T) in mice.

METHODS

In vitro, barrier permeability of ECs subjected to thrombin challenge was measured by transendothelial electrical resistance. In vivo, using an established mouse model of HS/T, we compared pulmonary vascular permeability among mice resuscitated with (1) lactated Ringer's solution (LR), (2) fresh frozen plasma (FFP), or (3) cryoprecipitate. Lung tissue from the mice in all groups was analyzed for markers of vascular integrity, inflammation, and inflammatory gene expression via NanoString messenger RNA quantification.

RESULTS

Cryoprecipitate attenuates EC permeability and EC junctional compromise induced by thrombin in vitro in a dose-dependent fashion. In vivo, resuscitation of HS/T mice with either FFP or cryoprecipitate attenuates pulmonary vascular permeability (sham, 297 ± 155; LR, 848 ± 331; FFP, 379 ± 275; cryoprecipitate, 405 ± 207; p < 0.01, sham vs. LR; p < 0.01, LR vs. FFP; and p < 0.05, LR vs. cryoprecipitate). Lungs from cryoprecipitate- and FFP-treated mice demonstrate decreased lung injury, decreased infiltration of neutrophils and activation of macrophages, and preserved pericyte-endothelial interaction compared with LR-treated mice. Gene analysis of lung tissue from cryoprecipitate- and FFP-treated mice demonstrates decreased inflammatory gene expression, in particular, IL-1β and NLRP3, compared with LR-treated mice.

CONCLUSION

Our data suggest that cryoprecipitate attenuates the endotheliopathy of trauma in HS/T similar to FFP. Further investigation is warranted on active components and their mechanisms of action.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Comparison of fresh frozen plasma vs. coagulation factor concentrates for reconstitution of blood: An in vitro study

BACKGROUND

Many trauma centres have adopted the administration of fixed ratios of packed red blood cells (PRBCs), platelet concentrates and fresh frozen plasma (FFP) for bleeding patients. However, the haemostatic efficacy of this concept is not well proven.

OBJECTIVE

Our objective was to characterise the haemostatic profile of different ratios (2 : 1 : 1, 1 : 1 : 1 and 1 : 1 : 2) of PRBCs, platelet concentrates and FFP in comparison with coagulation factor concentrates (fibrinogen and/or prothrombin complex concentrate).

DESIGN

An in vitro study.

SETTING

Research laboratories of the department of transfusion medicine, Linz, Austria.

MATERIALS

Whole blood donations from a total of 20 male volunteers.

INTERVENTION

Reconstitution of blood at different ratios of PRBCs, platelet concentrates and FFP or coagulation factor concentrates.

MAIN OUTCOME MEASURES

Cell count, conventional and thromboelastometric coagulation parameters, single coagulation factor activities as well as endogenous thrombin potential.

RESULTS

Fibrinogen levels and haematocrit were lower in the FFP group at any ratio compared with the concentrate-based groups (P < 0.0001). Reconstitution of blood with FFP at different ratios resulted in haematocrit or fibrinogen levels that were borderline with regard to recommended substitution triggers (haematocrit 41 ± 2% and fibrinogen 1.5 ± 0.3 g l at the 2 : 1 : 1 ratio vs. 21 ± 1% and 2.1 ± 0.4 g l respectively at the 1 : 1 : 2 ratio). Compared with FFP at any ratio, maximum clot firmness showed higher values in the groups using fibrinogen concentrate (P < 0.0001), whereas endogenous thrombin potential revealed higher values in the groups using prothrombin complex concentrate (P < 0.0001).

CONCLUSION

Use of coagulation factor concentrates for the reconstitution of blood allows for delivery of a higher haematocrit and a higher fibrinogen content compared with FFP. However, prothrombin complex concentrate might result in an unnecessary excess of thrombin generation. Clinical studies are warranted to further investigate these in vitro findings.

Efficacy of prehospital administration of fibrinogen concentrate in trauma patients bleeding or presumed to bleed (FIinTIC): A multicentre, double-blind, placebo-controlled, randomised pilot study

BACKGROUND

Trauma-induced coagulopathy (TIC) substantially contributes to mortality in bleeding trauma patients.

OBJECTIVE

The aim of the study was to administer fibrinogen concentrate in the prehospital setting to improve blood clot stability in trauma patients bleeding or presumed to bleed.

DESIGN

A prospective, randomised, placebo-controlled, double-blinded, international clinical trial.

SETTING

This emergency care trial was conducted in 12 Helicopter Emergency Medical Services (HEMS) and Emergency Doctors' vehicles (NEF or NAW) and four trauma centres in Austria, Germany and Czech Republic between 2011 and 2015.

PATIENTS

A total of 53 evaluable trauma patients aged at least 18 years with major bleeding and in need of volume therapy were included, of whom 28 received fibrinogen concentrate and 25 received placebo.

INTERVENTIONS

Patients were allocated to receive either fibrinogen concentrate or placebo prehospital at the scene or during transportation to the study centre.

MAIN OUTCOME MEASURES

Primary outcome was the assessment of clot stability as reflected by maximum clot firmness in the FIBTEM assay (FIBTEM MCF) before and after administration of the study drug.

RESULTS

Median FIBTEM MCF decreased in the placebo group between baseline (before administration of study treatment) and admission to the Emergency Department, from a median of 12.5 [IQR 10.5 to 14] mm to 11 [9.5 to 13] mm (P = 0.0226), but increased in the FC Group from 13 [11 to 15] mm to 15 [13.5 to 17] mm (P = 0.0062). The median between-group difference in the change in FIBTEM MCF was 5 [3 to 7] mm (P < 0.0001). Median fibrinogen plasma concentrations in the fibrinogen concentrate Group were kept above the recommended critical threshold of 2.0 g l-1 throughout the observation period.

CONCLUSION

Early fibrinogen concentrate administration is feasible in the complex and time-sensitive environment of prehospital trauma care. It protects against early fibrinogen depletion, and promotes rapid blood clot initiation and clot stability.

TRIAL REGISTRY NUMBERS

EudraCT: 2010-022923-31 and ClinicalTrials.gov: NCT01475344.

Effects of pathogen reduction technology and storage duration on the ability of cryoprecipitate to rescue induced coagulopathies in vitro

Background

Fibrinogen concentrates and cryoprecipitate are currently used for fibrinogen supplementation in bleeding patients with dysfibrinogenemia. Both products provide an abundant source of fibrinogen but take greater than 10 min to prepare for administration. Fibrinogen concentrates lack coagulation factors (i.e., factor VIII [FVIII], factor XIII [FXIII], von Willebrand factor [VWF]) important for robust hemostatic function. Cryoprecipitate products contain these factors but have short shelf lives (<6 h). Pathogen reduction (PR) of cryoprecipitate would provide a shelf‐stable immediately available adjunct containing factors important for rescuing hemostatic dysfunction.

Study Design and Methods

Hemostatic adjunct study products were psoralen‐treated PR‐cryoprecipitated fibrinogen complex (PR‐Cryo FC), cryoprecipitate (Cryo), and fibrinogen concentrates (FibCon). PR‐Cryo FC and Cryo were stored for 10 days at 20–24°C. Adjuncts were added to coagulopathies (dilutional, 3:7 whole blood [WB]:normal saline; or lytic, WB + 75 ng/ml tissue plasminogen activator), and hemostatic function was assessed by rotational thromboelastometry and thrombin generation.

Results

PR of cryoprecipitate did not reduce levels of FVIII, FXIII, or VWF. PR‐Cryo FC rescued dilutional coagulopathy similarly to Cryo, while generating significantly more thrombin than FibCon, which also rescued dilutional coagulopathy. Storage out to 10 days at 20–24°C did not diminish the hemostatic function of PR‐Cryo FC.

Discussion

PR‐Cryo FC provides similar and/or improved hemostatic rescue compared to FibCon in dilutional coagulopathies, and this rescue ability is stable over 10 days of storage. In hemorrhaging patients, where every minute delay is associated with a 5% increase in mortality, the immediate availability of PR‐Cryo FC has the potential to improve outcomes.

The fibrinogen levels on admission is a predictive marker of the contrast extravasation on enhanced computed tomography in sacral fracture

Sacral fracture is the most frequent posterior injury among unstable pelvic ring fractures and is prone to massive hemorrhage and hemodynamic instability. Contrast extravasation (CE) on computed tomography (CT) is widely used as an indicator of significant arterial bleeding. However, while CE is effective to detect significant arterial bleeding but negative result cannot completely rule out massive bleeding. Therefore, additional factors help to compensate CE for the prediction of early hemodynamically unstable condition.We evaluated the risk factors that predict CE on enhanced computed CT in patients with sacral fractures. Patients were classified into 2 groups: CE positive on enhanced CT of the pelvis [CE(+)] and CE negative [CE(-)]. We compared age, sex, injury severity score (ISS), systolic blood pressure (sBP), type of sacral fracture based on Denis classification, platelet (PLT), base excess, lactate, prothrombin time-international normalized ratio, hemoglobin (Hb), activated partial thromboplastin time, D-dimer, and fibrinogen between the 2 groups.A total of 82 patients were treated for sacral fracture, of whom 69 patients were enrolled. There were 17 patients (10 men and 7 women) in CE(+) and 52 patients (28 men and 24 women) in CE(-). Age, ISS, and blood transfusion within 24 hours were significantly higher in the CE(+) group than in the CE(-) group (P = .023, P < .001, P < .001). sBP, Hb, PLT, fibrinogen were significantly lower in the CE(+) group than in the CE(-) group (P < .001, P < .001, P < .001, P < .001). D-dimer and lactate were higher in the CE(+) group than in the CE(-) group (P = .036, P < .001) with significant differences. On multivariate analysis, the level of fibrinogen was an independent predictor of CE(+). The area under the curve value for fibrinogen was 0.88, and the optimal cut-off value for prediction was 199 mg/dL.The fibrinogen levels on admission can predict contrast extravasation on enhanced CT in patients with sacral fractures. The optimal cut-off value of fibrinogen for CE(+) prediction in sacral fracture was 199 mg/dL. The use of fibrinogen to predict CE(+) could lead to prompt and effective treatment of active arterial hemorrhage in sacral fracture.

Fibrinogen Early In Severe Trauma studY (FEISTY): results from an Australian multicentre randomised controlled pilot trial

Background: Haemorrhage is a major cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage, and early replacement using fibrinogen concentrate (FC) or cryoprecipitate (Cryo) is recommended by several international trauma guidelines. Limited evidence supports one product over the other, with widespread geographic and institutional variation in practice. Two previous trials have investigated the feasibility of rapid FC administration in severely injured trauma patients, with conflicting results. Objective: To compare the time to fibrinogen replacement using FC or Cryo in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia. Design, setting, patients and interventions: A multicentre controlled pilot trial in which adult trauma patients with haemorrhage were randomly assigned (1:1) to receive FC or Cryo for fibrinogen replacement, guided by FIBTEM A5 (functional fibrinogen assessment at 5 minutes after clot formation, using rotational thromboelastometry). Main outcome measures: The primary outcome was time to commencement of fibrinogen replacement. Secondary outcomes included effects of the intervention on plasma fibrinogen levels and clinical outcomes including transfusion requirements and mortality. Results: Of the 100 randomly assigned patients, 62 were hypofibrinogenaemic and received the intervention (n = 37) or Cryo (n = 25). Median (interquartile range [IQR]) time to delivery of FC was 29 min (23-40 min) compared with 60 min (40-80 min) for Cryo (P = 0.0001). All 62 patients were hypofibrinogenaemic before receiving FC or Cryo (FC: median FIBTEM A5, 8 mm [IQR, 7-9 mm]; Cryo: median FIBTEM A5, 9 mm [IQR, 5-10 mm]). In the FC arm patients received a median of 3 g FC (IQR, 2-4 g), and in the Cryo arm patients received a median of 8 units of Cryo (IQR, 8-14 units). Restoration of fibrinogen levels was achieved in both arms after the intervention. Blood product transfusion, fluid resuscitation and thromboembolic complications were similar in both arms. Overall mortality was 15.3%, with more deaths in the FC arm. Conclusion: Fibrinogen replacement in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia was achieved substantially faster using FC compared with Cryo. Fibrinogen levels increased appropriately using either product. The optimal method for replacing fibrinogen in traumatic haemorrhage is controversial. Our results will inform the design of a larger trial powered to assess patient-centred outcomes.

Outcome of Major Hemorrhage at a Major Cardiothoracic Center in Patients with Activated Major Hemorrhage Protocol versus Nonactivated Protocol

This study aimed to determine the impact of major hemorrhage (MH) protocol (MHP) activation on blood administration and patient outcome at a UK major cardiothoracic center. MH was defined in patients (> 16 years) as those who received > 5 units of red blood cells (RBCs) in < 4 hours, or > 10 units in 24 hours. Data were collected retrospectively from patient electronic records and hospital transfusion databases recording issue of blood products from January 2016 to December 2018. Of 134 patients with MH, 24 had activated MHP and 110 did not have activated MHP. Groups were similar for age, sex, baseline hemoglobin, platelet count, coagulation screen, and renal function with no difference in the baseline clinical characteristics. The total number of red cell units (median and [IQR]) transfused was no different in the patients with activated (7.5 [5-11.75]) versus nonactivated (9 [6-12]) MHP (p = 0.35). Patients in the nonactivated MHP group received significantly higher number of platelet units (median: 3 vs. 2, p = 0.014), plasma (median: 4.5 vs. 1.5, p = 0.0007), and cryoprecipitate (median: 2 vs. 1, p = 0.008). However, activation of MHP was associated with higher mortality at 24 hours compared with patients with nonactivation of MHP (33.3 vs. 10.9%, p = 0.005) and 30 days (58.3 vs. 30.9%, p = 0.01). The total RBC and platelet (but not fresh frozen plasma [FFP]) units received were higher in deceased patients than in survivors. Increased mortality was associated with a higher RBC:FFP ratio. Only 26% of patients received tranexamic acid and these patients had higher mortality at 30 days but not at 24 hours. Deceased patients at 30 days had higher levels of fibrinogen than those who survived (median: 2.4 vs. 1.8, p = 0.01). Patients with activated MHP had significantly higher mortality at both 24 hours and 30 days despite lack of difference in the baseline characteristics of the patients with activated MHP versus nonactivated MHP groups. The increased mortality associated with a higher RBC:FFP ratio suggests dilutional coagulopathy may contribute to mortality, but higher fibrinogen at baseline was not protective.

Early administration of fibrinogen concentrate in patients with polytrauma with thromboelastometry suggestive of hypofibrinogenemia: A randomized feasibility trial

OBJECTIVE

To evaluate the clinical effects of early administration of fibrinogen concentrate in patients with severe trauma and hypofibrinogenemia.

METHODS

We conducted an open randomized feasibility trial between December 2015 and January 2017 in patients with severe trauma admitted to the emergency department of a large trauma center. Patients presented with hypotension, tachycardia, and FIBTEM findings suggestive of hypofibrinogenemia. The intervention group received fibrinogen concentrate (50 mg/kg), and the control group did not receive early fibrinogen replacement. The primary outcome was feasibility assessed as the proportion of patients receiving the allocated treatment within 60 min after randomization. The secondary outcomes were transfusion requirements and other exploratory outcomes. Randomization was performed using sequentially numbered and sealed opaque envelopes. ClinicalTrials.gov: NCT02864875.

RESULTS

Thirty-two patients were randomized (16 in each group). All patients received the allocated treatment within 60 min after randomization (100%, 95% confidence interval, 86.7%-100%). The median length of intensive care unit stay was shorter in the intervention group (8 days, interquartile range [IQR] 5.75-10.0 vs. 11 days, IQR 8.5-16.0; p=0.02). There was no difference between the groups in other clinical outcomes. No adverse effects related to treatment were recorded in either group.

CONCLUSION

Early fibrinogen replacement with fibrinogen concentrate was feasible. Larger trials are required to properly evaluate clinical outcomes.

Effect of fibrinogen concentrate administration on early mortality in traumatic hemorrhagic shock: A propensity score analysis

BACKGROUND

Fibrinogen concentrate is widely used in traumatic hemorrhagic shock despite weak evidence in the literature. The aim of the study was to evaluate the effect of fibrinogen concentrate administration within the first 6 hours on 24-hour all-cause mortality in traumatic hemorrhagic shock using a causal inference approach.

METHODS

Observational study from a French multicenter prospective trauma registry was performed. Hemorrhagic shock was defined as transfusion of four or more red blood cell units within the first 6 hours after admission. The confounding variables for the outcome (24-hour all-cause mortality) and treatment allocation (fibrinogen concentrate administration within the first 6 hours) were chosen by a Delphi method. The propensity score was specified with a data-adaptive algorithm and a doubly-robust approach with inverse proportionality of treatment weighting allowed to compute the average treatment effect. Sensitivity analyses were performed.

RESULTS

Of 14,336 patients in the registry during the study period, 1,027 in hemorrhagic shock were analyzed (758 receiving fibrinogen concentrate within 6 hours and 269 not receiving fibrinogen concentrate). The average treatment effect, expressed as a risk difference, was -0.031 (95% confidence interval, -0.084 to 0.021). All sensitivity analysis confirmed the results.

CONCLUSIONS

Fibrinogen concentrate administration within the first 6 hours of a traumatic hemorrhagic shock did not decrease 24-hour all-cause mortality.

LEVEL OF EVIDENCE

Prognostic, level III.

Fibrinogen Diagnostics in Major Hemorrhage

Fibrinogen is one of the first factors to fall to critically low levels in the blood in many coagulopathic events. Patients with hypofibrinogenemia are at a significantly greater risk of major hemorrhage and death. The rapid replacement of fibrinogen early on in hypofibrinogenemia may significantly improve outcomes for patients. Fibrinogen is present at concentrations between 2 and 4 g/L in the plasma of healthy people. However, hypofibrinogenemia is diagnosed when the fibrinogen level drops below 1.5-2 g/L. This review analyses different types of fibrinogen assays that can be used for diagnosing hypofibrinogenemia. The scientific mechanisms and limitations behind these tests are then presented. Additionally, the current state of clinical major hemorrhage protocols (MHPs) is presented and the structure, function and physiological role of fibrinogen is summarized.

Pathophysiological Response to Trauma-Induced Coagulopathy: A Comprehensive Review

Hypercoagulability can occur after severe tissue injury, that is likely related to tissue factor exposure and impaired endothelial release of tissue plasminogen activator (tPA). In contrast, when shock and hypoperfusion occur, activation of the protein C pathway and endothelial tPA release induce a shift from a procoagulant to a hypocoagulable and hyperfibrinolytic state with a high risk of bleeding. Both thrombotic and bleeding phenotypes are associated with increased mortality and are influenced by the extent and severity of tissue injury and degree of hemorrhagic shock. Response to trauma is a complex, dynamic process in which risk can shift from bleeding to thrombosis depending on the injury pattern, hemostatic treatment, individual responses, genetic predisposition, and comorbidities. Based on this body of knowledge, we will review and consider future directions for the management of severely injured trauma patients.

Hemostatic agents for prehospital hemorrhage control: a narrative review

Hemorrhage is the leading cause of preventable death in combat trauma and the secondary cause of death in civilian trauma. A significant number of deaths due to hemorrhage occur before and in the first hour after hospital arrival. A literature search was performed through PubMed, Scopus, and Institute of Scientific Information databases for English language articles using terms relating to hemostatic agents, prehospital, battlefield or combat dressings, and prehospital hemostatic resuscitation, followed by cross-reference searching. Abstracts were screened to determine relevance and whether appropriate further review of the original articles was warranted. Based on these findings, this paper provides a review of a variety of hemostatic agents ranging from clinically approved products for human use to newly developed concepts with great potential for use in prehospital settings. These hemostatic agents can be administered either systemically or locally to stop bleeding through different mechanisms of action. Comparisons of current hemostatic products and further directions for prehospital hemorrhage control are also discussed.

Early administration of fibrinogen concentrate is associated with improved survival among severe trauma patients: a single-centre propensity score-matched analysis

Background

Fibrinogen plays an important role in haemostasis during the early phase of trauma, and low fibrinogen levels after severe trauma are associated with haemostatic impairment, massive bleeding, and poor outcomes. Aggressive fibrinogen supplementation may improve haemostatic function, as fibrinogen levels deteriorate before other routine coagulation parameters in this setting. Therefore, we evaluated whether early administration of fibrinogen concentrate (FC) was associated with improved survival in severe trauma patients.

Methods

This single-centre retrospective study evaluated patients with severe trauma (injury severity score ≥ 16) who were admitted to our emergency department between January 2010 and July 2018. The exclusion criteria included age < 18 years, cardiac arrest before emergency department arrival, cervical spinal cord injury not caused by a high-energy accident, and severe burn injuries. The FC and control groups included trauma patients who received and did not receive FC within 1 h after emergency department arrival, respectively. Propensity scores were used to balance the two groups based on the trauma and injury severity score (TRISS), heart rate at emergency department admission, and age. The primary outcome was the in-hospital survival rate.

Results

The propensity scoring model had a c-statistic of 0.734, the Hosmer-Lemeshow chi-squared value was 7.036 (degrees of freedom = 8), and the non-significant p value of 0.533 indicated a good model fit. The propensity score matching created 31 matched pairs of patients, who had appropriately balanced characteristics. The FC group had a significantly higher in-hospital survival rate than the control group (log-rank p = 0.013). The FC group also used significantly higher amounts of red blood cells and fresh frozen plasma within 6 h after emergency department admission. However, the two groups had similar transfusion amounts between 6 and 24 h after emergency department admission.

Conclusions

The present study revealed that early FC administration was associated with a favourable survival rate among severe trauma patients. Therefore, FC may be useful for the early management of trauma-induced coagulopathy and may improve outcomes in this setting.

Rapid, hand-held paper diagnostic for measuring Fibrinogen Concentration in blood

Critical bleeding causes over 2 million deaths a year. Early hypofibrinogenemia is a strong predictor of mortality in critically bleeding patients. The early replenishment of fibrinogen can significantly improve outcomes. However, over replenishment can also be dangerous. Furthermore, there is no rapid, cheap, hand-held diagnostic that can aid critically bleeding patients in fibrinogen replacement therapy. In this study, we have developed a hand-held paper diagnostic that measures plasma fibrinogen concentrations. The diagnostic has the potential to be used as a point of care device both inside and outside of hospital settings. It can vastly reduce the time to treatment for fibrinogen replacement therapy. The diagnostic is a two-step process. First, thrombin and plasma are added onto horizontially-orientated paper strips where the fibrinogen is converted into fibrin, drastically increasing the plasma's hydrophobicity. Second, an aqueous blue dye is pipetted onto the strips and allowed to wick through the fibrin. The distance the blue dye wicks through the strip correlates precisely to the fibrinogen concentration. The diagnostic can provide results within a minute. It can distinguish low fibrinogen concentrations (ie. <2 g/L) from normal fibrinogen concentrations. It shows remarkable reproducibility between healthy individuals. It is unaffected by common blood conditions such as acidosis, blood alcohol, severe hypertriglyceridemia, severe haemolysis and warfarin administration. Finally, it is unaffected by humidity and can withstand cold temperatures.

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.

Bad blood: A coagulopathy associated with trauma and massive transfusion review

Coagulopathy in trauma patients is a known contributor to death due to hemorrhage. In fact, it seen as frequently as 35% of the time. The complexity of the coagulopathy pathway requires a deliberate and planned approach. The methods used to assess and detect if a patient is coagulopathic remain challenging, but tools have been developed to assist the practitioner to effectively manage and even quickly reverse the coagulopathy. The purpose of this review is to educate trauma and emergency medicine staff on the currently available diagnostic tools to assess coagulopathy, to provide an overview of the coagulopathy pathway, as well as provide examples of how to intervene and treat coagulopathy, including the use of crew resource management during mass transfusion protocol activations.

Towards patient-specific management of trauma hemorrhage: the effect of resuscitation therapy on parameters of thromboelastometry

Essentials The response of thromboelastometry (ROTEM) parameters to therapy is unknown. We prospectively recruited hemorrhaging trauma patients in six level-1 trauma centres in Europe. Blood products and pro-coagulants prevent further derangement of ROTEM results. ROTEM algorithms can be used to treat and monitor trauma induced coagulopathy. SUMMARY: Background Rotational thromboelastometry (ROTEM) can detect trauma-induced coagulopathy (TIC) and is used in transfusion algorithms. The response of ROTEM to transfusion therapy is unknown. Objectives To determine the response of ROTEM profiles to therapy in bleeding trauma patients. Patients/Methods A prospective multicenter study in bleeding trauma patients (receiving ≥ 4 red blood cell [RBC] units) was performed. Blood was drawn in the emergency department, after administration of 4, 8 and 12 RBC units and 24 h post-injury. The response of ROTEM to plasma, platelets (PLTs), tranexamic acid (TXA) and fibrinogen products was evaluated in the whole cohort as well as in the subgroup of patients with ROTEM values indicative of TIC. Results Three hundred and nine bleeding and shocked patients were included. A mean dose of 3.8 g of fibrinogen increased FIBTEM CA5 by 5.2 mm (IQR: 4.1-6.3 mm). TXA administration decreased lysis by 5.4% (4.3-6.5%). PLT transfusion prevented further derangement of parameters of clot formation. The effect of PLTs on EXTEM ca5 values was more pronounced in patients with a ROTEM value indicative of TIC than in the whole cohort. Plasma transfusion decreased EXTEM clotting time by 3.1 s (- 10 s to 3.9 s) in the whole cohort and by 10.6 s (- 45 s to 24 s) in the subgroup of patients with a ROTEM value indicative of TIC. Conclusion The effects of therapy on ROTEM values were small, but prevented further derangement of test results. In patients with ROTEM values indicative of TIC, the efficacy of PLTs and plasma in correcting deranged ROTEM parameters is possibly more robust.

Impact of initial coagulation and fibrinolytic markers on mortality in patients with severe blunt trauma: a multicentre retrospective observational study

Background

Acute coagulopathy is a well-known predictor of poor outcomes in patients with severe trauma. However, using coagulation and fibrinolytic markers, how one can best predict mortality to find out potential candidates for treatment of coagulopathy remains unclear. This study aimed to determine preferential markers and their optimal cut-off values for mortality prediction.

Methods

We conducted a retrospective observational study of patients with severe blunt trauma (injury severity score ≥ 16) transferred directly from the scene to emergency departments at two trauma centres in Japan from January 2013 to December 2015. We investigated the impact and optimal cut-off values of initial coagulation (platelet counts, fibrinogen and prothrombin time-international normalised ratio) and a fibrinolytic marker (D-dimer) on 28-day mortality via classification and regression tree (CART) analysis. Multivariate logistic regression analysis confirmed the importance of these markers. Receiver operating characteristic curve analyses were used to examine the prediction accuracy for mortality.

Results

Totally 666 patients with severe blunt trauma were analysed. CART analysis revealed that the initial discriminator was fibrinogen (cut-off, 130 mg/dL) and the second discriminator was D-dimer (cut-off, 110 μg/mL in the lower fibrinogen subgroup; 118 μg/mL in the higher fibrinogen subgroup). The 28-day mortality was 90.0% (lower fibrinogen, higher D-dimer), 27.8% (lower fibrinogen, lower D-dimer), 27.7% (higher fibrinogen, higher D-dimer) and 3.4% (higher fibrinogen, lower D-dimer). Multivariate logistic regression demonstrated that fibrinogen levels < 130 mg/dL (adjusted odds ratio [aOR], 9.55; 95% confidence interval [CI], 4.50–22.60) and D-dimer ≥110 μg/mL (aOR, 5.89; 95% CI, 2.78–12.70) were independently associated with 28-day mortality after adjusting for probability of survival by the trauma and injury severity score (TRISS Ps). Compared with the TRISS Ps alone (0.900; 95% CI, 0.870–0.931), TRISS Ps with fibrinogen and D-dimer yielded a significantly higher area under the curve (0.942; 95% CI, 0.920–0.964; p < 0.001).

Conclusions

Fibrinogen and D-dimer were the principal markers for stratification of mortality in patients with severe blunt trauma. These markers could function as therapeutic targets because they were significant predictors of mortality, independent from severity of injury.

[Viscoelasticity-based treatment of bleeding injuries]

Uncontrolled bleeding is the leading preventable cause of death in patients with multiple injuries. Currently, trauma-induced coagulopathy is seen as an independent disease entity influencing survival. Severely bleeding trauma patients are often treated with classical blood products in predefined ratios (damage control resuscitation). Viscoelasticity-based and target-oriented approaches could possibly be given priority. Viscoelasticity-based diagnostics and therapy enable the qualitative investigation of whole blood and provide therapeutically usable information on initiation, dynamics and sustainability of thrombus formation. Due to the ease of handling and timely results this lends itself as a point-of-care procedure. This article presents the clinical issues with using viscoelastic procedures and current expert recommendations taking the literature into consideration.

Rapid paper diagnostic for plasma fibrinogen concentration

Fibrinogen is one of the first proteins to be depleted in heavily bleeding patients. In this study, we have developed a new paper-based diagnostic to quantify the fibrinogen concentration in blood at room temperature.

Markers of Fibrinolysis in Indian Patients with Isolated Head Trauma

Context

Head injury causes disseminated intravascular coagulation as the most severe complication which is associated with high mortality. Elevated levels of markers of fibrinolysis such as D-dimer and fibrinopeptide A (FPA) have been correlated with poor outcome in these patients.

Aim

The study aimed to correlate the levels of plasma fibrinogen, D-dimer, and FPA with outcome in patients with isolated head trauma.

Settings and Design

This cross-sectional descriptive study was conducted in the Departments of Pathology and Neurosurgery, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, on 100 patients admitted within 12 h of isolated head trauma.

Subjects and Methods

Plasma fibrinogen, D-dimer, and FPA were measured in 100 patients admitted within 12 h of isolated head trauma. While plasma fibrinogen and D-dimer were estimated in all patients, FPA was measured in 45 patients.

Statistical Analysis

SPSS (20.2) software was used for mean, standard deviation, and median values of the quantitative parameters, and for all qualitative parameters, their frequencies were obtained. P < 0.05 was considered significant.

Results

Elevated D-dimer (>250 ng/ml) and FPA (>3 ng/ml) were observed in 64% and 91.1% patients, respectively. Both D-dimer and FPA were elevated in 66.6% of patients. Disseminated intravascular coagulation (DIC) score, calculated using standard criteria, was ≥5 in 28% of patients indicating overt DIC. Hypofibrinogenemia was observed in 48% of patients. D-dimer, FPA, and DIC score was significantly (P < 0.001) higher and plasma fibrinogen significantly (P < 0.001) lower in nonsurvivors as compared to survivors. Elevated D-dimer and FPA and low fibrinogen levels were seen in patients irrespective of severity of injury.

Conclusions

Elevated D-dimer and FPA were frequently observed in patients with isolated head trauma. As these markers rise soon after injury and indicate poor outcome, their measurement will help identify patients who will benefit with additional therapy, thus reducing morbidity and mortality.

Thromboelastography and Thromboelastometry in Assessment of Fibrinogen Deficiency and Prediction for Transfusion Requirement: A Descriptive Review

Fibrinogen is crucial for the formation of blood clot and clinical outcomes in major bleeding. Both Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) have been increasingly used to diagnose fibrinogen deficiency and guide fibrinogen transfusion in trauma and surgical bleeding patients. We conducted a comprehensive and comparative review on the technologies and clinical applications of two typical functional fibrinogen assays using TEG (FF TEG) and ROTEM (FIBTEM) for assessment of fibrinogen level and deficiency, and prediction of transfusion requirement. Clot strength and firmness of FF TEG and ROTEM FIBTEM were the most used parameters, and their associations with fibrinogen levels as measured by Clauss method ranged from 0 to 0.9 for FF TEG and 0.27 to 0.94 for FIBTEM. A comparison of the interchangeability and clinical performance of the functional fibrinogen assays using the two systems showed that the results were correlated, but are not interchangeable between the two systems. It appears that ROTEM FIBTEM showed better associations with the Clauss method and more clinical use for monitoring fibrinogen deficiency and predicting transfusion requirements including fibrinogen replacement than FF TEG. TEG and ROTEM functional fibrinogen tests play important roles in the diagnosis of fibrinogen-related coagulopathy and guidance of transfusion requirements. Despite the fact that high-quality evidence is still needed, the two systems are likely to remain popular for the hemostatic management of bleeding patients.

Pediatric Massive Transfusion: A Systematic Review

INTRODUCTION

Balanced resuscitation of plasma, platelets, and red blood cells is now recognized as improving outcomes in traumatic bleeding in adults. The correct approach in children has yet to be determined.

METHODS

We performed a systematic review of the literature into transfusion protocols in traumatic hemorrhage in children by conducting an article search of significant databases to identify relevant articles. Studies of interest included interventional trials with comparisons relating to the transfusion of blood including blood component therapy. The search identified 422 articles of interest, the abstracts of which were independently reviewed by 2 authors for inclusion in the trial. This revealed 35 articles, the full texts of which were reviewed. There were no randomized controlled trials and 4 nonrandomized trials with a further 21 articles that were deemed relevant. The data were insufficient for meta-analysis, and so a descriptive analysis was performed.

RESULTS

There were 4 main trials. Two trials were small (approximately 100 patients) nonrandomized trials into pediatric hemorrhage managed as per a massive transfusion protocol or at physician discretion. One was a retrospective analysis of pediatric trauma patients who received red blood cell transfusion with differing platelet ratios, and one was a trauma database review of component ratios in hemorrhaging children. All 4 trials found increased ratios had no effect on mortality.

DISCUSSION

As well as blood component therapy, adjunctive therapies used in the management of bleeding children are discussed. These include tranexamic acid, viscoelastic hemostatic assays, factor VIIa, and fibrinogen use.

CONCLUSIONS

There is little evidence for improved outcomes using component-based transfusion in a rigid 1:1:1 strategy in children. A goal-directed approach using viscoelastic hemostatic assay-guided treatment with early institution of tranexamic acid and fibrinogen replacement is considered the way forward.