Fibrinogen depletion in trauma: early, easy to estimate and central to trauma-induced coagulopathy

Targeted cryoprecipitate transfusion in severe traumatic haemorrhage

BACKGROUND

Severe traumatic haemorrhage is the leading cause of death in young adults. Trauma Induced Coagulopathy is a complex and multifactorial phenomenon associated with severe traumatic haemorrhage. Fibrinogen is one of the first coagulation factors to become depleted in TIC and evidence suggests that severely injured trauma patients with hypofibrinogenaemia have poor outcomes. It is postulated that early fibrinogen replacement can improve clinical outcomes. This study investigated cryoprecipitate transfusion in hyopfibrinogeneamic trauma patients.

METHODS

This retrospective, single center, observational study investigated the use of cryoprecipitate in severely injured trauma patients admitted to an Australian Level I Trauma Centre. The primary outcome was time to administration of cryoprecipitate after identification of hypofibrinogenaemia using ROTEM (FIBTEM A5). Data collected included demographics, ISS, laboratory values of coagulation and blood product usage.

RESULTS

71 patients received cryoprecipitate with a median time of 61 minutes [IQR 37-93] from FIBTEM A5 result to initial cryoprecipitate administration. At 24 hours following admission to ED, Clauss Fibrinogen levels increased by 1.30g/L [IQR 0.45-1.85] and FIBTEM A5 assay increased by 8mm [IQR 3.0-11.3]. Changes in both variables were highly significant (p<0.001) and Clauss Fibrinogen versus FIBTEM A5 values showed moderate to strong correlation (R=0.75-0.80).

CONCLUSION

This study demonstrated that early administration of cryoprecipitate was both feasible and efficacious in fibrinogen replacement in severe traumatic haemorrhage. High-level evidence supporting cryoprecipitate or fibrinogen concentrate replacement with regards to efficacy and feasibility is required to guide future clinical practice. This study provided baseline data to inform the design of further clinical trials investigating fibrinogen replacement in traumatic haemorrhage.

Early coagulation support protocol: A valid approach in real-life management of major trauma patients. Results from two Italian centres

INTRODUCTION

Early coagulation support (ECS) includes prompt infusion of tranexamic acid, fibrinogen concentrate, and packed red blood cells for initial resuscitation of major trauma patients. The aim of this study was to determine the effects, in terms of blood product consumption, length of stay, and in-hospital mortality, of the ECS protocol, compared to the massive transfusion protocol (MTP) in the treatment of major trauma patients.

PATIENTS AND METHODS

A retrospective analysis was conducted using the registry data of two Italian trauma centres. Adult major trauma patients with, or at risk of, active bleeding who were managed according to the MTP during the years 2011-2012, or the ECS protocol during the years 2013-2014 and were considered at risk of multiple transfusions, were enrolled. The primary endpoint was to determine whether the ECS protocol reduces the use of blood products in the acute management of trauma patients. Secondary endpoints were the outcome measures of length of stay in ICU, length of stay in hospital, and mortality at 24-hours and 28-days after hospital admission.

RESULTS

Among the 518 major trauma patients admitted to the trauma centres during the study period, 235 patients (118 in the pre-ECS period and 117 in the ECS period) matched one of the inclusion criteria and were enrolled in the study. Compared with the pre-ECS period, the ECS period showed a reduction in the average consumption of packed red blood cells (-1.87 units, 95% confidence interval [CI], -2.40, -1.34), platelets (-1.28 units; 95% CI, -1.64, -0.91), and fresh frozen plasma (-1.69; 95% CI, -2.14, -1.25) in the first 24-hours. Furthermore, during the ECS period, we recorded a 10-day reduction in the hospital length of stay (-10 days, 95% CI, -11.6, -8.4) and a non-significant 28-day mortality increase.

CONCLUSIONS

The ECS protocol was effective in reducing blood product consumption compared to the MTP and confirmed the importance of early fibrinogen administration as a strategy of rapid coagulation. This novel approach may be adopted in real-life management of major trauma patients.

Values of detection of NF-κB activation level combined with IL-6 and TNF-α levels in peripheral neutrophils in the prediction of multiple organ dysfunction syndrome in patients with severe multiple trauma

The aim of this study was to analyze the dynamic changes and predictive values of nuclear factor-κB (NF-κB) combined with interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in peripheral blood in multiple organ dysfunction syndrome (MODS) in patients with severe multiple trauma. Seventy patients diagnosed with severe multiple trauma in Emergency Department of Sichuan Provincial People's Hospital (Chengdu, China) from April 2014 to April 2016 were selected and retrospectively analyzed. The patients enrolled were divided into the MODS group (n=25) and the non-MODS group (n=45). The injury severity scores (ISSs), acute physiology and chronic health evaluation II (APACHE II) scores, NF-κB, IL-6 and TNF-α levels in patients were detected at different time points (12, 24 and 48 h after admission), the changes in different indexes and the areas under the receiver operating characteristic (ROC) curve (AUC) were analyzed. The predictive values of different detection methods in MODS patients were discussed and compared. The ISS, APACHE II score, NF-κB, IL-6 and TNF-α levels in the MODS group at admission and 24 and 48 h after admission were higher than those in the non-MODS group (P<0.05). Those indexes in the deceased patients at 12, 24 and 48 h after admission were higher than those in survivors (P<0.05). The ISS, APACHE II score, NF-κB, IL-6 and TNF-α levels were not the risk factors of MODS in patients with severe multiple trauma (P>0.05). AUCs of ISS >22 points and APACHE II score >14 points in predicting MODS were lower than that of combined detection of NF-κB >1.20. In conclusion, the combined detection of NF-κB, IL-6 and TNF-α in peripheral blood of patients with acute multiple trauma is more helpful to predict the occurrence of MODS, which has a certain guiding significance for the prognosis of patients with MODS.

Early Predictive Factors of Hypofibrinogenemia in Acute Trauma Patients

Background:

Uncontrolled hemorrhage still remains a major cause of trauma-associated mortality. The events resulting in acute traumatic coagulopathy, particularly hypofibrinogenemia, make control of bleeding difficult. It is essential to timely predict, diagnose, and manage trauma-induced coagulopathy.

Aims:

The aim of this study is to determine clinical and easily available laboratory variables that are predictive of hypofibrinogenemia in acute trauma patients.

Settings and Design:

This 2-year retrospective work examined the data of major trauma patients that were referred to Shahid Rajaee Hospital's emergency room in hemorrhagic shock condition.

Materials and Methods:

Fibrinogen level was assessed for these patients on their arrival at our facility. Along with clinical and routine paraclinical variables, we evaluated the predictive value of these variables for a fibrinogen level below 100 mg/ml.

Results:

A total of 855 cases were included (females: 16.4%; and males: 83.6%) in the study. The mean ± SD age was 36 ± 17.9 years, and the mean ± SD injury severity score was 12.2 ± 9. Motor vehicle accident was the most common cause of injury. Three factors, including arterial pH (cut off point = 7.34; area under the curve [AUC]: 0.59), base excess (cutoff point = −4.3; AUC: 0.60), and patients' gender had a significant association with the fibrinogen level under 100 mg/ml. When three factors of pH, BE, and patients' gender are being assessed simultaneously, the AUC became 0.62 (the predictive ability improved).

Conclusions:

Variables, including arterial pH, BE level, and patients' gender have predictive value for fibrinogen transfusion in trauma.

Abnormalities of laboratory coagulation tests versus clinically evident coagulopathic bleeding: results from the prehospital resuscitation on helicopters study (PROHS)

BACKGROUND

Laboratory-based evidence of coagulopathy (LC) is observed in 25-35% of trauma patients, but clinically-evident coagulopathy (CC) is not well described.

METHODS

Prospective observational study of adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers in 2015. Patients meeting predefined highest-risk criteria were divided into CC+ (predefined as surgeon-confirmed bleeding from uninjured sites or injured sites not controllable by sutures) or CC-. We used a mixed-effects, Poisson regression with robust error variance to test the hypothesis that abnormalities on rapid thrombelastography (r-TEG) and international normalized ratio (INR) were independently associated with CC+.

RESULTS

Of 1,019 highest-risk patients, CC+ (n=41, 4%) were more severely injured (median ISS 32 vs 17), had evidence of LC on r-TEG and INR, received more transfused blood products at 4 hours (37 vs 0 units), and had greater 30-day mortality (59% vs 12%) than CC- (n=978, 96%). The overall incidence of LC was 39%. 30-day mortality was 22% vs 9% in those with and without LC. In two separate models, r-TEG K-time >2.5 min (RR 1.3, 95% CI 1.1-1.7), r-TEG mA <55 mm (RR 2.5, 95% CI 2.0-3.2), platelet count <150 x 10⁹/L (RR 1.2, 95% CI 1.1-1.3), and INR >1.5 (RR 5.4, 95% CI 1.8-16.3) were independently associated with CC+. A combined regression model was not generated because too few patients underwent both r-TEG and INR.

CONCLUSION

CC was rare compared to LC. CC was associated with poor outcomes and impairment of both clotting factor and platelet-mediated coagulation components.

Reversal of dabigatran anticoagulation ex vivo: Porcine study comparing prothrombin complex concentrates and idarucizumab

Urgent surgery or life-threatening bleeding requires prompt reversal of the anticoagulant effects of dabigatran. This study assessed the ability of three- and four-factor prothrombin complex concentrate (PCC) and idarucizumab (specific antidote for dabigatran) to reverse the anticoagulant effects of dabigatran in a porcine model of trauma. Twelve animals were given dabigatran etexilate (DE) orally and dabigatran intravenously, before infliction of trauma. Six animals received tranexamic acid plus fibrinogen concentrate 12 minutes post-injury. Six PCCs (each 30 and 60 U/kg) and idarucizumab (30 and 60 mg/kg) were added to blood samples ex vivo. Coagulation was assessed by several coagulation assays. All coagulation parameters were altered after dabigatran infusion (plasma level: 442 ± 138 ng/ml). Both threeand four-factor PCCs mostly or completely reversed the effects of dabigatran on thromboelastometry variables and PT but not on aPTT. Idarucizumab neutralised plasma concentrations of dabigatran, and reversed the effects of the drug on coagulation variables. Thrombin generation showed dose-dependent over-correction following the addition of PCC, implying that elevated levels of thrombin are required to overcome dabigatran-induced coagulopathy. In contrast, treatment with idarucizumab returned thrombin generation to baseline levels. Following trauma, therapy with tranexamic acid plus fibrinogen improved correction of coagulation parameters by PCC, and thromboelastometry parameters by idarucizumab. All investigated PCCs improved dabigatran- and trauma-induced coagulopathy to a similar degree. In conclusion, this study shows that three- and four-factor PCCs are similarly effective for dabigatran reversal. Idarucizumab also reversed the effects of dabigatran and, unlike PCCs, was not associated with over-correction of thrombin generation.

Note: This study was performed at the RWTH Aachen University Hospital, Pauwelsstrasse 30, D-52074 Aachen, Germany.

Recombinant human prothrombin reduced blood loss in a porcine model of dilutional coagulopathy with uncontrolled bleeding

: Uncontrolled bleeding remains one of the leading causes of trauma-induced death. Treatment recommendations focus on fresh frozen plasma and blood cell transfusions, whereas plasma concentrates or single coagulation factors have been studied in recent years. The effect of recombinant human prothrombin factor II (rhFII, 8 mg/kg), activated recombinant human factor VII (rhFVIIa, 300 μg/kg), plasma-derived human fibrinogen (pdhFib) (200 mg/kg), activated prothrombin complex concentrate (aPCC, 40 IU/kg), a three-factor combination intended as a minimal PCC (8 mg/kg rhFII, 640 μg/kg recombinant human factor X (rhFX), and 12 μg/kg rhFVIIa), and vehicle were investigated in a porcine model of dilutional coagulopathy with uncontrolled bleeding. Survival time and blood loss were determined up to 120 min after induction of liver injury. Rotational thromboelastometry EXTEM coagulation time and maximum clot firmness, prothrombin time, thrombin-antithrombin complex (TAT), thrombin generation (endogenous thrombin potential, ETP) were measured at baseline, after dilution, drug administration, and end of experiment. rhFII, the three-factor combination, and aPCC significantly (P < 0.01) decreased blood loss vs. vehicle and rhFII also vs. fibrinogen (P < 0.05). Survival times increased significantly for rhFII, aPCC, rhFVIIa, and pdhFib vs. vehicle (P < 0.05), and, coagulation time, maximum clot firmness, and prothrombin time improved in all groups. TAT and ETP increased transiently for rhFII and three-factor combination, whereas persistently increased for aPCC. PdhFib and rhFVIIa did not increase TAT and ETP. rhFII decreased blood loss and improved hemostatic markers and survival. In vivo, thrombin generation (TAT) and potential to form thrombin (ETP) were transiently elevated by rhFII. Addition of rhFVIIa and rhFX to rhFII did not further improve hemostatic efficacy.

Perioperatively acquired disorders of coagulation

Purpose of review

To provide an overview of acquired coagulopathies that can occur in various perioperative clinical settings. Also described are coagulation disturbances linked to antithrombotic medications and currently available strategies to reverse their antithrombotic effects in situations of severe hemorrhage.

Recent findings

Recent studies highlight the link between low fibrinogen and decreased fibrin polymerization in the development of acquired coagulopathy. Particularly, fibrin(ogen) deficits are observable after cardiopulmonary bypass in cardiac surgery, on arrival at the emergency room in trauma patients, and with ongoing bleeding after child birth. Regarding antithrombotic therapy, although new oral anticoagulants offer the possibility of efficacy and relative safety compared with vitamin K antagonists, reversal of their anticoagulant effect with nonspecific agents, including prothrombin complex concentrate, has provided conflicting results. Specific antidotes, currently being developed, are not yet licensed for clinical use, but initial results are promising.

Summary

Targeted hemostatic therapy aims to correct coagulopathies in specific clinical settings, and reduce the need for allogeneic transfusions, thus preventing massive transfusion and its deleterious outcomes. Although there are specific guidelines for reversing anticoagulation in patients treated with antiplatelet agents or warfarin, there is currently little evidence to advocate comprehensive recommendations to treat drug-induced coagulopathy associated with new oral anticoagulants.

Rapid measurement of fibrinogen concentration in whole blood using a steel ball coagulometer

Supplemental digital content is available in the text.

BACKGROUND

Fibrinogen plays a key role in hemostasis and is the first coagulation factor to reach critical levels in bleeding patients. Current European guidelines on the management of traumatic or perioperative bleeding recommend fibrinogen supplementation at specific threshold levels. Whole blood viscoelastic tests provide fast evaluation of fibrin deficits. Fast measurement of plasma fibrinogen concentration is not yet available. We investigated a method to rapidly determine whole blood fibrinogen concentration using standard Clauss assays and a steel ball coagulometer and provide an estimate of the “plasma-equivalent” fibrinogen concentration within minutes by adjustment of the measured whole blood fibrinogen concentration with a quickly measureable hemoglobin-derived hematocrit.

METHODS

The feasibility of this approach was tested with a Clauss assay using multiple porcine fresh blood samples obtained during in vivo bleeding, hemodilution, and after treatment with hemostatic therapy. Two different Clauss assays were then tested using multiple human volunteers’ blood samples diluted in vitro and supplemented with fibrinogen concentrate. Comparative measurements with fibrin-based thromboelastometry tests were performed.

RESULTS

Regression and Bland-Altman analyses of derived “plasma-equivalent” fibrinogen and measured plasma fibrinogen concentration was excellent in porcine and human blood samples, especially in the ranges relevant to traumatic or perioperative bleeding.

CONCLUSION

Fast whole blood fibrinogen measurements could be considered as an alternative to plasma fibrinogen measurement for acute bleeding management in trauma and perioperative care settings. Further studies are needed to prove this concept and determine the turnaround times for its clinical application in emergency departments and operating theaters.

Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

BACKGROUND

Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration.

METHODS

This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry.

RESULTS

All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site.

CONCLUSION

This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would be time consuming.

LEVEL OF EVIDENCE

Prospective, randomized, therapeutic feasibility study in an animal model, level V.

Deployed research

The Role 3 Medical Treatment Facility (Field Hospital) in Camp Bastion (R3 Bastion) is acknowledged to be one of the busiest dedicated trauma facilities in the world. Casualties typically present with severe injuries and in physiological extremis. These casualties form a unique cohort representing the most relevant population to evaluate the effectiveness of treating battlefield injuries as academic clinicians and scientists interested in trauma seek to improve outcomes for such patients in the future. This article describes four separate but related research projects that have been undertaken in Camp Bastion, Afghanistan, over the last year. They traverse the spectrum of clinical research, ranging from data collection to a randomised control trial. The aim is to discuss some of the problems encountered and the solutions that made it possible to undertake research in a theatre of operations, thereby providing a starting point for others who may wish to initiate research in a similar environment.