Haemotherapy algorithm for the management of trauma-induced coagulopathy: an Australian perspective

Resuscitation of adult shocked trauma patients using major haemorrhage protocol guided by viscoelastic haemostatic assays versus formulaic approach

BACKGROUND

The resuscitation of trauma patients with critical bleeding may follow a formulaic approach using high ratios of blood components or a viscoelastic haemostatic assay (VHA) guided approach. The aim of this study was to compare the two strategies for resuscitation of shocked trauma patients.

METHODS

This was a registry-based cohort study including shocked trauma patients from two trauma centres-one practising a formulaic approach, with VHA unavailable during trauma resuscitation and the other practicing a VHA-guided resuscitation strategy. The primary outcome was the total units of blood components transfused in 24 h after adjusting for differences in baseline characteristics and time to death.

RESULTS

Between 01 Jan 2020 and 31 Dec 2022, 152 eligible patients were categorised to the formulaic group and 40 to the VHA group. Prehospital times were longer in the formulaic group (2.0 vs. 1.4 h), and more patients in the VHA group (38% vs. 17%) were transfused prehospital blood components. Formulaic resuscitation was associated with significantly more blood components transfused (adjusted incidence rate ratio 1.5; 95%CI: 1.4-1.7, p < 0.001). Using a formulaic approach, patients were administered more red blood cells, plasma and platelets, but fewer cryoprecipitate. There was no significant association of the formulaic approach with in-hospital mortality (adjusted odds ratio 2.4; 95%CI: 0.7-8.0, p = 0.17).

CONCLUSIONS

Given the cost and potential adverse effects of blood component transfusions, VHA-guided transfusion strategies present an attractive option, particularly among centres managing high volumes of shocked patients. Further trials, enrolling the population most likely to benefit from precision transfusion strategies, are indicated.

Timing and volume of transfusion for adult major trauma patients with hemorrhagic shock: a registry-based cohort study

Introduction

Transfusion of blood components is vital for the resuscitation of injured patients in hemorrhagic shock. Delays in initiating transfusion have been associated with harm, as has excess transfusion. The aim of this study was to evaluate variables associated with hospital mortality, with a focus on the two modifiable risk factors- time to initiate transfusion and volume of blood components-with hospital mortality.

Methods

This was a registry-based cohort study, including all consecutive adult patients presenting with hemorrhagic shock (systolic blood pressure (SBP) ≤90 mm Hg and transfusion of blood components) to a level 1 adult trauma center during a 5-year period (January 1, 2017-December 31, 2021). Associations with hospital mortality were assessed using multivariable logistic regression analysis, with final models developed using backward elimination.

Results

There were 195 patients included and there were 49 (25.1%) in-hospital deaths. The median time to first transfusion was 10 (IQR 6-16) minutes. Age (adjusted OR (aOR) 1.06; 95% CI: 1.03 to 1.08), initial SBP (aOR 0.96; 95% CI: 0.3 to 0.98), intracranial bleeding or diffuse axonal injury (aOR 2.63; 95% CI: 1.11 to 6.23), and the volume of blood components in the first 4 hours (aOR 1.08; 95% CI: 1.03 to 1.13) were associated with mortality. Time to transfusion was not associated with in-hospital mortality (aOR 0.99; 95% CI: 0.95 to 1.03). Among the 90 patients who underwent urgent transfer to the operating room or angiography suite, the median time to transfer was 2.38 hours (IQR 1.5-3.7). In this subgroup, age (aOR 1.11; 95% CI: 1.05 to 1.18) and volume of blood components (aOR 1.20; 95% CI: 1.08 to 1.34) were associated with mortality.

Discussion

In this setting where times to transfusion are short, further reductions in the time to transfusion are unlikely to improve outcome. In our population, for every unit of blood component transfused, the adjusted odds of death increased by 8%. These findings suggest investigation into strategies to achieve earlier control of hemorrhage.

Level of evidence

III.

Rotational thromboelastometry values across age groups in all trauma patients presenting to a level 1 trauma centre: An observational study

OBJECTIVES

To describe rotational thromboelastometry (ROTEM) values (FIBTEM A5, EXTEM A5 and EXTEM CT) across age groups and assess for a statistical trend; and to determine whether any trend in ROTEM values is affected by severity of injury and packed red blood cells (PRBC) requirement.

METHODS

Retrospective observational study at a level 1 trauma centre in Queensland, Australia. A total of 1601 consecutive trauma patients presenting to the ED. ROTEM data described included FIBTEM A5, EXTEM A5 and EXTEM CT. These values are described by age group (≤30 years, 31-45 years, 46-60 years, 61-75 years and >75 years), Injury Severity Score (ISS) category (<12, ≥12, <25 and ≥25) and number of PRBCs transfused in the first 24 h of admission (0 units, 1-4 units, 5-9 units and ≥10 units).

RESULTS

The median age of participants was 37 years (interquartile range [IQR] 25-54 years), with 48.2% of patients had severe trauma (ISS >12) and 13.2% receiving at least one unit of PRBC in the first 24 h of admission. Median (IQR) values for FIBTEM A5, EXTEM A5 and EXTEM CT were 13 mm (10-16 mm), 45 mm (40-49 mm) and 62 s (56-71 s), respectively. A test for trend over progressive age groups showed an increase in FIBTEM A5 (P < 0.001) and EXTEM A5 values (P < 0.001) and a decrease in EXTEM CT values (P < 0.001).

CONCLUSION

The present study demonstrated a pattern of increasing coagulability, as defined by ROTEM, with increasing age group in trauma patients, even among the severely injured. Further investigation is required to determine the clinical impact of these findings on both the ROTEM-guided management and longitudinal outcomes of these patients and whether an age-specific approach is beneficial.

Getting hit by the bus around the world - a global perspective on goal directed treatment of massive hemorrhage in trauma

PURPOSE OF REVIEW

Major trauma remains one of the leading causes of death worldwide with traumatic brain injury and uncontrolled traumatic bleeding as the main determinants of fatal outcome. Interestingly, the therapeutic approach to trauma-associated bleeding and coagulopathy shows differences between geographic regions, that are reflected in different guidelines and protocols.

RECENT FINDINGS

This article summarizes main principles in coagulation diagnostics and compares different strategies for treatment of massive hemorrhage after trauma in different regions of the world. How would a bleeding trauma patient be managed if they got hit by the bus in the United States, United Kingdom, Germany, Switzerland, Austria, Denmark, Australia, or in Japan?

SUMMARY

There are multiple coexistent treatment standards for trauma-induced coagulopathy in different countries and different trauma centers. Most of them initially follow a protocol-based approach and subsequently focus on predefined clinical and laboratory targets.

Substitution of ROTEM FIBTEM A5 for A10 in trauma: an observational study building a case for more rapid analysis of coagulopathy

PURPOSE

Rotational thromboelastometry (ROTEM®) allows guided blood product resuscitation to correct trauma-induced coagulopathy in bleeding trauma patients. FIBTEM amplitude at 10 min (A10) has been widely used to identify hypofibrinogenaemia; locally a threshold of < 11 mm has guided fibrinogen replacement. Amplitude at 5 min (A5) carries an inherent time advantage. The primary aim was to explore the relationship between FIBTEM A5 and A10 in a trauma. Secondary aim was to investigate the use of A5 as a surrogate for A10 within a fibrinogen-replacement algorithm.

METHODS

Retrospective observational cohort study of arrival ROTEM results from 1539 consecutive trauma patients at a Level 1 trauma centre in Australia. Consistency of agreement between FIBTEM A5 and A10 was assessed. A new fibrinogen replacement threshold was developed for A5 using the A5-A10 bias; this was clinically compared to the existing A10 threshold.

RESULTS

FIBTEM A5 displayed excellent consistency of agreement with A10. Intraclass correlation coefficient = 0.972 (95% confidence interval [CI] 0.969-0.974). Bias of A5 to A10 was - 1.49 (95% CI 1.43-1.56) mm. 19.34% patients met the original local threshold of A10 < 11 mm; 19.28% patients met the new, bias-adjusted threshold of A5 < 10 mm.

CONCLUSION

ROTEM FIBTEM A5 reliably predicts A10 in trauma. This further validates use of the A5 result over A10 allowing faster decision-making in time-critical resuscitation of trauma patients. A modification of -1 to the A10 threshold might be appropriate for use with the A5 value in trauma patients.

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.

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.

Sufficient Thrombin Generation Despite 95% Hemodilution: An In Vitro Experimental Study

Guidelines for the treatment of severe bleeding comprise viscoelastic-test-guided use of coagulation factor concentrates as part of their recommendations. The aim of this study is to investigate the effects of substituting fibrinogen, prothrombin complex concentrate, and a combination of both on conventional coagulation tests, viscoelastic test results, and thrombin generation. Blood was drawn from seven healthy volunteers to obtain platelet-free plasma, which later was diluted by replacing 40%, 60%, 80%, 90%, 95%, and 99% with a crystalloid solution. The diluted samples were spiked with fibrinogen concentrate, prothrombin complex concentrate, a combination of both, or a corresponding amount of crystalloid solution. Up to a dilution level of 95%, viscoelastically determined clotting time was significantly shorter in the group substituted with fibrinogen only in comparison with the additional use of prothrombin complex concentrate. Clot firmness and endogenous thrombin potential remained at relatively stable values up to a dilution level of 95% with the substitution of fibrinogen but not prothrombin complex concentrate. Substitution of prothrombin complex concentrate led to an excessive overshoot of thrombin generation. The results of our study question currently propagated treatment algorithms for bleeding patients that include the use of prothrombin complex concentrate for patients without former intake of oral anticoagulants. Even in severely bleeding patients, thrombin generation might be sufficient to achieve adequate hemostasis.

Damage Control Resuscitation in polytrauma patient

Haemorrhagic shock is one of the main causes of mortality in severe polytrauma patients. To increase the survival rates, a combined strategy of treatment known as Damage Control has been developed. The aims of this article are to analyse the actual concept of Damage Control Resuscitation and its three treatment levels, describe the best transfusion strategy, and approach the acute coagulopathy of the traumatic patient as an entity. The potential changes of this therapeutic strategy over the coming years are also described.

Fibrinogen Early In Severe Trauma studY (FEISTY): study protocol for a randomised controlled trial

BACKGROUND

Haemorrhage is a leading cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage. Early fibrinogen replacement is recommended by several international trauma guidelines using either fibrinogen concentrate (FC) or cryoprecipitate (Cryo). There is limited evidence to support one product over the other with widespread geographic and institutional variation in practice. This pilot trial is the first randomised controlled trial comparing FC to Cryo in traumatic haemorrhage.

METHODS/DESIGN

The Fibrinogen Early In Severe Trauma studY (FEISTY) is an exploratory, multicentre, randomised controlled trial comparing FC to Cryo for fibrinogen supplementation in traumatic haemorrhage. This trial will utilise thromboelastometry (ROTEM®) to guide and dose fibrinogen supplementation. The trial will recruit 100 trauma patients at four major trauma centres in Australia. Adult trauma patients with evidence of haemorrhage will be enrolled on arrival in the trauma unit and randomised to receiving fibrinogen supplementation with either FC or Cryo. The primary outcome is the differential time to fibrinogen supplementation. There are a number of predetermined secondary outcomes including: effects of the intervention on plasma fibrinogen levels, feasibility assessments and clinical outcomes including transfusion requirements and mortality.

DISCUSSION

The optimal method for replacing fibrinogen in traumatic haemorrhage is fiercely debated. In this trial the feasibility and efficacy of fibrinogen supplementation using FC will be compared to Cryo. The results of this pilot study will facilitate the design of a larger trial with sufficient power to address patient-centred outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02745041 . Registered 4 May 2016.