New developments in massive transfusion in trauma

Blood Utilization and Thresholds for Mortality Following Major Trauma

INTRODUCTION

Blood loss is a hallmark of traumatic injury. Massive transfusion, historically defined as the replacement by transfusion of 10 units of packed red blood cells (PRBCs) in 4 h, is a response to uncontrolled hemorrhage. We sought to identify blood transfusion thresholds in which predicted mortality exceeds 50%.

METHODS

We analyzed the 2017-2019 National Trauma Database. Inclusion criteria included patients ≥18 y who received ≥1 unit of PRBCs. Statistical analysis included bivariate analysis, logistic regression for mortality, and adjusted predicted probability modeling was utilized.

RESULTS

We identified 61,676 patients for analysis. The 50% predicted mortality for all patients was 31 PRBC units. The 50% predicted mortality was 6 units of PRBCs for elderly trauma patients 80 y and older.

CONCLUSIONS

Blood remains as scarce resource in hospitals especially with trauma. Patients receiving a massive transfusion over a short period of time may exhaust blood bank supply with diminishing survival benefit. Surgeons should be judicious regarding continued blood usage once the 50% predicted mortality threshold is reached.

Efficacy of a massive transfusion protocol for hemorrhagic trauma resuscitation

OBJECTIVES

New paradigm shifts in trauma resuscitation recommend that early reconstitution of whole blood ratios with massive transfusion protocols (MTP) may be associated with improved survival. We performed a preliminary study on the efficacy of MTP at an urban, Level 1 trauma center and its impact on resuscitation goals.

METHODS

A case-control study was performed on consecutive critically-ill trauma patients over the course of 1 year. The trauma captain designated patients as either MTP activation (cases) or routine care without MTP (controls) in matched, non-randomized fashion. Primary outcomes were: time to initial transfusion; number of total units of packed red blood cells (pRBC) and fresh frozen plasma (FFP) transfused; and ratio of pRBC to fresh frozen plasma (pRBC:FFP). Secondary outcomes were in-hospital mortality, and length of stay.

RESULTS

Out of 226 patients screened, we analyzed 58 patients meeting study criteria (32 MTP, 26 non-MTP). Study characteristics for the MTP and non-MTP groups were similar except age (34.0 vs. 45.85 years, p=0.015). MTP patients received blood products more expeditiously (41.7 minutes vs. 62.1 minutes, p=0.10), with more pRBC (5.19 vs 3.08 units, p=0.05), more FFP (0.19 vs 0.08 units, p<0.01), and had larger pRBC:FFP ratios (1.90 vs 0.52, p<0.01). Secondary outcomes did not differ significantly but the MTP group was associated with a trend for decreased hospital length of stay (p=0.08).

CONCLUSIONS

MTP resulted in clinically significant improvements in transfusion times and volumes. Further larger and randomized studies are warranted to validate these findings to optimize MTP protocols.

Prehospital parameters can help to predict coagulopathy and massive transfusion in trauma patients

BACKGROUND

This study aimed to evaluate the accuracy of prehospital parameters, including vital signs and resuscitation (fluids, vasopressor), to predict trauma-induced coagulopathy (TIC, fibrinogen <1·5 g/l or PT_ratio > 1·5 or platelet count <100 × 10⁹ /l), and a massive transfusion (MT, ≥10 RBC units within the first 24 h).

METHODS

From a trauma registry (2011-2015), in which patients are prospectively included, we retrospectively retrieved the heart rate (HR), systolic blood pressure (SBP), volume of prehospital fluids and administration of noradrenaline. We calculated the shock index (SI: HR/SBP), the MGAP prehospital triage score and the Injury Severity Score (ISS). We also identified patients who had positive criteria from the Resuscitation Outcome Consortium (ROC, SBP < 70 mmHg or SBP 70-90 and HR > 107 pulse/min). For these parameters, we drew a ROC curve and defined a cut-off value to predict TIC or MT. The strength of association between prehospital parameters and TIC as well as MT was assessed using logistic regression, and cut-off values were determined using ROC curves.

RESULTS

Among the 485 patients included in the study, TIC was observed in 112 patients (23%) and MT in 22 patients (5%). For the prediction of TIC, ISS had good accuracy (AUC: 0·844, 95% confidence interval, CI: 0·799-0·879), as did the volume of fluids (>1000 ml) given during prehospital care (AUC: 0·801, 95% CI: 0·752-0·842). For the prediction of MT, ISS had excellent accuracy (AUC: 0·932, 95% CI: 0·866-0·966), whereas good accuracy was found for SI (> 0·9; AUC: 0·859, 95% CI: 0·705-0·936), vasopressor administration (AUC: 0·828, 95% CI: 0·736-0·890) and fluids (>1000 ml; AUC: 0·811, 95% CI: 0·737-0·867). Vasopressor administration, ISS and SI were independent predictors of TIC and MT, whereas fluid volume and ROC criteria were independent predictor of TIC but not MT. No independent relationship was found between MGAP and TIC or MT.

CONCLUSIONS

Prehospital parameters including the SI and resuscitation may help to better identify the severity of bleeding in trauma patients and the need for blood product administration at admission.

The use of massive transfusion protocol for trauma and non-trauma patients in a civilian setting: what can be done better?

INTRODUCTION

Massive transfusion protocol (MTP) is increasingly used in civilian trauma cases to achieve better haemostatic resuscitation in patients requiring massive blood transfusions (MTs), with improved survival outcomes. However, in non-trauma patients, evidence for MTP is lacking. This study aims to assess the outcomes of a newly established MTP in a civilian setting, for both trauma and non-trauma patients, in an acute surgical care unit.

METHODS

A retrospective cohort analysis was performed on 46 patients for whom MTP was activated in Changi General Hospital, Singapore. The patients were categorised into trauma and non-trauma groups. Assessment of Blood Consumption (ABC) score was used to identify MTP trauma patients and analyse over-activation rates.

RESULTS

Only 39.1% of all cases with MTP activation eventually received MTs; 39.8% of the MTs were for non-trauma patients. Mean fresh frozen plasma to packed red blood cells (pRBC) ratio achieved with MTP was 0.741, while mean platelet to pRBC ratio was 0.213. The 24-hour mortality rate for all patients who received an MT upon MTP activation was 33.3% (trauma vs. non-trauma group: 45.5% vs. 14.3%). The ABC scoring system used for trauma patients had a sensitivity and specificity of 81.8% and 41.2%, respectively.

CONCLUSION

MTP may be used for both trauma and non-trauma patients in acute care surgery. Scoring systems to predict the need for an MT, improved compliance to predefined transfusion ratios and regular reviews of the MTP are necessary to optimise MTPs and to improve the outcomes of patients receiving MTs.

Prolonged storage of packed red blood cells for blood transfusion

BACKGROUND

A blood transfusion is an acute intervention, used to address life- and health-threatening conditions on a short-term basis. Packed red blood cells are most often used for blood transfusion. Sometimes blood is transfused after prolonged storage but there is continuing debate as to whether transfusion of 'older' blood is as beneficial as transfusion of 'fresher' blood.

OBJECTIVES

To assess the clinical benefits and harms of prolonged storage of packed red blood cells, in comparison with fresh, on recipients of blood transfusion.

SEARCH METHODS

We ran the search on 1st May 2014. We searched the Cochrane Injuries Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), CINAHL (EBSCO Host) and two other databases. We also searched clinical trials registers and screened reference lists of the retrieved publications and reviews. We updated this search in June 2015 but these results have not yet been incorporated.

SELECTION CRITERIA

Randomised clinical trials including participants assessed as requiring red blood cell transfusion were eligible for inclusion. Prolonged storage was defined as red blood cells stored for ≥ 21 days in a blood bank. We did not apply limits regarding the duration of follow-up, or country where the study took place. We excluded trials where patients received a combination of short- and long-stored blood products, and also trials without a clear definition of prolonged storage.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, risk of bias assessment and data extraction by at least two review authors. The major outcomes were death from any cause, transfusion-related acute lung injury, and adverse events. We estimated relative risk for dichotomous outcomes. We measured statistical heterogeneity using I(2). We used a random-effects model to synthesise the findings.

MAIN RESULTS

We identified three randomised clinical trials, involving a total of 120 participants, comparing packed red blood cells with ≥ 21 days storage ('prolonged' or 'older') versus packed red blood cells with < 21 days storage ('fresh'). We pooled data to assess the effect of prolonged storage on death from any cause. The confidence in the results from these trials was very low, due to the bias in their design and their limited sample sizes.The estimated effect of packed red blood cells with ≥ 21 days storage versus packed red blood cells with < 21 days storage for the outcome death from any cause was imprecise (5/45 [11.11%] versus 2/46 [4.34%]; RR 2.36; 95% CI 0.65 to 8.52; I(2): 0%, P = 0.26, very low quality of evidence). Trial sequential analysis, with only two trials, shows that we do not yet have convincing evidence that older packed red blood cells induce a 20% relative risk reduction of death from any cause compared with fresher packed red blood cells. No trial included other outcomes of interest specified in this review, namely transfusion-related acute lung injury, postoperative infections, and adverse events. The safety profile is unknown.

AUTHORS' CONCLUSIONS

Recognising the limitations of the review, relating to the size and nature of the included trials, this Cochrane Review provides no evidence to support or reject the use of packed red blood cells for blood transfusion which have been stored for ≥ 21 days ('prolonged' or 'older') compared with those stored for < 21 days ('fresh'). These results are based on three small single centre trials with high risks of bias. There is insufficient evidence to determine the effects of fresh or older packed red blood cells for blood transfusion. Therefore, we urge readers to interpret the trial results with caution. The results from four large ongoing trials will help to inform future updates of this review.

Thrombelastography (TEG®): practical considerations on its clinical use in trauma resuscitation

Background

Thrombelastography is a laboratorial test that measures viscoelastic changes of the entire clotting process. There is growing interest in its clinical use in trauma resuscitation, particularly for managing acute coagulopathy of trauma and assisting decision making concerning transfusion. This review focuses on the clinical use of thrombelastography in trauma, with practical points to consider on its use in civilian and military settings.

Methods

A search in the literature using the terms “thrombelastography AND trauma” was performed in PUBMED database. We focused the review on the main clinical aspects of this viscoelastic method in diagnosing and treating patients with acute coagulopathy of trauma during initial resuscitation.

Results

Thrombelastography is not a substitute for conventional laboratorial tests such as INR and aPTT but offers additional information and may guide blood transfusion. Thrombelastography can be used as a point of care test but requires multiple daily calibrations, should be performed by trained personnel and its technique requires standardization. While useful partial results may be available in minutes, the whole test may take as long as other conventional tests. The most important data provided by thrombelastography are clot strength and fibrinolysis. Clot strength measure can establish whether the bleeding is due to coagulopathy or not, and is the key information in thrombelastography-based transfusion algorithms. Thrombelastography is among the few tests that diagnose and quantify fibrinolysis and thus guide the use of anti-fibrinolytic drugs and blood products such as cryoprecipitate and fibrinogen concentrate. It may also diagnose platelet dysfunction and hypercoagulability and potentially prevent inappropriate transfusions of hemostatic blood products to non-coagulopathic patients.

Conclusions

Thrombelastography has characteristics of an ideal coagulation test for use in early trauma resuscitation. It has limitations, but may prove useful as an additional test. Future studies should evaluate its potential to guide blood transfusion and the understanding of the mechanisms of trauma coagulopathy.

Massive transfusion in traumatic shock

BACKGROUND

Hemorrhage after trauma is a common cause of death in the United States and globally. The primary goals when managing traumatic shock are the restoration of oxygen delivery to end organs, maintenance of circulatory volume, and prevention of ongoing bleeding through source control and correction of coagulopathy. Achieving these goals may require massive transfusion of blood products. Although use of blood products may be lifesaving, dose-related adverse effects are well described.

DISCUSSION

Complications of massive transfusion include interdependent derangements such as coagulopathy, hypothermia, acidosis, and electrolyte abnormalities, as well as infectious and immunomodulatory phenomena. This article explores the pathogenesis, implications, prevention, and treatment of these complications through the use of massive transfusion protocols. Particular attention is given to the optimal ratio of blood products transfused in large volume resuscitation and prevention of secondary coagulopathy.

CONCLUSIONS

Observational data indicate that the development and use of a massive transfusion protocol may reduce the morbidity and mortality associated with large-volume resuscitation of patients with hemorrhagic shock. Such protocols should include a pre-defined ratio of packed red blood cells, fresh frozen plasma, and platelets transfused; most commonly, the ratio used is 1:1:1. Additionally, such protocols should monitor for and correct hypothermia, hypofibrinogenemia, and electrolyte disturbances such as hypocalcemia and hyperkalemia.

Trauma and Thrombelastography

Bleeding disorders associated with trauma are of paramount importance when dealing with the acutely injured individual. Statistically, up to 40% of trauma related deaths are assumed to be related to hemorrhage.1,2 Historically, there have been many varying positions on the way to handle this entity.3–5 Ironically, it is not always the injury but the physiologic sequelae of that injury that lead to trauma associated deaths.6,7 Over time, newer theories have been developed to help the clinician begin to understand the etiology and treatment of this process.6,8,9 The purpose of this paper is to review current literature and explain how these new concepts helped change practice in an urban, academic, Level One Trauma Center.

[Resuscitation damage control in the patient with severe trauma]

Severe trauma is the principle cause of death among young people in developed countries, with the main causes being due to road traffic accidents and accidents at work. The principle cause of death in severe trauma is the massive uncontrolled loss of blood. Most of the severe traumas with a massive haemorrhage develop coagulopathy, with some controversy over what is the best treatment for this. Patients with severe trauma are complex patients; they have a high mortality, they consume a significant amount of sources and can require rapid, intensive and multidisciplinary treatment encompassed within the concept of resuscitation damage control. In this article we attempt to present a current view of the pathophysiology of severe trauma and resuscitation damage control that may be applied to these types of patients.

Clinical review: Canadian National Advisory Committee on Blood and Blood Products--Massive transfusion consensus conference 2011: report of the panel

In June 2011 the Canadian National Advisory Committee on Blood and Blood Products sponsored an international consensus conference on transfusion and trauma. A panel of 10 experts and two external advisors reviewed the current medical literature and information presented at the conference by invited international speakers and attendees. The Consensus Panel addressed six specific questions on the topic of blood transfusion in trauma. The questions focused on: ratio-based blood resuscitation in trauma patients; the impact of survivorship bias in current research conclusions; the value of nonplasma coagulation products; the role of protocols for delivery of urgent transfusion; the merits of traditional laboratory monitoring compared with measures of clot viscoelasticity; and opportunities for future research. Key findings include a lack of evidence to support the use of 1:1:1 blood component ratios as the standard of care, the importance of early use of tranexamic acid, the expected value of an organized response plan, and the recommendation for an integrated approach that includes antifibrinolytics, rapid release of red blood cells, and a foundation ratio of blood components adjusted by results from either traditional coagulation tests or clot viscoelasticity or both. The present report is intended to provide guidance to practitioners, hospitals, and policy-makers.

Determinants of mortality in trauma patients following massive blood transfusion

Aim:

This study was designed to find out the factors influencing mortality in trauma patients receiving massive blood transfusion (MBT).

Materials and Methods:

Records of all patients admitted during December 2007 to November 2008 at a Level I Trauma Center emergency and who underwent massive transfusion (≥10 units of packed red cells in 24 h) were retrospectively analyzed. Death during the hospital stay was considered as the study outcome and various demographic, laboratory, and clinical parameters were included as its potential determinants.

Statistical Analysis:

Bivariate and multivariate logistic regression analyses were done to identify the risk factors associated with mortality.

Results:

Of the 4054 transfused patients who were admitted to the trauma center during the study period, 71 (1.8%) patients underwent massive transfusion. Of this, there were 37 survivors and 34 nonsurvivors (48%). The median overall ISS was 27 (22–34). The patients who died had shorter mean length of hospital stay, shorter mean duration of intensive care unit (ICU) stay, and low admission Glasgow Coma Scale (GCS) compared to the survivors (P < 0.01). The mean prothrombin time (PT) and the mean activated partial thromboplastin time was significantly high (P < 0.01) among nonsurvivors. Total leukocyte count (TLC ≥ 10,000 cells/cubic mm), GCS ≤ 8, the presence of coagulopathy and major vascular surgery were the four independent determinants of mortality in multivariate logistic regression analysis. The FFP:PRBC (fresh frozen plasma:packed red cells) ratio and PC:PRBC (platelet concentrate:packed red cells) ratio calculated in our study was not statistically significant in correlation to the in hospital mortality.

Conclusions:

Overall mortality among the MBT patients was comparable with the studies in the literature. Mortality is not affected by the amount of packed red cells given in the first 12 h and the total number of packed red cells transfused. Prospective studies are required to further validate the determinants of mortality and establish guidelines for MBT.

Update and new developments in the management of the exsanguinating patient

Definitive management of the exsanguinating patient continues to challenge providers in multiple specialties. Significant hemorrhage may be encountered in a variety of patient care circumstances. Over the past two decades, the vast majority of data and evidence regarding transfusion in the exsanguinating patient has been based upon the trauma literature, and a large amount of recent research has investigated this subject area. In addition to the care of trauma patients, the data which have emerged can also be extrapolated to the treatment of nontrauma patients undergoing transfusion for major hemorrhage. The concept of massive transfusion is an evolving paradigm, and numerous investigations have challenged old principles while creating new controversies. The current review will examine the latest developments in the management of patients with profound hemorrhage. The challenges of dealing with the "lethal triad" will be discussed, as will the various aspects of damage control and hemostatic resuscitation. The latest literature and controversy regarding massive transfusions and massive transfusion protocols will be elucidated with inclusion of data from recent military experiences. Finally, adjuncts including the most recent advances in hemorrhage control, identification of early predictors for massive transfusion, and utilization of pharmacologic and complementary factor agent therapy will be discussed.

Clinical and cellular effects of hypothermia, acidosis and coagulopathy in major injury

BACKGROUND

Hypothermia, acidosis and coagulopathy have long been considered critical combinations after severe injury. The aim of this review was to give a clinical update on this triad in severely injured patients.

METHODS

A non-systematic literature search on hypothermia, acidosis and coagulopathy after major injury was undertaken, with a focus on clinical data from the past 5 years.

RESULTS

Hypothermia (less than 35 °C) is reported in 1·6-13·3 per cent of injured patients. The occurrence of acidosis is difficult to estimate, but usually follows other physiological disturbances. Trauma-induced coagulopathy (TIC) has both endogenous and exogenous components. Endogenous acute traumatic coagulopathy is associated with shock and hypoperfusion. Exogenous effects of dilution from fluid resuscitation and consumption through bleeding and loss of coagulation factors further add to TIC. TIC is present in 10-34 per cent of injured patients, depending on injury severity, acidosis, hypothermia and hypoperfusion. More expedient detection of coagulopathy is needed. Thromboelastography may be a useful point-of-care measurement. Management of TIC is controversial, with conflicting reports on blood component therapy in terms of both outcome and ratios of blood products to other fluids, particularly in the context of civilian trauma.

CONCLUSION

The triad of hypothermia, acidosis and coagulopathy after severe trauma appears to be fairly rare but does carry a poor prognosis. Future research should define modes of early detection and targeted therapy.

Lack of effect of unrefrigerated young whole blood transfusion on patient outcomes after massive transfusion in a civilian setting

BACKGROUND

Warm fresh whole blood has been advocated for critical bleeding in the military setting. This study assessed whether unrefrigerated young whole blood transfusion, from donation to transfusion less than 24 hours, could reduce mortality of patients with critical bleeding in a civilian setting.

STUDY DESIGN AND METHODS

A linked data cohort study was conducted on a total of 353 consecutive patients requiring massive transfusion, defined as 10 units or more of red blood cells or whole blood transfusion within 24 hours, in a quaternary health care center in Australia.

RESULTS

Of the 353 patients with massive blood transfusion in the study, 77 received unrefrigerated young whole blood transfusion (mean, 4.0 units; interquartile range, 2-6). The diagnosis, severity of acute illness, age, sex, and ABO blood group were not significantly different between the patients who received unrefrigerated young whole blood and those who did not. Unrefrigerated young whole blood transfusions were associated with a slightly improved coagulation profile (lowest fibrinogen concentrations 1.7g/L vs. 1.4g/L, p=0.006; worst international normalization ratio, 2.4 vs. 2.8, p=0.05) but did not reduce the total utilization of allogeneic blood products and subsequent use of recombinant Factor VIIa (27% vs. 22%, p=0.358). Thirty-day mortality and 8-year survival after hospital discharge (hazard ratio, 1.05; 95% confidence interval, 0.41-2.65; p=0.93) were also not different after the use of unrefrigerated young whole blood transfusion.

CONCLUSIONS

Unrefrigerated young whole blood transfusion was not associated with a reduced mortality of patients requiring massive transfusion in a civilian setting when other blood products were readily available.