Variables predicting trauma patient survival following massive transfusion

Markers of Futile Resuscitation in Traumatic Hemorrhage: A Review of the Evidence and a Proposal for Futility Time-Outs during Massive Transfusion

The reduction in the blood supply following the 2019 coronavirus pandemic has been exacerbated by the increased use of balanced resuscitation with blood components including whole blood in urban trauma centers. This reduction of the blood supply has diminished the ability of blood banks to maintain a constant supply to meet the demands associated with periodic surges of urban trauma resuscitation. This scarcity has highlighted the need for increased vigilance through blood product stewardship, particularly among severely bleeding trauma patients (SBTPs). This stewardship can be enhanced by the identification of reliable clinical and laboratory parameters which accurately indicate when massive transfusion is futile. Consequently, there has been a recent attempt to develop scoring systems in the prehospital and emergency department settings which include clinical, laboratory, and physiologic parameters and blood products per hour transfused as predictors of futile resuscitation. Defining futility in SBTPs, however, remains unclear, and there is only nascent literature which defines those criteria which reliably predict futility in SBTPs. The purpose of this review is to provide a focused examination of the literature in order to define reliable parameters of futility in SBTPs. The knowledge of these reliable parameters of futility may help define a foundation for drawing conclusions which will provide a clear roadmap for traumatologists when confronted with SBTPs who are candidates for the declaration of futility. Therefore, we systematically reviewed the literature regarding the definition of futile resuscitation for patients with trauma-induced hemorrhagic shock, and we propose a concise roadmap for clinicians to help them use well-defined clinical, laboratory, and viscoelastic parameters which can define futility.

Traumatic Brain Injury as an Independent Predictor of Futility in the Early Resuscitation of Patients in Hemorrhagic Shock

This review explores the concept of futility timeouts and the use of traumatic brain injury (TBI) as an independent predictor of the futility of resuscitation efforts in severely bleeding trauma patients. The national blood supply shortage has been exacerbated by the lingering influence of the COVID-19 pandemic on the number of blood donors available, as well as by the adoption of balanced hemostatic resuscitation protocols (such as the increasing use of 1:1:1 packed red blood cells, plasma, and platelets) with and without early whole blood resuscitation. This has underscored the urgent need for reliable predictors of futile resuscitation (FR). As a result, clinical, radiologic, and laboratory bedside markers have emerged which can accurately predict FR in patients with severe trauma-induced hemorrhage, such as the Suspension of Transfusion and Other Procedures (STOP) criteria. However, the STOP criteria do not include markers for TBI severity or transfusion cut points despite these patients requiring large quantities of blood components in the STOP criteria validation cohort. Yet, guidelines for neuroprognosticating patients with TBI can require up to 72 h, which makes them less useful in the minutes and hours following initial presentation. We examine the impact of TBI on bleeding trauma patients, with a focus on those with coagulopathies associated with TBI. This review categorizes TBI into isolated TBI (iTBI), hemorrhagic isolated TBI (hiTBI), and polytraumatic TBI (ptTBI). Through an analysis of bedside parameters (such as the proposed STOP criteria), coagulation assays, markers for TBI severity, and transfusion cut points as markers of futilty, we suggest amendments to current guidelines and the development of more precise algorithms that incorporate prognostic indicators of severe TBI as an independent parameter for the early prediction of FR so as to optimize blood product allocation.

EFFECT OF GENDER ON 28-DAY SURVIVAL RATES AND TRANSFUSION VOLUME IN SEVERE TRAUMA PATIENTS: A MULTICENTER OBSERVATIONAL STUDY

ABSTRACT

Background: This study clarified the relationship between sex with survival and transfusion volume in severe trauma cases. Methods: A multicenter, collaborative post hoc analysis of patients with trauma in Japan was conducted. Patients aged ≥18 years with severe trauma indicated by an Injury Severity Score (ISS) of 16 or higher were enrolled. Patients were matched and analyzed by gender based on propensity score with factors determined at the time of injury. Subgroup analysis was performed on patients younger than 50 years and older than 50 years. The significance level was defined as P < 0.05. Results: The 1,189 patients included in this registry were divided into adjusted groups of 226 male and female patients each. In the main analysis, 28-day survival rates in females were significantly higher than those in males ( P = 0.046). In the subgroup analyses, there was no statistically significant prognostic effect of gender. Secondary outcomes, including transfusion volume, showed no significant gender-based variations. Logistic regression analyses consistently demonstrated that female sex was a significant favorable prognostic factor in all ages. This was true for the over-50 group on subgroup analysis, but no significant gender-prognosis relationship was identified in the under-50 age group. High ISSs were associated with poorer outcomes across all age groups. Conclusion: In severe trauma, survival at 28 days was significantly lower in males. However, this trend was not observed in patients aged <50 years. Factors other than sex hormones may be responsible for differences in posttraumatic outcomes by gender.

Finding the bleeding edge: 24-hour mortality by unit of blood product transfused in combat casualties from 2002-2020

BACKGROUND

Transfusion studies in civilian trauma patients have tried to identify a general futility threshold. We hypothesized that in combat settings there is no general threshold where blood product transfusion becomes unbeneficial to survival in hemorrhaging patients. We sought to assess the relationship between the number of units of blood products transfused and 24-hour mortality in combat casualties.

METHODS

A retrospective analysis of the Department of Defense Trauma Registry supplemented with data from the Armed Forces Medical Examiner. Combat casualties who received at least one unit of blood product at US military medical treatment facilities (MTFs) in combat settings (2002-2020) were included. The main intervention was the total units of any blood product transfused, which was measured from the point of injury until 24 hours after admission from the first deployed MTF. The primary outcome was discharge status (alive, dead) at 24 hours from time of injury.

RESULTS

Of 11,746 patients included, the median age was 24 years, and most patients were male (94.2%) with penetrating injury (84.7%). The median injury severity score was 17 and 783 (6.7%) patients died by 24 hours. Median units of blood products transfused was 8. Most blood products transfused were red blood cells (50.2%), followed by plasma (41.1%), platelets (5.5%), and whole blood (3.2%). Among the 10 patients who received the most units of blood product (164 units to 290 units), 7 survived to 24 hours. The maximum amount of total blood products transfused to a patient who survived was 276 units. Of the 58 patients who received over 100 units of blood product, 20.7% died by 24 hours.

CONCLUSION

While civilian trauma studies suggest the possibility of futility with ultra-massive transfusion, we report that the majority (79.3%) of combat casualties who received transfusions greater than 100 units survived to 24 hours. These results do not support a threshold for futility of blood product transfusion. Further analysis as to predictors for mortality will help in situations of blood product and resource constraints.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Narrative Review: Is There a Transfusion Cutoff Value After Which Nonsurvivability Is Inevitable in Trauma Patients Receiving Ultramassive Transfusion?

The institution of massive transfusion protocols (MTPs) has improved the timely delivery of large quantities of blood products and improves patient outcomes. In recent years, the cost of blood products has increased, compounded by significant blood product shortages. There is practical need for identification of a transfusion volume in trauma patients that is associated with increased mortality, or a threshold after which additional transfusion is futile and associated with nonsurvivability. This transfusion threshold is often described in the setting of an ultramassive transfusion (UMT). There are few studies defining what constitutes amount or outcomes associated with such large volume transfusion. The purpose of this narrative review is to provide an analysis of existing literature examining the effects of UMT on outcomes including survival in adult trauma patients and to determine whether there is a threshold transfusion limit after which mortality is inevitable. Fourteen studies were included in this review. The data examining the utility of UMT in trauma are of poor quality, and with the variability inherent in trauma patients, and the surgeons caring for them, no universally accepted cutoff for transfusion exists. Not surprisingly, there is a trend toward increasing mortality with increasing transfusions. The decision to continue transfusing is multifactorial and must be individualized, taking into consideration patient characteristics, institution factors, blood bank supply, and most importantly, constant reevaluation of the need for ongoing transfusion rather than blind continuous transfusion until the heart stops.

Cresting Mortality: Defining a Plateau in Ongoing Massive Transfusion

BACKGROUND

Blood-based balanced resuscitation is a standard of care in massively bleeding trauma patients. No data exists as to when this therapy no longer significantly affects mortality. We sought to determine if there is a threshold beyond which further massive transfusion will not affect in-hospital mortality.

METHODS

The Trauma Quality Improvement database was queried for all adult patients registered between 2013 and 2017 who received at least one unit of blood (PRBC) within 4 hours of arrival. In-hospital mortality was evaluated based on the total transfusion volume (TTV) at 4 and 24 hours in the overall cohort (OC) and in a balanced transfusion cohort (BC), composed of patients who received transfusion at a ratio of 1:1-2:1 PRBC-to-plasma. A bootstrapping method in combination with multivariable Poisson regression (MVR) was used to find a cutoff after which additional transfusion no longer affected in-hospital mortality. MVR was used to control for age, sex, race, highest abbreviated injury score in each body region, comorbidities, advanced directives limiting care, and the primary surgery performed for hemorrhage control.

RESULTS

The OC consisted of 99,042 patients of which 28,891 and 30,768 received a balanced transfusion during the first 4 and 24 hours, respectively. The mortality rate plateaued after a TTV of 40.5 units (95% CI, 40-41) in the OC at 4 hours and after a TTV of 52.8 units (95% CI, 52-53) at 24 hours following admission. In the BC, mortality plateaued at a TTV of 39 units (95% CI, 39-39) and 53 units (95% CI, 53-53) at 4- and 24-hours following admission, respectively.

CONCLUSION

Transfusion thresholds exist beyond which ongoing transfusion is not associated with any clinically significant change in mortality. These TTVs can be used as markers for resuscitation timeouts in order to assess the plan of care moving forward.

LEVEL OF EVIDENCE

Level V, prognostic and epidemiological.

Massive transfusions for critical bleeding: is everything old new again?

Massive transfusion or major haemorrhage protocols have been widely adopted in the treatment of critically bleeding patients. Following evidence that higher ratios of transfused plasma and platelets to red blood cells may offer survival benefits in military trauma patients, these ratios are now commonly incorporated into massive transfusion protocols. They more closely resemble the effects of whole blood transfusion, which in the second half of last century was largely replaced by individual blood component transfusion based on laboratory-guided indicators. However, high-quality evidence to guide transfusion support for critically bleeding patients across the range of bleeding contexts is lacking, including for both trauma and non-trauma patients. More data on major haemorrhage support and clinical outcomes are needed to inform guidelines and practice.

Improving decision making for massive transfusions in a resource poor setting: a preliminary study in Kenya

Background

The reality of finite resources has a real-world impact on a patient’s ability to receive life-saving care in resource-poor settings. Blood for transfusion is an example of a scarce resource. Very few studies have looked at predictors of survival in patients requiring massive transfusion. We used data from a rural hospital in Kenya to develop a prediction model of survival among patients receiving massive transfusion.

Methods

Patients who received five or more units of whole blood within 48 hours between 2004 and 2010 were identified from a blood registry in a rural hospital in Kenya. Presenting characteristics and in-hospital survival were collected from charts. Using stepwise selection, a logistic model was developed to predict who would survive with massive transfusion versus those who would die despite transfusion. An ROC curve was created from this model to quantify its predictive power.

Results

Ninety-five patients with data available met inclusion criteria, and 74% survived to discharge. The number of units transfused was not a predictor of mortality, and no threshold for futility could be identified. Preliminary results suggest that initial blood pressure, lack of comorbidities, and indication for transfusion are the most important predictors of survival. The ROC curve derived from our model demonstrates an area under the curve (AUC) equal to 0.757, with optimism of 0.023 based on a bootstrap validation.

Conclusions

This study provides a framework for making prioritization decisions for the use of whole blood in the setting of massive bleeding. Our analysis demonstrated an overall survival rate for patients receiving massive transfusion that was higher than clinical perception. Our analysis also produced a preliminary model to predict survival in patients with massive bleeding. Prediction analyses can contribute to more efficient prioritization decisions; these decisions must also include other considerations such as equity, acceptability, affordability and sustainability.

Recombinant factor VIIa in trauma patients with the 'triad of death'

INTRODUCTION

The use of recombinant factor VIIa (rFVIIa) in trauma patients is usually part of rescue therapy when haemorrhage and coagulopathy have not responded to conventional treatment. In this scenario, trauma patients are likely to have one or more components of the 'triad of death' (coagulopathy, acidosis and hypothermia). The aim of this study was to report on the outcome of trauma patients with the 'triad of death' immediately prior to receiving rFVIIa.

MATERIALS AND METHODS

Trauma patients receiving rFVIIa with the 'triad of death' were identified from the Australia and New Zealand Haemostasis Registry (ANZHR) and included in the study. The 'triad of death' was defined as an INR of >1.5, serum pH of <7.2 and a core temperature of <35 °C. Pre-dose clinical signs, investigations, adverse events and outcomes were analysed.

RESULTS

There were 2792 patients in the ANZHR, of which 386 were trauma patients and 45 patients had the 'triad of death'. Patients with the 'triad of death' were significantly older and had higher injury severity scores than other trauma patients, with a mortality of 68.9%. Survivors were significantly less acidaemic (p<0.001) and had significantly less packed red blood cell (PRBC) transfusion prior to rFVIIa administration (p=0.041) than non-survivors with the triad of death.

DISCUSSION

In the face of refractory bleeding, coagulopathy, acidosis and hypothermia following conventional resuscitation, the use of rFVIIa in trauma patients was associated with survival in 31% of patients and may be considered as a management option. Administration of rFVIIa in patients with a pH of <6.91 appears futile.

Recombinant factor VIIa and the patient with neurologic bleeding: separating fact from fiction

Notwithstanding its limited Food and Drug Administration-approved indications, rFVIIa has rapidly gained widespread use for the treatment of a variety of hemorrhagic conditions, including intracranial bleeding from spontaneous, traumatic, surgical, and coagulopathic causes. Although it appears that the drug only minimally increases the risk of thromboembolic events, its efficacy remains in question. The idea of finding a universal cure for hemorrhage in a medication bottle remains highly appealing, but enthusiasm for the concept is no replacement for evidence. Neuroscience nurses, who are the interface between patients and rFVIIa, need to balance hope and hype until the facts are all in.

Transfusion management of trauma patients

The management of massively transfused trauma patients has improved with a better understanding of trauma-induced coagulopathy, the limitations of crystalloid infusion, and the implementation of massive transfusion protocols (MTPs), which encompass transfusion management and other patient care needs to mitigate the "lethal triad" of acidosis, hypothermia, and coagulopathy. MTPs are currently changing in the United States and worldwide because of recent data showing that earlier and more aggressive transfusion intervention and resuscitation with blood components that approximate whole blood significantly decrease mortality. In this context, MTPs are a key element of "damage control resuscitation," which is defined as the systematic approach to major trauma that addresses the lethal triad mentioned above. MTPs using adequate volumes of plasma, and thus coagulation factors, improve patient outcome. The ideal amounts of plasma, platelet, cryoprecipitate and other coagulation factors given in MTPs in relationship to the red blood cell transfusion volume are not known precisely, but until prospective, randomized, clinical trials are performed and more clinical data are obtained, current data support a target ratio of plasma:red blood cell:platelet transfusions of 1:1:1. Future prospective clinical trials will allow continued improvement in MTPs and thus in the overall management of patients with trauma.

[Incidence and mortality of massive transfusion in a university hospital: study of the period 2001-2005]

BACKGROUND AND OBJECTIVE

There are few epidemiological studies on massive transfusion (MT), although they may be important to evaluate possible strategies to reduce the number of transfused units, as well as transfusion side-effects. We, therefore, retrospectively assessed the incidence of MT at our institution (a 700-bed university hospital) during a 5-year period.

PATIENTS AND METHOD

Local blood bank records were searched for MT episodes occurred from January 2001 to December 2005. MT was defined as the transfusion of 8 or more packed red cell (PRC) units within 24 h. Patient's clinical data were exclusively gathered from the blood requesting form.

RESULTS

Overall, 304 episodes of MT were identified in 288 patients (one episode per week), who received 4,845 PCR units (3,515 units within the first 24 h), because of ruptured aortic aneurism (n = 62), poly-trauma (n = 57), upper digestive bleeding (n = 51), cardiac surgery (n = 41), elective surgery (n = 36), emergency surgery (n = 30), and oncology surgery (n = 27). Mortality rate was 48%, and multivariate analysis identified age (odds ratio [OR] =1.023; 95% confidence interval [CI]. 1.006-1.040) and number of PRC transfused within the first 24 h (OR = 1.094; 95% CI, 1.0032-1.160) as weak but significant independent predictors of mortality, whereas poly-trauma diagnosis was a protective factor (OR = 0.325; 95% CI, 0.112 - 0,940).

CONCLUSIONS

Overall, the mortality rate among patients receiving MT was very high, and was influenced by the number of transfused units, patient's age, and admitting diagnose. As the majority of the MT episodes occurred within the surgical or polytrauma context, possible strategies to reduce the volume of MT are discussed.

Massive blood transfusion and outcome in 1062 polytrauma patients: a prospective study based on the Trauma Registry of the German Trauma Society

BACKGROUND AND OBJECTIVES

About 15% of polytrauma patients receive massive blood transfusion (MBT) defined as > or = 10 units of packed red blood cells (PRBC). In general, the prognosis of trauma patients receiving MBT is considered to be poor. The purpose of this study was to investigate the impact of MBT on the outcome of polytrauma patients.

MATERIALS AND METHODS

Records of 10 997 patients in the Trauma Registry of the German Trauma Society were analysed. Transfusion data were available from 8182 severe trauma patients with a mean injury severity score of 24.5 and, of these 8182 patients, 1062 received > or = 10 units of PRBC. First, a logistic regression model for the predictors of mortality was performed. Second, incidences of organ failure and sepsis as well as survival rates were analysed.

RESULTS

The highest risk for mortality was age over 55 years (odds ratios [OR] 4.7; confidence intervals [CI 95%], 3.5-6.5) followed by Glasgow Coma Scale < or = 8 (OR 4.6; 3.4-6.1), MBT > or = 20 units of PRBC (OR 3.3; 2.1-5.4), thromboplastin time < 50% (OR 3.2; 2.2-4.4) and injury severity score > or = 24 (OR 2.9; 2.1-4.1). Transfusion of 10-19 PRBC was identified as the variable with the lowest risk for mortality (OR 1.5; 1.0-2.3). Risk of organ failure, sepsis and death correlated with increasing transfusion amount. For the MBT patients, the survival rate was 56.9% (CI 95%, 53.9-59.9%) compared to 85.2% (84.4-86.0%) of non-MBT patients (P < 0.001). In the MBT group with > 30 PRBC (mean 40.6 PRBC) 39.6% survived (31.7-47.5%).

CONCLUSION

Massive blood transfusion is one main prognostic factor for mortality in trauma. Although MBT is generally considered to be critical, every second trauma patient with MBT survived. A cut-off value for the number of PRBC could not be determined. Extended transfusion management even with high amounts of PRBC seems to be justified.

Systemic hypotension is a late marker of shock after trauma: a validation study of Advanced Trauma Life Support principles in a large national sample

BACKGROUND

Systolic blood pressure is used extensively to triage trauma patients as stable or unstable, contrary to Advanced Trauma Life Support recommendations. We hypothesized that systemic hypotension is a late marker of shock.

METHODS

The National Trauma Data Bank was queried (n = 115,830). Base deficit was used as a measure of circulatory shock. Systolic blood pressure was correlated with the presence and the severity of base-deficit derangement.

RESULTS

Systolic blood pressure correlated poorly with base deficit (r = .28). There was wide variation in systolic blood pressure within each base-deficit group. The mean and median systolic blood pressure did not decrease to less than 90 mm Hg until the base deficit was worse than -20, with mortality reaching 65%.

CONCLUSIONS

We validated the Advanced Trauma Life Support principle that systemic hypotension is a late marker of shock. A normal blood pressure should not deter aggressive evaluation and resuscitation of trauma patients.