Transfusion medicine in trauma patients: an update

Association Between Blood Donor Demographics and Post-injury Multiple Organ Failure after Polytrauma

OBJECTIVE

To test the hypothesis that blood donor demographics are associated with transfused polytrauma patients' post-injury multiple organ failure (MOF) status.

SUMMARY OF BACKGROUND DATA

Traumatic shock and MOF are preventable causes of death and post-traumatic hemorrhage is a frequent indication for transfusion. The role of blood donor demographics on transfusion recipients is not well known.

METHODS

A log-linear analysis accounting for the correlated structure of the data based on our prospective MOF database was utilized. Tests for trend and interaction were computed using a likelihood ratio procedure.

RESULTS

A total of 229 critically injured transfused trauma patients were included, with 68% of them being males and a mean age of 45 years. On average 10 units of blood components were transfused per patient. A total of 4379 units of blood components were donated by donors aged 46 years on average, 74% of whom were males. Blood components used were red blood cells (47%), cryoprecipitate (29%), fresh frozen plasma (24%), and platelets (less than 1%). Donor-recipient sex mismatched red blood cells transfusions were more likely to be associated with MOF ( P = 0.0012); fresh frozen plasma and cryoprecipitate recipients were more likely to experience MOF when transfused with a male (vs female) component ( P = 0.0014 and <0.0001, respectively). Donor age was not significantly associated with MOF for all blood components.

CONCLUSIONS

Blood components donor sex, but not age, may be an important factor associated with post-injury MOF. Further validation of our findings will help guide future risk mitigation strategies specific to blood donor demographics.

CE: A Review of Current Practice in Transfusion Therapy

: In the United States, roughly 4.5 million patients per year receive transfusions of various blood products. Despite the lifesaving benefits of transfusion therapy, it is an independent risk factor for infection, morbidity, and death in critically ill patients. It's important for nurses to understand the potential complications patients face when blood products are administered and to recognize that patients who have received blood products in the past remain at risk for delayed reactions, including immune compromise and infection. Here, the authors review the blood products that are commonly transfused; discuss potential complications of transfusion, as well as their associated signs and symptoms; and outline current recommendations for transfusion therapy that are widely supported in the medical and nursing literature.

Optimizing transfusion strategies in damage control resuscitation: current insights

From clinical and laboratory studies of specific coagulation defects induced by injury, damage control resuscitation (DCR) emerged as the most effective management strategy for hemorrhagic shock. DCR of the trauma patient who has sustained massive blood loss consists of 1) hemorrhage control; 2) permissive hypotension; and 3) the prevention and correction of trauma-induced coagulopathies, referred to collectively here as acute coagulopathy of trauma (ACOT). Trauma patients with ACOT have higher transfusion requirements, may eventually require massive transfusion, and are at higher risk of exsanguinating. Distinct impairments in the hemostatic system associated with trauma include acquired quantitative and qualitative platelet defects, hypocoagulable and hypercoagulable states, and dysregulation of the fibrinolytic system giving rise to hyperfibrinolysis or a phenomenon referred to as fibrinolytic shutdown. Furthermore, ACOT is a component of a systemic host defense dysregulation syndrome that bears several phenotypic features comparable with other acute systemic physiological insults such as sepsis, myocardial infarction, and postcardiac arrest syndrome. Progress in the science of resuscitation has been continuing at an accelerated rate, and clinicians who manage catastrophic blood loss may be incompletely informed of important advances that pertain to DCR. Therefore, we review recent findings that further characterize the pathophysiology of ACOT and describe the application of this new information to optimization of resuscitation strategies for the patient in hemorrhagic shock.

Leukocyte filtration lesion impairs functional coagulation in banked whole blood

BACKGROUND

Whole blood (WB) transfusion is a promising alternative to component therapy in hemostatic resuscitation. Use of banked WB requires filtration of white blood cells (leukoreduction) and an established shelf life during which WB retains coagulant capacities. The goal of this study was to define the time course of coagulation stability in leukoreduced compared to unfiltered WB under standard refrigeration conditions.

METHODS

Twelve WB units were donated by healthy volunteers after routine screening. Five units underwent standard leukocyte filtration and five did not. Two units were aliquoted into filtered and unfiltered samples, with platelets added to each sample on day 14. Units were stored at 4°C and sampled on days 0, 1, 2, 3, 4, 5, 6, 7, 10, 14, 21, 28, and 35 for immediate thromboelastography (TEG) analysis, and centrifuged and stored at -80°C for later calibrated automated thrombogram and coagulation factor assays.

RESULTS

K-dependent factors and fibrinogen were low normal, decreased slightly over 35 days and were similar between unfiltered and filtered units. Labile factors were better preserved in filtered units, although unfiltered units did not show impaired coagulation over 35 days. Filtered blood had delayed clot initiation on days 0, 1, and 2 as measured by TEG R (p < 0.021); slower clot progression (TEG α-angle) on days 0, 1, 2, 3, 4, 5, and 6 (p < 0.023); weaker final clot (TEG MA) on all days (p < 0.0001). Thrombin generation was delayed on day 28 (p = 0.046) and decreased on days 10, 21, 28, and 35 (p < 0.034). Addition of platelets to filtered WB rescued TEG MA.

CONCLUSION

Filtered WB had decreased functional clotting capacity and thrombin generation and may not be suitable for hemostatic resuscitation as the sole blood product.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Damage Control Resuscitation for Catastrophic Bleeding

The timely recognition of shock secondary to hemorrhage from severe facial trauma or as a complication of complex oral and maxillofacial surgery presents formidable challenges. Specific hemostatic disorders are induced by hemorrhage and several extreme homeostatic imbalances may appear during or after resuscitation. Damage control resuscitation has evolved from massive transfusion to a more complex therapeutic paradigm that includes hemodynamic resuscitation, hemostatic resuscitation, and homeostatic resuscitation. Definitive control of bleeding is the principal objective of any comprehensive resuscitation scheme for hemorrhagic shock.

New understandings of post injury coagulation and resuscitation

Coagulopathy following injury is common and it predicts poor outcomes and increased mortality. For many decades, coagulopathy in trauma was considered as an iatrogenic phenomenon, and clinical practice focused on a resuscitation strategy using large volume crystalloid and packed red blood cells. The discovery of Acute Traumatic Coagulopathy as a distinct pathophysiologic state coupled with a transition towards balanced product resuscitation has fundamentally changed the paradigm of trauma care and represents one of the most active areas of current research in the field of trauma. In this review, we examine the development and current understanding of the mechanisms, implicated mediators, and physiology of Acute Traumatic Coagulopathy, with an emphasis on the role of the activated Protein C pathway. We will also review the state of resuscitation practice including the evidence for balanced product administration and the previously under-appreciated importance of platelet count and function. Importantly, we highlight ongoing knowledge deficits in traumatic coagulopathy and resuscitation as directions for future investigation in order to facilitate further insight into these rapidly evolving fields.

Long-term outcomes of patients receiving a massive transfusion after trauma

Resuscitation of patients presenting with hemorrhagic shock after major trauma has evolved to incorporate multiple strategies to maintain tissue perfusion and oxygenation while managing coagulation disorders. We aimed to study changes across time in long-term outcomes in patients with major trauma. A retrospective observational study in a single major trauma center in Australia was conducted. We included all patients with major trauma and massive blood transfusion within the first 24 h during a 6-year period (from 2006 to 2011). The main outcome measures were Glasgow Outcome Score-Extended (GOSE) and work capacity at 6 and 12 months. There were 5,915 patients with major trauma of which 365 (6.2%; 95% confidence interval [95% CI], 5.6 - 6.8) received a massive transfusion. The proportion of major trauma patients receiving a massive transfusion decreased across time from 8.2% to 4.4% (P < 0.01). There were statistically significant trends toward lower volumes of red blood cell transfusion and higher ratios of fresh-frozen plasma to red blood cells (P < 0.01). Among massively transfused patients, there was no significant change in measured outcomes during the study period, with a persistent 23% mortality in hospital, 52% unfavorable GOSE at 6 months, and 44% unfavorable GOSE at 12 months. Massive transfusion was independently associated with unfavorable outcomes at 6 months after injury (adjusted odds ratio, 1.56; 95% CI, 1.05 - 2.31) but not at 12 months (adjusted odds ratio, 0.85; 95% CI, 0.72 - 1.01). A significant reduction in massive transfusion rates was observed. Unfavorable long-term outcomes among patients receiving a massive transfusion after trauma were frequent with a substantial proportion of survivors experiencing poor functional status 1 year after injury.

Damage control resuscitation

The early recognition and management of hemorrhage shock are among the most difficult tasks challenging the clinician during primary assessment of the acutely bleeding patient. Often with little time, within a chaotic setting, and without sufficient clinical data, a decision must be reached to begin transfusion of blood components in massive amounts. The practice of massive transfusion has advanced considerably and is now a more complete and, arguably, more effective process. This new therapeutic paradigm, referred to as damage control resuscitation (DCR), differs considerably in many important respects from previous management strategies for catastrophic blood loss. We review several important elements of DCR including immediate correction of specific coagulopathies induced by hemorrhage and management of several extreme homeostatic imbalances that may appear in the aftermath of resuscitation. We also emphasize that the foremost objective in managing exsanguinating hemorrhage is always expedient and definitive control of the source of bleeding.

Hemorrhage and coagulopathy in the critically ill

Bleeding is the second leading cause of death after trauma. Initial care of the patient with hemorrhage focuses on restoring circulating blood volume and reversing coagulopathy. Trauma and injury can initiate the coagulation cascade. Patients with massive bleeding should be resuscitated with goal-directed therapy. Hemostatic resuscitation in conjunction with ratio-based transfusion and massive transfusion protocols should be utilized while awaiting hemorrhage control. The military initiated massive transfusion protocols in the battlefield. We discuss the coagulation cascade, recent recommendations of goal-directed therapy, massive transfusion protocols, fixed ratios, and the future of transfusion medicine.

Automated prediction of early blood transfusion and mortality in trauma patients

BACKGROUND

Prediction of blood transfusion needs and mortality for trauma patients in near real time is an unrealized goal. We hypothesized that analysis of pulse oximeter signals could predict blood transfusion and mortality as accurately as conventional vital signs (VSs).

METHODS

Continuous VS data were recorded for direct admission trauma patients with abnormal prehospital shock index (SI = heart rate [HR] / systolic blood pressure) greater than 0.62. Predictions of transfusion during the first 24 hours and in-hospital mortality using logistical regression models were compared with DeLong's method for areas under receiver operating characteristic curves (AUROCs) to determine the optimal combinations of prehospital SI and HR, continuous photoplethysmographic (PPG), oxygen saturation (SpO2), and HR-related features.

RESULTS

We enrolled 556 patients; 37 received blood within 24 hours; 7 received more than 4 U of red blood cells in less than 4 hours or "massive transfusion" (MT); and 9 died. The first 15 minutes of VS signals, including prehospital HR plus continuous PPG, and SpO2 HR signal analysis best predicted transfusion at 1 hour to 3 hours, MT, and mortality (AUROC, 0.83; p < 0.03) and no differently (p = 0.32) from a model including blood pressure. Predictions of transfusion based on the first 15 minutes of data were no different using 30 minutes to 60 minutes of data collection. SI plus PPG and SpO2 signal analysis (AUROC, 0.82) predicted 1-hour to 3-hour transfusion, MT, and mortality no differently from pulse oximeter signals alone.

CONCLUSION

Pulse oximeter features collected in the first 15 minutes of our trauma patient resuscitation cohort, without user input, predicted early MT and mortality in the critical first hours of care better than the currently used VS such as combinations of HR and systolic blood pressure or prehospital SI alone.

LEVEL OF EVIDENCE

Therapeutic/prognostic study, level II.

Factors influencing lengths of stay in the intensive care unit for surviving trauma patients: a retrospective analysis of 30,157 cases

Introduction

There are many potential influencing factors that affect the duration of intensive care treatment for patients who have survived multiple trauma. Yet the respective factors’ relevance to ICU length of stay (LOS) has been rarely studied. Thus, the aim of the present study was to investigate to what extent specific factors influence ICU LOS in surviving trauma patients.

Methods

We retrospectively analyzed a dataset of 30,157 surviving trauma patients from the TraumaRegister DGU® who were older than six years of age and received subsequent intensive care treatment for more than one day, from 2002 to 2011. Univariate analysis and multiple linear regression analysis were used to examine 25 categorical pre- and post-trauma parameters.

Results

Univariate analysis confirmed the impact of all analyzed factors. In subsequent multiple linear regression analyses, coefficients ranged from -1.3 to +8.2 days. The factors that influenced the prolongation of ICU LOS most were renal failure (+8.1 days), sepsis (+7.8 days) and respiratory failure (+4.9 days). Patients spent one additional day in the ICU for every 5 additional points on the Injury Severity Score (regression coefficient +0.2 per point). Furthermore, massive transfusion (+3.3 days), invasive ventilation (+3.1 days), and an initial Glasgow Coma Scale score ≤8 (+3.0 days) had a significant impact on ICU LOS. The coefficient of determination for the model was 44% (R²).

Conclusions

Treatment regimens, as well as secondary effects and complications of trauma and intensive care treatment, prolong ICU LOS more than the mechanism of trauma or pre-trauma patient conditions. Successful prevention of complicated courses of illness, such as sepsis and renal and respiratory failure, could significantly abbreviate the ICU stay in trauma patients. Therefore, the staff’s attention should be focused on preventive strategies.

[Damage control surgery: an update]

The damage control surgery is a widely accepted concept today among abdominal trauma specialists when it comes to the severely traumatized. In these patients, the death is due, in most cases, to the installation of the lethal triad (hypothermia, coagulopathy and acidosis) and not the inability to repair the serious initial damage. In this review, the authors address the lethal triad in its three phases and emphasize the measures taken to prevent them, as well as discussing the indication and employment of damage control surgery in its various stages. Restoring the physiological status of the patient in the ICU, so that he/she can be submitted to final operation and closure of the abdominal cavity, another challenge in severe trauma patients, is also discussed.

Characteristics and outcomes of patients administered blood in the prehospital environment by a road based trauma response team

OBJECTIVE

To describe the characteristics, clinical interventions and the outcomes of patients administered packed red blood cells (pRBCs) by a metropolitan, road based, doctor-paramedic trauma response team (TRT).

METHODS

A retrospective cohort study examining 18 months of historical data collated by the Queensland Ambulance Service TRT, the Pathology Queensland Central Transfusion Laboratory, the Royal Brisbane and Women's Hospital and the Princess Alexandra Hospital Trauma Services was undertaken.

RESULTS

Over an 18-month period (1 January 2011 to 30 June 2012), 71 trauma patients were administered pRBCs by the TRT. Seven patients (9.9%) died on scene and 39 of the 64 patients (60.9%) transported to hospital survived to hospital discharge. 57 (89.1%) of the transported patients had an Injury Severity Score (ISS) > 15, with a mean ISS, Revised Trauma Score (RTS) and Trauma-Injury Severity Score of 32.11, 4.70 and 0.57, respectively. No patients with an RTS < 2 survived to hospital discharge. 53 patients (82.8%) received additional pRBCs in hospital with 17 patients (26.6%) requiring greater than 10 units pRBCs in the first 24 h. 47 patients (73.4%) required surgical or interventional radiological procedures in the first 24 h.

CONCLUSIONS

There is a potential role for prehospital pRBC transfusions in an integrated civilian trauma system. The RTS calculated using the initial set of observations may be a useful tool in determining in which patients the administration of prehospital pRBC transfusions would be futile.

Thromboelastometry guided therapy of severe bleeding. Essener Runde algorithm

Both, severe haemorrhage and blood transfusion are associated with increased morbidity and mortality. Therefore, it is of particular importance to stop perioperative bleeding as fast and as possible to avoid unnecessary transfusion. Viscoelastic test (ROTEM® or TEG®) allow for early prediction of massive transfusion and goal-directed therapy with specific haemostatic drugs, coagulation factor concentrates, and blood products. Growing consensus points out, that plasma-based coagulation screening tests like aPTT and PT are inappropriate for monitoring coagulopathy or guide transfusion therapy. Increasing evidence of more than 5000 surgical or trauma patients points towards the beneficial effects of a thrombelastography or -metry based approach in diagnosis and goal-directed therapy of perioperative massive haemorrhage. The Essener Runde task force is a group of clinicians of various specialties (anaesthesiology, intensive care, haemostaseology, haematology, internal medicine, transfusion medicine, surgery) interested in perioperative coagulation management. The ROTEM diagnostic algorithm of the Essener Runde task force was created to standardise and simplify the interpretation of ROTEM® results in perioperative settings and to present their possible implications for therapeutic interventions in severe bleeding. To exemplify, this text mainly focuses on coagulation management in trauma.

The feasibility of civilian prehospital trauma teams carrying and administering packed red blood cells

OBJECTIVE

To evaluate the feasibility, limitations and costs involved in providing prehospital trauma teams with packed red blood cells (pRBCs) for use in the prehospital setting.

METHODS

A retrospective cohort study, examining 18 months of historical data collated by the Queensland Ambulance Service Trauma Response Team (TRT) and the Pathology Queensland Central Transfusion Laboratory was undertaken.

RESULTS

Over an 18-month period (1 January 2011-30 June 2012), of 500 pRBC units provided to the TRT, 130 (26%) were administered to patients in the prehospital environment. Of the non-transfused units, 97.8% were returned to a hospital blood bank and were available for reissue. No instances of equipment failure directly contributed to wastage of pRBCs. The cost of providing pRBCs for prehospital use was $A551 (£361) for each unit transfused.

CONCLUSIONS

It is feasible and practical to provide prehospital trauma teams with pRBCs for use in the field. Use of pRBCs in the prehospital setting is associated with similar rates of pRBC wastage to that reported in emergency departments.

Towards hemostatic resuscitation: the changing understanding of acute traumatic biology, massive bleeding, and damage-control resuscitation

During the past decade there has been a profound change in the understanding of postinjury coagulation. Concurrently, new data suggest that a resuscitative strategy to minimize large volumes of crystalloid while recreating whole is associated with reduced morbidity and mortality. This article outlines the history of resuscitation and transfusion practices in trauma, the changing understanding of coagulation and inflammation, and clinical data driving changes in resuscitative conduct. Finally, the current state of the science suggests future basic science and clinical investigation that will drive changes in transfusion and resuscitation in severely injured military personnel and civilian patients.