Early predictors of transfusion and mortality after injury: a review of the data-based literature

Observation on the effectiveness and safety of sodium bicarbonate Ringer's solution in the early resuscitation of traumatic hemorrhagic shock: a clinical single-center prospective randomized controlled trial

Background

Traumatic hemorrhagic shock (THS) is the main cause of death in trauma patients with high mortality. Rapid control of the source of bleeding and early resuscitation are crucial to clinical treatment. Guidelines recommend isotonic crystal resuscitation when blood products are not immediately available. However, the selection of isotonic crystals has been controversial. Sodium bicarbonate Ringer solutions (BRS), containing sodium bicarbonate, electrolyte levels, and osmotic pressures closer to plasma, are ideal. Therefore, in this study, we will focus on the effects of BRS on the first 6 h of resuscitation, complications, and 7-day survival in patients with THS.

Methods

/design.

This single-center, prospective, randomized controlled trial will focus on the efficacy and safety of BRS in early THS resuscitation. A total of 400 adults THS patients will be enrolled in this study. In addition to providing standard care, enrolled patients will be randomized in a 1:1 ratio to receive resuscitation with BRS (test group) or sodium lactate Ringer’s solution (control group) until successful resuscitation from THS. Lactate clearance at different time points (0.5, 1, 1.5, 3, and 6 h) and shock duration after drug administration will be compared between the two groups as primary end points. Secondary end points will compare coagulation function, temperature, acidosis, inflammatory mediator levels, recurrence of shock, complications, medication use, and 7-day mortality between the two groups. Patients will be followed up until discharge or 7 days after discharge.

Discussion

At present, there are still great differences in the selection of resuscitation fluids, and there is a lack of systematic and detailed studies to compare and observe the effects of various resuscitation fluids on the effectiveness and safety of early resuscitation in THS patients. This trial will provide important clinical data for resuscitation fluid selection and exploration of safe dose of BRS in THS patients.

Trial registration.

Chinese Clinical Trial Registry (ChiCTR), ChiCTR2100045044. Registered on 4 April 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06752-5.

Physiology of Human Hemorrhage and Compensation

Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.

Regionalization of trauma care by operative experience: Does the volume of emergent laparotomy matter?

INTRODUCTION

The volume-outcome relationship led to the regionalization of trauma care. The relationship between trauma centers' injury-specific laparotomy volume and outcomes has not been explored. The aim of our study was to examine the relationship between a trauma center's injury-specific laparotomy volume and outcomes in blunt and penetrating trauma patients.

METHODS

We performed a (2017) analysis of the Trauma Quality Improvement Program database. We included adult (age, ≥18 years) blunt and penetrating trauma patients who required emergent laparotomies for hemorrhage control. Trauma centers were stratified based on their blunt and penetrating laparotomy volumes: high volume (HV), ≥25 cases per year; medium volume (MV), 13 to 24 cases per year; and low volume (LV), ≤12 cases per year. Multivariate regression analysis was performed to explore predictors of in-hospital mortality.

RESULTS

A total of 8,588 patients underwent emergent laparotomy for either blunt (4,936; 57.5%) or penetrating injuries (3,652; 42.5%). Overall, mean ± SD age was 40 ± 17 years, abdomen Abbreviated Injury Scale was 3 (2-4), and Injury Severity Score was 26 (17-35). For American College of Surgeons (ACS) level I centers, 50% were HV; 29%, MV; and 21%, LV. For ACS level II centers, 7% were HV; 23%, MV; and 70%, LV. For ACS level III centers, 100% were LV. On multivariate regression analysis, admission of blunt and penetrating trauma patients to HV blunt and HV penetrating centers, respectively, was independently associated with improved in-hospital mortality. High-volume blunt centers had a significantly lower time to laparotomy (72 [41-144] minutes) versus MV (81 [49-145] minutes) and LV (94 [56-158] minutes) centers (p < 0.001). The same trend was observed for HV penetrating trauma centers (35 [24-52] minutes) versus MV (46 [33-63] minutes) and LV (51 [38-69] minutes) centers (p < 0.001).

CONCLUSION

Blunt and penetrating injury patients requiring emergent laparotomy had higher survival when admitted to trauma centers with HV operative experience for their particular mechanism of injury. The regionalization of trauma care should be based on a thorough evaluation of trauma centers' injury-specific operative experience.

LEVEL OF EVIDENCE

Prognostic, Level III; Therapeutic/Care management, Level IV.

Inferior Vena Cava Diameter is an Early Marker of Central Hypovolemia during Simulated Blood Loss

INTRODUCTION

Inferior vena cava (IVC) diameter decreases under conditions of hypovolemia. Point-of-care ultrasound (POCUS) may be useful to emergently assess IVC diameter. This study tested the hypothesis that ultrasound measurements of IVC diameter decreases during severe simulated blood loss.

METHODS

Blood loss was simulated in 14 healthy men (22 ± 2 years) using lower body negative pressure (LBNP). Pressure within the LBNP chamber was reduced 10 mmHg of LBNP every four minutes until participants experienced pre-syncopal symptoms or until 80 mmHg of LBNP was completed. IVC diameter was imaged with POCUS using B-mode in the long and short axis views between minutes two and four of each stage.

RESULTS

Maximum IVC diameter in the long axis view was lower than baseline (1.5 ± 0.4 cm) starting at -20 mmHg of LBNP (1.0 ± 0.3 cm; p < 0.01) and throughout LBNP (p < 0.01). The minimum IVC diameter in the long axis view was lower than baseline (0.9 ± 0.3 cm) at -20 mmHg of LBNP (0.5 ± 0.3 cm; p < 0.01) and throughout LBNP (p < 0.01). Maximum IVC diameter in the short axis view was lower than baseline (0.9 ± 0.2 cm) at 40 mmHg of LBNP (0.6 ± 0.2; p = 0.01) and the final LBNP stage (0.6 ± 0.2 cm; p < 0.01). IVC minimum diameter in the short axis view was lower than baseline (0.5 ± 0.2 cm) at the final LBNP stage (0.3 ± 0.2 cm; p = 0.01).

CONCLUSION

These data demonstrate that IVC diameter decreases prior to changes in traditional vital signs during simulated blood loss. Further study is needed to determine the view and diameter threshold that most accurate for identifying hemorrhage requiring emergent intervention.

Prediction of perioperative transfusions using an artificial neural network

BACKGROUND

Accurate prediction of operative transfusions is essential for resource allocation and identifying patients at risk of postoperative adverse events. This research examines the efficacy of using artificial neural networks (ANNs) to predict transfusions for all inpatient operations.

METHODS

Over 1.6 million surgical cases over a two year period from the NSQIP-PUF database are used. Data from 2014 (750937 records) are used for model development and data from 2015 (885502 records) are used for model validation. ANN and regression models are developed to predict perioperative transfusions for surgical patients.

RESULTS

Various ANN models and logistic regression, using four variable sets, are compared. The best performing ANN models with respect to both sensitivity and area under the receiver operator characteristic curve outperformed all of the regression models (p < .001) and achieved a performance of 70-80% specificity with a corresponding 75-62% sensitivity.

CONCLUSION

ANNs can predict >75% of the patients who will require transfusion and 70% of those who will not. Increasing specificity to 80% still enables a sensitivity of almost 67%. The unique contribution of this research is the utilization of a single ANN model to predict transfusions across a broad range of surgical procedures.

A review of hyperfibrinolysis in cats and dogs

The fibrinolytic system is activated concurrently with coagulation; it regulates haemostasis and prevents thrombosis by restricting clot formation to the area of vascular injury and dismantling the clot as healing occurs. Dysregulation of the fibrinolytic system, which results in hyperfibrinolysis, may manifest as clinically important haemorrhage. Hyperfibrinolysis occurs in cats and dogs secondary to a variety of congenital and acquired disorders. Acquired disorders associated with hyperfibrinolysis, such as trauma, cavitary effusions, liver disease and Angiostrongylus vasorum infection, are commonly encountered in primary care practice. In addition, delayed haemorrhage reported in greyhounds following trauma and routine surgical procedures has been attributed to a hyperfibrinolytic disorder, although this has yet to be characterised. The diagnosis of hyperfibrinolysis is challenging and, until recently, has relied on techniques that are not readily available outside referral hospitals. With the recent development of point-of-care viscoelastic techniques, assessment of fibrinolysis is now possible in referral practice. This will provide the opportunity to target haemorrhage due to hyperfibrinolysis with antifibrinolytic drugs and thereby reduce associated morbidity and mortality. The fibrinolytic system and the conditions associated with increased fibrinolytic activity in cats and dogs are the focus of this review article. In addition, laboratory and point-of-care techniques for assessing hyperfibrinolysis and antifibrinolytic treatment for patients with haemorrhage are reviewed.

Physiological comparison of hemorrhagic shock and V˙ O2max: A conceptual framework for defining the limitation of oxygen delivery

IMPACT STATEMENT

Disturbance of normal homeostasis occurs when oxygen delivery and energy stores to the body's tissues fail to meet the energy requirement of cells. The work submitted in this review is important because it advances the understanding of inadequate oxygen delivery as it relates to early diagnosis and treatment of circulatory shock and its relationship to disturbance of normal functioning of cellular metabolism in life-threatening conditions of hemorrhage. We explored data from the clinical and exercise literature to construct for the first time a conceptual framework for defining the limitation of inadequate delivery of oxygen by comparing the physiology of hemorrhagic shock caused by severe blood loss to maximal oxygen uptake induced by intense physical exercise. We also provide a translational framework in which understanding the fundamental relationship between the body's reserve to compensate for conditions of inadequate oxygen delivery as a limiting factor to V ˙ O2max helps to re-evaluate paradigms of triage for improved monitoring of accurate resuscitation in patients suffering from hemorrhagic shock.

iTACTIC - implementing Treatment Algorithms for the Correction of Trauma-Induced Coagulopathy: study protocol for a multicentre, randomised controlled trial

BACKGROUND

Traumatic injury is the fourth leading cause of death globally. Half of all trauma deaths are due to bleeding and most of these will occur within 6 h of injury. Haemorrhagic shock following injury has been shown to induce a clotting dysfunction within minutes, and this early trauma-induced coagulopathy (TIC) may exacerbate bleeding and is associated with higher mortality and morbidity. In spite of improved resuscitation strategies over the last decade, current transfusion therapy still fails to correct TIC during ongoing haemorrhage and evidence for the optimal management of bleeding trauma patients is lacking. Recent publications describe increasing the use of Viscoelastic Haemostatic Assays (VHAs) in trauma haemorrhage; however, there is insufficient evidence to support their superiority to conventional coagulation tests (CCTs).

METHODS/DESIGN

This multicentre, randomised controlled study will compare the haemostatic effect of an evidence-based VHA-guided versus an optimised CCT-guided transfusion algorithm in haemorrhaging trauma patients. A total of 392 adult trauma patients will be enrolled at major trauma centres. Participants will be eligible if they present with clinical signs of haemorrhagic shock, activate the local massive haemorrhage protocol and initiate first blood transfusion. Enrolled patients will be block randomised per centre to either VHA-guided or CCT-guided transfusion therapy in addition to that therapy delivered as part of standard care, until haemostasis is achieved. Patients will be followed until discharge or 28 days. The primary endpoint is the proportion of subjects alive and free of massive transfusion (less than 10 units of red blood cells) at 24 h. Secondary outcomes include the effect of CCT- versus VHA-guided therapy on organ failure, total hospital and intensive care lengths of stay, health care resources needed and mortality. Surviving patients will be asked to complete a quality of life questionnaire (EuroQol EQ-5D^TM) at day 90.

DISCUSSION

CCTs have traditionally been used to detect TIC and monitor response to treatment in traumatic major haemorrhage. The use of VHAs is increasing, but limited evidence exists to support the superiority of these technologies (or comparatively) for patient-centred outcomes. This knowledge gap will be addressed by this trial.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02593877 . Registered on 15 October 2015. Trial sponsor Queen Mary University of London The contact person of the above sponsor organisation is: Dr. Sally Burtles, Director of Research Services and Business Development, Joint Research Management Office, QM Innovation Building, 5 Walden Street, London E1 2EF; phone: 020 7882 7260; Email: sponsorsrep@bartshealth.nhs.uk Trial sites Academic Medical Centre, Amsterdam, The Netherlands Kliniken der Stadt Köln gGmbH, Cologne, Germany Rigshospitalet (Copenhagen University Hospital), Copenhagen, Denmark John Radcliff Hospital, Oxford, United Kingdom Oslo University Hospital, Oslo, Norway The Royal London Hospital, London, United Kingdom Centre for Trauma Sciences, Blizard Institute, Queen Mary University of London, London, United Kingdom Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom Sites that are planning to start recruitment in mid/late 2017 Nottingham University Hospitals, Queen's Medical Centre, Nottingham, United Kingdom University of Kansas Hospital (UKH), Kansas City, MO, USA Protocol version: 3.0/14.03.2017 (Additional file 1).

Activated Protein C Drives the Hyperfibrinolysis of Acute Traumatic Coagulopathy

BACKGROUND

Major trauma is a leading cause of morbidity and mortality worldwide with hemorrhage accounting for 40% of deaths. Acute traumatic coagulopathy exacerbates bleeding, but controversy remains over the degree to which inhibition of procoagulant pathways (anticoagulation), fibrinogen loss, and fibrinolysis drive the pathologic process. Through a combination of experimental study in a murine model of trauma hemorrhage and human observation, the authors' objective was to determine the predominant pathophysiology of acute traumatic coagulopathy.

METHODS

First, a prospective cohort study of 300 trauma patients admitted to a single level 1 trauma center with blood samples collected on arrival was performed. Second, a murine model of acute traumatic coagulopathy with suppressed protein C activation via genetic mutation of thrombomodulin was used. In both studies, analysis for coagulation screen, activated protein C levels, and rotational thromboelastometry (ROTEM) was performed.

RESULTS

In patients with acute traumatic coagulopathy, the authors have demonstrated elevated activated protein C levels with profound fibrinolytic activity and early depletion of fibrinogen. Procoagulant pathways were only minimally inhibited with preservation of capacity to generate thrombin. Compared to factors V and VIII, proteases that do not undergo activated protein C-mediated cleavage were reduced but maintained within normal levels. In transgenic mice with reduced capacity to activate protein C, both fibrinolysis and fibrinogen depletion were significantly attenuated. Other recognized drivers of coagulopathy were associated with less significant perturbations of coagulation.

CONCLUSIONS

Activated protein C-associated fibrinolysis and fibrinogenolysis, rather than inhibition of procoagulant pathways, predominate in acute traumatic coagulopathy. In combination, these findings suggest a central role for the protein C pathway in acute traumatic coagulopathy and provide new translational opportunities for management of major trauma hemorrhage.

Blood transfusion and coagulopathy in geriatric trauma patients

Background

Trauma resuscitation has undergone a paradigm shift with new emphasis on the early use of blood products and increased proportions of plasma and platelets. However, it is unclear how this strategy is applied or how effective it is in the elderly population. The study aim is to identify differences in transfusion practices and the coagulopathy of trauma in the elderly.

Methods

Data was prospectively collected on all consecutive patients that met trauma activation criteria at a Level I trauma centre. Data fields included patient demographics, co-morbidities, injury and resuscitation data, laboratory values, thromboelastography (TEG) results, and outcome measures. Elderly patients were defined as those 55 and older. Propensity-score matched analysis was completed for patients receiving blood product transfusion. Patients were matched by gender, mechanism, injury severity score (ISS), head injury, and time from injury.

Results

Total of 628 patients were included, of which 142 (23%) were elderly. Elderly patients were more likely to be female (41% vs. 24%), suffer blunt mechanism of trauma (96% vs. 80%), have higher ISS scores (mean 25.4 vs. 21.6) and mortality (19% vs. 8%). Elderly patients were significantly more likely to receive a blood transfusion (42% vs. 30%), specifically for red cells and plasma. Propensity-matched analysis resulted in no difference in red cell transfusion or mortality. Despite the broad similarities between the matched cohorts, trauma coagulopathy as measured by TEG was less commonly observed in the elderly.

Discussion

Our results suggest that elderly trauma patients are more likely to receive blood products when admitted to a trauma centre, though this may be attributed to under-triage. The results also suggest an altered coagulopathic response to traumatic injury which is partially influenced by increased anticoagulant and antiplatelet medication use in the geriatric population.

Conclusion

It is not clear whether the acute coagulopathy of trauma is equivalent in geriatric patients, and further study is therefore warranted.

Optimal Fluid Therapy for Traumatic Hemorrhagic Shock

The resuscitation of traumatic hemorrhagic shock has undergone a paradigm shift in the last 20 years with the advent of damage control resuscitation (DCR). Major principles of DCR include minimization of crystalloid, permissive hypotension, transfusion of a balanced ratio of blood products, and goal-directed correction of coagulopathy. In particular, plasma has replaced crystalloid as the primary means for volume expansion for traumatic hemorrhagic shock. Predicting which patient will require DCR by prompt and accurate activation of a massive transfusion protocol, however, remains a challenge.

Calcitriol decreases pro-inflammatory cytokines and protects against severe hemorrhagic shock induced-organ damage in rats

INTRODUCTION

Resuscitation after hemorrhagic shock (HS) could result in increased pro-inflammatory cytokines and then multiple organ dysfunctions. Calcitriol exerts pleiotropic effects in a wide variety of target tissues and has a role against anti-inflammation. The present study was aimed to investigate the modulatory effects of calcitriol on the pathophysiological and inflammatory markers following HS in rats.

MATERIALS AND METHODS

By withdrawing 60% of the total blood volume over 30min via a femoral artery catheter in rats, HS was induced. Afterwards, 10ng/kg calcitriol was injected intravenously in rats. After performing these procedures, hemodynamic status of mean arterial pressure (MAP) and heart rate (HR) were continuously monitored for 12h. Hemoglobin, lactic dehydrogenase (LDH), creatine phosphokinase (CPK), liver and renal function were measured at 30min before the induction of HS and 0, 1, 3, 6, 9, and 12h after HS, while an equal volume of normal saline as replacement fluid. At 1 and 12h after inducing HS, serum levels of tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were measured, and the livers, kidneys and lungs were taken out and then examined histo-pathologically at 48h after inducing HS.

RESULTS

Hemoglobin and MAP were significantly decreased, liver and renal function were significantly impaired, but HR and the levels of LDH, CPK, TNF-α and IL-6 were significantly increased after HS in rats. After being treated with calcitriol following HS resulted in better survival rate, lower serum levels of TNF-α and IL-6, and lesser hepatic, renal, and pulmonary histo-pathologic scores of injury in rats.

CONCLUSION

Being treated with calcitriol after HS could ameliorate the pro-inflammatory reactions by modulating the effects of cytokines, which lead to prevention of subsequent major organ damages.

Increased mortality in adult patients with trauma transfused with blood components compared with whole blood

Hemorrhage is a preventable cause of death among patients with trauma, and management often includes transfusion, either whole blood or a combination of blood components (packed red blood cells, platelets, fresh frozen plasma). We used the 2009 National Trauma Data Bank data set to evaluate the relationship between transfusion type and mortality in adult patients with major trauma (n = 1745). Logistic regression analysis identified 3 independent predictors of mortality: Injury Severity Score, emergency medical system transfer time, and type of blood transfusion, whole blood or components. Transfusion of whole blood was associated with reduced mortality; thus, it may provide superior survival outcomes in this population.

Detection of acute traumatic coagulopathy and massive transfusion requirements by means of rotational thromboelastometry: an international prospective validation study

Introduction

The purpose of this study was to re-evaluate the findings of a smaller cohort study on the functional definition and characteristics of acute traumatic coagulopathy (ATC). We also aimed to identify the threshold values for the most accurate identification of ATC and prediction of massive transfusion (MT) using rotational thromboelastometry (ROTEM) assays.

Methods

In this prospective international multicentre cohort study, adult trauma patients who met the local criteria for full trauma team activation from four major trauma centres were included. Blood was collected on arrival to the emergency department and analyzed with laboratory international normalized ratio (INR), fibrinogen concentration and two ROTEM assays (EXTEM and FIBTEM). ATC was defined as laboratory INR >1.2. Transfusion requirements of ≥10 units of packed red blood cells within 24 hours were defined as MT. Performance of the tests were evaluated by receiver operating characteristic curves, and calculation of area under the curve (AUC). Optimal cutoff points were estimated based on Youden index.

Results

In total, 808 patients were included in the study. Among the ROTEM parameters, the largest AUCs were found for the clot amplitude (CA) 5 value in both the EXTEM and FIBTEM assays. EXTEM CA5 threshold value of ≤37 mm had a detection rate of 66.3% for ATC. An EXTEM CA5 threshold value of ≤40 mm predicted MT in 72.7%. FIBTEM CA5 threshold value of ≤8 mm detected ATC in 67.5%, and a FIBTEM CA5 threshold value ≤9 mm predicted MT in 77.5%. Fibrinogen concentration ≤1.6 g/L detected ATC in 73.6% and a fibrinogen concentration ≤1.90 g/L predicted MT in 77.8%. Patients with either an EXTEM or FIBTEM CA5 below the optimum detection threshold for ATC received significantly more packed red blood cells and plasma.

Conclusions

This study confirms previous findings of ROTEM CA5 as a valid marker for ATC and predictor for MT. With optimum threshold for EXTEM CA5 ≤ 40 mm and FIBTEM CA5 ≤ 9 mm, sensitivity is 72.7% and 77.5% respectively. Future investigations should evaluate the role of repeated viscoelastic testing in guiding haemostatic resuscitation in trauma.

Ten-year follow-up on Dutch orthopaedic blood management (DATA III survey)

INTRODUCTION

Hip and knee arthroplasties are frequently complicated by the need for allogeneic blood transfusions. This survey was conducted to assess the current use of perioperative blood-saving measures and to compare it with prior results.

MATERIALS AND METHODS

All departments of orthopaedic surgery at Dutch hospitals were sent a follow-up survey on perioperative blood-saving measures, and data were compared to the results of two surveys conducted 5 and 10 years earlier.

RESULTS

The response rate was 94 out of 108 departments (87%). Most departments used erythropoietin prior to hip and knee replacements at the expense of preoperative autologous blood donation. The use of intraoperative autologous retransfusion in revision hip (56 vs. 54%) as well as revision knee arthroplasty (26 vs. 24%), was virtually unchanged. Postoperative autologous retransfusion is still used by the majority of departments after both primary arthroplasty and revision of hip (58/53%) and knee (65/61%).

CONCLUSIONS

Currently, just as in 2007, the majority of Dutch orthopaedic departments uses erythropoietin, normothermia and postoperative autologous retransfusion with hip and knee arthroplasty. Intraoperative retransfusion is used mainly with hip revision arthroplasty. Other effective blood management modalities such as tranexamic acid have not been widely implemented.

Blood administration in helicopter emergency medical services patients associated with hypothermia

INTRODUCTION

The infusion of packed red blood cells (PRBCs) in the severely injured patient is not a new practice. It is a potentially lifesaving procedure although it is not without inherent risk. This practice in the helicopter emergency medical services (HEMS) has not been examined in the literature. We attempt to determine factors associated with hypothermia (ie, < 35°C), including the transfusion of O negative blood.

METHODS

This was a retrospective review using our trauma registry on all patients who arrived at our rural level 1 trauma center by HEMS from January 1, 2005, through June 30, 2009. Patient temperature on arrival was compared for patients with and without hypothermia transported by our HEMS service.

RESULTS

During the study period, there were 707 HEMS transports by our service. Sixty (8.5%) were hypothermic, and 30 (4.2%) received PRBCs. There was a high likelihood of PRBC patients with hypothermia (odds ratio = 6.27; 95% confidence interval, 2.47-14.89; P < .05).

DISCUSSION

HEMS trauma patients who have received blood are more likely to arrive hypothermic (ie, < 35°C). The clinical impact of giving PRBCs in the HEMS prehospital setting was not determined.

Functional definition and characterization of acute traumatic coagulopathy

OBJECTIVE

To identify an appropriate diagnostic tool for the early diagnosis of acute traumatic coagulopathy and validate this modality through prediction of transfusion requirements in trauma hemorrhage.

DESIGN

Prospective observational cohort study.

SETTING

Level 1 trauma center.

PATIENTS

Adult trauma patients who met the local criteria for full trauma team activation. Exclusion criteria included emergency department arrival >2 hrs after injury, >2000 mL of intravenous fluid before emergency department arrival, or transfer from another hospital.

INTERVENTIONS

None.

MEASUREMENTS

Blood was collected on arrival in the emergency department and analyzed with laboratory prothrombin time, point-of-care prothrombin time, and rotational thromboelastometry. Prothrombin time ratio was calculated and acute traumatic coagulopathy defined as laboratory prothrombin time ratio >1.2. Transfusion requirements were recorded for the first 12 hrs following admission.

MAIN RESULTS

Three hundred patients were included in the study. Laboratory prothrombin time results were available at a median of 78 (62-103) mins. Point-of-care prothrombin time ratio had reduced agreement with laboratory prothrombin time ratio in patients with acute traumatic coagulopathy, with 29% false-negative results. In acute traumatic coagulopathy, the rotational thromboelastometry clot amplitude at 5 mins was diminished by 42%, and this persisted throughout clot maturation. Rotational thromboelastometry clotting time was not significantly prolonged. Clot amplitude at a 5-min threshold of ≤35 mm had a detection rate of 77% for acute traumatic coagulopathy with a false-positive rate of 13%. Patients with clot amplitude at 5 mins ≤35 mm were more likely to receive red cell (46% vs. 17%, p < .001) and plasma (37% vs. 11%, p < .001) transfusions. The clot amplitude at 5 mins could identify patients who would require massive transfusion (detection rate of 71%, vs. 43% for prothrombin time ratio >1.2, p < .001).

CONCLUSIONS

In trauma hemorrhage, prothrombin time ratio is not rapidly available from the laboratory and point-of-care devices can be inaccurate. Acute traumatic coagulopathy is functionally characterized by a reduction in clot strength. With a threshold of clot amplitude at 5 mins of ≤35 mm, rotational thromboelastometry can identify acute traumatic coagulopathy at 5 mins and predict the need for massive transfusion.

Reduced clot strength upon admission, evaluated by thrombelastography (TEG), in trauma patients is independently associated with increased 30-day mortality

INTRODUCTION

Exsanguination due to uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. About one third of trauma patients present with coagulopathy on admission, which is associated with increased mortality and will aggravate bleeding in a traumatized patient. Thrombelastographic (TEG) clot strength has previously been shown to predict outcome in critically ill patients. The aim of the present study was to investigate this relation in the trauma setting.

METHODS

A retrospective study of trauma patients with an injury severity qualifying them for inclusion in the European Trauma Audit and Research Network (TARN) and a TEG analysis performed upon arrival at the trauma centre.

RESULTS

Eighty-nine patients were included. The mean Injury Severity Score (ISS) was 21 with a 30-day mortality of 17%. Patients with a reduced clot strength (maximal amplitude < 50 mm) evaluated by TEG, presented with a higher ISS 27 (95% CI, 20-34) vs. 19 (95% CI, 17-22), p = 0.006 than the rest of the cohort. Clot strength correlated with the amount of packed red blood cells (p = 0.01), fresh frozen plasma (p = 0.04) and platelet concentrates (p = 0.03) transfused during the first 24 hours of admission. Patients with low clot strength demonstrated increased 30-day mortality (47% vs. 10%, p < 0.001). By logistic regression analysis reduced clot strength was an independent predictor of increased mortality after adjusting for age and ISS.

CONCLUSION

Low clot strength upon admission is independently associated with increased 30-day mortality in trauma patients and it could be speculated that targeted interventions based on the result of the TEG analysis may improve patient outcome. Prospective randomized trials investigating this potential are highly warranted.

Trauma-induced coagulopathy--a review of the systematic reviews: is there sufficient evidence to guide clinical transfusion practice?

Systematic reviews are accepted as a robust and less biased means of appraising and synthesizing results from high-quality studies. This report collated and summarized all the systematic review evidence relating to the diagnosis and management of trauma-related coagulopathy and transfusion, thereby covering the widest possible body of literature. We defined 4 key clinical questions: (1) What are the best methods of predicting and diagnosing trauma-related coagulopathy? (2) Which methods of clinical management correct coagulopathy? (3) Which methods of clinical management correct bleeding? and (4) What are the outcomes of transfusion in trauma? Thirty-seven systematic reviews were identified through searches of MEDLINE (1950-July 2010), EMBASE (1980-July 2010), The Cochrane Library (Issue 7, 2010), National Guidelines Clearing House, National Library for Health Guidelines Finder, and UKBTS SRI Transfusion Evidence Library (www.transfusionevidencelibrary.com). The evidence from the systematic review literature was scanty with many gaps, and we were not able to conclusively answer any of our 4 questions. Much more needs to be understood about how coagulopathy and bleeding in trauma are altered by transfusion practices and, most importantly, whether this translates into improved survival. There is a need for randomized controlled trials to answer these questions. The approach described in this report provides a framework for incorporating new evidence.

Comparison of 10 hemostatic dressings in a groin puncture model in swine

BACKGROUND

The use of mineral (clay) or biologic (chitosan) materials has improved the efficacy of dressings used in the bleeding control of noncompressible areas. A series of novel manufactured products already evaluated in a vascular transection model was further compared in a severe vascular puncture injury model.

METHODS

Ten hemostatic dressings were tested in anesthetized Yorkshire swine hemorrhaged for 45 seconds in a femoral arterial puncture model. Application of these dressings was followed by 5 minutes of compression (about 175 mm Hg), and at 15 minutes, 500 mL resuscitation fluid (Hextand) was infused during a 30-minute period. The animals were monitored for a 3-hour experimental observation period. Primary outcomes were incidence of bleeding after dressing application and animal survival.

RESULTS

Blood loss was 18.8% +/- 5.2% estimated blood volume (EBV) after 45 seconds of free bleeding. Relative performance of dressings is characterized as groups of dressings that performed similarly. Recurrence of bleeding after application was observed with most dressings and was lower with Woundstat, Celox, X-Sponge, and ACS+ (35% +/- 49%) compared with FP-21, Hemcon, Chitoflex, and Bloodstop (79% +/- 43%; P < .01). Blood loss after treatment was 25.3% +/- 18.4% EBV for the top four dressings and 53.0% +/- 18.4% EBV for the bottom four (P < .05). Survival was higher for top four vs bottom four dressings (78% +/- 12% vs 25% +/- 0%, respectively; P < .01). Overall performance of these dressings according to survival, incidence of bleeding, and post-treatment blood loss, yielded similar ranking as with a previously tested transection injury model.

CONCLUSIONS

The findings indicated that the efficacy of Woundstat, Celox, X-Sponge, and ACS+ were similar and superior in improving survival, hemostasis, and maintenance of mean arterial pressure in an actively bleeding wound caused in this severe vascular injury model.

Bench-to-bedside review: latest results in hemorrhagic shock

Hemorrhagic shock is a leading cause of death in trauma patients worldwide. Bleeding control, maintenance of tissue oxygenation with fluid resuscitation, coagulation support, and maintenance of normothermia remain mainstays of therapy for patients with hemorrhagic shock. Although now widely practised as standard in the USA and Europe, shock resuscitation strategies involving blood replacement and fluid volume loading to regain tissue perfusion and oxygenation vary between trauma centers; the primary cause of this is the scarcity of published evidence and lack of randomized controlled clinical trials. Despite enormous efforts to improve outcomes after severe hemorrhage, novel strategies based on experimental data have not resulted in profound changes in treatment philosophy. Recent clinical and experimental studies indicated the important influences of sex and genetics on pathophysiological mechanisms after hemorrhage. Those findings might provide one explanation why several promising experimental approaches have failed in the clinical arena. In this respect, more clinically relevant animal models should be used to investigate pathophysiology and novel treatment approaches. This review points out new therapeutic strategies, namely immunomodulation, cardiovascular maintenance, small volume resuscitation, and so on, that have been introduced in clinics or are in the process of being transferred from bench to bedside. Control of hemorrhage in the earliest phases of care, recognition and monitoring of individual risk factors, and therapeutic modulation of the inflammatory immune response will probably constitute the next generation of therapy in hemorrhagic shock. Further randomized controlled multicenter clinical trials are needed that utilize standardized criteria for enrolling patients, but existing ethical requirements must be maintained.

Financial and clinical outcomes associated with surgical bleeding complications

Anemia and bleeding are major sources of morbidity and mortality for a broad range of patients, and transfusion is the mainstay of treatment for the consequences of bleeding. The current literature raises, however, many questions about the independent association of poor outcome with transfusion of blood and blood products. In addition, as the availability of safe donors decreases, the costs of processing blood have escalated, mainly in response to increased demands for blood safety. New models for assessing the true costs of transfusion are discussed that allow incorporation and weighing of factors more often obscured in conventional discussions of the cost-effectiveness of transfusion.

Causes and consequences of critical bleeding and mechanisms of blood coagulation

Pharmacists who practice in the critical care setting require a solid background on the causes and consequences of bleeding, as well as the mechanisms of hemostasis. This article provides an overview of these topics. Bleeding and outcomes as a result of surgery and trauma, from medical and pharmacologic causes, and in obstetrics and gynecology are discussed. Patients with brain trauma, those with inherited and acquired bleeding disorders, and patients undergoing therapeutic anticoagulation are addressed, as these are populations at special risk for severe bleeding. Bleeding events as a result of hypothermia, acidosis, and disseminated intravascular coagulation are also discussed, as is the pathophysiology of massive blood loss. Traditional and newer cell-based models of coagulation mechanisms are described and compared. Application of this information in pharmacy practice will help ensure that therapies to manage and arrest blood loss are used appropriately in a wide variety of clinical scenarios.