TEG-guided resuscitation is superior to standardized MTP resuscitation in massively transfused penetrating trauma patients. J Trauma Acute Care Surg. 2013;74:378-385; discussion 385-386. [PMID: 23354228 DOI: 10.1097/ta.0b013e31827e20e0]

Fluid resuscitation in trauma: What you need to know

ABSTRACT

There have been numerous changes in resuscitation strategies for severely injured patients over the last several decades. Certain strategies, such as aggressive crystalloid resuscitation, have largely been abandoned because of the high incidence of complications and worsening of trauma-induced coagulopathy. Significant emphasis has been placed on restoring a normal coagulation profile with plasma or whole blood transfusion. In addition, the importance of the lethal consequences of trauma-induced coagulopathy, such as hyperfibrinolysis, has been easily recognized by the use of viscoelastic testing, and its treatment with tranexamic acid has been extensively studied. Furthermore, the critical role of early intravenous calcium administration, even before blood transfusion administration, has been emphasized. Other adjuncts, such as fibrinogen supplementation with fibrinogen concentrate or cryoprecipitate and prothrombin complex concentrate, are being studied and incorporated in some of the institutional massive transfusion protocols. Finally, balanced blood component transfusion (1:1:1 or 1:1:2) and whole blood have become commonplace in trauma centers in North America. This review provides a description of recent developments in resuscitation and a discussion of recent innovations and areas for future investigation.

Investigation and validation of the TEG6s during rotary wing aeromedical flight

INTRODUCTION

To improve rural and austere trauma care, hospital-based testing performed at the point of injury may shorten the time lapsed from injury to intervention. This study aimed to evaluate the use of the TEG6s device (Haemonetics(R), Clinton, PA) in a rotary wing aircraft. Prior attempts suffered from limitation related to lack of vibration mitigation.

METHODS

This was an investigator-initiated, industry-supported study. Haemonetics provided a TEG6s analyzer. The device underwent a standard validation. It was secured in place on the aircraft using shipping foam for vibration mitigation. Donors provided two tubes of sample blood in one sitting. Paired studies were performed on the aircraft during level flight and in the hospital, using the Global Hemostasis with Lysis Cartridge(Haemonetics (R), Clinton, PA). Both normal and presumed pathologic samples were tested in separate phases. Paired t tests were performed.

RESULTS

For normal donors, the mean R for laboratory compared with the aircraft was 6.2 minutes versus 7.2 minutes ( p = 0.025). The mean ± SD Citrated Rapid TEG Maximum Amplitude (CRT MA) was 59.3 ± 5.6 mm and 55.9 ± 7.3 mm ( p < 0.001) for laboratory and aircraft ( p < 0.001). Among normal donors, R was within normal range for 17 of 18 laboratory tests and 18 of 18 aircraft tests ( p > 0.99). During the testing of pathologic samples, the mean R time was 14.8 minutes for laboratory samples and 12.6 minutes for aircraft ( p = 0.02). Aircraft samples were classified as abnormal in 78% of samples; this was not significantly different than laboratory samples ( p = 0.5).

CONCLUSION

The use of the TEG6s for inflight viscoelastic testing appears promising. While statistically significant differences are seen in some results, these values are not considered clinically significant. Classifying samples as normal or abnormal demonstrated a higher correlation. Future studies should focus on longer flight times to evaluate for LY30, takeoff, and landing effects. Overall, this study suggests that TEG6s can be used in a prehospital environment, and further study is warranted.

LEVEL OF EVIDENCE

Diagnostic Tests or Criteria; Level III.

Using microfluidic shear to assess transfusion requirements in trauma patients

Background

Viscoelastic assays have widely been used for evaluating coagulopathies but lack the addition of shear stress important to in vivo clot formation. Stasys technology subjects whole blood to shear forces over factor-coated surfaces. Microclot formation is analyzed to determine clot area (CA) and platelet contractile forces (PCFs). We hypothesize the CA and PCF from this novel assay will provide information that correlates with trauma-induced coagulopathy and transfusion requirements.

Methods

Blood samples were collected on adult trauma patients from a single-institution prospective cohort study of high-level activations. Patient and injury characteristics, transfusion data, and outcomes were collected. Thromboelastography, coagulation studies, and Stasys assays were run on paired samples collected at admission. Stasys CA and PCFs were quantified as area under the curve calculations and maximum values. Normal ranges for Stasys assays were determined using healthy donors. Data were compared using Kruskal-Wallis tests and simple linear regression.

Results

From March 2021 to January 2023, 108 samples were obtained. Median age was 37.5 (IQR 27.5-52) years; patients were 77% male. 71% suffered blunt trauma, 26% had an Injury Severity Score of ≥25. An elevated international normalized ratio significantly correlated with decreased cumulative PCF (p=0.05), maximum PCF (p=0.05) and CA (p=0.02). Lower cumulative PCF significantly correlated with transfusion of any products at 6 and 24 hours (p=0.04 and p=0.05) as well as packed red blood cells (pRBCs) at 6 and 24 hours (p=0.04 and p=0.03). A decreased maximum PCF showed significant correlation with receiving any transfusion at 6 (p=0.04) and 24 hours (p=0.02) as well as transfusion of pRBCs, fresh frozen plasma, and platelets in the first 6 hours (p=0.03, p=0.03, p=0.03, respectively).

Conclusions

Assessing coagulopathy in real time remains challenging in trauma patients. In this pilot study, we demonstrated that microfluidic approaches incorporating shear stress could predict transfusion requirements at time of admission as well as requirements in the first 24 hours.

Level of evidence

Level II.

Postpartum haemorrhage in high-resource settings: Variations in clinical management and future research directions based on a comparative study of national guidelines

OBJECTIVE

To compare guidelines from eight high-income countries on prevention and management of postpartum haemorrhage (PPH), with a particular focus on severe PPH.

DESIGN

Comparative study.

SETTING

High-resource countries.

POPULATION

Women with PPH.

METHODS

Systematic comparison of guidance on PPH from eight high-income countries.

MAIN OUTCOME MEASURES

Definition of PPH, prophylactic management, measurement of blood loss, initial PPH-management, second-line uterotonics, non-pharmacological management, resuscitation/transfusion management, organisation of care, quality/methodological rigour.

CONCLUSIONS

Our study highlights areas where strong evidence is lacking. There is need for a universal definition of (severe) PPH. Consensus is required on how and when to quantify blood loss to identify PPH promptly. Future research may focus on timing and sequence of second-line uterotonics and non-pharmacological interventions and how these impact maternal outcome. Until more data are available, different transfusion strategies will be applied. The use of clear transfusion-protocols are nonetheless recommended to reduce delays in initiation. There is a need for a collaborative effort to develop standardised, evidence-based PPH guidelines.

RESULTS

Definitions of (severe) PPH varied as to the applied cut-off of blood loss and incorporation of clinical parameters. Dose and mode of administration of prophylactic uterotonics and methods of blood loss measurement were heterogeneous. Recommendations on second-line uterotonics differed as to type and dose. Obstetric management diverged particularly regarding procedures for uterine atony. Recommendations on transfusion approaches varied with different thresholds for blood transfusion and supplementation of haemostatic agents. Quality of guidelines varied considerably.

A Retrospective Study Comparing the Effect of Conventional Coagulation Parameters Vs. Thromboelastography-Guided Blood Product Utilization in Patients With Major Gastrointestinal Bleeding

Background

The use of thromboelastography (TEG) has demonstrated decreased blood product utilization in patients with specific etiologies of major gastrointestinal bleeding (GIB), such as variceal and non-variceal bleeding in cirrhosis patients; however, in a non-cirrhosis patient with GIB, there is far less evidence in the literature. Our retrospective study compares the effect of TEG-guided blood product utilization in patients with major GIB with all etiologies, including cirrhosis, admitted to medical intensive care unit (MICU).

Methods

A retrospective chart review was conducted on patients admitted to the MICU of a tertiary academic medical center diagnosed with GIB using ICD-9/10 codes from 2014 to 2018. A total of 1,889 patients were identified, and validation criteria such as "GI or hepatology consult note", type and screen, pantoprazole, or octreotide drip" were used, which resulted in 997 patients, out of which 369 had a diagnosis of cirrhosis. Propensity score matching was done for baseline variables (age, sex, and race), ICU length of stay, hospital length of stay, ventilator days, and vasopressor use. As a result, 88 patients were included in the final analysis, with 44 in TEG and 44 in non-TEG group. A sub-group analysis was done in 46 patients with cirrhosis, 23 in TEG group and 23 in non-TEG group after propensity score matching.

Results

There was significantly higher total blood volume (4,207 mL vs. 2,568 mL, P = 0.04) in the TEG group as compared to the non-TEG group, including total volume of cryoprecipitate (80 mL vs. 55 mL, P = 0.03) and total volume of platelet (543 mL vs. 327 mL, P = 0.03). In the cirrhosis sub-group, there was no significant difference in the amount of blood products transfused between the two groups.

Conclusion

This study revealed that TEG is not superior to conventional coagulation parameters in limiting the volume of blood product transfusion in major GIB patients in ICU settings.

Design and Development of a Clot Burst Pressure Device to Investigate Resuscitation Strategies

INTRODUCTION

A reduction in clot strength is a hallmark feature of trauma-induced coagulopathy. A better understanding of clot integrity can optimize resuscitation strategies. We designed a device to gauge clot strength by pressurizing fluids over a formed clot and measuring the pressure needed to dislodge the clot. We hypothesized that this device could distinguish between clots formed in hypocoagulable and hypercoagulable states by observing differences in the clot burst pressure.

METHODS

Whole blood from healthy volunteers was collected into sodium citrate tubes and was treated with heparin or fibrinogen to generate clots in a hypocoagulable or hypercoagulable state, respectively. Small bore holes were drilled into polystyrene plates, and recalcified blood was pipetted into the holes. Plates were incubated at 37°C for 30 min to form clots. A pressure cap with an inlet for fluid from a syringe pump and an outlet leading to a measurement column was secured in the wells with a watertight seal.

RESULTS

Clot burst pressure was normalized to individual baseline values to account for inherent differences in clot strength. The 1.0 g/L and 2.0 g/L fibrinogen groups were 1.65 ± 0.07 (P = 0.0078) and 2.26 ± 0.16 (P = 0.0078) times as strong as baseline, respectively. The 0.10, 0.15, or 0.20 USP units/mL groups were 0.388 ± 0.07 (P = 0.125), 0.31 ± 0.07 (P = 0.125), 0.21 ± 0.07 (P = 0.125) times as strong as baseline, respectively. Data were analyzed using Wilcoxon matched pairs signed rank testing.

CONCLUSIONS

This device tests clot strength using burst pressure, an easily interpreted clinical parameter not measured in existing devices. Future work can test blood from trauma patients to better understand trauma pathophysiology.

Thromboelastography in the Perioperative Period: A Literature Review

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

Impact on Blood Product Utilization with Thromboelastography Guided Resuscitation for Gastrointestinal Hemorrhage

BACKGROUND

Thromboelastography (TEG) can guide transfusion therapy in trauma and has been associated with decreased transfusion requirements. This population differs from the medical population where the most common bleeding source is gastrointestinal hemorrhage (GIB). The utility of TEG in patients with acute GIB is not well described. We sought to assess whether the use of TEG impacts blood product utilization in patients with medical GIB.

METHODS

A retrospective study looking at all adult patients admitted with a primary diagnosis of GIB to the George Washington University Intensive Care Unit (ICU) between 01/01/2017 to 12/31/2019. The primary intervention was the use of TEG to guide blood product resuscitation in addition to standard of care (TEG arm) versus standard of care alone (non-TEG arm).

RESULTS

The primary outcome was the total number of blood products utilized. Patients in the TEG arm used more blood products compared to the non-TEG arm (9.10 vs 3.60, p < 0.001). There was no difference in secondary endpoints except for an increased requirement for mechanical ventilation within the TEG arm (26.2% vs 13.4%, p  =  0.018).

CONCLUSIONS

The use of TEG to guide resuscitation in patients with acute GIB may be associated with increased blood product utilization without any clinical benefit to patient-centered outcomes.

Thromboelastography and Its Use in Pediatric Trauma Patients

BACKGROUND/PURPOSE

Thromboelastography's (TEG's) use in pediatric trauma patients is not widely studied. Identifying clotting cascade defects can direct decision making regarding blood product transfusion.

METHODS

We performed a single-center retrospective review of all level 1 pediatric trauma patients. Data collected included demographics, diagnoses, Injury Severity Score, intensive care unit length of stay (ICU LOS), mortality, TEG values, and blood products received. We identified TEG values associated with mortality, ICU LOS, and need for blood product transfusion.

RESULTS

A total of 237 trauma 1 patients were identified. After exclusions, 148 patients were included for analysis. Most patients were below TEG transfusion cut points. Patients with elevated reaction time, K value, and fibrinolysis at 30 minutes had increased odds of mortality with odds ratios of 1.71 (95% confidence interval [CI], 1.22-2.40), 1.94 (95% CI, 1.23-3.05), and 1.15 (95% CI, 1.03-1.28), respectively. For ICU LOS, elevated reaction time, K value, and fibrinolysis at 30 minutes, α angle, and maximum amplitude demonstrated hazard ratios of 0.76 (95% CI, 0.65-0.88), 0.82 (95% CI, 0.64-1.0), 0.95 (95% CI, 0.88-0.99), 1.05 (95% CI, 1.02-1.08), and 1.04 (95% CI, 1.01-1.06), respectively. There was no association between TEG and blood product transfusion.

CONCLUSIONS

Coagulopathic patients based on TEG had higher mortality. All TEG values, as they moved toward transfusion-trigger cut points, were associated with increased mortality.

The Role of Thromboelastography in Identifying Coagulopathy Among Geriatric Traumatic Brain Injury Patients

Background The geriatric population has the highest incidence of head injury, and those who are anticoagulated have an increased risk of traumatic intracranial hemorrhage (ICH). The availability of viscoelastic coagulation studies has coincided with the development of many anticoagulation reversal agents. In this study, our objective was to assess whether the thromboelastography (TEG) assay affected clinical decision-making regarding reversal agent administration among geriatric patients with ICH caused by blunt head trauma. Methodology We prospectively screened adults aged 65 and older with head trauma presenting to the emergency departments of two level-one trauma centers. International Classification of Diseases, Tenth Revision codes S00-09 were used to identify the diagnosis of head injury. Patients with CT head imaging positive for acute ICH were included. Each patient was assessed for home use of antiplatelet or anticoagulant medications, as well as in-hospital use of any reversal agents. Reversal agent administration and mortality were compared between patients who received TEG and those who did not. Results A total of 680 patients had acute ICH on head CT, and 324 (48%) patients received TEG. More patients screened with TEG were transfused platelets (30.2% vs. 10.7%, p < 0.001). This remained significant for patients taking anticoagulants, antiplatelets, or neither. There were no differences in the administration of other reversal agents (prothrombin complex concentrate or fresh frozen plasma) or mortality whether or not TEG was performed. Conclusions Patients who had TEG performed were more likely to receive platelet reversal agents, regardless of antiplatelet medication usage. Among elderly adults with ICH, TEG is a rapid screening test that may help identify patients with platelet function abnormalities requiring reversal.

Balanced blood component resuscitation in trauma: Does it matter equally at different transfusion volumes?

BACKGROUND

It remains unclear whether the association between balanced blood component transfusion and lower mortality is generalizable to trauma patients receiving varying transfusion volumes. We sought to study the role red blood cell transfusion volume plays in the relationships between red blood cell:platelet and red blood cell:fresh frozen plasma ratios and 4-hour mortality.

METHODS

Adult patients in the 2013 to 2018 American College of Surgeons Trauma Quality Improvement Program database receiving ≥6 red blood cell, ≥1 platelet, and ≥1 fresh frozen plasma within 4 hours were included. The following 4 cohorts were defined based on 4-hour red blood cell transfusion volume: (1) 6 to 10 units, (2) 11 to 15 units, (3) 16 to 20 units, and (4) >20 units. The association between red blood cell:fresh frozen plasma, red blood cell:platelet, and 4-hour mortality was evaluated discretely for each red blood cell transfusion volume category, statistically adjusting for confounders.

RESULTS

A total of 14,549 patients were included. In patients receiving 6 to 10 units of red blood cells, red blood cell:platelet ratios were not associated with 4-hour mortality, and only red blood cell:fresh frozen plasma ≥4:1 were associated with significantly higher odds of 4-hour mortality compared to 1:1. For patients receiving >10 red blood cell units, increasing red blood cell:platelet and red blood cell:fresh frozen plasma ratios were consistently associated with increased odds of 4-hour mortality. For example, in red blood cell volumes of 11 to 15, 16 to 20, and >20 units, risk-adjusted 4-hour mortality odds ratios for red blood cell:platelet ≥4:1 were 2.27 (1.47-3.51), 3.32 (2.26-4.90), and 3.01 (2.33-3.88), respectively.

CONCLUSION

The association between balanced blood component transfusion and 4-hour mortality is not homogenous in trauma patients requiring different transfusion volumes and is specifically less evident in patients receiving lower volumes. Such findings should be considered in the current and future blood shortage crises across the nation.

Utility of viscoelastic hemostatic assay to guide hemostatic resuscitation in trauma patients: a systematic review

Objective

Viscoelastic hemostatic assay (VHA) provides a graphical representation of a clot’s lifespan and reflects the real time of coagulation. It has been used to guide trauma resuscitation; however, evidence of the effectiveness of VHAs is still limited. This systematic review aims to summarize the published evidence to evaluate the VHA-guided strategy in resuscitating trauma patients.

Methods

The PubMed, Embase, and Web of Science databases were searched from their inception to December 13, 2021. Randomized controlled trials (RCTs) or observational studies comparing VHA-guided transfusion to controls in resuscitating trauma patients were included in this systematic review.

Results

Of the 7743 records screened, ten studies, including two RCTs and eight observational studies, met the inclusion criteria. There was great heterogeneity concerning study design, enrollment criterion, VHA device, VHA-guided strategy, and control strategy. Thrombelastography (TEG) was used as a guiding tool for transfusion in eight studies, and rotational thromboelastometry (ROTEM), and TEG or ROTEM were used in the other two studies. The overall risk of bias assessment was severe or mild in RCTs and was severe or moderate in observational studies. The main outcomes reported from the included studies were blood transfusion (n = 10), mortality (n = 10), hospital length of stay (LOS) (n = 7), intensive care unit LOS (n = 7), and cost (n = 4). The effect of the VHA-guided strategy was not always superior to the control. Most of the studies did not find significant differences in the transfusion amount of red blood cells (n = 7), plasma (n = 5), platelet (n = 7), cryoprecipitate/fibrinogen (n = 7), and mortality (n = 8) between the VHA-guided group and control group. Notable, two RCTs showed that the VHA-guided strategy was superior or equal to the conventional coagulation test-guided strategy in reducing mortality, respectively.

Conclusion

Although some studies demonstrated VHA-guided strategy probable benefit in reducing the need for blood transfusion and mortality when resuscitating trauma patients, the evidence is still not robust. The quality of evidence was primarily downgraded by the limited number of included studies and great heterogeneity and severe risk of bias in these. Further studies are strongly recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00454-8.

Change in outcomes for trauma patients over time: Two decades of a state trauma system

BACKGROUND

Trauma center mortality rates are benchmarked to expected rates of death based on patient and injury characteristics. The expected mortality rate is recalculated from pooled outcomes across a trauma system each year, obscuring system-level change across years. We hypothesized that risk-adjusted mortality would decrease over time within a state-wide trauma system.

METHODS

We identified adult trauma patients presenting to Level I and II Pennsylvania trauma centers, 1999-2018, using the Pennsylvania Trauma Outcomes Study. Multivariable logistic regression generated risk-adjusted models for mortality in all patients, and in key subgroups: penetrating torso injury, blunt multisystem trauma, and patients presenting in shock.

RESULTS

Of 162,646 included patients, 123,518 (76.1%) were white and 108,936 (67.0%) were male. The median age was 49 (interquartile range [IQR] 29-70), median injury severity score was 16 (IQR 10-24), and 87.5% of injuries were blunt. Overall, 9.9% of patients died, and compared to 1999, no year had significantly higher adjusted odds of mortality. Overall mortality was significantly lower in 2007-2009 and 2011-2018. Of patients with blunt, multisystem injuries, 17.7% died, and adjusted mortality improved over time. Mortality rates were 24.9% for penetrating torso injury, and 56.9% for shock, with no significant change. Mortality improved for patients with ISS < 25, but not for the most severely injured.

CONCLUSIONS

Over 20 years, Pennsylvania trauma centers demonstrated improved risk-adjusted mortality rates overall, but improvement remains lacking in high-risk groups despite numerous innovations and practice changes in this time period. Identifying change over time can help guide focus to these critical gaps.

Variations in clot phenotype following injury: The MA-R ratio and fragile clots

INTRODUCTION

Trauma-induced coagulopathy is a continuum ranging from hypercoagulable to hypercoagulable phenotypes. In single-center studies, the maximum amplitude (MA) to r-time (R) (MA-R) ratio has identified a phenotype of injured patients with high mortality risk. The purpose of this study was to determine the relationship between MA-R and mortality using multicenter data and to investigate fibrinogen consumption in the development of this specific coagulopathy phenotype.

METHODS

Using the Pragmatic Randomized Optimal Platelet and Plasma Ratios data set, patients were divided into blunt and penetrating injury cohorts. MA was divided by R time from admission thromboelastogram to calculate MA-R. MA-R was used to assess odds of early and late mortality using multivariable models. Multivariable models were used to assess thrombogram values in both cohorts. Refinement of the MA-R cut point was performed with Youden index. Repeat multivariable analysis was performed with a binary CRITICAL and NORMAL MA-R.

RESULTS

In initial analysis, MA-R quartiles were not associated with mortality in the penetrating cohort. In the blunt cohort, there was an association between low MA-R and early and late mortality. A refined cut point of 11 was identified (CRITICAL: MA-R, ≤11; NORMAL: MA-R, >11). CRITICAL MA-R was associated with mortality in both penetrating and blunt subgroups. In further injury subgroup analysis, CRITICAL patients had significantly decreased fibrinogen levels in the blunt subgroup only. In both blunt and penetrating injury, there was no difference in time to initiation of thrombin burst (lagtime). However, both endogenous thrombin potential and peak thrombin levels were significantly lower in CRITICAL patients.

CONCLUSIONS

MA-R identifies a trauma-induced coagulopathy phenotype characterized in blunt injury by impaired thrombin generation that is associated with early and late mortality. The endotheliopathy and tissue factor release likely plays a role in the cascade of impaired thrombin burst, possible early fibrinogen consumption and the weaker clot identified by MA-R.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Utilization and Efficacy of Resuscitation Endpoints in Trauma and Burn Patients: A Review Article

Shock is a sequelae in trauma and burn patients that substantially increases the risk for morbidity and mortality. The use of resuscitation endpoints allows for improved management of these patients, with the potential to prevent further morbidity/mortality. We conducted a review of the current literature on the efficacy of hemodynamic, metabolic, and regional resuscitation endpoints for use in trauma and burn patients. Hemodynamic endpoints included mean arterial pressure (MAP), heart rate (HR), urinary output (UO), compensatory reserve index (CRI), intrathoracic blood volume, and stroke volume variation (SVV). Metabolic endpoints measure cellular responses to decreased oxygen delivery and include serum lactic acid (LA), base deficit (BD), bicarbonate, anion gap, apparent strong ion difference, and serum pH. Mean arterial pressure, HR, UO, and LA are the most established markers of trauma and burn resuscitation. The evidence suggests LA is a superior metabolic endpoint marker. Newer resuscitation endpoint technologies such as point-of-care ultrasound (PoCUS), thromboelastography (TEG), and rotational thromboelastometry (ROTEM) may improve patient outcomes; however, additional research is needed to establish the efficacy in trauma and burn patients. The endpoints discussed have situational strengths and weaknesses and no single universal resuscitation endpoint has yet emerged. This review may increase knowledge and aid in guideline development. We recommend clinicians continue to integrate multiple endpoints with emphasis on MAP, HR, UO, LA, and BD. Future investigation should aim to standardize endpoints for each clinical presentation. The search for universal and novel resuscitation parameters in trauma and burns should also continue.

Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury

A unique coagulopathy often manifests following traumatic brain injury, leading the clinician down a difficult decision path on appropriate prophylaxis and therapy. Conventional coagulation assays—such as prothrombin time, partial thromboplastin time, and international normalized ratio—have historically been utilized to assess hemostasis and guide treatment following traumatic brain injury. However, these plasma-based assays alone often lack the sensitivity to diagnose and adequately treat coagulopathy associated with traumatic brain injury. Here, we review the whole blood coagulation assays termed viscoelastic tests and their use in traumatic brain injury. Modified viscoelastic tests with platelet function assays have helped elucidate the underlying pathophysiology and guide clinical decisions in a goal-directed fashion. Platelet dysfunction appears to underlie most coagulopathies in this patient population, particularly at the adenosine diphosphate and/or arachidonic acid receptors. Future research will focus not only on the utility of viscoelastic tests in diagnosing coagulopathy in traumatic brain injury, but also on better defining the use of these tests as evidence-based and/or precision-based tools to improve patient outcomes.

The Algorithm Examining the Risk of Massive Transfusion (ALERT) Score Accurately Predicts Massive Transfusion at the Scene of Injury and on Arrival to the Trauma Bay: A Retrospective Analysis

BACKGROUND

Massive transfusion (MT) is required to resuscitate traumatically injured patients with complex derangements. Scoring systems for MT typically require laboratory values and radiological imaging that may delay the prediction of MT.

STUDY DESIGN

The Trauma ALgorithm Examining the Risk of massive Transfusion (Trauma ALERT) study was an observational cohort study. Prehospital and admission ALERT scores were constructed with logistic regression of prehospital and admission vitals, and FAST examination results. Internal validation was performed with bootstrap analysis and cross-validation.

RESULTS

The development cohort included 2,592 patients. Seven variables were included in the prehospital ALERT score: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), SpO2, motor Glasgow Coma Scale (GCS) score, and penetrating mechanism. Eight variables from 2,307 patients were included in the admission ALERT score: admission SBP, HR, RR, GCS score, temperature, FAST examination result, and prehospital SBP and DBP.The area under the receiving operator characteristic curve for the prehospital and admission models were 0.754 (95% bootstrapped CI 0.735-0.794, P < 0.001) and 0.905 (95% bootstrapped CI 0.867-0.923, P < 0.001), respectively. The prehospital ALERT score had equivalent diagnostic accuracy to the ABC score (P = 0.97), and the admission ALERT score outperformed both the ABC and the prehospital ALERT scores (P < 0.0001).

CONCLUSION

The prehospital and admission ALERT scores can accurately predict massive transfusion in trauma patients without the use of time-consuming laboratory studies, although prospective studies need to be performed to validate these findings. Early identification of patients who will require MT may allow for timely mobilization of scarce resources and could benefit patients by making blood products available for treating hemorrhagic shock.

Management of a Pediatric Type 3C Open Femoral Fracture Following a High-Velocity Gunshot Wound at an Adult Level II Trauma Center

ABSTRACT

We present a case of a 10-year-old girl shot in the thigh by a stray bullet who had a favorable outcome when treated with a multidisciplinary approach at the nearest nonpediatric level II trauma center. Point-of-care thromboelastography facilitated effective resuscitation based on her coagulation profile, minimized blood product use, and allowed for damage-control surgery to stabilize and revascularize her complex femur fracture.

Effects of a Single Rapid Infusion System on Platelet Function in Stored Whole Blood: An Ex Vivo Study

Introduction

Rapid infusion systems (RIS) are used to warm and rapidly infuse crystalloids and blood products. Current guidelines do not approve of platelet transfusion through a RIS, but data supporting these guidelines are scarce. Our hypothesis was that an infusion of whole blood through a RIS would degrade platelet quantity, impede viscoelastic clot strength, and inhibit platelet aggregation response to adenosine diphosphate pathway (ADP) activation.

Methods

Ten iterations of a simulated scenario of transfusing whole blood via a single brand and make of RIS (Belmont Fluid Management System 2000, Belmont Medical Technologies, Billerica, MA) were performed. Units of whole blood, which were two to nine days old, were leukoreduced prestorage. Blood was used to prime the RIS and then warmed and infused at 100 mL/min into a reservoir. Blood samples were collected before and immediately after infusion. Samples were tested for platelet count, size, and viscoelastic clot strength using thromboelastographic and aggregation assays.

Results

The study sample (n = 10) included platelets with an average age of 5.3 days. The infusion through the RIS had a detrimental effect on all the maximal amplitudes (MA) of viscoelastic testing: MA ADP (mean difference = −18.7 mm; 95% CI: −24.1 to −13.3, P = 0.004), MA rapid thromboelastography (MA rTEG) (mean difference = −6.0; 95% CI: −10.0 to −2.0, P = 0.008), MA TEG (mean difference = −7.1; 95% CI: −10.9 to −3.4, P = 0.004), mean platelet volume (MPV) (mean difference = −0.3; 95% CI: −0.6 to −0.1, P = 0.02), and platelet count (mean difference = −68.3 × 10³/µL; 95% CI: −86.9 to −49.7, P = 0.004).

Conclusions

Platelet quantity, viscoelastic clot strength, and platelet aggregation response to ADP each decline after infusion through a RIS. Further studies regarding microaggregates and platelet activation are required.

Viscoelastic monitoring in trauma resuscitation

BACKGROUND

Traumatic injury results in both physical and physiologic insult. Successful care of the trauma patient depends upon timely correction of both physical and biochemical injury. Trauma-induced coagulopathy is a derangement of hemostasis and thrombosis that develops rapidly and can be fatal if not corrected. Viscoelastic monitoring (VEM) assays have been developed to provide rapid, accurate, and relatively comprehensive depictions of an individual's coagulation profile. VEM are increasingly being integrated into trauma resuscitation guidelines to provide dynamic and individualized guidance to correct coagulopathy.

STUDY DESIGN AND METHODS

We performed a narrative review of the search terms viscoelastic, thromboelastography, thromboelastometry, TEG, ROTEM, trauma, injury, resuscitation, and coagulopathy using PubMed. Particular focus was directed to articles describing algorithms for management of traumatic coagulopathy based on VEM assay parameters.

RESULTS

Our search identified 16 papers with VEM-guided resuscitation strategies in adult patients based on TEG, 12 such protocols in adults based on ROTEM, 1 protocol for children based on TEG, and 2 protocols for children based on ROTEM.

CONCLUSIONS

This review presents evidence to support VEM use to detect traumatic coagulopathy, discusses the role of VEM in trauma resuscitation, provides a summary of proposed treatment algorithms, and discusses pending questions in the field.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

A Decade of Damage Control Resuscitation: New Transfusion Practice, New Survivors, New Directions

OBJECTIVE

The aim of this study was to identify the effects of recent innovations in trauma major hemorrhage management on outcome and transfusion practice, and to determine the contemporary timings and patterns of death.

BACKGROUND

The last 10 years have seen a research-led change in hemorrhage management to damage control resuscitation (DCR), focused on the prevention and treatment of trauma-induced coagulopathy.

METHODS

A 10-year retrospective analysis of prospectively collected data of trauma patients who activated the Major Trauma Centre's major hemorrhage protocol (MHP) and received at least 1 unit of red blood cell transfusions (RBC).

RESULTS

A total of 1169 trauma patients activated the MHP and received at least 1 unit of RBC, with similar injury and admission physiology characteristics over the decade. Overall mortality declined from 45% in 2008 to 27% in 2017, whereas median RBC transfusion rates dropped from 12 to 4 units (massive transfusion rates from 68% to 24%). The proportion of deaths within 24 hours halved (33%-16%), principally with a fall in mortality between 3 and 24 hours (30%-6%). Survivors are now more likely to be discharged to their own home (57%-73%). Exsanguination is still the principal cause of early deaths, and the mortality associated with massive transfusion remains high (48%). Late deaths are now split between those due to traumatic brain injury (52%) and multiple organ dysfunction (45%).

CONCLUSIONS

There have been remarkable reductions in mortality after major trauma hemorrhage in recent years. Mortality rates continue to be high and there remain important opportunities for further improvements in these patients.

When and how should I transfuse during obstetric hemorrhage?

The incidence of maternal hemorrhage and blood transfusion has increased over time. Causes of massive hemorrhage, defined as a transfusion > 10 units of erythrocytes, include abnormal placental insertion, preeclampsia, and placental abruption. Although ratio-based transfusion has been described for managing massive hemorrhage, a goal-directed approach using laboratory or point-of-care data may lead to better outcomes. Autotransfusion, which involves the collection, washing, and filtration of maternal shed blood, avoids many of the complications associated with allogeneic blood transfusion. In this review, we provide an overview of transfusion practices related to the management of obstetric hemorrhage.

The role of cryoprecipitate in human and canine transfusion medicine

OBJECTIVE

To evaluate the current role of cryoprecipitate in human and canine transfusion medicine.

DATA SOURCES

Human and veterinary scientific reviews and original studies found using PubMed and CAB Abstract search engines were reviewed.

HUMAN DATA SYNTHESIS

In the human critical care setting, cryoprecipitate is predominantly used for fibrinogen replenishment in bleeding patients with acute traumatic coagulopathy. Other coagulopathic patient cohorts for whom cryoprecipitate is recommended include those undergoing cardiovascular or obstetric procedures or patients bleeding from advanced liver disease. Preferential selection of cryoprecipitate versus fibrinogen concentrate (when available) is currently being investigated. Also a matter of ongoing debate is whether to administer this product as part of a fixed-dose massive hemorrhage protocol or to incorporate it into a goal-directed transfusion algorithm applied to the individual bleeding patient.

VETERINARY DATA SYNTHESIS

Although there are sporadic reports of the use of cryoprecipitate in dogs with heritable coagulopathies, there are few to no data pertaining to its use in acquired hypofibrinogenemic states. Low fibrinogen in dogs (as in people) has been documented with acute traumatic coagulopathy, advanced liver disease, and disseminated intravascular coagulation. Bleeding secondary to these hypocoagulable states may be amenable to cryoprecipitate therapy. Indications for preferential selection of cryoprecipitate (versus fresh frozen plasma) remain to be determined.

CONCLUSIONS

In the United States, cryoprecipitate remains the standard of care for fibrinogen replenishment in the bleeding human trauma patient. Its preferential selection for this purpose is the subject of several ongoing human clinical trials. Timely incorporation of cryoprecipitate into the transfusion protocol of the individual bleeding patient with hypofibrinogenemia may conserve blood products, mitigate adverse transfusion-related events, and improve patient outcomes. Cryoprecipitate is readily available, effective, and safe for use in dogs. The role of this blood product in clinical canine patients with acquired coagulopathy remains unknown.

Viscoelastic Haemostatic Assays in Cardiovascular Critical Care

The initiation and management of anticoagulation is a fundamental practice for a wide variety of indications in cardiovascular critical care, including the management of patients with acute MI, stroke prevention in patients with AF or mechanical valves, as well as the prevention of device thrombosis and thromboembolic events with the use of mechanical circulatory support and ventricular assist devices. The frequent use of antiplatelet and anticoagulation therapy, in addition to the presence of concomitant conditions that may lead to a propensity to bleed, such as renal and liver dysfunction, present unique challenges. The use of viscoelastic haemostatic assays provides an additional tool allowing clinicians to strike a delicate balance of attaining adequate anticoagulation while minimising the risk of bleeding complications. In this review, the authors discuss the role that viscoelastic haemostatic assay plays in cardiac populations (including cardiac surgery, heart transplantation, extracorporeal membrane oxygenation, acute coronary syndrome and left ventricular assist devices), and identify areas in need of further study.

Acute traumatic coagulopathy and the relationship to prehospital care and on-scene red blood cell transfusion

OBJECTIVE

To identify the incidence of acute traumatic coagulopathy (ATC) in trauma patients presenting to the Royal Adelaide Hospital, analyse prehospital contributors, including red blood cell transfusion and assess the clinical significance of ATC.

METHODS

A retrospective database review was undertaken using conventional coagulation assays and viscoelastic testing (ROTEM) for diagnosis of ATC.

RESULTS

Baseline ATC incidence is 10% in trauma patients, increasing to over 80% among those where the prehospital team has attended and given a transfusion of red cells. ATC was significantly associated with higher severity of trauma (odds ratio [OR] 1.11, P < 0.0001), prehospital (OR 11.8, P < 0.0001) and in-hospital blood transfusions (OR 17.9, P < 0.0001), and massive transfusions (P < 0.001).

CONCLUSIONS

Prehospital blood transfusions are given to the most severely injured trauma patients and the incidence of ATC in this group is more than 80%. There is an association with prehospital blood transfusion and increased ATC in part related to patient selection and severity of trauma, with the contribution of red cell transfusions to ATC unclear. This association should allow earlier identification of patients at increased risk of ATC to ensure rapid correction of coagulopathy to decrease the morbidity and mortality of trauma.

Thromboelastography Use in the Acute Young Trauma Patient: Early Experience of Two Level One Trauma Centers

BACKGROUND

Thromboelastography (TEG) point-of-care systems allow for analysis of the sum of platelet function, coagulation proteases and inhibitors, and the fibrinolytic system within 30 minutes. This allows a clinician to guide transfusion more precisely with an appropriate type of blood product. Literature has supported that TEG-guided resuscitation had lower mortality compared to standardized 1:1:1 (red blood cells (RBC), fresh-frozen plasma (FFP), and platelets) massive transfusion protocol (MTP) in penetrating trauma patients, but data has been sparse in examining the young trauma patient.

METHODS

This was a cross-sectional chart review study performed with patients up to 30 years old seen in two level one trauma centers serving children with active bleeding resulting from trauma from January 1, 2010 to June 26, 2018. TEG use was evaluated in these patients.

RESULTS

258 patients were included in the analysis. 112 (43%) had penetrating trauma and 225 (87%) had polytrauma. MTP was instituted in 176 (69%) patients and 88 (34%) patients who had TEG measured. There were significant correlations between PTT and alpha (r=-0.46; p<0.001), PTT and Kinetics (r=0.53; p<0.001), PTT and maximum amplitude (r=0.449; p<0.001). There were also significant correlations between PT and alpha (r=-0.29; p=0.008), and PT and maximum amplitude (r= -0.27; p=0.013). There was no significant correlation between TEG measures and INR. There were significant associations with requiring surgery within 24 hours 45% vs 61% (p=0.018), receiving TXA 20% vs 59% (p<0.001), and with receiving MTP 62% vs 83% (p=0.001), respectively.

CONCLUSIONS

Measurement of TEG was associated with patients receiving TXA, MTP and larger amounts of blood products. Components of TEG correlated with PT and PTT levels. Although there was no association with survival to hospital discharge, patients having TEG measured were more likely to undergo surgery within the first 24 hours of hospital arrival.

Whole Blood, Fixed Ratio, or Goal-Directed Blood Component Therapy for the Initial Resuscitation of Severely Hemorrhaging Trauma Patients: A Narrative Review

This narrative review explores the pathophysiology, geographic variation, and historical developments underlying the selection of fixed ratio versus whole blood resuscitation for hemorrhaging trauma patients. We also detail a physiologically driven and goal-directed alternative to fixed ratio and whole blood, whereby viscoelastic testing guides the administration of blood components and factor concentrates to the severely bleeding trauma patient. The major studies of each resuscitation method are highlighted, and upcoming comparative trials are detailed.

Viscoelastic haemostatic assay augmented protocols for major trauma haemorrhage (ITACTIC): a randomized, controlled trial

PURPOSE

Contemporary trauma resuscitation prioritizes control of bleeding and uses major haemorrhage protocols (MHPs) to prevent and treat coagulopathy. We aimed to determine whether augmenting MHPs with Viscoelastic Haemostatic Assays (VHA) would improve outcomes compared to Conventional Coagulation Tests (CCTs).

METHODS

This was a multi-centre, randomized controlled trial comparing outcomes in trauma patients who received empiric MHPs, augmented by either VHA or CCT-guided interventions. Primary outcome was the proportion of subjects who, at 24 h after injury, were alive and free of massive transfusion (10 or more red cell transfusions). Secondary outcomes included 28-day mortality. Pre-specified subgroups included patients with severe traumatic brain injury (TBI).

RESULTS

Of 396 patients in the intention to treat analysis, 201 were allocated to VHA and 195 to CCT-guided therapy. At 24 h, there was no difference in the proportion of patients who were alive and free of massive transfusion (VHA: 67%, CCT: 64%, OR 1.15, 95% CI 0.76-1.73). 28-day mortality was not different overall (VHA: 25%, CCT: 28%, OR 0.84, 95% CI 0.54-1.31), nor were there differences in other secondary outcomes or serious adverse events. In pre-specified subgroups, there were no differences in primary outcomes. In the pre-specified subgroup of 74 patients with TBI, 64% were alive and free of massive transfusion at 24 h compared to 46% in the CCT arm (OR 2.12, 95% CI 0.84-5.34).

CONCLUSION

There was no difference in overall outcomes between VHA- and CCT-augmented-major haemorrhage protocols.

Integral Use of Thromboelastography With Platelet Mapping to Guide Appropriate Treatment, Avoid Complications, and Improve Survival of Patients With Coronavirus Disease 2019-Related Coagulopathy

OBJECTIVES

Coagulopathy of coronavirus disease 2019 is largely described as hypercoagulability, yet both thrombotic and hemorrhagic complications occur. Although therapeutic and prophylactic anticoagulant interventions have been recommended, empiric use of antifactor medications (heparin/enoxaparin) may result in hemorrhagic complications, including death. Furthermore, traditional (antifactor) anticoagulation does not address the impact of overactive platelets in coronavirus disease 2019. The primary aim was to evaluate if algorithm-guided thromboelastography with platelet mapping could better characterize an individual's coronavirus disease 2019-relatedcoagulopathic state and, secondarily, improve outcomes.

DESIGN SETTING AND PATIENTS

Coronavirus disease 2019 patients (n = 100), receiving thromboelastography with platelet mapping assay upon admission to an 800-bed tertiary-care hospital, were followed prospectively by a hospital-based thromboelastography team. Treating clinicians were provided with the option of using a pre-established algorithm for anticoagulation, including follow-up thromboelastography with platelet mapping assays. Two groups evolved: 1) patients managed by thromboelastography with platelet mapping algorithm (algorithm-guided-thromboelastography); 2) those treated without thromboelastography with platelet mapping protocols (non-algorithm-guided). Outcomes included thrombotic/hemorrhagic complications, pulmonary failure, need for mechanical ventilation, acute kidney injury, dialysis requirement, and nonsurvival.

INTERVENTIONS

Standard-of-care therapy with or without algorithm-guided-thromboelastography support.

MEASUREMENTS AND MAIN RESULTS

Although d-dimer, C-reactive protein, and ferritin were elevated significantly in critically ill (nonsurvivors, acute kidney injury, pulmonary failure), they did not distinguish between coagulopathic and noncoagulopathic patients. Platelet hyperactivity (maximum amplitude-arachidonic acid/adenosine diphosphate > 50 min), with or without thrombocytosis, was associated with thrombotic/ischemic complications, whereas severe thrombocytopenia (platelet count < 100,000/μL) was uniformly fatal. Hemorrhagic complications were observed with decreased factor activity (reaction time > 8 min). Non-algorithm-guided patients had increased risk for subsequent mechanical ventilation (relative risk = 10.9; p < 0.0001), acute kidney injury (relative risk = 2.3; p = 0.0017), dialysis (relative risk = 7.8; p < 0.0001), and death (relative risk = 7.7; p < 0.0001), with 17 of 28 non-algorithm-guided patients (60.7%) dying versus four algorithm-guided-thromboelastography patients (5.6%) (p < 0.0001). Thromboelastography with platelet mapping-guided antiplatelet treatment decreased mortality 82% (p = 0.0002), whereas non-algorithm-guided (compared with algorithm-guided-thromboelastography) use of antifactor therapy (heparin/enoxaparin) resulted in 10.3-fold increased mortality risk (p = 0.0001).

CONCLUSIONS

Thromboelastography with platelet mapping better characterizes the spectrum of coronavirus disease 2019 coagulation-related abnormalities and may guide more tailored, patient-specific therapies in those infected with coronavirus disease 2019.

Admission thrombelastography does not guide dose adjustment of enoxaparin in trauma patients

Background

Enoxaparin is used as chemoprophylaxis to reduce incidence of venous thromboembolism and its complications following trauma. Serum anti-Xa monitoring is used to assess efficacy but requires several doses to be administered. Thrombelastography assesses hypercoagulability and may have utility identifying high-risk patients for venous thromboembolism. The objective was to evaluate whether thrombelastography parameters could identify trauma patients requiring enoxaparin dose adjustment earlier than serum anti-Xa concentrations.

Methods

A single-center, retrospective medical record review evaluated patients admitted to a regional level I trauma center that received an admission thrombelastography and a dose of enoxaparin with a serum trough anti-Xa concentration drawn. Patients were divided into standard-dose or dose-adjusted enoxaparin. Venous thromboembolism incidence between groups and risk factors for enoxaparin dose adjustment and venous thromboembolism development were evaluated.

Results

A total of 204 patients were included. Differences observed between groups included age (standard-dose enoxaparin, 48.5 [29.3–72] vs dose-adjusted enoxaparin, 38.5 [25–55.7] years; P = .005), admission creatinine clearance (standard-dose enoxaparin, 92.9 [67.4–113.4] vs dose-adjusted enoxaparin, 102.1 [83.8–129.2] mL/min; P = .017), and time to venous thromboembolism prophylaxis initiation (standard-dose enoxaparin, 23.8 [11.2–36.4] vs dose-adjusted enoxaparin, 34.5 [18.3–52.7] hours; P = .004). No differences in thrombelastography parameters or venous thromboembolism incidence were observed. No independent risk factors for enoxaparin dose adjustment were identified; however, risk assessment profile score > 10 was an independent risk factor for venous thromboembolism development.

Conclusion

No relationship between admission thrombelastography and need for enoxaparin dose adjustment in trauma patients was observed. As thrombelastography continues growing in clinical use, it is prudent to investigate other potential applications. Currently, thrombelastography should not be used to guide enoxaparin dosing.

•

Admission thrombelastography does not predict need for enoxaparin dose adjustment.

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No thrombelastography parameter predicted need for dose adjustment.

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Physiologic criteria are better predictors of chemoprophylaxis pharmacodynamics.

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Risk assessment profile score > 10 continues to correlate with VTE risk in trauma patients.

New Uses for Thromboelastography and Other Forms of Viscoelastic Monitoring in the Emergency Department: A Narrative Review

Patients frequently visit the emergency department with conditions that place them at risk of worse outcomes when accompanied by coagulopathy. Routine tests of coagulation-prothrombin time, partial thromboplastin time, platelets, and fibrinogen-have shortcomings that limit their use in providing emergency care. One alternative is to investigate coagulation disturbance with viscoelastic monitoring (VEM), a coagulation test that measures the timing and strength of blood clot development in real time. VEM is widely used and studied in cardiac surgery, liver transplant surgery, anesthesia, and trauma. In this article, we review the technique of VEM and the biologic rationale of using it in addition to routine tests of coagulation in emergency clinical situations. Then, we review the evidence (or lack thereof) for using VEM in the diagnosis and treatment of specific conditions. Finally, we describe the limitations of the test and future directions for clinical use and research in emergency medicine.

Viscoelastic testing in combat resuscitation: Is it time for a new standard?

BACKGROUND

Traumatic hemorrhage and coagulopathy represent major sources of morbidity and mortality on the modern battlefield. Viscoelastic testing (VET) offers a potentially more personalized approach to resuscitation. We sought to evaluate outcomes of combat trauma patients who received VET-guided resuscitation compared with standard balanced blood product resuscitation.

METHODS

Retrospective analysis of the Department of Defense Trauma Registry, 2008 to 2016 was performed. Multivariate logistic regression analyses of all adult patients initially presenting to NATO Role III facilities who required blood products were performed to identify factors associated with VET-guided resuscitation and mortality. A propensity score matched comparison of outcomes in patient cohorts treated at VET versus non-VET Role III facilities was performed.

RESULTS

There are 3,320 patients, predominately male (98%), median age ranges from 25 years to 29 years, Injury Severity Score of 18.8, with a penetrating injury (84%) were studied. Overall mortality was 9.7%. Five hundred ninety-four patients had VET during their initial resuscitation. After adjusting for confounders, VET during initial resuscitation was independently associated with decreased mortality (odds ratio, 0.63; p = 0.04). Propensity analysis confirmed this survival advantage with a 57% reduction in overall mortality (7.3% vs. 13.1%; p = 0.001) for all patients requiring blood products.

CONCLUSION

Viscoelastic testing offers the possibility of a product-specific resuscitation for critically injured patients requiring transfusion in combat settings. Routine VET may be superior to non-VET-guided resuscitation for combat trauma victims.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Site-Of-Care Viscoelastic Assay in Major Trauma Improves Outcomes and Is Cost Neutral Compared with Standard Coagulation Tests

Major hemorrhage is often associated with trauma-induced coagulopathy. Targeted blood product replacement could achieve faster hemostasis and reduce mortality. This study aimed to investigate whether thromboelastography (TEG^®) goal-directed transfusion improved blood utilization, reduced mortality, and was cost effective. Data were prospectively collected in a U.K. level 1 trauma center, in patients with major hemorrhage one year pre- and post-implementation of TEG^® 6s Hemostasis Analyzers. Mortality, units of blood products transfused, and costs were compared between groups. Patient demographics in pre-TEG (n = 126) and post-TEG (n = 175) groups were similar. Mortality was significantly lower in the post-TEG group at 24 h (13% vs. 5%; p = 0.006) and at 30 days (25% vs. 11%; p = 0.002), with no difference in the number or ratio of blood products transfused. Cost of blood products transfused was comparable, with the exception of platelets (average £38 higher post-TEG). Blood product wastage was significantly lower in the post-TEG group (1.8 ± 2.1 vs. 1.1 ± 2.0; p = 0.002). No statistically significant difference in cost was observed between the two groups (£753 ± 651 pre-TEG; £830 ± 847 post-TEG; p = 0.41). These results demonstrate TEG 6s-driven resuscitation algorithms are associated with reduced mortality, reduced blood product wastage, and are cost neutral compared to standard coagulation tests.

The dose-dependent relationship between blood transfusions and infections after trauma: A population-based study

OBJECTIVE

The relationship between total transfusion volume and infection in the trauma patient remains unclear, especially at lower volumes of transfusion. We sought to quantify the cumulative, independent impact of transfusion within 24 hours of admission on the risk of infection in trauma patients.

METHODS

Using the Trauma Quality Improvement Program 2013 to 2016 database, we included all patients who received blood transfusions in the first 4 hours. Patients who were transferred or had incomplete/wrongly coded information on transfusion volume were excluded. Patients were divided into 20 cohorts based on the total blood product volume transfused in the first 24 hours. A composite infection variable (INF) was created, including surgical site infection, ventilator-associated pneumonia, urinary tract infection, central line associated blood stream infection, and sepsis. Univariate and stepwise multivariable logistic regression analyses were performed to study the relationship between blood transfusion and INF, controlling for demographics (e.g., age, sex), comorbidities (e.g., cirrhosis, diabetes, steroid use), severity of injury (e.g., vital signs on arrival, mechanism, Injury Severity Score), and operative and angiographic interventions.

RESULTS

Of 1,002,595 patients, 37,568 were included. The mean age was 42 ± 18.6 years, 74.6% were males, 68% had blunt trauma, and median Injury Severity Score was 25 [17-34]. Adjusting for all available confounders, odds of INF increased incrementally from 1.00 (reference, 0-2 units) to 1.23 (95% confidence interval, 1.11-1.37) for 4 units transfused to 4.89 (95% confidence interval, 2.72-8.80) for 40 units transfused. Each additional unit increased the odds of INF by 7.6%.

CONCLUSION

Transfusion of the bleeding trauma patient was associated with a dose-dependent increased risk of infectious complications. Trauma surgeons and anesthesiologists should resuscitate the trauma patient until prompt hemorrhage control while avoiding overtransfusion.

LEVEL OF EVIDENCE

Retrospective cohort study, Therapeutic IV.

Thromboelastography and rotational thromboelastometry for the surgical intensivist: A narrative review

BACKGROUND

Viscoelastic tests (VETs), specifically thromboelastography (TEG) and rotational thromboelastometry (ROTEM), are gaining popularity in the management of critically ill surgical patients with hemorrhage or thrombosis due to their comprehensive characterization of the coagulation process and point-of-care availability in comparison to conventional coagulation tests (CCTs). We review current evidence for VET use in patients in the surgical intensive care unit (SICU).

METHODS

We searched PUBMED, EMBASE and the Cochrane Library through May 30, 2018 for articles that evaluated the use of VETs in patient populations and clinical scenarios germane to the surgical intensivist. Individual articles were critically evaluated for relevance and appropriate methodology using a structured technique. Information on patient characteristics, timing and methods of CCTs/VETs, and outcomes was collected and summarized in narrative form.

RESULTS

Of 2,589 identified articles, 36 were included. Five (14%) were interventional studies and 31 (86%) were observational. Twenty-five (69%) evaluated TEG, 11 (31%) ROTEM and 18 (50%) CCTs. Investigated outcomes included quantitative blood loss (13 (36%)), blood product transfusion (9 (25%)), thromboembolic events (9 (25%)) and mortality (6 (17%)). We identified 12 clinical scenarios with sufficient available evidence, much of which was of limited quantity and poor methodological quality. Nonetheless, research supports the use of VETs for guiding early blood product administration in severe traumatic hemorrhage and for the prediction of abstract excess bleeding following routine cardiac surgery. In contrast, evidence suggests VET-based heparin dosing strategies for venous thromboembolism prophylaxis are not superior to standard dosing in SICU patients.

CONCLUSION

While VETs have the potential to impact the care of critically ill surgical patients in many ways, current evidence for their use is limited, mainly because of poor methodological quality of most available studies. Further high-quality research, including several ongoing randomized controlled trials, is needed to elucidate the role of TEG/ROTEM in the SICU population.

LEVEL OF EVIDENCE

Systematic review, level IV.

Modern Management of Bleeding, Clotting, and Coagulopathy in Trauma Patients: What Is the Role of Viscoelastic Assays?

Purpose of Review

The purpose of this review is to briefly outline the current state of hemorrhage control and resuscitation in trauma patients with a specific focus on the role viscoelastic assays have in this complex management, to include indications for use across all phases of care in the injured patient.

Recent Findings

Viscoelastic assay use to guide blood-product resuscitation in bleeding trauma patients can reduce mortality by up to 50%. Viscoelastic assays also reduce total blood products transfused, reduce ICU length of stay, and reduce costs. There are a large number of observational and retrospective studies evaluating viscoelastic assay use in the initial trauma resuscitation, but only one randomized control trial. There is a paucity of data evaluating use of viscoelastic assays in the operating room, post-operatively, and during ICU management in trauma patients, rendering their use in these settings extrapolative/speculative based on theory and data from other surgical disciplines and settings.

Summary

Both hypocoagulable and hypercoagulable states exist in trauma patients, and better indicate what therapy may be most appropriate. Further study is needed, particularly in the operating room and post-operative/ICU settings in trauma patients.

Impact of a goal-directed factor-based coagulation management on thromboembolic events following major trauma

BACKGROUND

A factor-based coagulation management following major trauma is recommended as standard of care by the European Trauma Treatment Guidelines. However, concerns about the thromboembolic risk of this approach are still prevalent. Our study therefore aims to assess if such a haemostatic management is associated with an increased risk for thromboembolic events.

METHODS

In this retrospective observational study carried out at the University Hospital Zurich we compared two three-year periods before (period 1: 2005-2007) and after (period 2: 2012-2014) implementation of a factor-based coagulation algorithm. We included all adult patients following major trauma primarily admitted to the University Hospital Zurich. Thromboembolic events were defined as a new in-hospital appearance of any peripheral thrombosis, arterial embolism, pulmonary embolism, stroke or myocardial infarction. A logistic regression was performed to investigate the association of thromboembolic events with possible confounders such as age, sex, specific Abbreviated Injury Scale (AIS) subgroups, allogeneic blood products, and the coagulation management.

RESULTS

Out of 1138 patients, 772 met the inclusion criteria: 344 patients in period 1 and 428 patients in period 2. Thromboembolic events were present in 25 patients (7.3%) of period 1 and in 42 patients (9.8%) of period 2 (raw OR 1.39, 95% CI 0.83 to 2.33, p = 0.21). Only AIS extremities (adjusted OR 1.26, 95% CI 1.05 to 1.52, p = 0.015) and exposure to allogeneic blood products (adjusted OR 2.39, 95% CI 1.33 to 4.30, p = 0.004) were independently associated with thromboembolic events in the logistic regression, but the factor-based coagulation management was not (adjusted OR 1.60, 95% CI 0.90-2.86, p = 0.11).

CONCLUSION

There is no evidence that a goal-directed, factor-based coagulation management is associated with an increased risk for thromboembolic events following major trauma.

TEG®6s system measures the contributions of both platelet count and platelet function to clot formation at the site-of-care

Knowledge of platelet count and function is key to ensuring appropriate hemostatic management. We hypothesized that the novel, portable TEG®6s coagulation assessment system could evaluate the contribution of both platelet count and function to clot formation. Whole-blood samples with variable platelet counts were prepared from healthy volunteers. Platelet function was adjusted using seven concentrations of abciximab and evaluated by light transmission aggregometry (LTA) with TRAP agonist. Maximum amplitude (MA), reaction time (R) and activated clotting time (ACT) were assessed in citrated kaolin (CK), CK with heparinase (CKH), citrated RapidTEG® (CRT), and citrated functional fibrinogen (CFF) assays. Positive correlations were observed between platelet count and CK.MA, CKH.MA, and CRT.MA (p < .0001), and CK.R, CKH.R, and CRT.ACT (p < .05). Platelet count could be accurately quantified in the range 28-91 k/μL, 28-86 k/μL and 28-74 k/μL for CK.MA, CKH.MA, and CRT.MA, respectively. CK.MA, CKH.MA, and CRT.MA showed significant negative relationships with abciximab concentration (p < .001). Platelet function inhibition was detected by all three assays at >68% measured by LTA and quantified in the range 68.4-82% (CK), 69.4-88% (CKH), and 69.7-76% (CRT). This demonstrates the TEG®6s analyzer can accurately evaluate platelet count and function at the site-of-care.

The Utility of Thromboelastography to Guide Blood Product Transfusion

OBJECTIVES

To provide an overview of the clot viscoelastic testing technology and to describe its utility in guiding blood product transfusions.

METHODS

A case scenario will be discussed as well as interpretation of thromboelastography (TEG) tracings. In addition, literature examining the utility of viscoelastic testing in guiding patient management and blood product transfusions will be reviewed.

RESULTS

TEG/rotational thromboelastometry (ROTEM) is useful in evaluating clot kinetics in trauma and acutely bleeding patients. TEG/ROTEM parameters are reflective of values measured using standard coagulation assays; however, TEG/ROTEM parameters are more rapidly available and more costly. TEG and ROTEM are used in three main settings: cardiac surgery, liver transplantation, and trauma to assess global hemostasis and administration of blood products.

CONCLUSIONS

TEG/ROTEM can be helpful in guiding resuscitation and blood product transfusion. Several studies have demonstrated a reduction in transfusion of blood components with TEG/ROTEM; however, other studies have suggested that TEG/ROTEM is not clinically effective in guiding transfusion.

Bad blood: A coagulopathy associated with trauma and massive transfusion review

Coagulopathy in trauma patients is a known contributor to death due to hemorrhage. In fact, it seen as frequently as 35% of the time. The complexity of the coagulopathy pathway requires a deliberate and planned approach. The methods used to assess and detect if a patient is coagulopathic remain challenging, but tools have been developed to assist the practitioner to effectively manage and even quickly reverse the coagulopathy. The purpose of this review is to educate trauma and emergency medicine staff on the currently available diagnostic tools to assess coagulopathy, to provide an overview of the coagulopathy pathway, as well as provide examples of how to intervene and treat coagulopathy, including the use of crew resource management during mass transfusion protocol activations.

[Viscoelasticity-based treatment of bleeding injuries]

Uncontrolled bleeding is the leading preventable cause of death in patients with multiple injuries. Currently, trauma-induced coagulopathy is seen as an independent disease entity influencing survival. Severely bleeding trauma patients are often treated with classical blood products in predefined ratios (damage control resuscitation). Viscoelasticity-based and target-oriented approaches could possibly be given priority. Viscoelasticity-based diagnostics and therapy enable the qualitative investigation of whole blood and provide therapeutically usable information on initiation, dynamics and sustainability of thrombus formation. Due to the ease of handling and timely results this lends itself as a point-of-care procedure. This article presents the clinical issues with using viscoelastic procedures and current expert recommendations taking the literature into consideration.

Viscoelastic Monitoring to Guide the Correction of Perioperative Coagulopathy and Massive Transfusion in Patients with Life-Threatening Hemorrhage

The resuscitation of patients with traumatic hemorrhage remains a challenging clinical scenario. The appropriate and aggressive support of the patient's coagulation is of critical importance. Conventional coagulation assays present several shortcomings in this setting. The integration of viscoelastic monitoring in clinical practice has the potential to result in significant improvements. In order to be successful, the provider must understand basics of the methodology, read outs, and the limitations of the technique.