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]

Quality Management of massive transfusion protocol incorporating tranexamic acid adherence

Massive transfusion protocols (MTP) vary at different institutions. We implemented an algorithm in the transfusion service to support our Level I trauma center in 2007 and periodically monitor MTP utilization as part of ongoing quality management. At the last review in 2013, median plasma: RBC ratio was 1:1.8. We undertook a retrospective 3-year review of MTP activations stratifying by trauma versus non-trauma indications, and blood component utilization of the massive transfusion (MT) cases, adding a review of tranexamic acid (TXA) administration to the audit. The median transfused plasma: RBC ratio was 1:1.9 in trauma MT, and 1:1.6 in the non-trauma MT cases. Non-trauma MT patients at our institution were significantly older and more coagulopathic at MTP initiation compared to trauma MT patients, received fewer RBC units (15.5 versus 20.2), and had higher mortality. TXA adherence increased over the 3-year period to 60% of all trauma MTP activations in 2017.

Hemostatic Management of Trauma-Induced Coagulopathy

Trauma-induced coagulopathy is a primary factor in many trauma-related fatalities. Management hinges upon rapid diagnosis of coagulation abnormalities and immediate administration of appropriate hemostatic agents. Use of crystalloids and packed red blood cells has traditionally been the core of trauma resuscitation, but current massive transfusion protocols include combination therapy with fresh frozen plasma and predefined ratios of platelets to packed red blood cells, limiting crystalloid administration. Hemostatic agents such as tranexamic acid, prothrombin complex concentrate, fibrinogen concentrate, and, in cases of refractory bleeding, recombinant activated factor VIIa may also be warranted. Goal-directed resuscitation using viscoelastic tools allows specific component-centered therapy based on individual clotting abnormalities that may limit blood product use and thromboembolic risks and may lead to reduced mortality. Because of the complex management of patients with trauma-induced coagulopathy, critical care nurses must be familiar with the pathophysiology, acute diagnostics, and pharmacotherapeutic options used to treat these patients.

The practicalities and barriers of using TEG6s in code red traumas: an observational study in one London major trauma centre

OBJECTIVE

Trauma induced coagulopathy is a disorder of the coagulation pathway that occurs following major trauma. "Code red trauma" require massive hemorrhage protocol activation. The aim was to qualitatively establish the reasons TEG is not currently utilized and the ongoing practicalities in performing a TEG sample for trauma-related massive hemorrhage.

METHODS

A pilot study was performed using a TEG6s machine within one central London Major Trauma Centre's resuscitation department. Staff were asked to run a TEG sample on any "code red" patient who attended during the trial. Staff were given questionnaires both before and after the trial to assess the knowledge around TEG.

RESULTS

A TEG sample was performed in 75% of the sixteen "code red traumas," with one sample being unsuccessful. Only one patient had their blood component management altered due to the TEG result with only 50% of consultants and registrars surveyed feeling confident in interpreting TEG results.

CONCLUSION

TEG6s samples can be run within the resuscitation department in a "code red trauma." However, there is a significant lack of knowledge relating to TEG within the emergency department which is likely to hinder its impact on personalized blood component management. More research is required in how to provide appropriate education in a busy setting to enable TEG to be utilized appropriately.

Empiric transfusion strategies during life-threatening hemorrhage

BACKGROUND

Resuscitation guided by thrombelastography improves survival after injury. If bleeding is rapid, however, or if no thrombelastography data are available, the optimal strategy remains controversial. Our current practice gives fresh frozen plasma and red blood cells (1:2) empirically in patients with life-threatening hemorrhage, with subsequent administration based on rapid thrombelastography. We identified patients at risk of massive transfusion at 1 hour, examined their initial rapid thrombelastography, and used this value to provide empiric recommendations about transfusions.

METHODS

Massive transfusion was defined as >4 units of red blood cells in the first hour. Patients managed by a trauma activation (2014-2017) had an admission rapid thrombelastography analyzed to determine what proportion met thresholds for administration of cryoprecipitate or platelets.

RESULTS

Overall, 35 patients received >4 units of red blood cells in the first hour. Based on the admission rapid thrombelastography, 37% met criteria for both platelets and cryoprecipitate, 35% for either platelets or cryoprecipitate and 29% for neither. Kaplan-Meier analysis showed a significant delay in the administration of cryoprecipitate and platelets compared to fresh frozen plasma.

CONCLUSION

Patients who require >4 units of red blood cells within the first hour should receive cryoprecipitate and platelets if thrombelastography results are not available. Point-of-care devices are needed for optimal care of trauma-induced-coagulopathy, but these data offer guidance in their absence.

Using rotational thromboelastometry clot firmness at 5 minutes (ROTEM® EXTEM A5) to predict massive transfusion and in-hospital mortality in trauma: a retrospective analysis of 1146 patients

Viscoelastic assays such as TEG^® and ROTEM^® are increasingly used to guide transfusion of blood products. The EXTEM assay maximum clot firmness (MCF) is a ROTEM measure available after 25–29 min used to guide early decisions. EXTEM A10, the clot firmness at 10 min, is an accepted early surrogate, but investigators differ on whether A5, the clot firmness at 5 min, is acceptable. We re‐examined this in a retrospective observational analysis of 1146 trauma patients in one centre who had ROTEM data recorded. A5 and A10 both correlated well with maximum clot firmness, with Pearson coefficients of r = 0.92 and r = 0.96, respectively. The correlations of A5, A10 and maximum clot firmness with requirement for massive transfusion were all similarly high, with c‐stats of 0.87, 0.89 and 0.90, respectively. The correlations with mortality were also similar but weaker, with c‐stats of 0.67, 0.69 and 0.69, respectively. Using a previously validated cut‐off of A5 < 35 mm to predict massive transfusion gave a sensitivity of 95%, specificity 83%, positive predictive value 9.3% and negative predictive value 100%. Using a value of A5 < 29 mm, for a pragmatic positive predictive value of 20%, gave a sensitivity of 67%, specificity 95% and negative predictive value 99%. Whether aiming for a high sensitivity or a strong predictive value, A5 was non‐inferior to A10 and actually missed fewer cases needing massive transfusion. A5 has similar utility to both A10 and maximum clot firmness as an early measure of clot firmness, and a low A5 value is strongly predictive of the need for massive transfusion.

Comparison of two different coagulation algorithms on the use of allogenic blood products and coagulation factors in severely injured trauma patients: a retrospective, multicentre, observational study

Background

At the University Hospital Zurich (USZ) and the Cantonal Hospital of Lucerne (LUKS) an individualized goal-directed coagulation and transfusion algorithm was introduced and implemented before 2012 (Coagulation algorithm of the USZ: USZ-Alg; of the LUKS: LUKS-Alg). Main differences between both algorithms are: 1) A target haematocrit-range of 0.21–0.24 (USZ-Alg) vs. a lower haematocrit limit only (LUKS-Alg). 2) Blind coagulation-package in selected cases (LUKS-Alg only). 3) Factor XIII substitution is considered earlier according to the USZ-Alg.

The Aim of this study was to analyse the impact of two different coagulation algorithms on the administration of allogeneic blood products, coagulation factors, the frequency of point of care measurements and haemoglobin level during resuscitation in trauma patients.

Methods

This retrospective, multicentre, observational study included all adult trauma patients with an injury severity score (ISS) ≥ 16 primarily admitted to the USZ or the LUKS in the period of 2012 to 2014. Referred patients and patients with missing/incomplete records of the initial treatment at the emergency department (ED) were excluded. Two propensity score matched groups were created using a non-parsimonious logistic regression to account for potential differences in patient and trauma epidemiology.

Results

A total of 632 patients meeting the inclusion criteria were admitted to the two hospitals: 428 to the USZ and 204 to the LUKS. Two Propensity score matched groups (n = 172 per group) were created. Treatment with USZ-Alg compared with LUKS-Alg resulted in a lower number of patients receiving RBC transfusion (11.6% vs. 29.7%, OR 3.2, 95% CI 1.8–5.7, p < 0.001) and lower amount of RBC transfusion (0.5 SD 1.9 vs. 1.5 SD 3.9, p < 0.001). The different treatment algorithms resulted in lower mean haemoglobin levels in the USZ during resuscitation (8.0 SD 1.7 vs. 9.4 SD 1.8 g/dl, p < 0.001) and at admission to the ICU (8.3 SD 1.2 vs. 10.6 SD 1.9 g/dl, p < 0.001. Blood gas analyses to monitor treatment and haematocrit were made more frequently in the USZ (1.4 SD 0.8 vs. 1.0 SD 0.7 measurements per hour, p = 0.004).

Conclusion

A goal-directed coagulation algorithm including a target haematocrit-range including frequent and repeated haematocrit measurement may lead to less transfusion of RBC compared to only a lower haematocrit limit, when treating severely traumatized patients.

Electronic supplementary material

The online version of this article (10.1186/s13049-017-0463-0) contains supplementary material, which is available to authorized users.

A Pilot Study of Viscoelastic Monitoring in Pediatric Trauma: Outcomes and Lessons Learned

Background:

Examine the characteristics and outcomes of pediatric trauma patients at risk for coagulopathy following implementation of viscoelastic monitoring.

Materials and Methods:

Injured children, aged <18 years, from September 7, 2014, to December 21, 2015, at risk for trauma-induced coagulopathy were identified from a single, level-1 American College of Surgeons verified pediatric trauma center. Patients were grouped by coagulation assessment: no assessment (NA), conventional coagulation testing alone (CCT), and conventional coagulation testing with rapid thromboelastography (rTEG). Coagulation assessment was provider preference with all monitoring options continuously available. Groups were compared and outcomes were evaluated including blood product utilization, Intensive Care Unit (ICU) utilization, duration of mechanical ventilation, and mortality.

Results:

A total of 155 patients were identified (NA = 78, CCT = 54, and rTEG = 23). There was no difference in age, gender, race, or mechanism. In practice, rTEG patients were more severely injured, more anemic, and received more blood products and crystalloid (P < 0.001). rTEG patients also had increased mortality with fewer ventilator and ICU-free days. Multivariate logistic regression and covariance analysis indicated that while rTEG use was not associated with mortality, it was associated with increased use of blood products, duration of mechanical ventilation, and ICU length of stay.

Conclusions:

Viscoelastic monitoring was infrequently performed, but utilized in more severely injured patients. Well-designed prospective studies in patients at high risk of coagulopathy are needed to evaluate goal-directed hemostatic resuscitation strategies in children.

Resuscitation

Blast injuries can produce complex patterns of injury and can easily result in hemorrhagic shock. Adequate resuscitation of blast-injured patients is critical, as both under- and over-resuscitation can result in a number of fatal complications. Consideration must be given to the choice of resuscitative fluid, the volume of resuscitation, the timing of resuscitation relative to definitive surgical management, and the determination of endpoints at which resuscitation can be stopped. This chapter explores resuscitation of blast-injured patients, beginning in the prehospital phase with initial choice of fluid and continuing through definitive resuscitation at a higher echelon of care. Particular consideration is given to the effect of resuscitation on the unique physiologic derangements seen following blast injury. Drawing upon the enormous amount of literature on resuscitation from the recent coalition experiences in Iraq and Afghanistan, we advocate for the use of early hemostatic resuscitation with a high ratio of plasma, platelets, and packed red blood cells, with a transition to resuscitation guided by viscoelastic testing or coagulation status immediately following definitive control of hemorrhage.

Thromboelastography does not provide additional information to guide resuscitation in the severely injured

Background

Haemostasis assessment is essential to determine the early need for massive transfusion in the treatment of polytrauma. Strategies to guide correction of coagulopathy vary widely. In order to evaluate thromboelastography (TEG) for this goal, a prospective study was performed comparing TEG to conventional coagulation assays (CCAs) in severely injured patients.

Methods

Consecutive polytrauma patients admitted to the intensive care unit of a level‐1 trauma centre were prospectively included over a 30‐month period. All patients had CCA on arrival in emergency department. Patients who needed massive transfusion and underwent urgent surgery had additionally a Kaolin‐activated TEG.

Results

One hundred and thirty‐five patients were included, 76% male, median age 45 years, 96% blunt injuries and median injury severity score was 29. One hundred and fourteen patients had CCA only and 21 patients had both CCA and TEG. Patients who had both CCA and TEG were acidotic, hypothermic and coagulopathic on arrival in emergency department. All 21 patients had normal TEG results even though prothrombin time was prolonged.

Conclusions

TEGs were normal in all polytrauma patients even though patients were severely injured. They had prolonged prothrombin time, acidosis and hypothermia both on arrival and when TEG was measured. Caution should be exercised in interpretation of TEG results in treating polytrauma patients. In our system, with aggressive early haemostatic resuscitation, TEG does not provide additional information in guiding resuscitation.

Initiation and Termination of Massive Transfusion Protocols: Current Strategies and Future Prospects

The advent of massive transfusion protocols (MTP) has had a significant positive impact on hemorrhaging trauma patient morbidity and mortality. Nevertheless, societal MTP guidelines and individual MTPs at academic institutions continue to circulate opposing recommendations on topics critical to MTPs. This narrative review discusses up-to-date information on 2 such topics, the initiation and termination of an MTP. The discussion for each begins with a review of the recommendations and supporting literature presented by MTP guidelines from 3 prominent societies, the American Society of Anesthesiologists, the American College of Surgeons, and the task force for Advanced Bleeding Care in Trauma. This is followed by an in-depth analysis of the main components within those recommendations. Societal recommendations on MTP initiation in hemorrhaging trauma patients emphasize the use of retrospectively validated massive transfusion (MT) prediction score, specifically, the Assessment of Blood Consumption and Trauma-Associated Severe Hemorrhage scores. Validation studies have shown that both scoring systems perform similarly. Both scores reliably identify patients that will not require an MT, while simultaneously overpredicting MT requirements. However, each scoring system has its unique advantages and disadvantages, and this review discusses how specific aspects of each scoring system can affect widespread applicability and statistical performance. In addition, we discuss the often overlooked topic of initiating MT in nontrauma patients and the specific tools physicians have to guide the MT initiation decision in this unique setting. Despite the serious complications that can arise with transfusion of large volumes of blood products, there is considerably less research pertinent to the topic of MTP termination. Societal recommendations on MTP termination emphasize applying clinical reasoning to identify patients who have bleeding source control and are adequately resuscitated. This review, however, focuses primarily on the recommendations presented by the Advanced Bleeding Care in Trauma's MTP guidelines that call for prompt termination of the algorithm-guided model of resuscitation and rapidly transitioning into a resuscitation model guided by laboratory test results. We also discuss the evidence in support of laboratory result-guided resuscitation and how recent literature on viscoelastic hemostatic assays, although limited, highlights the potential to achieve additional benefits from this method of resuscitation.

Targeting resuscitation to normalization of coagulating status: Hyper and hypocoagulability after severe injury are both associated with increased mortality

INTRODUCTION

The prevalence and impact of hypercoagulability (hypo) in severely injured patients early after injury remains unclear. We hypothesize that the predominant phenotype of postinjury coagulopathy is hypercoagulability (hyper) and it is associated with increased mortality.

MATERIAL AND METHODS

Blood samples from 141 healthy volunteers assayed with thrombelastography (TEG) were used to identify thresholds of hypo and hypercoagulability (above 95th/below the 5thpercentile) in four TEG indices. These cutoffs were subsequently evaluated in severely injured trauma patients (ISS>15) from two level 1 trauma centers.

RESULTS

2540 patients with a median ISS of 25 were analyzed. Normal TEG was present in 36% of patients. Hyper was found in 38% of patients, with mixed (11%) and hypo (15%) being less common. Compared to normal coagulation patients and after controlling for age, sex, blood pressure, and injury hyper (0.013), mixed (p < 0.001) and hypo (p < 0.001) were all independent predictors of mortality.

CONCLUSION

These data support the ongoing need for goal directed resuscitation in trauma patients, it appears the optimal resuscitation strategy should be targeted towards normalization of coagulation status as both early hyper and hypocoagulability are associated with increased mortality.

Resuscitation for Hypovolemic Shock

Hemorrhage is the leading cause of preventable deaths in trauma patients. After presenting a brief history of hemorrhagic shock resuscitation, this article discusses damage control resuscitation and its adjuncts. Massively bleeding patients in hypovolemic shock should be treated with damage control resuscitation principles including limited crystalloid, whole blood or balance blood component transfusion to permissive hypotension, preventing hypothermia, and stopping bleeding as quickly as possible.

The impact of early thromboelastography directed therapy in trauma resuscitation

Background

Conventional coagulation tests do not provide an accurate representation of the complex nature of trauma induced coagulopathy. Thrombelastography provides a prompt global overview of all dynamic sequential aspects of trauma induced coagulopathy. The objective of this study was to evaluate the impact of using thrombelastography on blood products utilization, crystalloids utilization, hospital, and intensive care using length of stay, and cost savings.

Methods

We retrospectively reviewed 134 patients (May of 2012 to February of 2015) meeting Class I trauma activation. Outcome data was compared between two groups: patients prior to thrombelastography implementation (n = 87) and patients with thrombelastography guided trauma resuscitation (n = 47). Blood product usage was compared for three time periods: first 4 h, the next 20 h, and first 24 h.

Results

For the first 24 h of treatment, patients with thrombelastography guided trauma resuscitation had lower packed red blood cells (p = 0.0022) and fresh frozen plasma (p = 0.0474), but higher jumbo pack platelets (p = 0.0476) utilization when compared to the patients prior to thrombelastography implementation. There was no statistical significant difference in the utilization of crystalloids for any of the three time intervals. Patients with thrombelastography guided trauma resuscitation had a shorter hospital length of stay (p = 0.0011) and intensive care unit length of stay (p = 0.0059) than the patients prior to thrombelastography implementation. Cost savings in blood products transfusion were most pronounced in patients with penetrating injuries.

Discussion

Using visco-elastic tests to guide blood transfusion was first used for liver transplant patients and then applied to cardiovascular surgery and trauma. Similar to other studies, this study showed using visco-elastic tests for trauma patietns corresponded to an overall reduction in the use of packed red blood cells and fresh frozen plasma during the first 24 hours of resuscitation. In addition, this study showed using visco-elastic tests corresponded to a significant reduction in both hospital and intensive care unit length of stay.

Conclusion

This study demonstrates that Thrombelastography guided trauma resuscitation decreases the overall transfusion requirements of packed red blood cells and fresh frozen plasma. However, given the nature of under-recognized jumbo pack platelets dysfunction in the conventional laboratory parameters, jumbo pack platelets utilization is higher when following Thrombelastography directed resuscitation. The utilization of Thrombelastography corresponded to a reduction in hospital length of stay, intensive care unit length of stay and cost of transfused blood products.

Electronic supplementary material

The online version of this article (10.1186/s13049-017-0443-4) contains supplementary material, which is available to authorized users.

Rotational thromboelastometry significantly optimizes transfusion practices for damage control resuscitation in combat casualties

BACKGROUND

Up to 40% of combat casualties with a truncal injury die of massive hemorrhage before reaching a surgeon. This hemorrhage can be prevented with damage control resuscitation (DCR) methods, which are focused on replacing shed whole blood by empirically transfusing blood components in a 1:1:1:1 ratio of platelets:fresh frozen plasma:erythrocytes:cryoprecipitate (PLT:FFP:RBC:CRYO). Measurement of hemostatic function with rotational thromboelastometry (ROTEM) may allow optimization of the type and quantity of blood products transfused. Our hypothesis was that incorporating ROTEM measurements into DCR methods at the US Role 3 hospital at Bagram Airfield, Afghanistan would change the standard transfusion ratios of 1:1:1:1 to a product mix tailored specifically for the combat causality.

METHODS

This retrospective study collected data from the Department of Defense Trauma Registry to compare transfusion practices and outcomes before and after ROTEM deployment to Bagram Airfield. Over the course of six months, 134 trauma patients received a transfusion (pre-ROTEM) and 85 received a transfusion and underwent ROTEM testing (post-ROTEM). Trauma teams received instruction on ROTEM use and interpretation, with no provision of a specific transfusion protocol, to supplement their clinical judgment and practice.

RESULTS

The pre and post groups were not significantly different in terms of mortality, massive transfusion protocol activation, mean injury severity score, or coagulation measurements. Despite the difference in size, each group received an equal total number of transfusions. However, the post-ROTEM group received a significant increase in PLT and CRYO transfusions ratios, 4× and 2×, respectively.

CONCLUSION

The introduction of ROTEM significantly improved adherence to DCR practices. The transfusion differences suggest that aggressive DCR without thromboelastometry data may result in reduced hemostatic support and underestimate the need for PLT and CRYO. Thus, future controlled trials should include ROTEM-guided coagulation management in trauma resuscitation.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Targeted Thromboelastographic (TEG) Blood Component and Pharmacologic Hemostatic Therapy in Traumatic and Acquired Coagulopathy

Trauma-induced coagulopathy (TIC) is a recently described condition which traditionally has been diagnosed by the common coagulation tests (CCTs) such as prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), platelet count, and fibrinogen levels. The varying sensitivity and specificity of these CCTs have led trauma coagulation researchers and clinicians to use Viscoelastic Tests (VET) such as Thromboelastography (TEG) to provide Targeted Thromboelastographic Hemostatic and Adjunctive Therapy (TTHAT) in a goal directed fashion to those trauma patients in need of hemostatic resuscitation. This review describes the utility of VETs, in particular, TEG, to provide TTHAT in trauma and acquired non-trauma-induced coagulopathy.

[Modern coagulation management in bleeding trauma patients : Point-of-care guided administration of coagulation factor concentrates and hemostatic agents]

BACKGROUND

Uncontrolled bleeding with trauma-induced coagulopathy (TIC) is still the leading cause of preventable death following severe multiple injury. Rapid diagnosis and treatment are associated with improved outcome. Early individualized goal-directed therapy and the use of point-of-care technology may be superior to empiric and ratio-based therapies with conventional blood products.

MATERIALS AND METHODS

Selective review of the literature considering current recommendations/expert opinion for coagulation management in bleeding trauma patients via individualized goal-directed therapy and the use of viscoelastic point-of-care (ROTEM®)-guided substitution of coagulation factor concentrates and hemostatic agents.

RESULTS

The administration of fibrinogen concentrate in bleeding trauma patients may be considered if ROTEM®-FIBTEM A10 < 10 mm (FIBTEM A5 < 9 mm; FIBTEM MCF < 12 mm) and EXTEM A10 < 45 mm (EXTEM A5 < 35 mm; EXTEM MCF < 55 mm); the administration of prothrombin complex concentrate (PCC) may be considered if signs of delayed coagulation initiation (ROTEM®-EXTEM CT > 80 s). At this stage, no concluding statement can be made for monitoring or treatment guidance with factor XIII by using point-of-care technology. Viscoelastic assays display high sensitivity and specificity for the detection of hyperfibrinolysis with subsequent administration of an antifibrinolytic.

CONCLUSIONS

Individualized therapeutic concepts based upon viscoelastic point-of-care (ROTEM®) assays present an alternative to empiric and ratio-based therapies with conventional blood products in bleeding trauma patients and may be associated with reduced need for allogenic blood products and morbidity.

Comparison of the impact of applications of Targeted Transfusion Protocol and Massive Transfusion Protocol in trauma patients

Background

The current study assessed a recently developed resuscitation protocol for bleeding trauma patients called the Targeted Transfusion Protocol (TTP) and compared its results with those of the standard Massive Transfusion Protocol (MTP).

Methods

Per capita utilization of blood products such as packed red blood cells (RBCs), fresh frozen plasma (FFP), and platelet concentrates was compared along with mortality rates during two 6-month periods, one in 2011 (when the standard MTP was followed) and another in 2014 (when the TTP was used). In the TTP, patients were categorized into three groups based on the presence of head injuries, long bone fractures, or penetrating injuries involving the trunk, extremities, or neck who were resuscitated according to separate algorithms. All cases had experienced motor vehicle accidents and had injury severity scores over 16.

Results

No statistically significant differences were observed between the study groups at hospital admission. Per capita utilization of RBC (4.76 ± 0.92 vs. 3.37 ± 0.55; P = 0.037), FFP (3.71 ± 1.00 vs. 2.40 ± 0.52; P = 0.025), and platelet concentrate (1.18 ± 0.30 vs. 0.55 ± 0.18; P = 0.006) blood products were significantly lower in the TTP epoch. Mortality rates were similar between the two study periods (P = 0.74).

Conclusions

Introduction of the TTP reduced the requirements for RBCs, FFP, and platelet concentrates in severely injured trauma patients.

Rapid thrombelastography thresholds for goal-directed resuscitation of patients at risk for massive transfusion

BACKGROUND

Uncontrolled hemorrhage is a leading cause of mortality after trauma accounting for up to 40% of deaths. Massive transfusion protocols offer a proven benefit in resuscitation of these patients. Recently, the superiority of thrombelastography (TEG)-guided resuscitation over strategies guided by conventional clotting assays has been established. We seek to determine optimal thresholds for rapid (r)-TEG driven resuscitation.

METHODS

The r-TEG data were reviewed for 190 patients presenting to our level 1 trauma center from 2010 to 2015. Criteria for inclusion were highest level trauma activation in patients 18 years or older with hypotension presumed due to acute blood loss. Exclusion criteria included isolated gunshot wound to the head, pregnancy, and chronic liver disease. Receiver operating characteristic (ROC) analysis was performed to test the predictive performance of r-TEG for massive transfusion requirement defined by need for (1) >10 units of RBCs total or death in the first 6 hours or (2) >4 units of RBCs in any hour within the first 6 hours. Cutpoint analysis was then performed to determine optimal thresholds for TEG-based resuscitation.

RESULTS

The ROC analysis of r-TEG yielded areas under the curve (AUC) greater than 70% for all outputs with respect to both transfusion thresholds considered, with exception of activated clotting time and lysis at 30 minutes for greater than 4 U RBC in any hour in the first 6 hours. Optimal cutpoint analysis of the resultant ROC curves was performed and for each value, the most sensitive cutpoint was identified, respectively activated clotting time of 128 seconds or longer, angle (α) of 65 degrees or less, maximum amplitude of 55 mm or less, and lysis at 30 minutes of 5% or greater.

CONCLUSIONS

Through ROC analysis of prospective TEG data, we have identified optimal thresholds to guide hemostatic resuscitation. These thresholds should be validated in a prospective multicenter trial.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Damage control resuscitation in patients with severe traumatic hemorrhage: A practice management guideline from the Eastern Association for the Surgery of Trauma

BACKGROUND

The resuscitation of severely injured bleeding patients has evolved into a multi-modal strategy termed damage control resuscitation (DCR). This guideline evaluates several aspects of DCR including the role of massive transfusion (MT) protocols, the optimal target ratio of plasma (PLAS) and platelets (PLT) to red blood cells (RBC) during DCR, and the role of recombinant activated factor VII (rVIIa) and tranexamic acid (TXA).

METHODS

Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, a subcommittee of the Practice Management Guidelines (PMG) Section of EAST conducted a systematic review using MEDLINE and EMBASE. Articles in English from1985 through 2015 were considered in evaluating four PICO questions relevant to DCR.

RESULT

A total of 37 studies were identified for analysis, of which 31 met criteria for quantitative meta-analysis. In these studies, mortality decreased with use of an MT/DCR protocol vs. no protocol (OR 0.61, 95% CI 0.43-0.87, p = 0.006) and with a high ratio of PLAS:RBC and PLT:RBC (relatively more PLAS and PLT) vs. a low ratio (OR 0.60, 95% CI 0.46-0.77, p < 0.0001; OR 0.44, 95% CI 0.28-0.71, p = 0.0003). Mortality and blood product use were no different with either rVIIa vs. no rVIIa or with TXA vs. no TXA.

CONCLUSION

DCR can significantly improve outcomes in severely injured bleeding patients. After a review of the best available evidence, we recommend the use of a MT/DCR protocol in hospitals that manage such patients and recommend that the protocol target a high ratio of PLAS and PLT to RBC. This is best achieved by transfusing equal amounts of RBC, PLAS, and PLT during the early, empiric phase of resuscitation. We cannot recommend for or against the use of rVIIa based on the available evidence. Finally, we conditionally recommend the in-hospital use of TXA early in the management of severely injured bleeding patients.

Targeted Coagulation Management in Severe Trauma: The Controversies and the Evidence

Hemorrhage in the setting of severe trauma is a leading cause of death worldwide. The pathophysiology of hemorrhage and coagulopathy in severe trauma is complex and remains poorly understood. Most clinicians currently treating trauma patients acknowledge the presence of a coagulopathy unique to trauma patients-trauma-induced coagulopathy (TIC)-independently associated with increased mortality. The complexity and incomplete understanding of TIC has resulted in significant controversy regarding optimum management. Although the majority of trauma centers utilize fixed-ratio massive transfusion protocols in severe traumatic hemorrhage, a widely accepted "ideal" transfusion ratio of blood to blood products remains elusive. The recent use of viscoelastic hemostatic assays (VHAs) to guide blood product replacement has further provoked debate as to the optimum transfusion strategy. The use of VHA to quantify the functional contributions of individual components of the coagulation system may permit targeted treatment of TIC but remains controversial and is unlikely to demonstrate a mortality benefit in light of the heterogeneity of the trauma population. Thus, VHA-guided algorithms as an alternative to fixed product ratios in trauma are not universally accepted, and a hybrid strategy starting with fixed-ratio transfusion and incorporating VHA data as they become available is favored by some institutions. We review the current evidence for the management of coagulopathy in trauma, the rationale behind the use of targeted and fixed-ratio approaches and explore future directions.

Strategies for Intravenous Fluid Resuscitation in Trauma Patients

Intravenous fluid management of trauma patients is fraught with complex decisions that are often complicated by coagulopathy and blood loss. This review discusses the fluid management in trauma patients from the perspective of the developing world. In addition, the article describes an approach to specific circumstances in trauma fluid decision-making and provides recommendations for the resource-limited environment.

Haemotherapy algorithm for the management of trauma-induced coagulopathy: an Australian perspective

PURPOSE OF REVIEW

Recent advances in the understanding of the pathophysiological processes associated with traumatic haemorrhage and trauma-induced coagulopathy have resulted in improved outcomes for seriously injured trauma patients. However, a significant number of trauma patients still die from haemorrhage. This article reviews the various transfusion strategies utilized in the management of traumatic haemorrhage and describes the major haemorrhage protocol (MHP) strategy employed by an Australian trauma centre.

RECENT FINDINGS

Few topics in trauma resuscitation incite as much debate and controversy as to what constitutes the 'ideal' MHP. There is a widespread geographical and institutional variation in clinical practice. Three strategies are commonly utilized; fixed ratio major haemorrhage protocol (FRMHP), viscoelastic haemostatic assay (VHA)-guided MHP and hybrid MHP. The majority of trauma centres utilize an FRMHP and there is high-level evidence to support the use of high blood product ratios. It can be argued that the FRMHP is too simplistic to be applied to all trauma patients and that the use of VHA-guided MHP with predominant factor concentrate transfusion can allow rapid individualized interventions. In between these two strategies is a hybrid MHP, combining early FRMHP with subsequent VHA-guided transfusion.

SUMMARY

There are advantages and disadvantages to each of the various MHP strategies and the evidence base to support one above another with any certainty is lacking at this time. One strategy cannot be considered superior to the other and the choice of MHP is dependent on interpretation of the current literature and local institutional logistical considerations. A number of exciting studies are currently underway that will certainly increase the evidence base and help inform clinical practice.

Goal-directed Hemostatic Resuscitation of Trauma-induced Coagulopathy: A Pragmatic Randomized Clinical Trial Comparing a Viscoelastic Assay to Conventional Coagulation Assays

BACKGROUND

Massive transfusion protocols (MTPs) have become standard of care in the management of bleeding injured patients, yet strategies to guide them vary widely. We conducted a pragmatic, randomized clinical trial (RCT) to test the hypothesis that an MTP goal directed by the viscoelastic assay thrombelastography (TEG) improves survival compared with an MTP guided by conventional coagulation assays (CCA).

METHODS

This RCT enrolled injured patients from an academic level-1 trauma center meeting criteria for MTP activation. Upon MTP activation, patients were randomized to be managed either by an MTP goal directed by TEG or by CCA (ie, international normalized ratio, fibrinogen, platelet count). Primary outcome was 28-day survival.

RESULTS

One hundred eleven patients were included in an intent-to-treat analysis (TEG = 56, CCA = 55). Survival in the TEG group was significantly higher than the CCA group (log-rank P = 0.032, Wilcoxon P = 0.027); 20 deaths in the CCA group (36.4%) compared with 11 in the TEG group (19.6%) (P = 0.049). Most deaths occurred within the first 6 hours from arrival (21.8% CCA group vs 7.1% TEG group) (P = 0.032). CCA patients required similar number of red blood cell units as the TEG patients [CCA: 5.0 (2-11), TEG: 4.5 (2-8)] (P = 0.317), but more plasma units [CCA: 2.0 (0-4), TEG: 0.0 (0-3)] (P = 0.022), and more platelets units [CCA: 0.0 (0-1), TEG: 0.0 (0-0)] (P = 0.041) in the first 2 hours of resuscitation.

CONCLUSIONS

Utilization of a goal-directed, TEG-guided MTP to resuscitate severely injured patients improves survival compared with an MTP guided by CCA and utilizes less plasma and platelet transfusions during the early phase of resuscitation.

Point-of-care testing in the acute management of traumatic brain injury: Identifying the coagulopathic patient

Background:

The use of anticoagulants or antiplatelet medications has become increasingly common and is a well-established risk factor for worsening of hemorrhages in trauma patients. The current study addresses the need to investigate the efficacy of point-of-care tests (POC) as an adjunct to conventional coagulation testing in traumatic brain injury (TBI) patients.

Methods:

A retrospective review of 190 TBI patients >18 years of age who underwent both conventional and POC testing as part of their admission coagulopathy workup was conducted. Coagulation deficiency was defined as an international normalized ratio (INR) >1.4, a reaction time (r-value) on rapid thromboelastography >50 seconds, or a VerifyNow Aspirin (VN-ASA) level of < 550 Aspirin Reaction Units.

Results:

Among 190 patients, 91 (48%) disclosed a history of either warfarin or antiplatelet use or had documented INR >1.4. Of the 18 (9%) patients who reported warfarin use, 83% had elevated INR and 61% had elevated r-value. However, 41% of the patients without reported anticoagulant usage revealed significantly elevated r-value consistent with a post-traumatic hypocoagulable state. Of 64 (34%) patients who reported taking ASA, 51 (80%) demonstrated therapeutic VN-ASA. Interestingly, 31 of 126 (25%) patients not reporting ASA use were also noted to have therapeutic VN-ASA suggestive of platelet dysfunction.

Conclusions:

The coagulopathy POC panel consisting of r-TEG and VN-ASA successfully identified a subset of TBI patients with an occult coagulopathy that would have otherwise been missed. Standardization of these POC assays on admission in TBI may help guide patient resuscitation in the acute setting.

Traumatic Abdominal Solid Organ Injury Patients Might Benefit From Thromboelastography-Guided Blood Component Therapy

BACKGROUND

Thromboelastography (TEG) has been utilized for the guidance of blood component therapy (BCT). We aimed to investigate the association between emergent TEG-guided BCT and clinical outcomes in patients with traumatic abdominal solid organ (liver and/or spleen) injuries.

METHODS

A single center retrospective study of patients who sustained traumatic liver and/or spleen injuries receiving emergent BCT was conducted. TEG was ordered in all these patients. Patient demographics, general injury information, outcomes, BCT, and TEG parameters were analyzed and compared in patients receiving TEG-guided BCT versus those without.

RESULTS

A total of 166 patients were enrolled, of whom 52% (86/166) received TEG-guided BCT. A mortality of 12% was noted among patients with TEG-guided BCT when compared with 19% of mortality in patients with non-TEG-guided BCT (P > 0.05). An average of 4 units of packed red blood cell (PRBC) was received in patients with TEG-guided BCT when compared to an average of 9 units of PRBC received in non-TEG-guided BCT patients (P < 0.01). A longer hospital length of stay (LOS, 19 ± 16 days) was found among non-TEG-guided BCT patients when compared to the TEG-guided BCT group (14 ± 12 days, P < 0.05). TEG-guided BCT showed as an independent factor associated with hospital LOS after other variables were adjusted (coefficiency: 5.44, 95% confidence interval: 0.69 - 10.18).

CONCLUSIONS

Traumatic abdominal solid organ injury patients receiving blood transfusions might benefit from TEG-guided BCT as indicated by less blood products needed and less hospitalization stay among the cohort.

Management of Trauma-Induced Coagulopathy with Thrombelastography

Viscoelastic assays, such as thrombelastography (TEG) and rotational thrombelastometry (ROTEM), have emerged as point-of-care tools that can guide the hemostatic resuscitation of bleeding injured patients. This article describes the role of TEG in contemporary trauma care by explaining this assay's methodology, clinical applications, and result interpretation through description of supporting studies to provide the reader with an evidence-based user's guide. Although TEG and ROTEM are assays based on the same viscoelastic principle, this article is focused on data supporting the use of TEG in trauma, because it is available in trauma centers in North America; ROTEM is mostly available in Europe.

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.

Viscoelastic hemostatic assays in the management of the pediatric trauma patient

Viscoelastic hemostatic assays (VHA), such as TEG and ROTEM, are whole blood tests that depict functional coagulation both numerically and graphically. The development of rapid VHA technology, which allows for the first data points to result within minutes of test initiation, has increased the utility of these tests in the treatment of trauma patients. Both adult and pediatric centers have integrated VHAs into trauma resuscitation and transfusion protocols. Literature regarding the use of VHAs for injured children is limited. Here, we discuss the mechanics and interpretation of VHAs as well as the use of VHAs in data-driven resuscitation of pediatric trauma patients. Novel research on fibrinolysis states after injury as well as hypercoagulable state diagnosed with VHAs are presented.

Association of Blood Component Ratio With Clinical Outcomes in Patients After Trauma and Massive Transfusion: A Systematic Review

Component ratios that mimic whole blood may produce survival benefit in patients massively transfused after trauma; other outcomes have not been reviewed. The purpose of this review was to systematically analyze studies where clinical outcomes were compared on the basis of the component ratios administered during massive transfusion in adult patients after trauma. PubMed, CINAHL, and MEDLINE (Ovid) were searched for studies published in English between 2007 and 2015, performed at Level I or major trauma centers. Twenty-one studies were included in the analysis. We used an adapted 9-item instrument to assess bias risk. The average bias score for the studies was 2.86 ± 1.39 out of 16, indicating a low bias risk. The most common bias sources were lack of data about primary outcomes and adverse events. Those who received high ratios experienced not only greater survival benefit but also higher rates of multiple-organ failure; all other clinical outcomes findings were equivocal.

pH modulation ameliorates the red blood cell storage lesion in a murine model of transfusion

BACKGROUND

Prolonged storage of packed red blood cells (pRBCs) induces a series of harmful biochemical and metabolic changes known as the RBC storage lesion. RBCs are currently stored in an acidic storage solution, but the effect of pH on the RBC storage lesion is unknown. We investigated the effect of modulation of storage pH on the RBC storage lesion and on erythrocyte survival after transfusion.

METHODS

Murine pRBCs were stored in Additive Solution-3 (AS3) under standard conditions (pH, 5.8), acidic AS3 (pH, 4.5), or alkalinized AS3 (pH, 8.5). pRBC units were analyzed at the end of the storage period. Several components of the storage lesion were measured, including cell-free hemoglobin, microparticle production, phosphatidylserine externalization, lactate accumulation, and byproducts of lipid peroxidation. Carboxyfluorescein-labeled erythrocytes were transfused into healthy mice to determine cell survival.

RESULTS

Compared with pRBCs stored in standard AS3, those stored in alkaline solution exhibited decreased hemolysis, phosphatidylserine externalization, microparticle production, and lipid peroxidation. Lactate levels were greater after storage in alkaline conditions, suggesting that these pRBCs remained more metabolically viable. Storage in acidic AS3 accelerated erythrocyte deterioration. Compared with standard AS3 storage, circulating half-life of cells was increased by alkaline storage but decreased in acidic conditions.

CONCLUSIONS

Storage pH significantly affects the quality of stored RBCs and cell survival after transfusion. Current erythrocyte storage solutions may benefit from refinements in pH levels.

Thromboelastography (TEG) or thromboelastometry (ROTEM) to monitor haemostatic treatment versus usual care in adults or children with bleeding

BACKGROUND

Severe bleeding and coagulopathy are serious clinical conditions that are associated with high mortality. Thromboelastography (TEG) and thromboelastometry (ROTEM) are increasingly used to guide transfusion strategy but their roles remain disputed. This review was first published in 2011 and updated in January 2016.

OBJECTIVES

We assessed the benefits and harms of thromboelastography (TEG)-guided or thromboelastometry (ROTEM)-guided transfusion in adults and children with bleeding. We looked at various outcomes, such as overall mortality and bleeding events, conducted subgroup and sensitivity analyses, examined the role of bias, and applied trial sequential analyses (TSAs) to examine the amount of evidence gathered so far.

SEARCH METHODS

In this updated review we identified randomized controlled trials (RCTs) from the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1); MEDLINE; Embase; Science Citation Index Expanded; International Web of Science; CINAHL; LILACS; and the Chinese Biomedical Literature Database (up to 5 January 2016). We contacted trial authors, authors of previous reviews, and manufacturers in the field. The original search was run in October 2010.

SELECTION CRITERIA

We included all RCTs, irrespective of blinding or language, that compared transfusion guided by TEG or ROTEM to transfusion guided by clinical judgement, guided by standard laboratory tests, or a combination. We also included interventional algorithms including both TEG or ROTEM in combination with standard laboratory tests or other devices. The primary analysis included trials on TEG or ROTEM versus any comparator.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data; we resolved any disagreements by discussion. We presented pooled estimates of the intervention effects on dichotomous outcomes as risk ratio (RR) with 95% confidence intervals (CIs). Due to skewed data, meta-analysis was not provided for continuous outcome data. Our primary outcome measure was all-cause mortality. We performed subgroup and sensitivity analyses to assess the effect based on the presence of coagulopathy of a TEG- or ROTEM-guided algorithm, and in adults and children on various clinical and physiological outcomes. We assessed the risk of bias through assessment of trial methodological components and the risk of random error through TSA.

MAIN RESULTS

We included eight new studies (617 participants) in this updated review. In total we included 17 studies (1493 participants). A total of 15 trials provided data for the meta-analyses. We judged only two trials as low risk of bias. The majority of studies included participants undergoing cardiac surgery.We found six ongoing trials but were unable to retrieve any data from them. Compared with transfusion guided by any method, TEG or ROTEM seemed to reduce overall mortality (7.4% versus 3.9%; risk ratio (RR) 0.52, 95% CI 0.28 to 0.95; I(2) = 0%, 8 studies, 717 participants, low quality of evidence) but only eight trials provided data on mortality, and two were zero event trials. Our analyses demonstrated a statistically significant effect of TEG or ROTEM compared to any comparison on the proportion of participants transfused with pooled red blood cells (PRBCs) (RR 0.86, 95% CI 0.79 to 0.94; I(2) = 0%, 10 studies, 832 participants, low quality of evidence), fresh frozen plasma (FFP) (RR 0.57, 95% CI 0.33 to 0.96; I(2) = 86%, 8 studies, 761 participants, low quality of evidence), platelets (RR 0.73, 95% CI 0.60 to 0.88; I(2) = 0%, 10 studies, 832 participants, low quality of evidence), and overall haemostatic transfusion with FFP or platelets (low quality of evidence). Meta-analyses also showed fewer participants with dialysis-dependent renal failure.We found no difference in the proportion needing surgical reinterventions (RR 0.75, 95% CI 0.50 to 1.10; I(2) = 0%, 9 studies, 887 participants, low quality of evidence) and excessive bleeding events or massive transfusion (RR 0.38, 95% CI 0.38 to 1.77; I(2) = 34%, 2 studies, 280 participants, low quality of evidence). The planned subgroup analyses failed to show any significant differences.We graded the quality of evidence as low based on the high risk of bias in the studies, large heterogeneity, low number of events, imprecision, and indirectness. TSA indicates that only 54% of required information size has been reached so far in regards to mortality, while there may be evidence of benefit for transfusion outcomes. Overall, evaluated outcomes were consistent with a benefit in favour of a TEG- or ROTEM-guided transfusion in bleeding patients.

AUTHORS' CONCLUSIONS

There is growing evidence that application of TEG- or ROTEM-guided transfusion strategies may reduce the need for blood products, and improve morbidity in patients with bleeding. However, these results are primarily based on trials of elective cardiac surgery involving cardiopulmonary bypass, and the level of evidence remains low. Further evaluation of TEG- or ROTEM-guided transfusion in acute settings and other patient categories in low risk of bias studies is needed.

Massive haemorrhage in liver transplantation: Consequences, prediction and management

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

Thromboelastography in Orthopaedic Trauma Acute Pelvic Fracture Resuscitation: A Descriptive Pilot Study

OBJECTIVES

To describe the adjunctive use of thromboelastography (TEG) in directing initial blood component therapy resuscitation of patients with polytrauma with acute pelvic/acetabular fractures.

DESIGN

Retrospective cohort review.

SETTING

Level-2 trauma center.

PATIENTS

Forty adult trauma activations with acute pelvic and/or acetabular fractures were treated with standard fracture care and TEG with adjuvant platelet mapping (TEG/PM) analysis to guide their initial 24-hour resuscitation.

INTERVENTION

TEG with PM provided goal-directed hemostatic resuscitation using component blood products and an established hospital transfusion protocol. Transfusions were triggered by abnormal TEG/PM results and/or the presence of active hemorrhage, persistent hemorrhagic shock, and abnormal base deficit levels.

MAIN OUTCOME MEASUREMENT

The correction of trauma-induced coagulopathy was determined by the return of a normal TEG/PM tracing. The numbers of component blood products transfused in the first 24 hours using TEG/PM were calculated. Subgroup analysis of transfusion requirements and differences between pelvic ring and acetabular fracture patterns were determined.

RESULTS

More than 90% of patients received a transfusion of at least 1 blood product with 84% of transfusions occurring within 6 hours of admission. TEG/PM-guided resuscitation yielded greater volumes of platelets and packed red blood cells (PRBCs) versus fresh frozen plasma (FFP) (P = 0.018) with an average transfusion ratio of 2.5:1:2.8 (PRBC:FFP:platelet). There was a trend toward greater transfusion requirements in combined injuries versus pelvic ring or acetabular fractures (P = 0.08).

CONCLUSION

TEG with PM is a valuable adjunct to guide the acute phase of resuscitation in patients with polytrauma with pelvic injuries because it allows a real-time assessment of the coagulation status. The routine use of TEG/PM may result in transfusion ratios of blood products different from those of the current empiric 1:1:1 guidelines.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Protective effects of taurine in traumatic brain injury via mitochondria and cerebral blood flow

In mammalian tissues, taurine is an important natural component and the most abundant free amino acid in the heart, retina, skeletal muscle, brain, and leukocytes. This study is to examine the taurine's protective effects on neuronal ultrastructure, the function of the mitochondrial respiratory chain complex, and on cerebral blood flow (CBF). The model of traumatic brain injury (TBI) was made for SD rats by a fluid percussion device, with taurine (200 mg/kg) administered by tail intravenous injection once daily for 7 days after TBI. It was found that CBF was improved for both left and right brain at 30 min and 7 days post-injury by taurine. Reaction time was prolonged relative to the TBI-only group. Neuronal damage was prevented by 7 days taurine. Mitochondrial electron transport chain complexes I and II showed greater activity with the taurine group. The improvement by taurine of CBF may alleviate edema and elevation in intracranial pressure. Importantly taurine improved the hypercoagulable state.

Viscoelastic point-of-care testing to assist with the diagnosis, management and monitoring of haemostasis: a systematic review and cost-effectiveness analysis

BACKGROUND

Patients with substantive bleeding usually require transfusion and/or (re-)operation. Red blood cell (RBC) transfusion is independently associated with a greater risk of infection, morbidity, increased hospital stay and mortality. ROTEM (ROTEM® Delta, TEM International GmbH, Munich, Germany; www.rotem.de), TEG (TEG® 5000 analyser, Haemonetics Corporation, Niles, IL, USA; www.haemonetics.com) and Sonoclot (Sonoclot® coagulation and platelet function analyser, Sienco Inc., Arvada, CO) are point-of-care viscoelastic (VE) devices that use thromboelastometry to test for haemostasis in whole blood. They have a number of proposed advantages over standard laboratory tests (SLTs): they provide a result much quicker, are able to identify what part of the clotting process is disrupted, and provide information on clot formation over time and fibrinolysis.

OBJECTIVES

This assessment aimed to assess the clinical effectiveness and cost-effectiveness of VE devices to assist with the diagnosis, management and monitoring of haemostasis disorders during and after cardiac surgery, trauma-induced coagulopathy and post-partum haemorrhage (PPH).

METHODS

Sixteen databases were searched to December 2013: MEDLINE (OvidSP), MEDLINE In-Process and Other Non-Indexed Citations and Daily Update (OvidSP), EMBASE (OvidSP), BIOSIS Previews (Web of Knowledge), Science Citation Index (SCI) (Web of Science), Conference Proceedings Citation Index (CPCI-S) (Web of Science), Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA) database, Latin American and Caribbean Health Sciences Literature (LILACS), International Network of Agencies for Health Technology Assessment (INAHTA), National Institute for Health Research (NIHR) HTA programme, Aggressive Research Intelligence Facility (ARIF), Medion, and the International Prospective Register of Systematic Reviews (PROSPERO). Randomised controlled trials (RCTs) were assessed for quality using the Cochrane Risk of Bias tool. Prediction studies were assessed using QUADAS-2. For RCTs, summary relative risks (RRs) were estimated using random-effects models. Continuous data were summarised narratively. For prediction studies, the odds ratio (OR) was selected as the primary effect estimate. The health-economic analysis considered the costs and quality-adjusted life-years of ROTEM, TEG and Sonoclot compared with SLTs in cardiac surgery and trauma patients. A decision tree was used to take into account short-term complications and longer-term side effects from transfusion. The model assumed a 1-year time horizon.

RESULTS

Thirty-one studies (39 publications) were included in the clinical effectiveness review. Eleven RCTs (n=1089) assessed VE devices in patients undergoing cardiac surgery; six assessed thromboelastography (TEG) and five assessed ROTEM. There was a significant reduction in RBC transfusion [RR 0.88, 95% confidence interval (CI) 0.80 to 0.96; six studies], platelet transfusion (RR 0.72, 95% CI 0.58 to 0.89; six studies) and fresh frozen plasma to transfusion (RR 0.47, 95% CI 0.35 to 0.65; five studies) in VE testing groups compared with control. There were no significant differences between groups in terms of other blood products transfused. Continuous data on blood product use supported these findings. Clinical outcomes did not differ significantly between groups. There were no apparent differences between ROTEM or TEG; none of the RCTs evaluated Sonoclot. There were no data on the clinical effectiveness of VE devices in trauma patients or women with PPH. VE testing was cost-saving and more effective than SLTs. For the cardiac surgery model, the cost-saving was £43 for ROTEM, £79 for TEG and £132 for Sonoclot. For the trauma population, the cost-savings owing to VE testing were more substantial, amounting to per-patient savings of £688 for ROTEM compared with SLTs, £721 for TEG, and £818 for Sonoclot. This finding was entirely dependent on material costs, which are slightly higher for ROTEM. VE testing remained cost-saving following various scenario analyses.

CONCLUSIONS

VE testing is cost-saving and more effective than SLTs, in both patients undergoing cardiac surgery and trauma patients. However, there were no data on the clinical effectiveness of Sonoclot or of VE devices in trauma patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005623.

FUNDING

The NIHR Health Technology Assessment programme.

Can the Viscoelastic Parameter α-Angle Distinguish Fibrinogen from Platelet Deficiency and Guide Fibrinogen Supplementation?

Viscoelastic tests such as thrombelastography (TEG, Haemoscope Inc., Niles, IL) and thromboelastometry (ROTEM, Tem International GmbH, Munich, Germany), performed in whole blood, are increasingly used at the point-of-care to characterize coagulopathic states and guide hemostatic therapy. An algorithm, based on a mono-analysis (kaolin-activated assay) approach, was proposed in the TEG patent (issued in 2004) where the α-angle and the maximum amplitude parameters are used to guide fibrinogen supplementation and platelet administration, respectively. Although multiple assays for both the TEG and ROTEM devices are now available, algorithms based on TEG mono-analysis are still used in many institutions. In light of more recent findings, we discuss here the limitations and inaccuracies of the mono-analysis approach. Research shows that both α-angle and maximum amplitude parameters reflect the combined contribution of fibrinogen and platelets to clot strength. Therefore, although TEG mono-analysis is useful for identifying a coagulopathic state, it cannot be used to discriminate between fibrin/fibrinogen and/or platelet deficits, respectively. Conversely, the use of viscoelastic methods where 2 assays can be run simultaneously, one with platelet inhibitors and one without, can effectively allow for the identification of specific coagulopathic states, such as insufficient fibrin formation or an insufficient contribution of platelets to clot strength. Such information is critical for making the appropriate choice of hemostatic therapy.

Recent developments in the assessment of the multiply injured trauma patient

PURPOSE OF REVIEW

To provide an update on the recent developments and controversies in the assessment of the traumatically injured patient.

RECENT FINDINGS

Recent literature suggests that: whole-body computed tomography (CT) is an effective strategy in more severely injured blunt trauma patients; 64-slice CT scanning now provides an effective noninvasive screening method for blunt cerebrovascular injury; the need for MRI imaging, in addition to CT, for the diagnosis of occult ligamentous injury of the cervical spine remains an unresolved controversy; point-of-care testing has made significant improvements in our ability to predict which patients will need a massive transfusion; and thromboelastography has enhanced our ability to tailor a hemostatic resuscitation more accurately.

SUMMARY

The recent advances in the assessment of the multiply injured patient allow clinicians to more efficiently diagnose a patient's injuries and implement treatment in a more timely manner.