Transfusion strategies in postinjury coagulopathy:

The pathophysiology of pelvic ring injuries: a review

Traumatic pelvic ring injuries continue to represent a major challenge due to the high rates of post-injury mortality of around 30-40% in the peer-reviewed literature. The main root cause of potentially preventable mortality relates to the delayed recognition of the extent of retroperitoneal hemorrhage and post-injury coagulopathy. The understanding of the underlying pathophysiology of pelvic trauma is predicated by classification systems for grading of injury mechanism and risk stratification for developing post-injury coagulopathy with subsequent uncontrolled exsanguinating hemorrhage. This review article elaborates on the current understanding of the pathophysiology of severe pelvic trauma with a focus on the underlying mechanisms of retroperitoneal bleeding and associated adverse outcomes.

The Role of TEG and ROTEM in Damage Control Resuscitation

ABSTRACT

Trauma-induced coagulopathy is associated with very high mortality, and hemorrhage remains the leading preventable cause of death after injury. Directed methods to combat coagulopathy and attain hemostasis are needed. The available literature regarding viscoelastic testing, including thrombelastography (TEG) and rotational thromboelastometry (ROTEM), was reviewed to provide clinically relevant guidance for emergency resuscitation. These tests predict massive transfusion and developing coagulopathy earlier than conventional coagulation testing, within 15 min using rapid testing. They can guide resuscitation after trauma, as well. TEG and ROTEM direct early transfusion of fresh frozen plasma when clinical gestalt has not activated a massive transfusion protocol. Reaction time and clotting time via these tests can also detect clinically significant levels of direct oral anticoagulants. Slowed clot kinetics suggest the need for transfusion of fibrinogen via concentrates or cryoprecipitate. Lowered clot strength can be corrected with platelets and fibrinogen. Finally, viscoelastic tests identify fibrinolysis, a finding associated with significantly increased mortality yet one that no conventional coagulation test can reliably detect. Using these parameters, guided resuscitation begins within minutes of a patient's arrival. A growing body of evidence suggests this approach may improve survival while reducing volumes of blood products transfused.

Freeze-dried plasma for major trauma - Systematic review and meta-analysis

BACKGROUND

Treatment of acute trauma coagulopathy has shifted toward rapid replacement of coagulation factors with frozen plasma (FP). There are logistic difficulties in providing FP. Freeze-dried plasma (FDP) may have logistical advantages including easier storage and rapid preparation time. This review assesses the feasibility, efficacy, and safety of FDP in trauma.

STUDY DESIGN AND METHODS

Studies were searched from Medline, Embase, Cochrane Controlled Trials Register, ClinicalTrials.gov, and Google Scholar. Observational and randomized controlled trials (RCTs) assessing FDP use in trauma were included. Trauma animal models addressing FDP use were also included. Bias was assessed using validated tools. Primary outcome was efficacy, and secondary outcomes were feasibility and safety. Meta-analyses were conducted using random-effect models. Evidence was graded using Grading of Recommendations Assessment, Development, and Evaluation profile.

RESULTS

Twelve human studies (RCT, 1; observational, 11) and 15 animal studies were included. Overall, studies demonstrated moderate risk of bias. Data from two studies (n = 119) were combined for meta-analyses for mortality and transfusion of allogeneic blood products (ABPs). For both outcomes, no difference was identified. For mortality, pooled odds ratio was 0.66 (95% confidence interval, 0.29-1.49), with I2 = 0%. Use of FDP is feasible, and no adverse events were reported. Animal data suggest similar results for coagulation and anti-inflammatory profiles for FP and FDP.

CONCLUSION

Human data assessing FDP use in trauma report no difference in mortality and transfusion of ABPs in patients receiving FDP compared with FP. Data from animal trauma studies report no difference in coagulation factor and anti-inflammatory profiles between FP and FDP. Results should be interpreted with caution because most studies were observational and have heterogeneous population (military and civilian trauma) and a moderate risk of bias. Well-designed prospective observational studies or, preferentially, RCTs are warranted to answer FDP's effect on laboratory (coagulation factor levels), transfusion (number of ABPs), and clinical outcomes (organ dysfunction, length of stay, and mortality).

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level IV.

Does the evidence support the importance of high transfusion ratios of plasma and platelets to red blood cells in improving outcomes in severely injured patients: a systematic review and meta-analyses

BACKGROUND

Deaths by exsanguination in trauma are preventable with hemorrhage control and resuscitation with allogeneic blood products (ABPs). The ideal transfusion ratio is unknown. We compared efficacy and safety of high transfusion ratios of FFP:RBC and PLT:RBC with low ratios in trauma.

STUDY DESIGN AND METHODS

Medline, Embase, Cochrane, and Controlled Clinical Trials Register were searched. Observational and randomized data were included. Risk of bias was assessed using validated tools. Primary outcome was 24-h and 30-day mortality. Secondary outcomes were exposure to ABPs and improvement of coagulopathy. Meta-analysis was conducted using a random-effects model. Strength and evidence quality were graded using GRADE profile RESULTS: 55 studies were included (2 randomized and 53 observational), with low and moderate risk of bias, respectively, and overall low evidence quality. The two RCTs showed no mortality difference (odds ratio [OR], 1.35; 95% confidence interval [CI], 0.40-4.59). Observational studies reported lower mortality in high FFP:RBCs ratio (OR, 0.38 [95% CI, 0.22-0.68] for 1:1 vs. <1:1; OR, 0.42 [95% CI, 0.22-0.81] for 1:1.5 vs. <1:1.5; and OR, 0.47 [95% CI, 0.31-0.71] for 1:2 vs. <1:2, respectively). Meta-analyses in observational studies showed no difference in exposure to ABPs. No data on coagulopathy for meta-analysis was identified.

CONCLUSIONS

Meta-analyses in observational studies suggest survival benefit and no difference in exposure to ABPs. No survival benefit in RCTs was identified. These conflicting results should be interpreted with caution. Studies are mostly observational, with relatively small sample sizes, nonrandom treatment allocation, and high potential for confounding. Further research is warranted.

Endocrine-Metabolic Response in Patients Undergoing Multiple Body Contouring Surgeries After Massive Weight Loss

BACKGROUND

The endocrine-metabolic response to trauma is directly related to its magnitude, but little is known about the adverse effects of combined surgical procedures on morbidity.

OBJECTIVES

The authors sought to evaluate risk factors by measuring the endocrine-metabolic response in patients who underwent multiple body-contouring surgeries after massive weight loss.

METHODS

This prospective, randomized, interventional study included 46 massive weight loss patients who experienced a weight loss >30% of their body mass index (BMI) and were referred for body contouring surgery. Patients were randomly allocated to the control group (n = 10) or intervention group (n = 36), which in turn was divided into 3 subgroups (n = 12, each) according to BMI, surgical time, and scar length values. Blood samples were collected from all patients at different time points to assess biological stress markers.

RESULTS

Levels of IL-6 in patients in the higher ranges of BMI and operating time and with more extensive scar length were significantly higher in the immediate postoperative period compared with baseline. Concentrations of noradrenaline were significantly higher 24 hours after surgery compared with baseline only in patients in the higher range of operating time. A higher level of IL-6 at 72 hours after surgery compared with baseline was associated with more extensive scar length. Levels of other biological stress markers did not significantly differ.

CONCLUSIONS

The combination of surgical procedures did not significantly affect the concentrations of most biological stress markers. The variable of operating time most influenced increase in plasma concentrations of stress markers.

LEVEL OF EVIDENCE: 1

Pelvic trauma: WSES classification and guidelines

Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.

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.

Prolonged storage of packed red blood cells for blood transfusion

BACKGROUND

A blood transfusion is an acute intervention, used to address life- and health-threatening conditions on a short-term basis. Packed red blood cells are most often used for blood transfusion. Sometimes blood is transfused after prolonged storage but there is continuing debate as to whether transfusion of 'older' blood is as beneficial as transfusion of 'fresher' blood.

OBJECTIVES

To assess the clinical benefits and harms of prolonged storage of packed red blood cells, in comparison with fresh, on recipients of blood transfusion.

SEARCH METHODS

We ran the search on 1st May 2014. We searched the Cochrane Injuries Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), CINAHL (EBSCO Host) and two other databases. We also searched clinical trials registers and screened reference lists of the retrieved publications and reviews. We updated this search in June 2015 but these results have not yet been incorporated.

SELECTION CRITERIA

Randomised clinical trials including participants assessed as requiring red blood cell transfusion were eligible for inclusion. Prolonged storage was defined as red blood cells stored for ≥ 21 days in a blood bank. We did not apply limits regarding the duration of follow-up, or country where the study took place. We excluded trials where patients received a combination of short- and long-stored blood products, and also trials without a clear definition of prolonged storage.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, risk of bias assessment and data extraction by at least two review authors. The major outcomes were death from any cause, transfusion-related acute lung injury, and adverse events. We estimated relative risk for dichotomous outcomes. We measured statistical heterogeneity using I(2). We used a random-effects model to synthesise the findings.

MAIN RESULTS

We identified three randomised clinical trials, involving a total of 120 participants, comparing packed red blood cells with ≥ 21 days storage ('prolonged' or 'older') versus packed red blood cells with < 21 days storage ('fresh'). We pooled data to assess the effect of prolonged storage on death from any cause. The confidence in the results from these trials was very low, due to the bias in their design and their limited sample sizes.The estimated effect of packed red blood cells with ≥ 21 days storage versus packed red blood cells with < 21 days storage for the outcome death from any cause was imprecise (5/45 [11.11%] versus 2/46 [4.34%]; RR 2.36; 95% CI 0.65 to 8.52; I(2): 0%, P = 0.26, very low quality of evidence). Trial sequential analysis, with only two trials, shows that we do not yet have convincing evidence that older packed red blood cells induce a 20% relative risk reduction of death from any cause compared with fresher packed red blood cells. No trial included other outcomes of interest specified in this review, namely transfusion-related acute lung injury, postoperative infections, and adverse events. The safety profile is unknown.

AUTHORS' CONCLUSIONS

Recognising the limitations of the review, relating to the size and nature of the included trials, this Cochrane Review provides no evidence to support or reject the use of packed red blood cells for blood transfusion which have been stored for ≥ 21 days ('prolonged' or 'older') compared with those stored for < 21 days ('fresh'). These results are based on three small single centre trials with high risks of bias. There is insufficient evidence to determine the effects of fresh or older packed red blood cells for blood transfusion. Therefore, we urge readers to interpret the trial results with caution. The results from four large ongoing trials will help to inform future updates of this review.

Functional capacity of reconstituted blood in 1:1:1 versus 3:1:1 ratios: a thrombelastometry study

INTRODUCTION

Different transfusion ratio concepts of packed red blood cells (pRBCs), fresh frozen plasma (FFP) and platelets (PLTs) have been implemented in trauma care, but the optimal ratios are still discussed. In this study the hemostatic potential of two predefined ratios was assessed by using an in vitro thrombelastometric approach. Furthermore, age effects of reconstituted blood were analyzed.

METHODS

Whole blood (WB) of voluntary donors was separated into pRBCs, FFP and PLTs and reconstituted into the ratios 1:1:1 and 3:1:1 at day 1, 4, 14, and 24. Standard blood count, electrolytes and coagulation proteins were quantified. The functional coagulation in ratio- and age-specific groups was evaluated using rotational thromboelastometry (ROTEM).

RESULTS

Several coagulation factors reduced significantly in the 3:1:1 ratio and were consistent with increased INR, decelerated clot formation times and A10 (amplitude 10 minutes after clotting time (CT)), flattened α-angle during the EXTEM and diminished MCF for distinct time points during the INTEM, FIBTEM and APTEM assays. With rising age of pRBCs the pH, sodium and potassium reached non-physiological levels.

CONCLUSION

Under standardized in vitro conditions the higher amount of pRBCs in the 3:1:1 ratio diluted coagulation factors significantly on the expense of its functional coagulation capacity as revealed by ROTEM results. Thus, the coagulation functionality of the 1:1:1 ratio predominated.

Strategies for the management of haemorrhage following pelvic fractures and associated trauma-induced coagulopathy

Exsanguination is the second most common cause of death in patients who suffer severe trauma. The management of haemodynamically unstable high-energy pelvic injuries remains controversial, as there are no universally accepted guidelines to direct surgeons on the ideal use of pelvic packing or early angio-embolisation. Additionally, the optimal resuscitation strategy, which prevents or halts the progression of the trauma-induced coagulopathy, remains unknown. Although early and aggressive use of blood products in these patients appears to improve survival, over-enthusiastic resuscitative measures may not be the safest strategy. This paper provides an overview of the classification of pelvic injuries and the current evidence on best-practice management of high-energy pelvic fractures, including resuscitation, transfusion of blood components, monitoring of coagulopathy, and procedural interventions including pre-peritoneal pelvic packing, external fixation and angiographic embolisation.

High-energy proximal femur fractures in geriatric patients: a retrospective analysis of short-term complications and in-hospital mortality in 32 consecutive patients

BACKGROUND

There is limited information in the literature on the outcomes and complications in elderly patients who sustain high-energy hip fractures. As the population ages, the incidence of high-energy geriatric hip fractures is expected to increase. The purpose of this study was to analyze the outcomes and complications in patients aged 65 years or older, who sustained a high-energy proximal femur fracture.

METHODS

Retrospective review of a prospective trauma database from January 2000 to April 2011 at a single US academic level-1 trauma center. Inclusion criteria consisted of all patients of age 65 years or older, who sustained a proximal femur fracture related to a high-energy trauma mechanism. Details concerning injury, acute treatment, and clinical course and outcome were obtained from medical records and radiographs.

RESULTS

We identified 509 proximal femur fractures in patients older than 65 years of age, of which 32 (6.3%) were related to a high-energy trauma mechanism. The mean age in the study group was 72.2 years (range 65-87), with a mean injury severity score of 20 points (range 9-57). Three patients died before discharge (9.4%), and 22 of 32 patients sustained at least one complication (68.8%). Blunt chest trauma represented the most frequently associated injury, and the main root cause of pulmonary complications. The patients' age and comorbidities did not significantly correlate with the rate of complications and the 1-year mortality.

CONCLUSIONS

High-energy proximal femur fractures in elderly patients are not very common and are associated with a low in-hospital mortality rate of less than 10%, despite high rate of complications of nearly 70%. This selective cohort of patients requires a particular attention to respiratory management due to the high incidence of associated chest trauma.

Different recovery profiles of coagulation factors, thrombin generation, and coagulation function after hemorrhagic shock in pigs

BACKGROUND

Hemorrhagic shock contributes to coagulopathy after trauma. We investigated daily changes of coagulation components and coagulation function for 5 days in hemorrhaged and resuscitated pigs.

METHODS

Fourteen pigs were randomized into the sham control (C) and the hemorrhage and lactated Ringer's resuscitation (H-LR) groups. On day 1, hemorrhage was induced in the H-LR group by bleeding 35% of the total blood volume, followed by LR resuscitation at three times the bled volume. Pigs in the C group were not hemorrhaged or resuscitated. Hemodynamics and coagulation were measured daily after H-LR on day 1 to day 5.

RESULTS

No changes in hemodynamics and coagulation function occurred in C. Hemorrhage decreased mean arterial pressure and increased heart rate. LR resuscitation corrected these changes within 2 hours. Compared with the baseline values (BL) on day 1, fibrinogen levels were decreased to 76% ± 6% by H-LR on day 1, increased to 217% ± 16% on day 2, and remained increased thereafter; platelet counts were decreased to 63% ± 5% by H-LR on day 1 and remained lower on days 2 and 3 but returned to BL by days 4 and 5 (all p < 0.05). Thrombin generation was decreased by H-LR on days 1 and 2 but then increased to above BL on days 4 and 5. Coagulation factor levels were decreased by H-LR on day 1 but returned to BL on day 3 except for factor XIII. Clot strength was decreased by H-LR on day 1 and returned to BL by day 2. Clot rapidity did not change on day 1 but was decreased on days 2 and 3 and returned to BL on days 4 and 5.

CONCLUSION

Hemorrhage and resuscitation reduced coagulation components and compromised coagulation function, which showed different recovery profiles over the 5-day study period.

Revisiting early postinjury mortality: are they bleeding because they are dying or dying because they are bleeding?

BACKGROUND

Intense debate continues in the search of the optimal ratio of blood components to deliver preemptively in the critically injured patient anticipated to require a massive transfusion. A major challenge is distinguishing patients with refractory coagulopathy versus those with overwhelming injuries who will perish irrespective of blood component administration. The hypothesis of this clinical study is that a predominant number of early deaths from hemorrhage are irretrievable despite an aggressive transfusion policy.

MATERIALS AND METHODS

During the 7-y period ending in December 2009, there were 772 in-hospital trauma deaths. Each of these deaths had been assigned a cause of death via concurrent review by the multidisciplinary hospital trauma quality improvement committee. Emergency department deaths and patients arriving from outside facilities were excluded from this study.

RESULTS

Of the 382 patients (49.5% of total) who died secondary to acute blood loss, 84 (22.0%) survived beyond the ED; of these 84, 68 (81%) were male, mean age was 31 y, and 30 (36%) sustained blunt trauma. Cause of death was determined to be exsanguination in 63 (75%), coagulopathy in 13 (15%), metabolic failure in 5 (6%), and indeterminate in 3 patients (4%).

CONCLUSION

These data indicate that 75% of patients who succumb to postinjury acute blood loss are bleeding because they are dying rather than dying because they are bleeding. Conversely, only 13 (2%) of the hospital deaths were attributed to refractory coagulopathy. These critical facts need to be considered in designing studies to determine optimal massive transfusion protocols.

[Resuscitation damage control in the patient with severe trauma]

Severe trauma is the principle cause of death among young people in developed countries, with the main causes being due to road traffic accidents and accidents at work. The principle cause of death in severe trauma is the massive uncontrolled loss of blood. Most of the severe traumas with a massive haemorrhage develop coagulopathy, with some controversy over what is the best treatment for this. Patients with severe trauma are complex patients; they have a high mortality, they consume a significant amount of sources and can require rapid, intensive and multidisciplinary treatment encompassed within the concept of resuscitation damage control. In this article we attempt to present a current view of the pathophysiology of severe trauma and resuscitation damage control that may be applied to these types of patients.

Survival following a vertical free fall from 300 feet: the crucial role of body position to impact surface

We report the case of a 28-year old rock climber who survived an "unsurvivable" injury consisting of a vertical free fall from 300 feet onto a solid rock surface. The trauma mechanism and injury kinetics are analyzed, with a particular focus on the relevance of body positioning to ground surface at the time of impact. The role of early patient transfer to a level 1 trauma center, and "damage control" management protocols for avoiding delayed morbidity and mortality in this critically injured patient are discussed.

Management of major trauma haemorrhage: treatment priorities and controversies

The severely injured trauma patient often arrives in the emergency department bleeding, coagulopathic and in need of a blood transfusion. The diagnosis and management of these patients has vastly improved with a better understanding of acute traumatic coagulopathy (ATC). In the emergency setting, traditional laboratory coagulation screens are of limited use in the diagnosis and management of life-threatening bleeding. Whole blood assays, such as thrombelastography (TEG) and rotational thrombelastometry (ROTEM) provide a rapid evaluation of clot formation, strength and lysis. Rapid diagnosis of ATC and aggressive haemostatic transfusion strategies utilizing early high doses of plasma are associated with improved outcomes in trauma. At present there is no accurate guide for transfusion in trauma, therefore blood and clotting products are administered on an empiric basis. Targeted transfusion therapy for major trauma haemorrhage based on comprehensive and rapid measures of coagulation e.g. TEG/ROTEM may lead to improved outcomes while optimizing blood utilization. Evidence for the clinical application of TEG and ROTEM in trauma is emerging with a number of studies evaluating their ability to diagnose coagulopathy early and facilitate goal-directed transfusion. This review explores current controversies and best practice in the diagnosis and management of major haemorrhage in trauma.

Fibrinogen availability and coagulation function after hemorrhage and resuscitation in pigs

Hemorrhagic coagulopathy (without neurological injuries) constitutes 40% of injury-related death in civilian hospitals and on the battlefield, and the underlying contributing mechanisms remain unclear. The purpose of this study is to investigate the effects of fibrinogen availability on coagulation function after hemorrhage in pigs. Sixteen crossbred commercial Yorkshire swine were randomized into the control group (group C) (n = 8) and hemorrhage group (group H) (n = 8). Hemorrhage was induced in group H by bleeding 35% of the estimated total blood volume, followed by resuscitation with lactated Ringer solution at three times the bled volume. Pigs in group C were not hemorrhaged or resuscitated. Blood samples were withdrawn at baseline, 15 min, 3 h, 6 h, and 24 h after hemorrhage and lactated Ringer (LR) resuscitation (H-LR). Coagulation was assessed by using thrombelastography. All baseline measurements were similar between groups C and H. Hemorrhage caused a decrease in mean arterial pressure and an increase in heart rate in group H, but LR resuscitation corrected these changes within 1 h. Compared to baseline values, fibrinogen concentrations in group H decreased at 15 min, 3 h and 6 h after H-LR, but increased to double that of the baseline value at 24 h; platelet counts decreased throughout the study; clot strength was decreased at 15 min, 3 h and 6 h, but returned to baseline value at 24 h after H-LR. Hemorrhage caused decreases in fibrinogen and platelets, and compromised clot strength. The rebound of fibrinogen at 24 h restored clot strength despite platelet deficit. These data suggest the potential compensatory role of fibrinogen in restoring coagulation function in vivo after hemorrhagic shock.

Hemostatic effects of fresh frozen plasma may be maximal at red cell ratios of 1:2

BACKGROUND

Damage control resuscitation targets acute traumatic coagulopathy with the early administration of high-dose fresh frozen plasma (FFP). FFP is administered empirically and as a ratio with the number of packed red blood cells (PRBC). There is controversy over the optimal FFP:PRBC ratio with respect to outcomes, and their hemostatic effects have not been studied. We report preliminary findings on the effects of different FFP:PRBC ratios on coagulation.

METHODS

This is a prospective observational cohort study of trauma patients requiring >4 U of PRBCs. Blood was drawn before and after each 4-U PRBC interval for prothrombin time and analysis by rotational thromboelastometry. Interval change in coagulation parameters were compared with the FFP:PRBC ratio received during each interval.

RESULTS

Sixty 4-U PRBC intervals from 50 patients were available for analysis. All measures of coagulation deteriorated with low FFP:PRBC ratios (<1:2). Maximal hemostatic effect was observed in the 1:2 to 3:4 group: 12% decrease in prothrombin time (p=0.006), 56% decrease in clotting time (p=0.047), and 38% increase in maximum clot firmness (p=0.024). Transfusion with ≥1:1 ratio did not confer any additional improvement. There was a marked variability in response to FFP, and hemostatic function deteriorated in some patients exposed to 1:1 ratios. The beneficial effects of plasma were confined to patients with coagulopathy.

CONCLUSIONS

Interim results from this prospective study suggest that FFP:PRBC ratios of ≥1:1 do not confer any additional advantage over ratios of 1:2 to 3:4. Hemostatic benefits of plasma therapy are limited to patients with coagulopathy.

Logistics of Massive Transfusions

Care of the patient with massive bleeding involves more than aggressive surgery and infusion of large amounts of blood products. The proper management of massive transfusions—whether they are in trauma patients or other bleeding patients—requires coordination of the personnel in the surgical suite or the emergency department, the blood bank, and laboratory.

The contemporary role of blood products and components used in trauma resuscitation

INTRODUCTION

There is renewed interest in blood product use for resuscitation stimulated by recent military experience and growing recognition of the limitations of large-volume crystalloid resuscitation.

METHODS

An editorial review of recent reports published by investigators from the United States and Europe is presented. There is little prospective data in this area.

RESULTS

Despite increasing sophistication of trauma care systems, hemorrhage remains the major cause of early death after injury. In patients receiving massive transfusion, defined as 10 or more units of packed red blood cells in the first 24 hours after injury, administration of plasma and platelets in a ratio equivalent to packed red blood cells is becoming more common. There is a clear possibility of time dependent enrollment bias. The early use of multiple types of blood products is stimulated by the recognition of coagulopathy after reinjury which may occur as many as 25% of patients. These patients typically have large-volume tissue injury and are acidotic. Despite early enthusiasm, the value of administration of recombinant factor VIIa is now in question. Another dilemma is monitoring of appropriate component administration to control coagulopathy.

CONCLUSION

In patients requiring large volumes of blood products or displaying coagulopathy after injury, it appears that early and aggressive administration of blood component therapy may actually reduce the aggregate amount of blood required. If recombinant factor VIIa is given, it should be utilized in the fully resuscitated patient. Thrombelastography is seeing increased application for real-time assessment of coagulation changes after injury and directed replacement of components of the clotting mechanism.

Coagulation abnormalities in the trauma patient: the role of point-of-care thromboelastography

Current recommendations for resuscitation of the critically injured patient are limited by a lack of point-of-care (POC) assessment of coagulation status. Accordingly, the potential exists for indiscriminant blood component administration. Furthermore, although thromboembolic events have been described shortly after injury, the time sequence of post-injury coagulation changes is unknown. Our current understanding of hemostasis has shifted from a classic view, in which coagulation was considered a chain of catalytic enzyme reactions, to the cell-based model (CBM), representing the interplay between the cellular and plasma components of clot formation. Thromboelastography (TEG), a time-sensitive dynamic assay of the viscoelastic properties of blood, closely parallels the CBM, permitting timely, goal-directed restoration of hemostasis via POC monitoring of coagulation status. TEG-based therapy allows for goal-directed blood product administration in trauma, with potential avoidance of the complications resulting from overzealous component administration, as well as the ability to monitor post-injury coagulation status and thromboprophylaxis. This overview addresses coagulation status and thromboprophylaxis management in the trauma patient and the emerging role of POC TEG.

Thromboelastographic changes in liver and pancreatic cancer surgery: hypercoagulability, hypocoagulability or normocoagulability?

BACKGROUND AND OBJECTIVE

Despite clinical and laboratory evidence of perioperative hypercoagulability, alterations in haemostasis after potentially haemorrhagic oncologic surgery are difficult to predict. This study aims to evaluate the entity, the extent and the duration of perioperative coagulative alterations following pancreas and liver oncologic surgery, by the use of both routine tests and thromboelastogram (TEG).

METHODS

Fifty-six patients undergoing liver (n = 38) and pancreatic (n = 18) surgery were studied. The coagulation profile was evaluated by platelet count, prothrombin time-international normalized ratio, activated partial thromboplastin time, antithrombin III and TEG at the beginning, at the end of the operation and on postoperative days 1, 3, 5 and 10.

RESULTS

All preoperative coagulative screening and TEG traces were normal before incision. In the postoperative period of the liver and pancreas groups, despite an increase in prothrombin time-international normalized ratio, a reduction in antithrombin III and platelet count and normal activated partial thromboplastin time and fibrinogen, TEG evidenced a normocoagulability in the liver group, with a major tendency towards hypocoagulability in the pancreas group, as evidenced by a transient increase in R-time and K-time between postoperative days 1 and 3. During the study period, four cases of pulmonary embolism, resolved with heparin infusion, were recorded, in the absence of laboratory and thromboelastographic evidence of hypercoagulability.

CONCLUSION

Despite laboratory tests evidencing hypocoagulability in both groups, TEG traces showed a normocoagulability in liver resections, whereas a transient thromboelastographic hypocoagulability was evident in patients undergoing pancreas surgery. The discrepancy between laboratory values and thromboelastographic variables was even more evident in patients undergoing major liver resections compared with minor ones. Our study supports the role of thromboelastography, despite its limitations, as a valuable tool for the evaluation of the perioperative whole coagulation process and hypercoagulability changes and to increase patient safety through better management of antithrombotic therapy.

"Metabolic staging" after major trauma - a guide for clinical decision making?

Metabolic changes after major trauma have a complex underlying pathophysiology. The early posttraumatic stress response is associated with a state of hyperinflammation, with increased oxygen consumption and energy expenditure. This hypercatabolic state must be recognized early and mandates an early nutritional management strategy. A proactive concept of early enteral "immunonutrition" in severely injured patients, is aimed at counterbalancing the negative aspects of hyperinflammation and hypercatabolism in order to reduce the risk of late complications, including infections and posttraumatic organ failure. Recently, the concept of "metabolic staging" has been advocated, which takes into account the distinct inflammatory phases and metabolic phenotypes after major trauma, including the "ischemia/reperfusion phenotype", the "leukocytic phenotype", and the "angiogenic phenotype". The potential clinical impact of metabolic staging, and of an appropriately adapted "metabolic control" and nutritional support, remains to be determined.

Postinjury coagulopathy management: goal directed resuscitation via POC thrombelastography

Progressive postinjury coagulopathy remains the fundamental rationale for damage control surgery, but the decision to abort operative intervention must occur before laboratory confirmation of coagulopathy. Current massive transfusion protocols have embraced pre-emptive resuscitation strategies emphasizing administration of packed red blood cells, fresh frozen plasma, and platelets in ratios approximating 1:1:1 during the first 24 hours postinjury, based on US military retrospective experience and recent noncontrolled civilian data. This policy, termed "damage control resuscitation" assumes that patients presenting with life threatening hemorrhage at risk for postinjury coagulopathy should receive component therapy in rations approximating those found in whole blood during the first 24 hours. While we concur with the concept of pre-emptive coagulation factor replacement, and initially suggested this in 1982, we remain concerned for the continued unbridled administration of fresh frozen plasma and platelets without objective evidence of their specific requirement. A major limitation of current massive transfusion protocols is the lack of real time assessment of coagulation function to guide evolving blood component requirements. Existing laboratory coagulation testing was originally designed for evaluation of hemophilia and subsequently used for monitoring anticoagulation therapy. Consequently, the applicability of these tests in the trauma setting has never been proven and the time required to conduct these assays is incompatible with prompt correction of the coagulopathy in the trauma setting. This review examines the current approach to postinjury coagulopathy, including identification of patients at risk, resuscitation strategies, design and implementation of institutional massive transfusion protocols, and the potential benefits of goal-directed therapy by real time assessment of coagulation function via point of care rapid thromboelastography.

New insights into acute coagulopathy in trauma patients

Abnormal coagulation parameters can be found in 25% of trauma patients with major injuries. Furthermore, trauma patients presenting with coagulopathy on admission have worse clinical outcome. Tissue trauma and systemic hypoperfusion appear to be the primary factors responsible for the development of acute traumatic coagulopathy immediately after injury. As a result of overt activation of the protein C pathway, the acute traumatic coagulopathy is characterised by coagulopathy in conjunction with hyperfibrinolysis. This coagulopathy can then be exacerbated by subsequent physiologic and physical derangements such as consumption of coagulation factors, haemodilution, hypothermia, acidemia and inflammation, all factors being associated with ongoing haemorrhage and inadequate resuscitation or transfusion therapies. Knowledge of the different mechanisms involved in the pathogenesis of acute traumatic coagulopathy is essential for successful management of bleeding trauma patients. Therefore, early evidence suggests that treatment directed at aggressive and targeted haemostatic resuscitation can lead to reductions in mortality of severely injured patients.

Femur shaft fracture fixation in head-injured patients: when is the right time?

The ideal timing and modality of femur shaft fracture fixation in head-injured patients remains a topic of debate. Several groups advocate the immediate definitive fixation of femur fractures ("early total care"), whereas others support the concept of "damage control orthopaedics" with temporary fracture fixation by means of external fixation and staged, planned conversion to internal fixation. The present review was designed to address this unresolved controversy by outlining the underlying immunopathophysiology of traumatic brain injury and providing clinical recommendations on the timing of femur shaft fracture fixation in patients with severe head injuries.

Current trends in resuscitation strategy for the multiply injured patient

The ideal resuscitation strategy for multiply injured patients remains a topic of ongoing debate. At present, no consensus has been reached on the ideal fluid for early resuscitation and on the threshold for blood product transfusions. The concept of "permissive hypotension" for bleeding trauma patients furthermore contributes to the controversy in the field, particularly as it relates to blunt trauma and to patients with associated head injuries. Finally, postinjury coagulopathy is a poorly defined entity, and current resuscitation strategies lack strong evidence-based scientific support. This review article provides a brief overview of the existing resuscitation protocols for multiply injured patients, including ATLS and "damage control", and will address developing controversies in the field.

Rapid thrombelastography (r-TEG) identifies hypercoagulability and predicts thromboembolic events in surgical patients

BACKGROUND

Despite routine prophylaxis, thromboembolic events (TEs) in surgical patients remain a substantial problem. Furthermore, the timing and incidence of hypercoagulability, which predisposes to these events is unknown, with institutional screening programs serving primarily to establish a diagnosis after an event has occurred. Emerging evidence suggests that point of care (POC) rapid thrombelastography (r-TEG) provides a real-time analysis of comprehensive thrombostatic function, which represents an analysis of both enzymatic and platelet components of thrombus formation. We hypothesized that r-TEG can be used as a screening tool to identify hypercoagulable states in surgical patients and would predict subsequent thromboembolic events.

METHODS

Rapid thrombelastography r-TEG analyses were performed on 152 critically ill patients in the surgical intensive care unit (ICU) during 7 months. Hypercoagulability was defined as clot strength (G)>12.4 dynes/cm(2). Variables of interest for identifying hypercoagulability and thromboembolic events included sex, age, operating hospital service, specific injury patterns, injury severity score (ISS), transfusion within first 24 h, ICU duration of stay, ventilator days, hospital admission days, and thromboprophylaxis. Comparisons between the hypercoagulable and normal groups or between the groups with and without thromboembolic events were performed using Chi-square tests or the Fisher exact test for categorical variables and independent sample t tests or Wilcoxon rank sum tests for continuous variables. Multivariate logistic regression analysis (LR) was performed to identify independent predictors of thromboembolic events. A receiver operating characteristic curve was used to measure the performance of G for predicting the occurrence of a TE event. All tests were 2-sided with significance of P < .05.

RESULTS

In all, 86 patients (67%) were hypercoagulable by r-TEG. More than 85% of patients in the hypercoagulable group and 79% in the normal group received thromboprophylaxis during the study period. The differences between hypercoagulable and normal groups by bivariate analysis included high-risk injuries (52% vs 35%; P = .03), spinal cord injury (27% vs 12%; P = .03), median ICU duration of stay (13 vs 7 days; P < .001), median ventilator days (6 vs 2; P < .001), and median hospital duration of stay (20 vs 13 days; P < .001). A total of 16 patients (19%) of the hypercoagulable group suffered a thromboembolic event, and 10 hypercoagulable patients (12%) had thromboembolic events predicted by prior r-TEG hypercoagulability. No patients with normal coagulability by r-TEG had an event (P < .001). LR analysis showed that the strongest predictor of TE after controlling for the presence of thromboprophylaxis was elevated G value (odds ratio: 1.25, 95% confidence interval [CI]: 1.12-1.39). For every 1 dyne/cm(2) increase in G, the odds of a TE increased by 25%.

CONCLUSION

These results indicate that the presence of hypercoagulability identified by r-TEG is predictive of thromboembolic events in surgical patients. Subsequent study is necessary to define optimal prophylactic treatment strategies for patients with r-TEG proven hypercoagulability.

Advocating "spine damage control" as a safe and effective treatment modality for unstable thoracolumbar fractures in polytrauma patients: a hypothesis

BACKGROUND

The "ideal" timing and modality of fracture fixation for unstable thoracolumbar spine fractures in multiply injured patients remains controversial. The concept of "damage control orthopedics" (DCO), which has evolved globally in the past decade, provides a safe guidance for temporary external fixation of long bone or pelvic fractures in multisystem trauma. In contrast, "damage control" concepts for unstable spine injuries have not been widely implemented, and the scarce literature in the field remains largely anecdotal. The current practice standards are reflected by two distinct positions, either (1) immediate "early total care" or (2) delayed spine fixation after recovery from associated injuries. Both concepts have inherent risks which may contribute to adverse outcome.

PRESENTATION OF HYPOTHESIS

We hypothesize that the concept of "spine damage control" - consisting of immediate posterior fracture reduction and instrumentation, followed by scheduled 360 degrees completion fusion during a physiological "time-window of opportunity" - will be associated with less complications and improved outcomes of polytrauma patients with unstable thoracolumbar fractures, compared to conventional treatment strategies.

TESTING OF HYPOTHESIS

We propose a prospective multicenter trial on a large cohort of multiply injured patients with an associated unstable thoracolumbar fracture. Patients will be assigned to one of three distinct study arms: (1) Immediate definitive (anterior and/or posterior) fracture fixation within 24 hours of admission; (2) Delayed definitive (anterior and/or posterior) fracture fixation at > 3 days after admission; (3) "Spine damage control" procedure by posterior reduction and instrumentation within 24 hours of admission, followed by anterior 360 degrees completion fusion at > 3 days after admission, if indicated. The primary and secondary endpoints include length of ventilator-free days, length of ICU and hospital stay, mortality, incidence of complications, neurological status and functional recovery.

IMPLICATIONS OF HYPOTHESIS

A "spine damage control" protocol may save lives and improve outcomes in severely injured patients with associated spine injuries.