The Effect of Platelet and Desmopressin Administration on Early Radiographic Progression of Traumatic Intracranial Hemorrhage

Antiplatelet Reversal Is Not Associated With Decreased Progression of Intracranial Hemorrhage in Near-Isolated Traumatic Brain Injury: A Retrospective Clustered Analysis From Two Trauma Centers

INTRODUCTION

Antiplatelet agents (AAs) may increase the risk of intracranial hemorrhage (ICH). It is unclear whether reversal of antiplatelet effects (REV = desmopressin acetate [DDAVP] + Platelets) decreases ICH progression. The goal of the study was to determine whether REV was associated with decreased progression of ICH on repeat brain computed tomography (CT) scan.

METHODS

This is a clustered study (November 2019 to March 2022) at two regionally distinct trauma centers (TCs) with differing standards of practice in patients with ICH, one reversal with DDAVP + Platelets (REV+) and the other no reversal with DDAVP + Platelets (REV-). Using electronic and manual chart review, data were collected on inpatients aged ≥ 18 y on preinjury AAs with CT proven ICH (abbreviated injury scale head ≥ 2) and no other abbreviated injury scale > 2 injuries, who had at least one repeat CT scan within 120 h of admission. ICH progression on repeat brain CT scan, mortality, and resource utilization were compared via univariate analysis (α = 0.05).

RESULTS

One hundred fourteen patients were enrolled: 72 REV+ at the first TC and 42 REV- at the second TC. REV+ group had fewer White patients and a lower proportion on preinjury aspirin but were otherwise similar. ICH progression rate was 24/72 (33.3%) for REV+ and 11/42 (26.2%) for REV- (P = 0.43). Isolated subarachnoid hemorrhage was the most common lesion, followed by isolated subdural hemorrhage. No patients required cranial surgery. All-cause mortality (expired + hospice) was 5/72 (6.9%) and 1/42 (2.4%), respectively (P = 0.29).

CONCLUSIONS

In this study of patients on preinjury AAs, REV was not associated with decreased ICH progression, lower mortality, or less resource utilization. These findings should be confirmed in a larger, prospective study.

Dosing Medications for Coagulopathy Reversal in Patients with Extreme Obesity

BACKGROUND

The reversal of anticoagulant or antiplatelet medications is a priority in the management of patients with severe injury with the goal of minimizing further bleeding without thrombotic complications. There are few studies, however, evaluating the dosing of reversal agents in the setting of trauma specific to patients with extreme obesity. Nevertheless, clinicians must still make decisions, balancing concerns of ongoing bleeding with excessive thrombosis.

OBJECTIVES

We describe the literature pertaining to dosing of medications used for the reversal of both drug-induced and trauma-related coagulopathy with the intent of providing a framework for clinicians to make dosing decisions in this challenging population.

DISCUSSION

Obesity is known to impact both the volume of distribution and the clearance of medications, but these changes are not usually linear with size nor are they uniform across drugs. Current strategies for dosing reversal agents in obesity include a capped dose (e.g., prothrombin complex concentrates), fixed dosages (e.g., andexanet alfa, idarucizumab, and tranexamic acid), and weight-based dosing (e.g., desmopressin). Extreme obesity, however, was not highly prevalent in the studies that have validated these dosing strategies. In fact, many of the clinical studies fail to report the average weight of the patients included.

CONCLUSION

Future studies should make efforts to increase reporting of patients with obesity included in clinical trials along with results stratified by weight class. In the meantime, doses listed in product labels should be used. Desmopressin should be dosed using either ideal body weight or a dose-capping strategy.

Platelet Transfusion for Trauma Resuscitation

Purpose of Review

To review the role of platelet transfusion in resuscitation for trauma, including normal platelet function and alterations in behavior following trauma, blood product transfusion ratios and the impact of platelet transfusion on platelet function, platelet function assays, risks of platelet transfusion and considerations for platelet storage, and potential adjunct therapies and synthetic platelets.

Recent Findings

Platelets are a critical component of clot formation and breakdown following injury, and in addition to these hemostatic properties, have a complex role in vascular homeostasis, inflammation, and immune function. Evidence supports that platelets are activated following trauma with several upregulated functions, but under conditions of severe injury and shock are found to be impaired in their hemostatic behaviors. Platelets should be transfused in balanced ratios with red blood cells and plasma during initial trauma resuscitation as this portends improved outcomes including survival. Multiple coagulation assays can be used for goal-directed resuscitation for traumatic hemorrhage; however, these assays each have drawbacks in terms of their ability to measure platelet function. While resuscitation with balanced transfusion ratios is supported by the literature, platelet transfusion carries its own risks such as bacterial infection and lung injury. Platelet supply is also limited, with resource-intensive storage requirements, making exploration of longer-term storage options and novel platelet-based therapeutics attractive. Future focus on a deeper understanding of the biology of platelets following trauma, and on optimization of novel platelet-based therapeutics to maintain hemostatic effects while improving availability should be pursued.

Summary

While platelet function is altered following trauma, platelets should be transfused in balanced ratios during initial resuscitation. Severe injury and shock can impair platelet function, which can persist for several days following the initial trauma. Assays to guide resuscitation following the initial period as well as storage techniques to extend platelet shelf life are important areas of investigation.

Application of a TEG-Platelet Mapping Algorithm to Guide Reversal of Antiplatelet Agents in Adults with Mild-to-Moderate Traumatic Brain Injury: An Observational Pilot Study

BACKGROUND

Traumatic intracranial hemorrhages expand in one third of cases, and antiplatelet medications may exacerbate hematoma expansion. However, the reversal of an antiplatelet effect with platelet transfusion has been associated with harm. We sought to determine whether a thromboelastography platelet mapping (TEG-PM)-guided algorithm could limit platelet transfusion in patients with hemorrhagic traumatic brain injury (TBI) prescribed antiplatelet medications without a resultant clinically significant increase in hemorrhage volume, late hemostatic treatments, or delayed operative intervention.

METHODS

A total of 175 consecutive patients with TBI were admitted to our university-affiliated, level I trauma center between March 2016 and December 2019: 54 preintervention patients (control) and 121 patients with TEG-PM (study). After exclusion for anticoagulant administration, availability of neuroimaging and emergent neurosurgery, 62 study patients and 37 control patients remained. Intervention consisted of administration of desmopressin (DDAVP) for nonsurgical patients with significant inhibition at the arachidonic acid or adenosine diphosphate receptor sites. For surgical patients with significant inhibition, dual therapy with DDAVP and platelet transfusion was employed. Study patients were compared with a group of historical controls, which were identified from a prospectively maintained registry and typically treated with empiric platelet transfusion.

RESULTS

Median age was 75 years (interquartile range 85-67) and 77 years (interquartile range 81-65) in the TEG-PM and control patient groups, respectively. Admission hemorrhage volumes were similar (10.7 cm³ [20.1] in patients with TEG-PM vs. 14.1 cm³ [19.7] in controls; p = 0.41). There were no significant differences in admission Glasgow Coma Scale, mechanism of trauma, or baseline comorbidities. A total of 57% of controls versus 10% of patients with TEG-PM (p < 0.001) were transfused platelets; 52% of intervention patients and 0% controls were treated with DDAVP. Expansion hemorrhage volumes were not significantly different (14.0 cm³ [20.2] patients with TEG-PM versus 13.6 cm³ [23.7] controls; p = 0.93). There was no significant difference in rates of clinical deterioration, delayed neurosurgical intervention, or late platelet transfusion between groups.

CONCLUSIONS

Among patients with hemorrhagic TBI prescribed preinjury antiplatelet therapy, our study suggests that the use of a TEG-PM algorithm may reduce platelet transfusions without a concurrent increase in clinically significant hematoma expansion. Further study is required to prove a causative relationship.

Transfusion strategies in bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

PURPOSE

To develop evidence-based clinical practice recommendations regarding transfusion practices and transfusion in bleeding critically ill adults.

METHODS

A taskforce involving 15 international experts and 2 methodologists used the GRADE approach to guideline development. The taskforce addressed three main topics: transfusion support in massively and non-massively bleeding critically ill patients (transfusion ratios, blood products, and point of care testing) and the use of tranexamic acid. The panel developed and answered structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

RESULTS

The taskforce generated 26 clinical practice recommendations (2 strong recommendations, 13 conditional recommendations, 11 no recommendation), and identified 10 PICOs with insufficient evidence to make a recommendation.

CONCLUSIONS

This clinical practice guideline provides evidence-based recommendations for the management of massively and non-massively bleeding critically ill adult patients and identifies areas where further research is needed.

Platelet dysfunction in patients with traumatic intracranial hemorrhage: Do desmopressin and platelet therapy help or harm?

BACKGROUND

Pre-injury anti-platelet use has been associated with increased risk of progression of traumatic intracranial hemorrhage (TICH) and worse outcomes. VerifyNow® assays assess platelet inhibition due to aspirin/clopidogrel. This study assesses the outcomes of patients with TICH and platelet dysfunction treated with desmopressin and/or platelets.

METHODS

We performed a retrospective chart review of patients with mild TICH at a level 1 trauma center 1/1/2013-6/1/2016. Patients with documented platelet dysfunction who received desmopressin and/or platelets were compared to those who were untreated. Primary outcomes were progression of TICH and neurologic outcomes at discharge.

RESULTS

Of 565 patients with a mild TICH, 200 patients had evidence of platelet dysfunction (a positive VerifyNow® assay). Patients had similar baseline demographics, injury characteristics, and rate of TICH progression; but patients who received desmopressin and/or platelets had worse Glasgow Outcomes Score at discharge.

CONCLUSION

Treatment of patients with mild TICH and platelet dysfunction with desmopressin and/or platelets did not affect TICH progression but correlated with worse neurologic status at discharge.

The Safety and Efficacy of Desmopressin in Patients With Intracranial Hemorrhage and a History of Alcohol Use

BACKGROUND

Patients with a history of alcohol use disorder are at an increased risk of hematoma expansion following intracranial hemorrhage (ICH) due to the effects of alcohol on platelet aggregation. Desmopressin (DDAVP) improves platelet aggregation and may decrease hematoma expansion in patients with ICH. However, DDAVP may also increase the risk of hyponatremia and thrombotic events. Evidence is limited regarding the safety and efficacy of DDAVP in alcohol use (AU)-associated ICH.

METHODS

This was a retrospective chart review of adult patients with radiographic evidence of ICH and a confirmed or suspected history of alcohol use upon admission. Patients were categorized into groups based on DDAVP administration. Safety outcomes included hyponatremia (serum sodium <135 mEq/L or decrease in serum sodium of ≥ 5 mEq/L for patients with baseline sodium <135 mEq/L) within 24 hours of ICH and thrombotic events within 7 days of ICH. The primary efficacy outcome was the incidence of hematoma expansion, defined as any expansion of the hemorrhage noted on repeat imaging within 32 hours.

RESULTS

In total, 52 patients were included in the safety analysis (27 DDAVP and 25 non-DDAVP). Although hyponatremia was numerically higher in the DDAVP group, there was no significant difference between groups (19.2% vs 4.2%, P = 0.192). Thrombotic complications were similar between the DDAVP and non-DDAVP groups (11.1% vs. 8%, P = 1.0). Thirty-nine patients met criteria for hemostatic efficacy analysis. There was no difference in hematoma expansion between the DDAVP and non-DDAVP groups (23.1% vs 34.6%, P = 0.71) and these findings were consistent after adjusting for differences in baseline characteristics (OR 0.63, 95% CI 0.1-3.3).

CONCLUSION

The administration of DDAVP was not associated with adverse safety events, but did not significantly reduce the incidence of hematoma expansion in patients with AU-associated ICH.

Desmopressin Administration and Impact on Hypertonic Saline Effectiveness in Intracranial Hemorrhage

INTRODUCTION

Desmopressin improves hemostasis through the release of factor VIII, von Willebrand factor, and tissue plasminogen activator, and increases platelet adhesion. Neurocritical Care guidelines recommend consideration of desmopressin in antiplatelet-associated intracranial hemorrhage. Studies supporting its use have not evaluated the potential impact of desmopressin on serum sodium levels in patients receiving hypertonic saline therapy. The purpose of this study was to assess the impact of desmopressin on sodium levels and hypertonic saline effectiveness in intracranial hemorrhage.

METHODS

This was a single center retrospective observational chart review. Patients were included in the desmopressin group if they were diagnosed with intracranial hemorrhage, administered desmopressin, and received hypertonic saline infusion. Patients in the hypertonic saline alone group were then matched 1:1 to the patients in the desmopressin group. The primary end point was the effect of desmopressin on reaching a sodium goal of 145-155 mEq/L. The secondary end points included intensive care unit and hospital length of stay, change in sodium, time to reach sodium goal, thrombotic events, mortality, and a composite of increased cerebral edema, hematoma expansion, midline shift, herniation, need for neurosurgical intervention, and neurologic decompensation.

RESULTS

Of 112 patients screened, 25 patients met inclusion criteria for the desmopressin group, and 25 patients were matched with patients in the hypertonic saline alone group. The percentage of patients who reached goal sodium in the desmopressin group compared with hypertonic saline alone was similar (80% vs. 88%, respectively). There were no differences in the secondary end points. In the subgroup analysis, patients in the hypertonic saline group met the predefined sodium goal of 150-155 mEq/L within 48 h more often than those in the desmopressin group (82% vs. 60%, respectively, p = 0.042).

CONCLUSIONS

The use of desmopressin in intracranial hemorrhage does not appear to negatively impact the ability for patients to reach goal sodium of 145-155 mEq/L. However, in patients with higher sodium goals, desmopressin may decrease hypertonic saline effectiveness.

Time Course of Hemostatic Disruptions After Traumatic Brain Injury: A Systematic Review of the Literature

Almost two-thirds of patients with severe traumatic brain injury (TBI) develop some form of hemostatic disturbance, which contributes to poor outcome. While the initial head injury often leads to impaired clot formation, TBI is also associated with an increased risk of thrombosis. Most likely there is a progression from early bleeding to a later prothrombotic state. In this paper, we systematically review the literature on the time course of hemostatic disruptions following TBI. A MEDLINE search was performed for TBI studies reporting the trajectory of hemostatic assays over time. The search yielded 5,049 articles, of which 4,910 were excluded following duplicate removal as well as title and abstract review. Full-text assessment of the remaining articles yielded 33 studies that were included in the final review. We found that the first hours after TBI are characterized by coagulation cascade dysfunction and hyperfibrinolysis, both of which likely contribute to lesion progression. This is then followed by platelet dysfunction and decreased platelet count, the clinical implication of which remains unclear. Later, a poorly defined prothrombotic state emerges, partly due to fibrinolysis shutdown and hyperactive platelets. In the clinical setting, early administration of the antifibrinolytic agent tranexamic acid has proved effective in reducing head-injury-related mortality in a subgroup of TBI patients. Further studies evaluating the time course of hemostatic disruptions after TBI are warranted in order to identify windows of opportunity for potential treatment options.

Desmopressin for Antiplatelet-Associated Intracranial Hemorrhage: A Concise Review

OBJECTIVE

To provide a concise review of the literature on desmopressin use for antiplatelet reversal in patients with intracranial hemorrhage.

DATA SOURCES

Source data were obtained from a PubMed literature review.

STUDY SELECTION

Studies addressing desmopressin for antiplatelet reversal.

DATA EXTRACTION

Relevant studies were reviewed and included through consensus of the authors. The following aspects of each study were identified, abstracted, and analyzed: study population, study design, methods, results, and relevant implications for practice.

DATA SYNTHESIS

A growing body of evidence continues to provide mixed results for the use of desmopressin in patients presenting with antiplatelet-associated intracranial hemorrhage. The potential benefit outweighs the possible risks associated with a one-time dose. In addition to desmopressin, platelets should only be considered in patients undergoing a neurosurgical procedure until further and superior evidence is available. Guidelines recommend a weight-based approach for desmopressin dosing at 0.4 mcg/kg over 30 min.

CONCLUSIONS

The available evidence supports desmopressin as potentially beneficial with minimal risk for use in patients with antiplatelet-associated intracranial hemorrhage.

Effect of Chronic Alcoholism on Traumatic Intracranial Hemorrhage

BACKGROUND

Traumatic intracranial hemorrhage (TICH) is one of the commonest indications for neurosurgical consultation after trauma. Worsening neurologic examination results, size of initial TICH, presence of displaced skull fracture, and concomitant anticoagulant use at the time of injury drive the recommendations for repeat computed tomography of head (RCTH), to assess for stability of intracranial hemorrhage. Chronic alcohol use is not generally considered an indication for repeat head computed tomography (CT).

METHODS

A retrospective study of 423 patients with TICH with normal admission platelet (PLT) counts was reviewed for this study, taken as a subset of 1330 patients with TICH admitted to Lahey Hospital and Medical Center over a 3-year period. Of these 423 patients, 330 were classified as nonalcoholics and 93 were classified as alcoholics, based on whether alcohol use disorder was documented in the patient's medical record, present before injury. The normal PLT level was defined as ≥100,000 μ/L. Patients were excluded from review if they had comorbid conditions that could cause PLT dysfunction or coagulopathy. Continuous and categorical variables were compared using independent t test and χ², respectively. Binary logistic regression was used to predict outcome: stable versus worsening of TICH on RCTH. Statistical analysis was conducted using SPSS version 25.

RESULTS

The mean age of the nonalcoholic and alcoholic cohorts were 71.9 years and 54.8 years, respectively. A significantly higher percentage of alcoholics were male. There was a statistically significant difference (χ² = 8.14; P < 0.004) in radiologic progression of TICH between the 2 groups, with the alcoholics having a worsening RCTH 16.1% of the time compared with only 6.7% in nonalcoholics. Chronic alcohol use was an independent predictor of radiologic progression in patients with normal PLT level (odds ratio, 2.69; confidence interval, 1.34-5.43; P < 0.006).

CONCLUSIONS

Chronic alcohol use was an independent predictor of radiologic progression of TICH in the setting of normal PLT level. Modification of this risk of progression with transfusion of fresh PLTs in chronic alcoholic patients with TICH needs to be investigated in a prospective trial.

A systematic review and meta-analysis of traumatic intracranial hemorrhage in patients taking prehospital antiplatelet therapy: Is there a role for platelet transfusions?

BACKGROUND

Platelet transfusion has been utilized to reverse platelet dysfunction in patients on preinjury antiplatelets who have sustained a traumatic intracranial hemorrhage (tICH); however, there is little evidence to substantiate this practice. The objective of this study was to perform a systematic review on the impact of platelet transfusion on survival, hemorrhage progression and need for neurosurgical intervention in patients with tICH on prehospital antiplatelet medication.

METHODS

Controlled, observational and randomized, prospective and retrospective studies describing tICH, preinjury antiplatelet use, and platelet transfusion reported in PubMed, Embase, Cochrane Reviews, Cochrane Trials and Cochrane DARE databases between January 1987 and March 2019 were included. Investigations of concomitant anticoagulant use were excluded. Risk of bias was assessed using the Newcastle-Ottawa scale. We calculated pooled estimates of relative effect of platelet transfusion on the risk of death, hemorrhage progression and need for neurosurgical intervention using the methods of Dersimonian-Laird random-effects meta-analysis. Sensitivity analysis established whether study size contributed to heterogeneity. Subgroup analyses determined whether antiplatelet type, additional blood products/reversal agents, or platelet function assays impacted effect size using meta-regression.

RESULTS

Twelve of 18,609 screened references were applicable to our questions and were qualitatively and quantitatively analyzed. We found no association between platelet transfusion and the risk of death in patients with tICH taking prehospital antiplatelets (odds ratio [OR], 1.29; 95% confidence interval [CI], 0.76-2.18; p = 0.346; I = 32.5%). There was no significant reduction in hemorrhage progression (OR, 0.88; 95% CI, 0.34-2.28; p = 0.788; I = 78.1%). There was no significant reduction in the need for neurosurgical intervention (OR, 1.00; 95% CI, 0.53-1.90, p = 0.996; I = 59.1%; p = 0.032).

CONCLUSION

Current evidence does not support the use of platelet transfusion in patients with tICH on prehospital antiplatelets, highlighting the need for a prospective evaluation of this practice.

LEVEL OF EVIDENCE

Systematic Reviews and Meta-Analyses, Level III.

Retrospective Assessment of Desmopressin Effectiveness and Safety in Patients With Antiplatelet-Associated Intracranial Hemorrhage

OBJECTIVE

Current international guidelines offer a conditional recommendation to consider a single dose of IV desmopressin (DDAVP) for antiplatelet-associated intracranial hemorrhage based on low-quality evidence. We provide the first comparative assessment analyzing DDAVP effectiveness and safety in antiplatelet-associated intracranial hemorrhage.

DESIGN

Retrospective chart review.

SETTING

Single tertiary care academic medical center.

PATIENTS

Adult patients taking at least one antiplatelet agent based on presenting history and documented evidence of intracranial hemorrhage on cerebral CT scan were included. Patients were excluded for the following reasons: repeat cerebral CT scan not performed within the first 24 hours, noncomparative repeat cerebral CT scan, chronic anticoagulation, administration of fibrinolytic medications, concurrent ischemic stroke, and neurosurgical intervention. In total, 124 patients were included, 55 received DDAVP and 69 did not.

INTERVENTIONS

DDAVP treatment at recognition of antiplatelet-associated intracranial hemorrhage versus nontreatment.

MEASUREMENTS AND MAIN RESULTS

Primary effectiveness outcome was intracranial hemorrhage expansion greater than or equal to 3 mL during the first 24 hospital hours. Primary safety outcomes were the largest absolute decrease from baseline serum sodium during the first 3 treatment days and new-onset thrombotic events during the first 7 days. DDAVP was associated with 88% decreased likelihood of intracranial hemorrhage expansion during the first 24 hours ([+] DDAVP, 10.9% vs [-] DDAVP, 36.2%; p = 0.002; odds ratio [95% CI], 0.22 [0.08-0.57]). Largest median absolute decrease from baseline serum sodium ([+] DDAVP, 0 mEq/L [0-5 mEq/L] vs [-] DDAVP, 0 mEq/L [0-2 mEq/L]; p = 0.089) and thrombotic events ([+] DDAVP, 7.3% vs [-] DDAVP, 1.4%; p = 0.170; odds ratio [95% CI], 5.33 [0.58-49.16]) were similar between groups.

CONCLUSIONS

DDAVP was associated with a decreased likelihood of intracranial hemorrhage expansion during the first 24 hours. DDAVP administration did not significantly affect serum sodium and thrombotic events during the study period.

Cohort analysis of desmopressin effect on hematoma expansion in patients with spontaneous intracerebral hemorrhage and documented pre-ictus antiplatelet use

Antiplatelet therapy at the time of spontaneous intracerebral hemorrhage (sICH) may increase risk for hemorrhage expansion and mortality. Current guidelines recommend considering a single dose of desmopressin in sICH associated with cyclooxygenase-1 inhibitors or adenosine diphosphate receptor inhibitors. Adult subjects with sICH and concomitant antiplatelet therapy admitted to a large, tertiary care center were included. We sought to compare the risk of hematoma expansion in patients that received desmopressin for antiplatelet reversal in the setting of sICH to similar patients that did not receive desmopressin. The primary outcomes were the incidence of relative and absolute hematoma expansion. In total, 71 patients (29 received desmopressin, 42 did not receive desmopressin) were analyzed. All patients in the desmopressin group received a 0.3 mcg/kg intravenous dose prior to hematoma expansion assessment. Relative hematoma expansion occurred in 5/29 (17%) with desmopressin compared to 11/42 (26%) without desmopressin (OR 0.59 [95% CI 0.18-1.92]). Absolute hematoma expansion occurred in 9/29 (30%) with desmopressin compared to 12/42 (28%) without desmopressin (OR 1.13 [95% CI 0.40-3.16]). Multiple logistic regression controlling for significant covariates did not reveal a significant effect of desmopressin on relative or absolute hematoma expansion (OR 0.65 [95% CI 0.18-2.43] and OR 1.55 [0.48-4.99], respectively). We failed to find evidence that desmopressin administration for antiplatelet reversal in sICH reduces the incidence of hematoma expansion. Larger studies, focusing on the early phase of sICH, are needed to characterize the clinical efficacy and safety of desmopressin for antiplatelet reversal before widespread implementation.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Diagnostic and therapeutic approach in adult patients with traumatic brain injury receiving oral anticoagulant therapy: an Austrian interdisciplinary consensus statement

There is a high degree of uncertainty regarding optimum care of patients with potential or known intake of oral anticoagulants and traumatic brain injury (TBI). Anticoagulation therapy aggravates the risk of intracerebral hemorrhage but, on the other hand, patients take anticoagulants because of an underlying prothrombotic risk, and this could be increased following trauma. Treatment decisions must be taken with due consideration of both these risks. An interdisciplinary group of Austrian experts was convened to develop recommendations for best clinical practice. The aim was to provide pragmatic, clear, and easy-to-follow clinical guidance for coagulation management in adult patients with TBI and potential or known intake of platelet inhibitors, vitamin K antagonists, or non-vitamin K antagonist oral anticoagulants. Diagnosis, coagulation testing, and reversal of anticoagulation were considered as key steps upon presentation. Post-trauma management (prophylaxis for thromboembolism and resumption of long-term anticoagulation therapy) was also explored. The lack of robust evidence on which to base treatment recommendations highlights the need for randomized controlled trials in this setting.

Not all head injured patients on antiplatelet drugs need platelets: Integrating platelet reactivity testing into platelet transfusion guidelines

INTRODUCTION

Antiplatelet medication use continues to rise in an aging population, and these agents can have a deleterious effect for patients with traumatic intracranial hemorrhage (tICH). The purpose of the current investigation is to assess the safety and efficacy of using platelet reactivity testing (PRT) to direct platelet transfusion for tICH patients.

PATIENTS AND METHODS

A Level I trauma center adopted a targeted platelet transfusion guideline using PRT to determine whether platelets were inhibited by an antiplatelet medication (aspirin or P2Y12 inhibitors). Non-inhibited patients were monitored without platelet transfusion, regardless of severity of the head injury. The guideline was analyzed retrospectively to evaluate patient outcomes during the study period (June 2014-December 2016). All patients sustained blunt tICH and received a PRT for known or suspected antiplatelet medication use. Differences were assessed with Kruskal-Wallis and Fisher's Exact tests.

RESULTS

166 patients met study inclusion criteria. PRT results indicated that 48 patients (29%) were not inhibited by an antiplatelet medication, and 92% of those patients (n = 44) were spared platelet transfusion. Seven percent (n = 11) of all patients had a clinically significant progression of the head bleed, but this did not differ by inhibition or transfusion status. Implementation of this guideline reduced platelet transfusions by an estimated 30-50% and associated healthcare costs by 42%.

CONCLUSIONS

A targeted platelet transfusion guideline using PRT reduced platelet usage for patients with tICH. If appropriately tested, results suggest that not all tICH patients taking or suspected of taking antiplatelet drugs need platelet transfusion. Platelet reactivity testing can significantly reduce healthcare costs and resource usage.

STING-mediated type-I interferons contribute to the neuroinflammatory process and detrimental effects following traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) represents a major cause of disability and death worldwide with sustained neuroinflammation and autophagy dysfunction contributing to the cellular damage. Stimulator of interferon genes (STING)-induced type-I interferon (IFN) signalling is known to be essential in mounting the innate immune response against infections and cell injury in the periphery, but its role in the CNS remains unclear. We previously identified the type-I IFN pathway as a key mediator of neuroinflammation and neuronal cell death in TBI. However, the modulation of the type-I IFN and neuroinflammatory responses by STING and its contribution to autophagy and neuronal cell death after TBI has not been explored.

METHODS

C57BL/6J wild-type (WT) and STING^-/- mice (8-10-week-old males) were subjected to controlled cortical impact (CCI) surgery and brains analysed by QPCR, Western blot and immunohistochemical analyses at 2 h or 24 h. STING expression was also analysed by QPCR in post-mortem human brain samples.

RESULTS

A significant upregulation in STING expression was identified in late trauma human brain samples that was confirmed in wild-type mice at 2 h and 24 h after CCI. This correlated with an elevated pro-inflammatory cytokine profile with increased TNF-α, IL-6, IL-1β and type-I IFN (IFN-α and IFN-β) levels. This expression was suppressed in the STING^-/- mice with a smaller lesion volume in the knockout animals at 24 h post CCI. Wild-type mice also displayed increased levels of autophagy markers, LC3-II, p62 and LAMP2 after TBI; however, STING^-/- mice showed reduced LAMP2 expression suggesting a role for STING in driving dysfunctional autophagy after TBI.

CONCLUSION

Our data implicates a detrimental role for STING in mediating the TBI-induced neuroinflammatory response and autophagy dysfunction, potentially identifying a new therapeutic target for reducing cellular damage in TBI.

Perhaps it's not the platelet: Ristocetin uncovers the potential role of von Willebrand factor in impaired platelet aggregation following traumatic brain injury

BACKGROUND

Injury to the blood-brain barrier exposes endothelium rich in von Willebrand factor (vWF), which may play a role in altered platelet aggregation following traumatic brain injury (TBI). Ristocetin is an antimicrobial substance that induces vWF-mediated aggregation of platelets. We examined these mechanisms in injured patients by measuring the aggregation response of platelets to stimulating agonists (including ristocetin) via whole-blood multiple-electrode platelet aggregometry. We hypothesized that patients with TBI have an altered platelet aggregation response to ristocetin stimulation compared with patients without TBI.

METHODS

Blood was collected from 233 trauma patients without thrombocytopenia. Platelet aggregation was assessed using multiple-electrode platelet aggregometry (Multiplate). Platelet aggregation response to stimulating agonists collagen, thrombin receptor-activating peptide 6, adenosine diphosphate, arachidonic acid, and ristocetin was measured. Factor activity was measured.

RESULTS

Of the 233 patients, 23% had TBI. There were no differences in platelet aggregation responses to any agonists between TBI and non-TBI patients except ristocetin. Platelet aggregation response to ristocetin stimulation was significantly lower in TBI patients (p = 0.03). Patients with TBI also had higher factor VIII activity (215% vs. 156%, p = 0.01). In multivariate analysis, there was a significant independent association of impaired platelet aggregation response to ristocetin stimulation with TBI (odds ratio, 3.05; p = 0.04).

CONCLUSIONS

Given the importance of platelets in hemostasis, understanding the mechanisms of impaired platelet aggregation following injury is critical. The impaired platelet aggregation response to ristocetin stimulation and corresponding increase in factor VIII activity in TBI patients may be secondary to a TBI-induced effect on vWF quantity (due to injury-driven consumption of vWF) or vWF function with resultant increase in circulating factor VIII activity (due to impaired carrying capacity of vWF). Given there are multiple known therapies for vWF deficits including desmopressin, purified and recombinant vWF, and estrogens, these lines of investigation are particularly compelling in patients with TBI and hemorrhage.

LEVEL OF EVIDENCE

Prognostic study, level II.

Coagulopathy induced by traumatic brain injury: systemic manifestation of a localized injury

Traumatic brain injury (TBI)-induced coagulopathy is a common and well-recognized risk for poor clinical outcomes, but its pathogenesis remains poorly understood, and treatment options are limited and ineffective. We discuss the recent progress and knowledge gaps in understanding this lethal complication of TBI. We focus on (1) the disruption of the brain-blood barrier to disseminate brain injury systemically by releasing brain-derived molecules into the circulation and (2) TBI-induced hypercoagulable and hyperfibrinolytic states that result in persistent and delayed intracranial hemorrhage and systemic bleeding.

Use of Aspirin and P2Y12 Response Assays in Detecting Reversal of Platelet Inhibition With Platelet Transfusion in Patients With Traumatic Brain Injury on Antiplatelet Therapy

BACKGROUND

At present, guidelines are lacking on platelet transfusion in patients with a traumatic intracranial bleed and history of antiplatelet therapy. The aspirin and P2Y 12 response unit (ARU and PRU, respectively) assays detect the effect of aspirin and P2Y 12 inhibitors in the cardiac population.

OBJECTIVE

To describe the reversal of platelet inhibition after platelet transfusion using the ARU and PRU assays in patients with traumatic brain injury.

METHODS

Between 2010 and 2015, we conducted a prospective comparative cohort study of patients presenting with a positive head computed tomography and a history of antiplatelet therapy. ARU and PRU assays were performed on admission and 6 hours after transfusion, with a primary end point of detection of disinhibition after platelet transfusion.

RESULTS

One hundred seven patients were available for analysis. Seven percent of patients taking aspirin and 27% of patients taking clopidogrel were not therapeutic on admission per the ARU and PRU, respectively. After platelet transfusion, 51% of patients on any aspirin and 67% of patients on any clopidogrel failed to be reversed. ARU increased by 71 ± 76 per unit of apheresis platelets for patients taking any aspirin, and PRU increased by 48 ± 46 per unit of apheresis platelets for patients taking any clopidogrel.

CONCLUSION

A significant percentage of patients taking aspirin or clopidogrel were not therapeutic and thus would be unlikely to benefit from a platelet transfusion. In patients with measured platelet inhibition, a single platelet transfusion was not sufficient to reverse platelet inhibition in almost half.

The use of desmopressin acetate in patients presenting with intracranial hemorrhage: A review

Objective

This review presents current literature on desmopressin acetate as mono- and adjuvant therapy and its ability to stabilize platelet function in patients presenting with intracranial hemorrhage on pre-injury antiplatelet agents of aspirin, clopidogrel, prasugrel and/or ticagrelor.

Design

PubMed, MEDLINE and International Pharmaceutical Abstracts were searched through to 1st March 2016. Inclusion criteria were case reports, reviews, short communications and brief reports on reported patients with any type of intracranial hemorrhage while on oral antiplatelet agents. Reports on desmopressin acetate in surgical candidates were excluded due to the nature of the bleed.

Results

A scoping search was performed in three databases with 89 articles identified based on the search criteria. All returned articles were evaluated by the authors with four articles suitable for inclusion.

Conclusion

While desmopressin acetate has a promising mechanism of action for enhancing primary hemostasis, the articles reported conflicting results possibly due to limited study sample sizes, lack of standards on measuring platelet function, data on weight-based dosing and guidelines. Further research is needed to evaluate desmopressin acetate as monotherapy. If used, it should be considered adjunct therapy to platelet transfusions for patients on oral antiplatelet agents requiring emergent hemostasis.

The acute respiratory distress syndrome following isolated severe traumatic brain injury

BACKGROUND

Acute respiratory distress syndrome (ARDS) is common after traumatic brain injury (TBI) and is associated with worse neurologic outcomes and longer hospitalization. However, the incidence and associated causes of ARDS in isolated TBI have not been well studied.

METHODS

We performed a subgroup analysis of 210 consecutive patients with isolated severe TBI enrolled in a prospective observational cohort at a Level 1 trauma center between 2005 and 2014. Subjects required endotracheal intubation and had isolated severe TBI defined by a head Abbreviated Injury Scale (AIS) score of 3 or greater and AIS score lower than 3 in all other categories. ARDS within the first 8 days of admission was rigorously adjudicated using Berlin criteria. Regression analyses were used to test the association between predictors of interest and ARDS.

RESULTS

The incidence of ARDS in the first 8 days after severe isolated TBI was 30%. Patients who developed ARDS were administered more crystalloids (4.3 L vs. 3.5 L, p = 0.005) and blood products in the first 12 hours of admission. Patients with ARDS had significantly worse clinical outcomes measured at 28 days, including longer median intensive care unit and hospital stays (4 days vs. 13 days, p < 0.001, and 7.5 days vs. 14.5 days, p < 0.001, respectively). In unadjusted logistic regression analyses, the odds of developing ARDS were significantly associated with head AIS score (odds ratio [OR], 1.8; p = 0.018), male sex (OR, 2.9; p = 0.012), and early transfusion of platelets (OR, 2.8; p = 0.003). These associations were similar in a multivariate logistic regression model.

CONCLUSION

In the era of balanced hemostatic resuscitation practices, severity of head injury, male sex, early crystalloids, and early transfusion of platelets are associated with a higher risk of ARDS after severe isolated TBI. Early transfusion of platelets after severe TBI may be a modifiable risk factor for ARDS, and these findings invite further investigation into causal mechanisms driving this observed association.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were reconsidered and revised based on new scientific evidence and observed shifts in clinical practice; new recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.