Utility of platelet transfusion in adult patients with traumatic intracranial hemorrhage and preinjury antiplatelet use: a systematic review

A multicenter study of DDAVP versus platelet transfusions for antiplatelet agent reversal in patients with traumatic brain injury

BACKGROUND

Antiplatelet agents have been shown to worsen outcomes following traumatic injury. Research on desmopressin (DDAVP) and platelet transfusion for antiplatelet reversal is limited. We aimed to evaluate the effect of these agents on patients taking pre-injury antiplatelet medications who experienced traumatic brain injury (TBI) after blunt trauma.

METHODS

This is a retrospective cohort study of adult trauma patients from 2014 to 2021 on aspirin and/or a P2Y12 inhibitor. Patients were stratified into groups based on if they received DDAVP, platelets, both agents, or neither.

RESULTS

Of 5525 included patients, 4696 (85.4%) were not reversed, 461 (8.4%) received platelets, 173 (3.1%) received DDAVP, and 172 (3.1%) received both reversals. There was no statistically significant difference in length of stay between, but patients who received platelets or both reversals were more likely to have hospital complications (p < 0.05), longer hospital length of stay (p < 0.001), and longer ICU length of stay (p < 0.001) compared to those who did not receive reversal. A subgroup analysis of patients with a head AIS of 4 or 5 confirmed these findings.

CONCLUSIONS

Patients who received platelets or both reversals had a longer length of hospital stay and length of ICU stay. It is difficult to recommend one treatment over another based on our results alone. Further studies are needed to help clarify the risks and benefits of reversal agents in this patient population.

Management of Antithrombotic Drugs in Patients with Isolated Traumatic Brain Injury: An Intersociety Consensus Document

BACKGROUND

All available recommendations about the management of antithrombotic therapies (ATs) in patients who experienced traumatic brain injury (TBI) are mainly based on expert opinion because of the lack of strength in the available evidence-based medicine. Currently, the withdrawal and the resumption of AT in these patients is empirical, widely variable, and based on the individual assessment of the attending physician. The main difficulty is to balance the thrombotic and hemorrhagic risks to improve patient outcome.

METHODS

Under the endorsement of the Neurotraumatology Section of Italian Society of Neurosurgery, the Italian Society for the Study about Haemostasis and Thrombosis, the Italian Society of Anaesthesia, Analgesia, Resuscitation, and Intensive Care, and the European Association of Neurosurgical Societies, a working group (WG) of clinicians completed two rounds of questionnaires, using the Delphi method, in a multidisciplinary setting. A table for thrombotic and bleeding risk, with a dichotomization in high risk and low risk, was established before questionnaire administration. In this table, the risk is calculated by matching different isolated TBI (iTBI) scenarios such as acute and chronic subdural hematomas, extradural hematoma, brain contusion (intracerebral hemorrhage), and traumatic subarachnoid hemorrhage with patients under active AT treatment. The registered indication could include AT primary prevention, cardiac valve prosthesis, vascular stents, venous thromboembolism, and atrial fibrillation.

RESULTS

The WG proposed a total of 28 statements encompassing the most common clinical scenarios about the withdrawal of antiplatelets, vitamin K antagonists, and direct oral anticoagulants in patients who experienced blunt iTBI. The WG voted on the grade of appropriateness of seven recommended interventions. Overall, the panel reached an agreement for 20 of 28 (71%) questions, deeming 11 of 28 (39%) as appropriate and 9 of 28 (32%) as inappropriate interventions. The appropriateness of intervention was rated as uncertain for 8 of 28 (28%) questions.

CONCLUSIONS

The initial establishment of a thrombotic and/or bleeding risk scoring system can provide a vital theoretical basis for the evaluation of effective management in individuals under AT who sustained an iTBI. The listed recommendations can be implemented into local protocols for a more homogeneous strategy. Validation using large cohorts of patients needs to be developed. This is the first part of a project to update the management of AT in patients with iTBI.

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.

Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury

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

Aspirin does not increase the need for haemostatic interventions in blunt liver and spleen injuries

PURPOSE

The prohemorrhagic effect of aspirin may cause concern about worse prognoses when treating blunt hepatic or splenic injuries. This study investigated whether preinjury aspirin yields an increasing need for haemostatic interventions.

METHODS

Admission and outpatient records were extracted from the Taiwan National Health Insurance Research Database (NHIRD) from 2003 to 2015. Patients with splenic or hepatic injuries were identified, and those with preinjury nonaspirin APAC or with penetrating injuries were excluded. The primary outcome measurement was the necessity of invasive procedures to stop bleeding, including transarterial embolization (TAE) and surgeries. One-to-two propensity score matching (PSM) was used to minimize selection bias. Multilogistic regression (MLR) analysis was used to identify factors associated with haemostatic interventions.

RESULTS

A total of 20,470 patients had blunt hepatic injuries, and 15,235 had blunt splenic injuries, of whom 691 (3.4%) and 667 (4.4%) used preinjury aspirin, respectively. In the blunt hepatic injury cohort, there was no significant difference in the need for haemostatic procedures (TAE (6.1% vs 6.1%, p = 1.000), exploratory laparotomy (3.3% vs 4.3%, p = 0.312), hepatectomy (3.0% vs 2.7%, p = 0.686) or hepatorrhaphy (14.3% vs 15.0%, p = 0.683)). Regarding the blunt splenic injury cohort, there was no significant difference in the need for haemostatic procedures (TAE (11.5% vs 10.6%, p = 0.553), splenectomy (43.5% vs 41.4%, p = 0.230) or splenorrhaphy (3.0% vs 3.3%, p = 0.117)). An MLR analysis showed that preinjury aspirin did not increase the need for haemostatic interventions in either cohort.

CONCLUSIONS

Preinjury aspirin use is not associated with increased haemostatic procedures in blunt hepatic or splenic injuries.

Alterations in platelet behavior after major trauma: adaptive or maladaptive?

Platelets are damage sentinels of the intravascular compartment, initiating and coordinating the primary response to tissue injury. Severe trauma and hemorrhage induce profound alterations in platelet behavior. During the acute post-injury phase, platelets develop a state of impaired ex vivo agonist responsiveness independent of platelet count, associated with systemic coagulopathy and mortality risk. In patients surviving the initial insult, platelets become hyper-responsive, associated with increased risk of thrombotic events. Beyond coagulation, platelets constitute part of a sterile inflammatory response to injury: both directly through release of immunomodulatory molecules, and indirectly through modifying behavior of innate leukocytes. Both procoagulant and proinflammatory aspects have implications for secondary organ injury and multiple-organ dysfunction syndromes. This review details our current understanding of adaptive and maladaptive alterations in platelet biology induced by severe trauma, mechanisms underlying these alterations, potential platelet-focused therapies, and existing knowledge gaps and their research implications.

Platelet Reactivity Testing for Aspirin Patients Who Sustain Traumatic Intracranial Hemorrhage

BACKGROUND

Patients who take aspirin and sustain traumatic intracranial hemorrhage (tICH) are often transfused platelets in an effort to prevent bleeding progression. The efficacy of platelet transfusion is questionable, however, and some medical societies recommend that platelet reactivity testing (PRT) should guide transfusion decisions. The study hypothesis was that utilization of PRT to guide platelet transfusion for tICH patients suspected of taking aspirin would safely identify patients who did not require platelet transfusion.

METHODS

This was a retrospective study of patients with blunt tICH who received PRT for known or suspected aspirin use between June 2014 and December 2017 at a level I trauma center. Chart abstraction was conducted to determine home aspirin status, and PRT values were used to classify patients as therapeutic or nontherapeutic on aspirin. Differences were assessed with Kruskal-Wallis and chi-square tests.

RESULTS

157 patients met study inclusion criteria, and 118 (75%) patients had documented prior aspirin use. PRT results were available approximately 1.7 h (IQR: 0.9, 3.2) after arrival. Upon initial PRT, 70% of patients were considered inhibited and 88% of those patients had aspirin documented as a home medication. Conversely, 18% of patients with home aspirin use had normal platelet reactivity. Clinically significant worsening of the tICH did not significantly differ when comparing those who received platelet transfusion with those who did not (8% versus 7%, P = 0.87).

CONCLUSIONS

Platelet reactivity testing can detect platelet inhibition related to aspirin and should guide transfusion decisions for head injured patients in the initial hours after trauma.

The Effect of Antithrombotics on Hematoma Expansion in Small- to Moderate-Sized Traumatic Intraparenchymal Hemorrhages

BACKGROUND

Although pre-injury antithrombotic agents, including antiplatelets and anticoagulants, are historically associated with expansion of traumatic intraparenchymal hemorrhage (tIPH), the literature has poorly elucidated the actual risk of hematoma expansion on repeat computed tomography (CT). The objective was to determine the effect of antithrombotic agents on hematoma expansion in tIPH by comparing patients with and without pre-injury antithrombotic medication.

METHODS

The volume of all tIPHs over a 5-year period at an academic Level 1 trauma center was measured retrospectively. The initial tIPH was divided into 3 equally sized quantiles. The third tercile, representing the largest subset of tIPH, was then removed from the study population because these patients reflect a different pathophysiologic mechanism that may require a more acute and aggressive level of care with reversal agents and/or operative management. Per institutional policy, all patients with small- to moderate-sized hemorrhages received a 24-hour stability CT scan. Patients who received reversal agents were excluded.

RESULTS

Of the 105 patients with a tIPH on the initial head CT scan, small- to moderate-sized hemorrhages were <5 cm³. The size of tIPH on initial imaging did not statistically significantly differ between the antithrombotic cohort (0.7 ± 0.1 cm³) and the non-antithrombotic cohort (0.5 ± 0.1 cm³) (P = 0.091). Similarly, the volume of tIPH failed to differ on 24-hour repeat imaging (1.0 ± 0.2 cm³ vs. 0.6 ± 0.1 cm³, respectively, P = 0.172). Following a multiple linear regression, only history of stroke, not antithrombotic medications, predicted increased tIPH on 24-hour repeat imaging.

CONCLUSIONS

In small- to moderate-sized tIPH, withholding antithrombotic agents without reversal may be sufficient.

Global Characterisation of Coagulopathy in Isolated Traumatic Brain Injury (iTBI): A CENTER-TBI Analysis

BACKGROUND

Trauma-induced coagulopathy in patients with traumatic brain injury (TBI) is associated with high rates of complications, unfavourable outcomes and mortality. The mechanism of the development of TBI-associated coagulopathy is poorly understood.

METHODS

This analysis, embedded in the prospective, multi-centred, observational Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study, aimed to characterise the coagulopathy of TBI. Emphasis was placed on the acute phase following TBI, primary on subgroups of patients with abnormal coagulation profile within 4 h of admission, and the impact of pre-injury anticoagulant and/or antiplatelet therapy. In order to minimise confounding factors, patients with isolated TBI (iTBI) (n = 598) were selected for this analysis.

RESULTS

Haemostatic disorders were observed in approximately 20% of iTBI patients. In a subgroup analysis, patients with pre-injury anticoagulant and/or antiplatelet therapy had a twice exacerbated coagulation profile as likely as those without premedication. This was in turn associated with increased rates of mortality and unfavourable outcome post-injury. A multivariate analysis of iTBI patients without pre-injury anticoagulant therapy identified several independent risk factors for coagulopathy which were present at hospital admission. Glasgow Coma Scale (GCS) less than or equal to 8, base excess (BE) less than or equal to - 6, hypothermia and hypotension increased risk significantly.

CONCLUSION

Consideration of these factors enables early prediction and risk stratification of acute coagulopathy after TBI, thus guiding clinical management.

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.

The Role of Platelet Transfusions After Intracranial Hemorrhage in Patients on Antiplatelet Agents: A Systematic Review and Meta-Analysis

The evidence suggests that antiplatelet agents (APA) slightly increase the risk of death and disease progression in patients with traumatic brain injury or spontaneous intracranial hemorrhage (ICH). There is little evidence that APA reversal with platelet (PLT) transfusion may improve the outcome. In this systematic review and meta-analysis, our goal was to evaluate the differences in mortality, severe disability, and hematoma expansion related to PLT transfusion. We retrieved randomized or cohort studies comparing adult patients on APA with traumatic brain injury or ICH who were treated with PLT or not. We calculated the standardized risk difference and 95% confidence interval. A random-effects model was applied to analyze the data. The heterogeneity of the retrieved trials was evaluated through the I² statistic. Our review included 16 clinical trials. We observed a significant difference between the 2 groups only for hematoma expansion: risk difference was -0.10 (10%; 95% confidence interval, -0.14 to -0.05; P < 0.0001; I² = 0.90) in favor of PLT transfusion. Performing subgroups analyses according to the type of bleeding mechanism, we observed the same results. The use of PLT in patients on APA affected by ICH seemed to have no clear beneficial effect for the outcomes evaluated; conversely, PLT seemed to slightly increase the odds for adverse events of thromboembolic origin, even although not significantly.

Relationship of Coagulopathy and Platelet Dysfunction to Transfusion Needs After Traumatic Brain Injury

BACKGROUND

Coagulopathy and platelet dysfunction commonly develop after traumatic brain injury (TBI). Thromboelastography (TEG) and platelet function assays (PFAs) are often performed at the time of admission; however, their roles in assessing post-TBI coagulopathy have not been investigated. We hypothesized that compared to blunt TBI, penetrating TBI would (1) demonstrate greater coagulopathy by TEG, (2) be associated with abnormal PFA results, and (3) require more blood product transfusions.

METHODS

We performed a retrospective study of patients admitted to the neuroscience intensive care unit of a level 1 trauma center from 2013 to 2015 with head Abbreviated Injury Scale ≥3. Patients were compared by mechanism of injury (blunt vs. penetrating). Admission demographics, injury characteristics, and laboratory parameters were evaluated. VerifyNow^® Aspirin and P2Y12 tests were used for platelet function analysis.

RESULTS

Five hundred and thirty-four patients were included in the analysis. There were no differences between groups in platelet count or international normalized ratio; however, patients with penetrating TBI were more coagulopathic by TEG, with all of the TEG parameters being significantly different except for R time. Patients with penetrating head trauma were not more likely than their blunt counterparts to have abnormal PFA results, and PFA results did not correlate with any TEG parameter in either group. The penetrating cohort received more units of blood products in the first 4 and 24 h than the blunt cohort.

CONCLUSIONS

Patients presenting with penetrating TBI demonstrated increased coagulopathy compared to those with blunt TBI as measured by TEG and need for transfusion. PFA results did not correlate with TEG findings in this population.

Intracranial Hemorrhage and Intracranial Hypertension

Central nervous system hemorrhage has multiple pathophysiologic etiologies, including intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), and traumatic brain injury (TBI). Given the nuances intrinsic to each of these etiologies and pathophysiologic processes, optimal blood pressure varies significantly and depends on type of hemorrhage and individual characteristics. This article reviews the most current evidence regarding blood pressure targets and provides guidance on reversal of anticoagulation for TBI, ICH, and SAH. It also describes the assessment, optimal therapeutic targets, and interventions to treat intracranial hypertension that can result from TBI, ICH, or SAH.

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.

Inability to Reverse Aspirin and Clopidogrel-induced Platelet Dysfunction with Platelet Infusion

Background Platelets are commonly administered to trauma patients to reverse the effects of pre-injury anti-platelet drugs if these individuals are judged to be at risk for ongoing bleeding (i.e., traumatic brain injury). In the U.S. blood banks, platelets are maintained at room temperature and are not infused prior to 72 hours storage due to rigorous screening methods. Recent work suggested that cold refrigerated platelets may be effective at restoring platelet function. We hypothesized that refrigerated platelets might be superior to room temperature platelets in reversing aspirin and clopidogrel-induced platelet dysfunction. Methods Using a cross-over design, 10 healthy, adult subjects underwent platelet removal by apheresis, received anti-platelet drugs (aspirin 325 mg and clopidogrel 75 mg) daily for three days, and then had return of their own platelets (about 3 x 10¹¹ platelets). Five subjects were randomly assigned to receive platelets stored at 4°C, and five received platelets stored at room temperature. One month later, this entire process was repeated with each subject receiving platelets stored by the alternative method. Thus, subjects served as their own controls. At multiple time points during the study in vivo platelet function was assessed by bleeding times, which were measured by a single observer blinded to patient group. Results Bleeding times rose dramatically after anti-platelet drugs were given, but remained well above the normal range (seven minutes) despite reinfusion of platelets. There were no differences in platelet function according to the method of storage. Conclusions Transfusion with autologous platelets appears to be ineffective in reversing the anti-platelet effects of aspirin and clopidogrel. Cold refrigerated platelets were no more effective than room temperature stored platelets in restoring platelet function. This abstract was presented at American College of Surgeons-clinical congress, Boston 10-22-2018. (Khoury L, Cohn S, Panzo M. Inability to Reverse Aspirin and Clopidogrel-Induced Platelet Dysfunction with Platelet Infusion. Journal of the American College of Surgeons. 2018. 227. S265. DOI: 10.1016/j.jamcollsurg.2018.07.546).

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.

Effects of platelet dysfunction and platelet transfusion on outcomes in traumatic brain injury patients

OBJECTIVE

Platelet inhibition in traumatic brain injury (TBI) may be due to injury or antiplatelet medication use pre-injury. This study aims to identify factors associated with increased platelet arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition and determine if platelet transfusion reduces platelet dysfunction and affects outcome.

METHODS

Prospective thromboelastography (TEG) assays were collected on adult patients with TBI with intracranial injuries detected by computed tomography (CT). Outcomes included in-hospital mortality, and CT lesion expansion.

RESULTS

Of 153 patients, ADP inhibition was increased in moderate and severe TBI compared to mild TBI (p = 0.0011). P2Y12 inhibiting medications had increased ADP inhibition (p = 0.0077). Admission ADP inhibition was not associated with in-hospital mortality (p = 0.24) or CT lesion expansion (p = 0.94). Mean reduction of ADP inhibition from platelet transfusion (-15.1%) relative to no transfusion (+ 11.7%) was not statistically different (p = 0.0472).

CONCLUSIONS

Mild TBI results in less ADP inhibition compared to moderate and severe TBI, suggesting a dose response relationship between TBI severity and degree of platelet dysfunction. Further, study is warranted to determine efficacy and parameters for platelet transfusion in patients with TBI.

Management of Subdural Hematomas: Part I. Medical Management of Subdural Hematomas

PURPOSE OF REVIEW

Subdural hematomas (SDH) represent common neurosurgical problem associated with significant morbidity, mortality, and high recurrence rates. SDH incidence increases with age; numbers of patients affected by SDH continue to rise with our aging population and increasing number of people taking antiplatelet agents or anticoagulation. Medical and surgical SDH management remains a subject of investigation.

RECENT FINDINGS

Initial management of patients with concern for altered mental status with or without trauma starts with Emergency Neurological Life Support (ENLS) guidelines, with a focus on maintaining ICP < 22 mmHg, CPP > 60 mmHg, MAP 80-110 mmHg, and PaO₂ > 60 mmHg, followed by rapid sequence intubation if necessary, and expedited acquisition of imaging to identify a space-occupying lesion. Patients are administered anti-seizure medications, and their antiplatelet medications or anticoagulation may be reversed if neurosurgical interventions are anticipated, or until hemorrhage is stabilized on imaging. Medical SDH care focuses on (a) management of intracranial hypertension; (b) maintenance of adequate cerebral perfusion; (c) seizure prevention and treatment; (d) maintenance of normothermia, eucarbia, euglycemia, and euvolemia; and (e) early initiation of enteral feeding, mobilization, and physical therapy. Post-operatively, SDH patients require ICU level care and are co-managed by neurointensivists with expertise in treating increased intracranial pressure, seizures, and status epilepticus, as well as medical complications of critical illness. Here, we review various aspects of medical management with a brief overview of pertinent literature and clinical trials for patients diagnosed with SDH.

The currency, completeness and quality of systematic reviews of acute management of moderate to severe traumatic brain injury: A comprehensive evidence map

OBJECTIVE

To appraise the currency, completeness and quality of evidence from systematic reviews (SRs) of acute management of moderate to severe traumatic brain injury (TBI).

METHODS

We conducted comprehensive searches to March 2016 for published, English-language SRs and RCTs of acute management of moderate to severe TBI. Systematic reviews and RCTs were grouped under 12 broad intervention categories. For each review, we mapped the included and non-included RCTs, noting the reasons why RCTs were omitted. An SR was judged as 'current' when it included the most recently published RCT we found on their topic, and 'complete' when it included every RCT we found that met its inclusion criteria, taking account of when the review was conducted. Quality was assessed using the AMSTAR checklist (trichotomised into low, moderate and high quality).

FINDINGS

We included 85 SRs and 213 RCTs examining the effectiveness of treatments for acute management of moderate to severe TBI. The most frequently reviewed interventions were hypothermia (n = 17, 14.2%), hypertonic saline and/or mannitol (n = 9, 7.5%) and surgery (n = 8, 6.7%). Of the 80 single-intervention SRs, approximately half (n = 44, 55%) were judged as current and two-thirds (n = 52, 65.0%) as complete. When considering only the most recently published review on each intervention (n = 25), currency increased to 72.0% (n = 18). Less than half of the 85 SRs were judged as high quality (n = 38, 44.7%), and nearly 20% were low quality (n = 16, 18.8%). Only 16 (20.0%) of the single-intervention reviews (and none of the five multi-intervention reviews) were judged as current, complete and high-quality. These included reviews of red blood cell transfusion, hypothermia, management guided by intracranial pressure, pharmacological agents (various) and prehospital intubation. Over three-quarters (n = 167, 78.4%) of the 213 RCTs were included in one or more SR. Of the remainder, 17 (8.0%) RCTs post-dated or were out of scope of existing SRs, and 29 (13.6%) were on interventions that have not been assessed in SRs.

CONCLUSION

A substantial number of SRs in acute management of moderate to severe TBI lack currency, completeness and quality. We have identified both potential evidence gaps and also substantial research waste. Novel review methods, such as Living Systematic Reviews, may ameliorate these shortcomings and enhance utility and reliability of the evidence underpinning clinical care.

Platelets loaded with liposome-encapsulated thrombin have increased coagulability

Essentials Platelet transfusions can have limited efficacy during hemorrhage associated with coagulopathy. Thrombin can be shielded by encapsulation into nanoliposomes and delivered to platelets ex vivo. Loading platelets with liposomal thrombin improved several aspects of platelet coagulability. Platelets loaded with liposomal thrombin can overcome some coagulopathic deficiencies in vitro.

SUMMARY

Background Platelets are integral to clot formation and are often transfused to stop or prevent bleeding. However, transfusions of platelets are not always effective, particularly in the most severe cases of hemorrhage. Nanoparticle systems have been developed to mimic platelets but inherently lack important aspects of platelet function, which limits their potential effectiveness. Objectives Increasing the natural coagulability of transfusable platelets could increase their efficacy during treatment of severe hemorrhage. Thrombin is a potent platelet agonist that currently cannot be used intravenously because of the risk of thrombosis. We hypothesized that delivery of thrombin to ex vivo platelets via liposomal encapsulation would enable transfusable platelets to become more coagulable in response to platelet agonists. Methods Thrombin was encapsulated into nanoliposomes and delivered to platelets ex vivo. Platelet coagulability was measured by monitoring platelet activation, clot contraction, clot time and clot stability in several in vitro assays. These parameters were also measured under conditions where coagulation is compromised, including during acidosis, antiplatelet drugs, hemophilia A and trauma-induced coagulopathy. Results Liposomal thrombin was endocytosed and used by platelets ex vivo but was not secreted upon activation. These modified platelets became more sensitive and responsive to agonists and improved clotting time even under conditions that normally cause platelet dysfunction or have impaired coagulation. Conclusions Several aspects of platelet function were enhanced by ex vivo delivery of liposomal thrombin.

Assessment of Platelet Function in Traumatic Brain Injury-A Retrospective Observational Study in the Neuro-Critical Care Setting

BACKGROUND

Despite seemingly functional coagulation, hemorrhagic lesion progression is a common and devastating condition following traumatic brain injury (TBI), stressing the need for new diagnostic techniques. Multiple electrode aggregometry (MEA) measures platelet function and could aid in coagulopathy assessment following TBI. The aims of this study were to evaluate MEA temporal dynamics, influence of concomitant therapy, and its capabilities to predict lesion progression and clinical outcome in a TBI cohort.

MATERIAL AND METHODS

Adult TBI patients in a neurointensive care unit that underwent MEA sampling were retrospectively included. MEA was sampled if the patient was treated with antiplatelet therapy, bled heavily during surgery, or had abnormal baseline coagulation values. We assessed platelet activation pathways involving the arachidonic acid receptor (ASPI), P2Y12 receptor, and thrombin receptor (TRAP). ASPI was the primary focus of analysis. If several samples were obtained, they were included. Retrospective data were extracted from hospital charts. Outcome variables were radiologic hemorrhagic progression and Glasgow Outcome Scale assessed prospectively at 12 months posttrauma. MEA levels were compared between patients on antiplatelet therapy. Linear mixed effect models and uni-/multivariable regression models were used to study longitudinal dynamics, hemorrhagic progression and outcome, respectively.

RESULTS

In total, 178 patients were included (48% unfavorable outcome). ASPI levels increased from initially low values in a time-dependent fashion (p < 0.001). Patients on cyclooxygenase inhibitors demonstrated low ASPI levels (p < 0.001), while platelet transfusion increased them (p < 0.001). The first ASPI (p = 0.039) and TRAP (p = 0.009) were significant predictors of outcome, but not lesion progression, in univariate analyses. In multivariable analysis, MEA values were not independently correlated with outcome.

CONCLUSION

A general longitudinal trend of MEA is identified in this TBI cohort, even in patients without known antiplatelet therapies. Values appear also affected by platelet inhibitory treatment and by platelet transfusions. While significant in univariate models to predict outcome, MEA values did not independently correlate to outcome or lesion progression in multivariable analyses. Further prospective studies to monitor coagulation in TBI patients are warranted, in particular the interpretation of pathological MEA values in patients without antiplatelet therapies.

Platelet transfusion does not improve outcomes in patients with brain injury on antiplatelet therapy

INTRODUCTION

Platelet dysfunction following traumatic brain injury (TBI) is associated with worse outcomes. The efficacy of platelet transfusion to reverse antiplatelet medication (APM) remains unknown. Thrombelastography platelet mapping (TEG-PM) assesses platelet function. We hypothesize that platelet transfusion can reverse the effects of APM but does not improve outcomes following TBI.

METHODS

An observational study at six US trauma centres was performed. Adult patients on APM with CT evident TBI after blunt injury were enrolled. Demographics, brain CT and TEG-PM results before/after platelet transfusion, length of stay (LOS), and injury severity score (ISS) were abstracted.

RESULTS

Sixty six patients were enrolled (89% aspirin, 50% clopidogrel, 23% dual APM) with 23 patients undergoing platelet transfusion. Transfused patients had significantly higher ISS and admission CT scores. Platelet transfusion significantly reduced platelet inhibition due to aspirin (76.0 ± 30.2% to 52.7 ± 31.5%, p < 0.01), but had a non-significant impact on clopidogrel-associated inhibition (p = 0.07). Platelet transfusion was associated with longer length of stay (7.8 vs. 3.5 days, p < 0.01), but there were no differences in mortality.

CONCLUSION

Platelet transfusion significantly decreases platelet inhibition due to aspirin but is not associated with change in outcomes in patients on APM following TBI.

Update in mild traumatic brain injury

There has been concern for many years regarding the identification of patients with mild traumatic brain injury (TBI) at high risk of developing an intracranial lesion (IL) that would require neurosurgical intervention. The small percentage of patients with these characteristics and the exceptional mortality associated with mild TBI with IL have led to the high use of resources such as computerised tomography (CT) being reconsidered. The various protocols developed for the management of mild TBI are based on the identification of risk factors for IL, which ultimately allows more selective indication or discarding both the CT application and the hospital stay for neurological monitoring. Finally, progress in the study of brain injury biomarkers with prognostic utility in different clinical categories of TBI has recently been incorporated by several clinical practice guidelines, which has allowed, together with clinical assessment, a more accurate prognostic approach for these patients to be established.

Coagulopathy and haemorrhagic progression in traumatic brain injury: advances in mechanisms, diagnosis, and management

Normal haemostasis depends on an intricate balance between mechanisms of bleeding and mechanisms of thrombosis, and this balance can be altered after traumatic brain injury (TBI). Impaired haemostasis could exacerbate the primary insult with risk of initiation or aggravation of bleeding; anticoagulant use at the time of injury can also contribute to bleeding risk after TBI. Many patients with TBI have abnormalities on conventional coagulation tests at admission to the emergency department, and the presence of coagulopathy is associated with increased morbidity and mortality. Further blood testing often reveals a range of changes affecting platelet numbers and function, procoagulant or anticoagulant factors, fibrinolysis, and interactions between the coagulation system and the vascular endothelium, brain tissue, inflammatory mechanisms, and blood flow dynamics. However, the degree to which these coagulation abnormalities affect TBI outcomes and whether they are modifiable risk factors are not known. Although the main challenge for management is to address the risk of hypocoagulopathy with prolonged bleeding and progression of haemorrhagic lesions, the risk of hypercoagulopathy with an increased prothrombotic tendency also warrants consideration.

Repeat Head CT? Not Necessary for Patients with a Negative Initial Head CT on Anticoagulation or Antiplatelet Therapy Suffering Low-Altitude Falls

Anticoagulation and antiplatelet (ACAP) medications are increasingly prescribed to patients at high risk for falls. Many trauma centers have developed protocols for obtaining repeat head CT (HCT) for patients with low-altitude falls on ACAP therapy. We assess the need for routine scheduled repeat HCT in this population. Prospective, observational analysis of all low-altitude fall (<6 feet) patients on ACAP therapy evaluated at a Level II trauma center. All low-altitude fall patients with visible or suspected head trauma received an initial HCT. Patients were admitted and repeat HCT was obtained 12 hours later or earlier if acute neurologic decline developed. Chisquared, Fischer exact, t, and Wilcoxon rank-sum tests were used. Statistical significance was defined as P < 0.05. Total of 1501 patients enrolled suffering low-altitude falls with initial HCT. Among them 1379(91.2%) were negative and 122(8.1%) were initially positive for intracranial hemorrhage. Mean age was 79.9 ± 11.4 years, 61 per cent were female and 85 per cent had visible head trauma at presentation. One hundred ninety-nine were excluded secondary to not receiving repeat HCT. Of the 1180 patients with normal initial HCT who underwent repeat HCT, only 7 (0.51%) had delayed intracranial hemorrhage. None of these patients required surgery, major changes in medical management or suffered head trauma–related mortality; 69 per cent were taking aspirin (acetylsalicylic acid, ASA), 19 per cent warfarin, 17 per cent clopidogrel, 6 per cent other anticoagulants, and 11 per cent were on combination therapy. Repeat HCT for patients on any ACAP therapy after low-altitude fall with a negative initial HCT is not necessary. Thorough neurologic examination and close monitoring is as effective as obtaining a repeat HCT.

Neurocritical Care of Acute Subdural Hemorrhage

Although urgent surgical hematoma evacuation is necessary for most patients with subdural hematoma (SDH), well-orchestrated, evidenced-based, multidisciplinary, postoperative critical care is essential to achieve the best possible outcome. Acute SDH complicates approximately 11% of mild to moderate traumatic brain injuries (TBIs) that require hospitalization, and approximately 20% of severe TBIs. Acute SDH usually is related to a clear traumatic event, but in some cases can occur spontaneously. Management of SDH in the setting of TBI typically conforms to the Advanced Trauma Life Support protocol with airway taking priority, and management breathing and circulation occurring in parallel rather than sequence.

Management of neurologic complications of coagulopathies

Coagulopathy is common in intensive care units (ICUs). Many physiologic derangements lead to dysfunctional hemostasis; these may be either congenital or acquired. The most devastating outcome of coagulopathy in the critically ill is major bleeding, defined by transfusion requirement, hemodynamic instability, or intracranial hemorrhage. ICU coagulopathy often poses complex management dilemmas, as bleeding risk must be tempered with thrombotic potential. Coagulopathy associated with intracranial hemorrhage bears directly on prognosis and outcome. There is a paucity of high-quality evidence for the management of coagulopathies in neurocritical care; however, data derived from studies of patients with intraparenchymal hemorrhage may inform treatment decisions. Coagulopathy is often broadly defined as any derangement of hemostasis resulting in either excessive bleeding or clotting, although most typically it is defined as impaired clot formation. Abnormalities in coagulation testing without overt clinical bleeding may also be considered evidence of coagulopathy. This chapter will focus on acquired conditions, such as organ failure, pharmacologic therapies, and platelet dysfunction that are associated with defective clot formation and result in, or exacerbate, intracranial hemorrhage, specifically spontaneous intraparenchymal hemorrhage and traumatic brain injury.

Systematic Review and Meta-Analysis: Is Pre-Injury Antiplatelet Therapy Associated with Traumatic Intracranial Hemorrhage?

The objective of this systematic review and meta-analysis is to evaluate whether the pre-injury use of antiplatelet therapy (APT) is associated with increased risk of traumatic intracranial hemorrhage (tICH) on CT scan. PubMed, Medline, Embase, Cochrane Central, reference lists, and national guidelines on traumatic brain injury were used as data sources. Eligible studies were cohort studies and case-control studies that assessed the relationship between APT and tICH. Studies without control group were not included. The primary outcome of interest was tICH on CT. Two reviewers independently selected studies, assessed methodological quality, and extracted outcome data. This search resulted in 10 eligible studies with 20,247 patients with head injury that were included in the meta-analysis. The use of APT in patients with head injury was associated with significant increased risk of tICH compared with control (odds ratio [OR] 1.87, 95% confidence interval [CI]1.27-2.74). There was significant heterogeneity in the studies (I2 84%), although almost all showed an association between APT use and tICH. This association could not be established for patients receiving aspirin monotherapy. When considering only patients with mild traumatic brain injury (mTBI), the OR is 2.72 (95% CI 1.92-3.85). The results were robust to sensitivity analysis on study quality. In summary, APT in patients with head injury is associated with increased risk of tICH; this association is most relevant in patients with mTBI. Whether this association is the result of a causal relationship and whether this relationship also exists for patients receiving aspirin monotherapy cannot be established with the current review and meta-analysis.

Safety of Antithrombotic Agents in Elderly Patients with Acute Coronary Syndromes

There are unique challenges in the treatment and prevention of acute coronary syndromes (ACS) with antithrombotics in elderly patients: elderly patients usually require multiple drugs due to comorbidities, are highly susceptible to adverse drug reactions and drug-drug interactions, may have cognitive problems affecting compliance and complications, are especially exposed to the risk of falls and, most importantly, ageing is an independent risk factor for bleeding. Antithrombotic drugs, alone or in association, further and variously amplify age-related bleeding risk. Moreover, age-related changes in primary haemostasis may potentially affect the pharmacodynamics of some antiplatelet drugs. Thus, elderly subjects might be more or less sensitive to standard antiplatelet regimens depending on individual characteristics affecting antiplatelet drug response. Importantly, elderly patients are a rapidly growing population worldwide, have the highest incidence of ACS, but are poorly represented in clinical trials. As a consequence, evidence on antithrombotic drug benefits and risks is limited. Thus, in the real-world setting, older people are often denied antithrombotic drugs because of unjustified concerns, or might be over-treated and exposed to excessive bleeding risk. Personalized antithrombotic therapy in elderly patients is particularly critical, to minimize risks without affecting efficacy.

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.

[Traumatic brain injury in anticoagulated patients : Hemostatic therapy for the treatment of intracranial hemorrhage]

Impaired hemostasis represents a major risk factor for increased morbidity and mortality in patients with traumatic intracranial hemorrhage. In cases of polytrauma with major bleeding, hyperfibrinolysis may develop and this may result in excessive coagulopathy. Patients receiving antithrombotic medication and suffering from intracranial hemorrhage are at particular risk for the development of neurological sequelae due to the increased tendency to bleeding. This article outlines the principles of hemostatic therapy of traumatic intracranial hemorrhage during antithrombotic treatment. The basic principles of the pathophysiology and effects of coagulation impairment in this patient population are reviewed. Furthermore, the use of specific coagulation tests and the administration of hemostatic substances are discussed.