The slippery slope of platelet transfusion for intracerebral hemorrhage

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.

Diagnosis and Management of Spontaneous Intracerebral Hemorrhage

PURPOSE OF REVIEW

This article updates neurologists on recent insights and management strategies of intracerebral hemorrhage (ICH).

RECENT FINDINGS

Blood pressure reduction likely improves outcomes in patients with intracerebral hemorrhage, although not by the expected mechanism of reducing hematoma growth. One formulation of prothrombin complex concentrate for reversing severe bleeding associated with warfarin is now approved by the US Food and Drug Administration (FDA), and specific reversal therapies for the novel oral anticoagulants are in development. Neurologic monitoring frequently detects ICH worsening that requires an intervention. Platelet transfusion and pharmacologic platelet activation are promising and often used as part of patient management but have not yet been shown to improve patient outcomes.

SUMMARY

Measurable progress continues toward establishing effective therapies to improve outcomes in patients with ICH. Blood pressure reduction and reversal of medications that exacerbate bleeding are likely to improve outcomes. Recommendations for neuromonitoring will help clinicians at the bedside attend to the most important abnormalities and optimize later quality of life. This article reviews standards for diagnosis and severity of ICH, monitoring and treatment of complications in the hospital, available interventions, and the measurement of outcomes.

Blood component transfusion in critically ill patients

PURPOSE OF REVIEW

This review summarizes the current evidence base for commonly transfused blood components with a particular focus on the nonacutely bleeding patient.

RECENT FINDINGS

There remains little definitive evidence to guide transfusion practices in the critically ill. The most rigorous evidence to guide red blood cell (RBC) transfusion practice is derived from the Transfusion in Critical Care Trial (TRICC Trial) that was published in 1999. Specific subgroups of patients may be at particular risk of the adverse effects of anemia, and require further study. There are no randomized controlled trials addressing clinically important outcomes evaluating frozen plasma, platelet thresholds, or impaired platelet activity in the critically ill.

SUMMARY

As all blood components have some level of risk, the general approach to transfusion should be one of minimization. For the nonacutely bleeding critically ill patient, a RBC transfusion trigger of 70 g/l is clinically acceptable. For patients at potentially higher risk of adverse effects related to anemia such as those with septic shock, severe and/or acute ischemic heart disease, or brain injury, a higher threshold (80-90 g/l) may be considered. There is insufficient evidence to recommend specific thresholds for transfusion of frozen plasma or platelets in the critically ill.