Platelet dysfunction and platelet transfusion in traumatic brain injury

Area of Science:

• Trauma and surgical critical care
• Hematology
• Platelet physiology

Background:

• Traumatic intracranial hemorrhage (ICH) is associated with impaired platelet function, worsening patient outcomes.
• Platelet transfusion is a common intervention for ICH patients on aspirin, yet its efficacy in improving platelet function and outcomes remains unproven.
• Aspirin and trauma independently impair platelet function.

Purpose of the Study:

• To investigate the effect of platelet transfusion on platelet dysfunction in patients with traumatic ICH.
• To determine if platelet transfusion improves aspirin-induced platelet dysfunction differently from trauma-induced platelet dysfunction.

Main Methods:

• Prospective trial involving patients with traumatic ICH at a level 1 trauma center.
• Platelet function assessed using Multiplate multiple electrode aggregometry, with activation induced by collagen (COL) and arachidonic acid (AA).
• Patients on aspirin therapy received one apheresis unit of platelets; platelet function was measured before and after transfusion.

Main Results:

• Twelve of seventeen enrolled patients were taking aspirin. All received platelet transfusions.
• Aspirin users showed abnormal platelet response to both AA and COL upon admission.
• Platelet transfusion significantly improved response to AA (median 19.0 U to 26.0 U, P=0.012) but not COL in aspirin users.
• Patients not on aspirin had abnormal response to COL, unaffected by transfusion.

Conclusions:

• Traumatic ICH leads to platelet dysfunction.
• Aspirin use exacerbates platelet dysfunction, particularly affecting response to arachidonic acid (AA).
• Platelet transfusion effectively improves aspirin-induced platelet dysfunction but not trauma-induced dysfunction in ICH patients.