What is the recommended number of units of platelets (platelet transfusion) to transfuse in a 75-year-old male with thrombocytopenia (platelet count of 30,000) and an acute subdural hematoma?

Platelet Transfusion for Acute Subdural Hematoma with Thrombocytopenia

For a 75-year-old male weighing 82kg with an acute subdural hematoma and a platelet count of 30,000/μL, administer one apheresis platelet unit (equivalent to 4-8 units of pooled platelets) to achieve a target platelet count above 100,000/μL. 1

Rationale for Platelet Transfusion

Target Platelet Count

• For patients with traumatic brain injury (TBI) and ongoing bleeding, a platelet count above 100,000/μL is recommended 1
• This higher threshold is specifically indicated for patients with intracranial hemorrhage, including subdural hematomas, due to the catastrophic consequences of continued bleeding 1
• The normal therapeutic threshold for most bleeding conditions is only 50,000/μL, but TBI requires a more aggressive approach 1

Dosing Considerations

• One apheresis platelet product (single-donor) contains approximately 3-4 × 10¹¹ platelets 1, 2
• This is equivalent to 4-8 units of pooled platelets 1
• This dose should increase the platelet count by 30-50 × 10⁹/L in a patient of average size 1, 2
• For this 82kg patient, one apheresis unit should be sufficient to raise the count from 30,000/μL to above 100,000/μL

Administration Protocol

Pre-transfusion Considerations

• Obtain blood type to provide ABO-compatible platelets if possible 1
• Platelets should be transfused as soon as possible given the acute nature of subdural hematoma
• No need to wait for further platelet count decrease as the current level (30,000/μL) is already well below the target for TBI (100,000/μL) 1

Post-transfusion Monitoring

• Check post-transfusion platelet count 1 hour after completion to confirm adequate increment 2
• If target platelet count of >100,000/μL is not achieved, consider administering an additional apheresis unit
• Monitor for clinical signs of continued bleeding and neurological status

Special Considerations

Efficacy Assessment

• The effectiveness of platelet transfusion should be assessed both by laboratory values and clinical response 2
• In TBI, if ADP response improves after platelet administration, the need for neurosurgical intervention may decrease 1

Common Pitfalls to Avoid

• Do not delay transfusion while waiting for further platelet count decrease - immediate transfusion is warranted with this combination of severe thrombocytopenia and acute subdural hematoma 1
• Do not underdose - inadequate platelet transfusion may fail to achieve hemostasis in this critical situation 1
• Do not rely solely on platelet count - clinical assessment remains essential as platelet dysfunction may occur despite adequate numbers 1

Surgical Considerations

• If neurosurgical intervention is planned, maintaining platelet count >100,000/μL is crucial throughout the perioperative period 1
• Ensure platelets are available on short notice in case intraoperative or postoperative bleeding occurs 1

While one study suggested that platelet transfusion may not benefit patients with non-surgical traumatic subdural hematomas on antiplatelet therapy 3, the current guidelines strongly support platelet transfusion in cases of severe thrombocytopenia with TBI to reduce mortality and improve outcomes 1.