Management of Subdural Hematoma
Immediate Reversal of Anticoagulation/Antiplatelet Therapy
For any patient with acute subdural hematoma (SDH) on anticoagulation, immediately reverse coagulopathy using prothrombin complex concentrate (preferred over fresh frozen plasma) plus vitamin K, regardless of hematoma size. 1
- Elevated INR significantly increases hematoma volume and expansion risk, with volumes significantly higher when INR >3.0 1
- 30-40% of intracranial hemorrhages expand during the first 12-36 hours, prolonged with anticoagulation 1
- Prothrombin complex concentrate normalizes INR within 15 minutes and is preferred in most national guidelines 1
- Vitamin K must be administered with either product to maintain the beneficial effect 1
- Do not routinely transfuse platelets for patients on antiplatelet agents, as this increases odds of death or dependence 1
Surgical Decision-Making for Acute SDH
Proceed with urgent craniotomy (with or without craniectomy) if any of the following criteria are met:
Absolute Surgical Indications 2, 3, 4, 5
- Hematoma thickness >10 mm, regardless of GCS score 5
- Midline shift >5 mm, regardless of GCS score 2, 5
- GCS score <9 with hematoma thickness <10 mm AND midline shift <5 mm IF any of: 5
- GCS decreased by ≥2 points from injury to admission
- Asymmetric or fixed dilated pupils
- Intracranial pressure >20 mmHg
Surgical Timing and Technique 3, 4, 5
- Perform evacuation as soon as possible once indicated 5
- Use craniotomy or craniectomy (NOT burr holes) for acute SDH 4, 5
- Consider decompressive craniectomy for significant mass effect and cerebral edema 3
- Place ICP monitor in all comatose patients (GCS <9) with acute SDH 5
Conservative Management Criteria 6
- No patient with initial SDH ≤3 mm required surgery in recent studies, though 11% enlarged to maximum 10 mm 6
- Hematomas <10 mm thick with <5 mm midline shift in non-comatose patients may be observed with serial imaging 4, 5
Risk Factors for Hematoma Expansion
Monitor closely for expansion if any of these high-risk features are present: 6
- Larger initial SDH size (8.5 mm threshold best predicts need for surgery) 6
- Concurrent subarachnoid hemorrhage 6
- Hypertension 6
- Convexity location 6
- Initial midline shift present 6
Management of Subacute/Chronic SDH
Subacute or chronic SDH that fails conservative management requires different surgical approach: 3, 7
- Burr hole evacuation is appropriate for most chronic SDH without septations 3, 7
- Consider small craniotomy or full craniotomy if: 7
- Septations present on imaging
- Diffusion-weighted MRI shows two-layered hematoma structure
- Solid clot component suspected beneath dura
- Twist drill craniostomy with subdural evacuating port system is acceptable for chronic SDH in patients who cannot tolerate anesthesia 3
Anticoagulation Resumption After SDH
Hold all anticoagulants and antiplatelets for at least 1-2 weeks after hemorrhage. 1
Timing of Resumption 1
- Risk of ischemic event during cessation is 2.1% within 30 days 1
- Median safe duration off warfarin is 10 days, with no ischemic strokes reported up to 19 days 1
- For mechanical heart valves: 2.9% ischemic event risk during cessation 1
- For atrial fibrillation with prior embolic stroke: 2.6% ischemic event risk 1
Resumption Strategy 1
- If early resumption required (after 3-4 weeks), intravenous heparin may be safer than oral anticoagulation 1
- Maintain INR at lower end of therapeutic range when restarting oral anticoagulation 1
- Do not resume anticoagulation for lobar SDH with suspected cerebral amyloid angiopathy (higher recurrence risk) 1
Special Considerations
Thrombocytopenia 1
- Therapeutic LMWH may be administered if platelet count maintained >50 × 10⁹/L 1
- Half-dose LMWH for platelet counts 20-50 × 10⁹/L 1
- Hold therapeutic anticoagulation if platelets <20 × 10⁹/L 1