Management of Subacute Subdural Hematoma

Clinical Manifestations and Monitoring

30-40% of subdural hematomas expand during the first 12-36 hours, typically manifesting as neurological deterioration 1
Postoperative intracranial hypertension occurs in more than 40% of patients after hematoma evacuation, with secondary bleeding, new extra-axial collections, or increased cerebral edema driving this early worsening 2
Declining Glasgow Coma Scale motor score is the most sensitive indicator of worsening, according to the Anaesthesia society 2
New or worsening anisocoria or bilateral mydriasis signals impending herniation, as indicated by the Anaesthesia society 2
Compressed basal cisterns and midline shift >5mm on follow-up CT indicate dangerous mass effect requiring intervention, as recommended by the Anaesthesia society 2, 4

Serial neurological examinations at least every 4 hours initially are recommended for patients managed conservatively, according to the Praxis Medical Insights society 5
Maintaining cerebral perfusion pressure 60-70 mmHg is recommended if ICP monitoring is in place, as suggested by the Anaesthesia and Praxis Medical Insights societies 2, 5, 6
Systolic blood pressure >100 mmHg or mean arterial pressure 80-110 mmHg is recommended, according to the Praxis Medical Insights society 5, 6

ICP monitoring is strongly indicated after subdural hematoma evacuation if preoperative Glasgow Coma Scale motor response ≤5, preoperative anisocoria or bilateral mydriasis, preoperative hemodynamic instability, compressed basal cisterns or midline shift >5mm on imaging, intraoperative cerebral edema, or postoperative appearance of new intracranial lesions, as recommended by the Anaesthesia society 2

Patients on anticoagulants or antiplatelets have increased risk of hematoma expansion and require more aggressive monitoring, according to the Praxis Medical Insights society 3
Rapid normalization of INR is mandatory in acute settings with therapeutic INR, as elevated INR enhances expansion, as indicated by the Stroke society 1