RECOMMENDATIONS(see Methodology) Indications for Surgery • An acute subdural hematoma (SDH) with a thickness greater than 10 mm or a midline shift greater than 5 mm on computed tomographic (CT) scan should be surgically evacuated, regardless of the patient's Glasgow Coma Scale (GCS) score. • All patients with acute SDH in coma (GCS score less than 9) should undergo intracranial pressure (ICP) monitoring. • A comatose patient (GCS score less than 9) with an SDH less than 10-mm thick and a midline shift less than 5 mm should undergo surgical evacuation of the lesion if the GCS score decreased between the time of injury and hospital admission by 2 or more points on the GCS and/or the patient presents with asymmetric or fixed and dilated pupils and/or the ICP exceeds 20 mm Hg. Timing • In patients with acute SDH and indications for surgery, surgical evacuation should be performed as soon as possible. Methods• If surgical evacuation of an acute SDH in a comatose patient (GCS Ͻ 9) is indicated, it should be performed using a craniotomy with or without bone flap removal and duraplasty.