Nonsurgical acute traumatic subdural hematoma: what is the risk?

OBJECT: The Brain Trauma Foundation has published guidelines on the surgical management of traumatic subdural hematoma (SDH). However, no data exist on the proportion of patients with SDH that can be selected for conservative management and what is the outcome of these patients. The goals of this study were as follows: 1) to establish what proportion of patients are initially treated conservatively; 2) to determine what proportion of patients will deteriorate and require surgical evacuation; and 3) to identify risk factors associated with deterioration and delayed surgery. METHODS: All cases of acute traumatic SDH (869 when inclusion criteria were met) presenting over a 4-year period were reviewed. For all conservatively treated SDH, the proportion of delayed surgical intervention and the Glasgow Outcome Scale score were taken as outcome measures. Multiple factors were compared between patients who required delayed surgery and patients without surgery. RESULTS: Of the 869 patients with acute traumatic SDH, 646 (74.3%) were initially treated conservatively. A good outcome was achieved in 76.7% of the patients. Only 6.5% eventually required delayed surgery, and the median delay for surgery was 9.5 days. Factors associated with deterioration were as follows: 1) thicker SDH (p<0.001); 2) greater midline shift (p<0.001); 3) location at the convexity (p=0.001); 4) alcohol abuse (p=0.0260); and 5) history of falls (p=0.018). There was no significant difference in regard to age, sex, Glasgow Coma Scale score, Injury Severity Score, abnormal coagulation, use of blood thinners, and presence of cerebral atrophy or white matter disease. CONCLUSIONS: The majority of patients with SDH are treated conservatively. Of those, only 6.5% later required surgery, for raised intracranial pressure or SDH progression. Patients at risk can be identified and followed more carefully.