Factors Associated with Early versus Delayed Expansion of Acute Subdural Hematomas Initially Managed Conservatively
David Robinson, Logan Pyle, Brandon Foreman, Laura B. Ngwenya, Opeolu Adeoye, Daniel Woo, Natalie Kreitzer
Abstract
Acute subdural hematomas (ASDHs) are highly morbid and increasingly common. Hematoma expansion is a potentially fatal complication, and few studies have examined whether factors associated with hematoma expansion vary over time. To answer this, we performed a case-control study in a cohort of initially conservatively managed patients with ASDH. Two time periods were considered, early (<72 h from injury) and delayed (>72 h from injury). Cases were defined as patients who developed ASDH expansion in the appropriate period; controls were patients who had stable imaging. Associated factors were determined with logistic regression. We identified 68 cases and 237 controls in the early follow-up cohort. Early ASDH expansion was associated with coagulopathy (adjusted odds ratio [aOR] 2.3, 95 % CI: 1.2-4.5; p = 0.02), thicker ASDHs (aOR 1.1, 95% CI: 1.03-1.2; p = 0.006), additional intracranial lesions (aOR 3, 95% CI: 1.6-6.2; p = 0.002), no/minimal trauma history (aOR 0.4, 95% CI: 0.2-0.9; p = 0.03), and duration between injury and initial scan (aOR 0.9, 95% CI: 0.8-0.97; p = 0.04). In the delayed follow-up cohort, there were 41 cases and 126 controls. Delayed ASDH expansion was associated with older age (aOR 1.3 per 10 years, 95% CI: 1.1-1.6; p = 0.01), systolic blood pressure (SBP) >160 on hospital presentation (aOR 4.5, 95% CI: 1.8-11.3; p = 0.001), midline shift (aOR 1.5 per 1 mm, 95% CI: 1.3-1.9; p < 0.001), and convexity location (aOR 14.1, 95% CI: 2.6-265; p = 0.013). We conclude that early and delayed ASDH expansion are different processes with different associated factors, and that elevated SBP may be a modifiable risk factor of delayed expansion.