Revisiting the Hunt Hess Scale: Evaluation after EVD placement better predicts mortality

Objective: To determine whether there is a difference in hospital mortality among high grade subarachnoid hemorrhage patients (Hunt Hess (HH) grade of 4–5) based on whether or not their neurologic exam improves in the first three days after external ventricular drainage (EVD). Background: Traditionally, higher HH grade has been associated with worse outcomes; grade 4–5 patients have reported mortality rates of 24 and 71% respectively. EVD placement is a common procedure to treat acute hydrocephalus after aSAH and may be associated with early neurologic improvement. It is unknown whether patients who experience neurologic improvement after EVD placement have different outcomes than those who do not improve. Design/Methods: Retrospective analysis of all poor grade (HH4-5) aSAH treated at a single academic center from September 2018 – October 2019. Those who did not receive EVD were excluded. A total of 24 patients were included. Clinical improvement was defined as documented command following up to post-EVD day 3. Primary outcome was in-hospital mortality. Secondary outcomes included discharge destination and need for ventriculoperitoneal shunt (VPS). Fisher’s exact test was used to assess associations between categorical variables. Results: Of 24 patients, 58% improved (n=14) and 42% did not (n=10). Patients with clinical improvement, compared to those without, had significantly lower mortality 21% vs 80%. Patients with clinical improvement were 12.65 times less likely to die (p=0.01). Among survivors, 9/11 (81.8%) in the group that had neurologic improvement were ultimately discharged to home or acute rehab compared to 1/2 (50%) in those without improvement. VPS was required in 7/13 (53.8%) of those who survived in both groups. Conclusions: Among high grade aSAH patients, there appear to be two phenotypes – one that has rapid neurologic improvement after ventricular drainage, and another that does not. Patients who demonstrate early improvement after EVD placement have significantly lower mortality than those who do not. Disclosure: Dr. Mohammadi has nothing to disclose. Dr. Reilly has nothing to disclose. Dr. Liang has nothing to disclose. Dr. Chada has nothing to disclose. Dr. Romano Spica has nothing to disclose. Dr. Reynolds has nothing to disclose. Dr. Dangayach has nothing to disclose. Dr. Kellner has nothing to disclose. Dr. Lay has nothing to disclose. Dr. Research Group has nothing to disclose.