Background and Purpose
Rapid recognition of those at high-risk for malignant edema after stroke would facilitate triage for monitoring and potential surgery. Admission data may be insufficient for accurate triage decisions. We developed a risk prediction score using clinical and radiographic variables within 24 hours of ictus to better predict potentially lethal malignant edema (PLME).
Methods
Patients admitted with diagnosis codes of “Cerebral Edema” and “Ischemic Stroke,” NIHSS ≥ 8, and head CTs within 24 hours of stroke-onset were included. Primary outcome of PLME was defined as death with midline shift (MLS) ≥ 5mm or Decompressive Hemicraniectomy. We performed multivariate analyses on data available within 24 hours of ictus. Bootstrapping was used to internally validate the model and a risk score was constructed from the results.
Results
33% of 222 patients developed PLME. The final model c-statistic was 0.76 (CI 0.68-0.82) in the derivation cohort, and 0.75 (0.72-0.77) in the bootstrapping validation sample. The EDEMA score was developed using the following independent predictors: Basal cistern effacement (=3); Glucose ≥150 (=2); No tPA or thrombectomy (=1), MLS >0-3 (=1), 3-6 (=2), 6-9 (=4); >9 (=7); No prior stroke (=1). A score over 7 was associated with 93% positive predictive value.
Conclusion
The EDEMA score identifies patients at high risk for PLME. While it requires external validation, this scale could help expedite triage decisions in this patient population.