Quantitative Modeling of External Ventricular Drain Output to Predict Shunt Dependency in Aneurysmal Subarachnoid Hemorrhage: Cohort Study.

Abstract

Acute hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH); however, attempts to predict shunt-dependent chronic hydrocephalus using clinical parameters have been equivocal. Cohort study of aSAH is treated with external ventricular drainage (EVD) placement at our institution, 2001-2016, via logistic regression. EVD-related parameters included mean/total EVD output (days 0-2), EVD days, EVD days ≤ 5mmHg, and wean/clamp fails. aSAH outcomes assessed included ventriculoperitoneal shunt (VPS) placement, delayed cerebral ischemia (DCI), radiographic infarction (RI), symptomatic vasospasm (SV), age, and aSAH grades. Two hundred and ten aSAH patients underwent EVD treatment for a median 12days (range 1-54); 85 required VPS (40%). On univariate analysis, EVD output, total EVD days, EVD days ≤ 5mmHg, and wean/clamp trial failures were significantly associated with VPS placement (p < 0.01 for all parameters). No EVD output parameter demonstrated a significant association with DCI, RI, or SV. On multivariate analysis, EVD output was a significant predictor of VPS placement, after adjusting for age and clinical and radiological grades; the optimal threshold for predicting VPS placement was mean daily output > 204ml on days 0-2 (OR 2.59, 95% CI 1.31-5.07). Multiple wean failures were associated with unfavorable functional outcome, after adjusting for age, grade, and VPS placement (OR 1.65, 95% CI 1.10-2.47). We developed a score incorporating age, grade and EVD parameters (MAGE) for predicting VPS placement after aSAH. EVD output parameters and wean/clamp trial failures predicted shunt dependence in an age- and grade-adjusted multivariable model. Early VPS placement may be warranted in patients with MAGE score ≥ 4, particularly following 2 failed wean trials.