Prediction of ventriculoperitoneal shunt placement based on type of failure during external ventricular drain wean

There are multiple etiologies for failure while weaning an external ventricular drain (EVD) after subarachnoid hemorrhage (SAH), but there is little data on the relationship between etiology of wean failure and ventriculoperitoneal shunt (VPS) placement.

We performed a retrospective analysis of SAH patients who had an EVD placed between January 2008 and June 2012 at our institution. For each wean step (defined as raising or clamping the EVD), we recorded success or failure. We categorized failure as lowering or opening the EVD due to elevated intracranial pressure (ICP), clinical failure (due to headache or vomiting or altered mental status), leakage from the EVD site, or development of radiographic hydrocephalus. We evaluated the relationship between etiology of wean failure and subsequent need for VPS.

Of 116 patients with an EVD placed, 35 required VPS placement (30%). Patients who required VPS placement had a median of 2 (interquartile range (IQR) 1-4) wean failures and those who did not require VPS placement had a median of 1 (IQR 0-1) wean failure (p=0.001). There was no significant relationship between age, sex, Hunt Hess score, Fisher score, Glasgow coma scale, aneurysm location, aneurysm size, aneurysm treatment method, vasospasm and need for VPS. There was a significant relationship between patients with at least one wean failure due to clinical changes or radiographic hydrocephalus and need for VPS (p=0.007 and p=0.029, respectively). After multivariate analysis, there was only a significant relationship between clinical changes and need for VPS (OR 2.76, CI 1.03-7.36, p=0.04).

There is a significant association between wean failure due to clinical changes and requirement for VPS placement after SAH.