Management of External Ventricular Drains After Subarachnoid Hemorrhage: A Multi-Institutional Survey

Patients with aneurysmal subarachnoid hemorrhage (SAH) often develop hydrocephalus requiring an external ventricular drain (EVD). The best available evidence suggests that a rapid EVD wean and intermittent CSF drainage is safe, reduces complications, and shortens ICU and hospital length of stay as compared to a gradual wean and continuous drainage. However, optimal EVD management remains controversial and the baseline practice among neurological ICUs is unclear. Therefore, we sought to determine current institutional practices of EVD management for patients with aneurysmal SAH.

An e-mail survey was sent to attending intensivists and neurosurgeons from 72 neurocritical care units that are registered with the Neurocritical Care Research Network or have been previously associated with the existing literature on the management of EVDs in critically ill patients. Only one response was counted per institution.

There were 45 out of 72 institutional responses (63%). The majority of responding institutions (80%) had a single predominant EVD management approach. Of these, 78% favored a gradual EVD weaning strategy. For unsecured aneurysms, 81% kept the EVD continuously open and 19% used intermittent drainage. For secured aneurysms, 94% kept the EVD continuously open and 6% used intermittent drainage. Among continuously drained patients, the EVD was leveled at 18 (unsecured) and 11 cm H₂O (secured) (p < 0.0001). When accounting for whether the EVD strategy was to enhance or minimize CSF drainage, there was a significant difference in the management of unsecured versus secured aneurysms with 42% using an enhance drainage approach in unsecured patients and 92% using an enhance drainage approach in secured patients (p < 0.0001).

Most institutions utilize a single predominant EVD management approach, with a consensus toward a continuously open EVD to enhance CSF drainage in secured aneurysm patients coupled with a gradual weaning strategy. This finding is surprising given that the best available evidence suggests that the opposite approach is safe and can reduce ICU and hospital length of stay. We recommend a critical reassessment of the approach to the management of EVDs. Given the potential impact on patient outcomes and length of stay, more research needs to be done to reach a threshold for practice change, ideally via multicenter and randomized trials.