external ventricular drain
Pronunciation: ek-STUR-nal ven-TRIK-yuh-lar drayn
Also written as: EVD — external ventricular drain
Surgically placed catheter that drains cerebrospinal fluid from brain ventricles to an external collection system.
Full Definition
An external ventricular drain (EVD) is a temporary neurosurgical device consisting of a catheter inserted through the skull into the brain's ventricular system, connected to an external drainage and monitoring system. In pediatric neurology, EVDs serve dual purposes: monitoring intracranial pressure and draining excess cerebrospinal fluid in conditions like hydrocephalus, traumatic brain injury, or following neurosurgical procedures. The system allows precise control of CSF drainage by adjusting the height of the collection chamber relative to the patient's head. EVDs require intensive monitoring for complications including infection, catheter malposition, and over- or under-drainage.
Usage
Usage note: Distinguish from permanent shunt systems. Specify drainage level and ICP monitoring parameters when relevant.
In Context
- "An EVD was placed emergently for acute hydrocephalus following posterior fossa tumor resection." — Neurosurgical operative note
- "The EVD output decreased significantly, prompting evaluation for catheter obstruction or malposition." — PICU daily progress note