abstract:An external ventricular drain (EVD), also known as an extraventricular drain or ventriculostomy, is a device used in neurosurgery that relieves elevated intracranial pressure and hydrocephalus when the normal flow of cerebrospinal fluid around the brain is obstructed. This is a plastic tube placed by neurosurgeons and managed by ICU nurses and Critical Care Paramedics to drain fluid from the ventricles of the brain and thus keep them decompressed, as well as to monitor intracranial pressure.