External Ventricular Drain

External ventricular drainage (EVD) is one of the most frequent neurosurgical procedures experienced in neurocritical care units. Patients in neurocritical care require EVD placement for the purpose of diverting the cerebrospinal fluid (CSF) flow extra-cranially or to monitor intracranial pressure (ICP). The most common indications include acute hydrocephalus (HCP) due to subarachnoid hemorrhage (SAH), intracranial hemorrhage (ICH), intraventricular hemorrhage (IVH), and traumatic brain injury (TBI). Other indications include shunt failure, brain tumors, and intraventricular administration of medications such as antibiotics, recombinant tissue plasminogen activator (rTPA), nicardipine, or chemotherapy. It consists of placing a catheter into the ventricular system and connecting to either collection bag or pressure transducer with the help of a three-way connector. Once in place, the EVD management approach differs for different indications and specific intracranial pathology. Most important aspects of EVD management are height of transducer (if purpose is ICP monitoring) or collecting system and rate of CSF drainage (i.e., mL/h) which is determined by the underlying pathology and opening pressure of CSF. Entire EVD system should be regularly inspected for change in color and clarity of CSF (reflect the change in intracranial pathology) and the presence of CSF leak which may predispose to infection. Constant vigilance of EVD status and patient’s neurological status is required during patient transport or change in position. Because of its invasive nature, presence of multiple connections and complex management, EVD is associated with complications such as accidental disconnection, catheter occlusion, CSF overdrainage, and infection. Once the patient is clinical stable and the indication for EVD insertion (ICP monitoring or acute HCP) has been resolved, EVD can be removed after a successful weaning trial. The implementation of management protocols for maintenance, troubleshooting, and monitoring for EVD is essential to reduce the complications rate and improve the clinical outcome.