What is the function of an External Ventricular Drain?

• A. Device used to monitor brain oxygenation.
• B. Shunt used to drain CSF from the subarachnoid space.
• C. Electrode array for recording brain activity.
• D. Catheter placed into the lateral ventricle to monitor intracranial pressure and drain CSF.

Answer: (D)

An External Ventricular Drain is a catheter placed into the lateral ventricle that sits outside the skull to both monitor intracranial pressure and drain CSF. This setup lets clinicians continuously measure ICP with the attached transducer and, as needed, drain CSF to reduce high pressure after severe brain injury. It’s external and temporary, unlike a ventriculoperitoneal shunt that drains internally to the peritoneal cavity for long-term CSF management. It’s not designed to monitor brain oxygen levels or to record brain activity with electrodes.