An external ventricular drain (EVD) is a device used to drain cerebrospinal fluid (CSF) from the ventricles of the brain. It is often implemented to manage intracranial pressure (ICP) in patients with conditions such as hydrocephalus, traumatic brain injury, or subarachnoid hemorrhage. Prior to repositioning a patient with an EVD, the drain is typically clamped. This involves temporarily stopping the flow of CSF through the drainage system.
Cessation of drainage offers several benefits. It prevents potential siphoning, a phenomenon where gravity causes excessive drainage of CSF, potentially leading to complications such as subdural hematoma or ventricular collapse. Clamping helps to maintain a more stable intracranial pressure during movement, minimizing abrupt fluctuations. This practice aligns with established clinical protocols aimed at patient safety and optimal management of neurological conditions.