In our clinical work, we often give lumbar pool drainage to patients with subarachnoid hemorrhage, patients with intracranial infections, patients with small amounts of ventricular hemorrhage, and even patients with cerebrospinal fluid leaks. Drainage of bloody and inflammatory cerebrospinal fluid to facilitate the closure of the leak, and even temporary reduction of intracranial pressure in partial traffic hydrocephalus have good efficacy. However, sometimes we find that when we remove the drainage, some patients develop acute hydrocephalus, which leads to worsening of the patient’s symptoms in the short term. A ventriculoperitoneal shunt is required.