Subarachnoid hemorrhage drainage, also known as cerebrospinal fluid replacement surgery, often occurs due to the rupture of cerebral aneurysms. The blood clots enter the subarachnoid space causing severe headaches, increased intracranial pressure, nausea, vomiting, and other symptoms. It is essential to drain the blood clots as early as possible to achieve effective treatment results. The subarachnoid space is a gap between the pia mater and arachnoid mater, which are two of the three membranes covering the brain and spinal cord—the innermost layer being the pia mater, followed by the arachnoid and the outermost dura mater. Normally, the subarachnoid space contains cerebrospinal fluid that is continuously circulating. Hence, in patients with subarachnoid hemorrhage, performing a lumbar puncture can drain the bloody cerebrospinal fluid. During this procedure, a puncture is made in the lumbar region to drain the bloody cerebrospinal fluid, followed by the injection of an equal volume of saline solution. This facilitates the replacement of the blood clots in the subarachnoid space with saline solution. Conducting this procedure once daily, continuously for three to five days, can significantly alleviate the symptoms of subarachnoid hemorrhage. Essentially, this process is also known as cerebrospinal fluid puncture or cerebrospinal fluid replacement surgery.