Educational scope notice: This is a study note for medical students, not medical advice, diagnosis, or treatment guidance. Clinical management should follow local protocols and current guidelines.
Securing the aneurysm does not end the danger. Blood around the brain surface triggers three delayed problems: rebleeding before the aneurysm is secured, vasospasm with delayed ischemia days later, and hydrocephalus from blocked cerebrospinal fluid flow. Each has its own mechanism and its own management.
Rebleeding
Acute rebleeding worsens mortality and outcome, so the ruptured aneurysm is evaluated and treated promptly, preferably within 24 hours. Routine antifibrinolytic therapy did not improve functional outcomes and must not be presented as protection.
Vasospasm and delayed cerebral ischemia
Early enteral nimodipine prevents delayed cerebral ischemia and improves functional outcomes after aneurysmal hemorrhage. Transcranial Doppler, CT angiography, and CT perfusion can detect vasospasm and predict delayed ischemia when performed by trained expert interpreters. Rescue for symptomatic delayed ischemia is blood-pressure elevation with maintained euvolemia. Prophylactic hemodynamic augmentation and hypervolemia should not be performed.
Hydrocephalus
Blood in the subarachnoid space obstructs cerebrospinal fluid circulation and absorption. Hydrocephalus is managed with cerebrospinal fluid diversion by external ventricular drain. Optimal drain management strategies remain an evidence gap calling for further investigation.
Evidence anchors
- Hoh BL, et al. 2023 Guideline for the management of patients with aneurysmal subarachnoid hemorrhage: https://pubmed.ncbi.nlm.nih.gov/37212182/