Complications of Subarachnoid Hemorrhage

General Complications

The American Heart Association recommends that patients with subarachnoid hemorrhage be managed in centers that treat many patients (>35 subarachnoid hemorrhage admissions per year) and have neurovascular teams and neurointensive care units or similar 1, 3, 6
Subarachnoid hemorrhage complications include rebleeding (13% of patients), delayed cerebral ischemia (20-40% of patients), hydrocephalus (15-87% of patients), seizures (5-15% of patients), and systemic medical complications including hyponatremia, fever, anemia, and deep vein thrombosis 1, 2

Rebleeding occurs in 7-26% of patients (average 13%) before aneurysm repair, with the highest risk in the first 24 hours (15% "ultra-early rebleeding"), and 70% occurring within the first 2 hours 1, 3
The median time to rebleeding was 180 minutes in a study of 293 patients 1
Factors associated with rebleeding include proximity to the initial hemorrhage, higher blood pressure, worse neurological grade, intraventricular or intracerebral hemorrhage, and larger aneurysm size 1
The American College of Cardiology recommends repairing the aneurysm as soon as possible (as soon as feasible) through surgical clipping or endovascular embolization to prevent rebleeding 1, 3

Delayed cerebral ischemia develops in 20-40% of patients, typically between days 3-5 after the hemorrhage, with maximum narrowing at 5-14 days 5
The American Heart Association recommends administering oral nimodipine 60 mg every 4 hours for 21 consecutive days, starting within 96 hours of hemorrhage onset (Class I, Level of Evidence A) 3
Nimodipine reduces cerebral infarct by 34% and poor outcomes by 40%, although it does not prevent angiographic vasospasm 3
Maintaining euvolemia and normal circulating volume, and avoiding prophylactic hypervolemia and hemodilution (triple-H therapy) are recommended 3, 4

Hydrocephalus occurs in 15-87% of patients with subarachnoid hemorrhage 3
The American Heart Association recommends treating symptomatic acute hydrocephalus with external ventricular drainage or lumbar drainage, depending on the clinical scenario (Class I, Level of Evidence B) 3

The American Heart Association recommends controlling fever aggressively to a target of normothermia using standard or advanced temperature modulation systems in the acute phase of subarachnoid hemorrhage (Class IIa, Level of Evidence B) 8, 4
The use of fludrocortisone acetate and hypertonic saline is reasonable to prevent and correct hyponatremia (Class IIa, Level of Evidence B) 8
The use of packed red blood cell transfusion to treat anemia may be reasonable in patients with subarachnoid hemorrhage who are at risk of cerebral ischemia, although the optimal hemoglobin target is still to be determined (Class IIb, Level of Evidence B) 8

The American Heart Association recommends referring all survivors for comprehensive multidisciplinary evaluation, including cognitive, behavioral, and psychosocial assessments using validated screening tools 3
Early identification of mood disorders allows for interventions that improve long-term outcomes 3, 6
Maintaining systolic blood pressure <160 mmHg in the chronic phase to prevent aneurysm recurrence is recommended 3