Critical Care Monitoring and Management of Aneurysmal Subarachnoid Hemorrhage

Introduction

Aneurysmal subarachnoid hemorrhage (SAH), a type of hemorrhagic stroke due to rupture of a cerebral aneurysm, accounts for 2–5% of all new strokes, but results in 22–25% of cerebrovascular deaths 1. Nearly one-third of patients require lifelong care 2, 3. Worldwide incidence is 10.5/100 000 personyears 2. The incidence of this disease has remained stable over the past three decades, but the case-fatality index has improved significantly from 50% to 60% to approximately 30–35% 4–6. Reasons for improved survival likely include earlier diagnosis of brain aneurysms, alternatives to surgery for ruptured aneurysms, endovascular therapy for cerebral vasospasm, and dedicated neurointensive care units for the care of patients with SAH. A thorough understanding of SAH and its complications, as well as a familiarity with modern multimodality neuromonitoring technology facilitate optimal patient care. This article reviews strategies for the optimal management of SAH in the intensive care setting.

Abstract

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disease with nearly one-third of patients requiring life-long care. The worldwide incidence of this disease has remained stable, but mortality rates are improving likely due to early diagnosis, endovascular treatments, novel therapies for delayed cerebral ischemia (DCI), and dedicated neurointensive care units. The most consistently identified independent risk factors for aneurysmal SAH include female gender, hypertension, tobacco use, and heavy alcohol consumption. Large aneurysm size and posterior location increase the risk of rupture. Successful management requires a prompt and accurate diagnosis, anticipation of the natural history and complications of the disease, and prevention of further neurological injury. This article reviews the acute, early, and late strategies for critical care management of SAH including the use of new imaging modalities and modern multimodality monitoring tools. Aneurysmal rebleeding, hydrocephalus, seizures, vasospasm, and delayed neurological ischemic deficits represent major threats. Systemic complications, such as hypotension, hyponatremia, and cardiac dysfunction, can exacerbate neurological deficits and cause further damage. Early identification and treatment of these disturbances improves outcome.

Keywords

Aneurysm, subarachnoid hemorrhage, delayed cerebral ischemia, cerebral vasospasm, stroke, cerebral infarction, ICU management, hypertension