Published data show that more than 30,000 Americans suffer from subarachnoid hemorrhage (SAH), a devastating acute neurological disease, each year. Mortality risk factors for SAH include poor clinical grade at presentation, older age, aneurysm rebleeding, large aneurysm size, and cerebral infarction from vasospasm. “There have been significant advances in the medical and surgical management of SAH as mortality rates have improved over the past 20 years,” says Stephan A. Mayer, MD, FCCM. “However, SAH continues to be a major cause of premature mortality.” Studies indicate that SAH accounts for 27 % of all stroke-related potential years of life lost before the age of 65.
For a study published Critical Care, Dr. Mayer and colleagues sought to re-evaluate the causes and mechanisms of in-hospital mortality after SAH. They studied 1,200 consecutive SAH patients who were prospectively enrolled in the Columbia University SAH Outcomes Project between July 1996 and January 2009. “We found that the in-hospital mortality for SAH was about 18% overall,” Dr. Mayer says. The largest mortality percentages were seen among patients who had a Hunt-Hess grade of 4 (24%) or 5 (71%).
The most common primary causes of death from SAH or neurological devastation leading to withdrawal of support were direct effects of:
- The primary hemorrhage: 55 %
- Aneurysm rebleeding: 17%
- Medical complications: 15%.
Brain death was declared in 42% of patients who had died in the study. About one-half of patients had do-not-resuscitate orders at the time of cardiac death and 8% died despite full support.
The study also identified several admission predictors of mortality among patients with SAH. These included age, loss of consciousness at ictus, admission Glasgow Coma Scale score, large aneurysm size, Acute Physiology and Chronic Health Evaluation II physiologic subscore, and Modified Fisher Scale score. Several hospital complications further increased the risk of dying, including rebleeding, global cerebral edema, hypernatremia, clinical signs of brain stem herniation, hypotension of less than 90 mm Hg treated with pressors, pulmonary edema, myocardial ischemia, and hepatic failure. Conversely, delayed cerebral ischemia from vasospasm did not predict mortality.
Dr. Mayer says the findings on SAH mortality may serve as useful benchmark for evaluating and comparing quality of care. “Our findings demonstrate that it is possible to reduce mortality from this devastating disease and that we shouldn’t give up on patients because they have a high Hunt-Hess grade,” he says. “Strategies that aim to minimize early brain injury and aneurysm rebleeding are promising to further help reduce mortality after SAH. More widespread adoption of the use of antifibrinolytic therapy is also important to preventing rebleeding and should be given to patients early in their treatment course.” In addition, the study notes that efforts are warranted to offer SAH patients preventive therapies and treatments for cardiovascular complications.