Subarachnoid hemorrhage grading scales: a systematic review

Numerous systems are reported for grading the clinical condition of patients following subarachnoid hemorrhage (SAH). The literature was reviewed for articles pertaining to the grading of such patients, including publications on the Hunt and Hess Scale, Fisher Scale, Glasgow Coma Score (GCS), and World Federation of Neurological Surgeons Scale. This article reviews the advantages and limitations of these scales as well as more recent proposals for other grading systems based on these scales with or without addition of other factors known to be prognostic for outcome after SAH. There remain substantial deficits in the literature regarding grading of patients with SAH. Most grading scales were derived retrospectively, and the intra- and interobserver variability has seldom been assessed. Inclusion of additional factors increases the complexity of the scale, possibly making it less likely to be adopted for routine usage and increasing (only marginally in some cases) the ability to predict prognosis. Until further data are available, it is recommended that publications on patients with SAH report at least the admission GCS as well as factors commonly known to influence prognosis, such as age, pre-existing hypertension, the amount of blood present on admission computed tomography, time of admission after SAH, aneurysm location and size, presence of intracerebral or intraventricular hemorrhage, and blood pressure at admission.