Global Cerebral Edema After Subarachnoid Hemorrhage

TLDR

Cerebral edema seen on CT is common after subarachnoid hemorrhage and is thought to arise from inflammatory or circulatory mechanisms. The study aimed to determine the frequency, causes, and outcome impact of early and delayed global cerebral edema after SAH. The authors retrospectively analyzed 374 SAH patients, assessing global edema on admission and follow‑up CT scans and using multivariate analysis to identify predictors and evaluate 3‑month outcomes with the modified Rankin Scale. Global edema occurred in 20% of patients, was independently associated with death or severe disability at 3 months, and was predicted by loss of consciousness at ictus, aneurysm size > 10 mm, vasopressor use, higher SAH sum scores, NIHSS, and older age, indicating that strategies to reduce edema may improve outcomes.

Abstract

Cerebral edema visualized by CT is often seen after subarachnoid hemorrhage (SAH). Inflammatory or circulatory mechanisms have been postulated to explain this radiographic observation after SAH. We sought to determine the frequency, causes, and impact on outcome of early and delayed global cerebral edema after SAH.We evaluated the presence of global edema on admission and follow-up CT scans in 374 SAH patients admitted within 5 days of onset to our Neurological Intensive Care Unit between July 1996 and February 2001. Using multivariate analysis, we identified predictors of global cerebral edema and evaluated the impact of global edema on outcome 3 months after onset with the modified Rankin Scale.Global edema was present on admission CT scans in 8% (n=29) and developed secondarily in 12% (n=44) of the patients. Global edema on admission was predicted by loss of consciousness at ictus and increasing Hunt-Hess grade. Delayed global edema was predicted by aneurysm size >10 mm, loss of consciousness at ictus, use of vasopressors, and increased SAH sum scores. Thirty-seven percent (n=137) of the patients were dead or severely disabled (modified Rankin Scale 4 to 6) at 3 months. Death or severe disability was predicted by any global edema, aneurysm size >10 mm, loss of consciousness at ictus, increased National Institutes of Health Stroke Scale scores, and older age.Global edema is an independent risk factor for mortality and poor outcome after SAH. Loss of consciousness, which may reflect ictal cerebral circulatory arrest, is a risk factor for admission global edema, and vasopressor-induced hypertension is associated with the development of delayed global edema. Critical care management strategies that minimize edema formation after SAH may improve outcome.