Anoxic Brain Injury Presenting as Pseudosubarachnoid Hemorrhage in the Medical Intensive Care Unit

Anoxic encephalopathy is frequently encountered in the medical intensive care unit (ICU). Cerebral edema as a result of anoxic brain injury can result in increased attenuation in the basal cisterns and subarachnoid spaces on computerized tomography (CT) scans of the head. These findings can mimic those seen in acute subarachnoid hemorrhage (SAH) and are referred to as pseudosubarachnoid hemorrhage (pseudo-SAH). Pseudo-SAH is a diagnosis critical care physicians should be aware of as they treat and evaluate their patients with presumed SAH, which is a medical emergency. This lack of awareness could have important clinical implications on outcomes and impact management decisions if patients with anoxic brain injury are inappropriately treated for SAH. We describe three patients who presented to the hospital with anoxic brain injury. Subsequent CT head suggested SAH, which was subsequently proven to be pseudo-SAH.