Early ED management certainly should focus on airway assessment, emergent CT scanning, continuous caridac monitoring, and serial neurologic exams
A few other pearls regarding management:
Volume management - maintain euvolemia with an isotonic crystalloid fluid
Anticonvulsants - routine use is associated with cognitive impairment and is not recommended
Steroids - once used to reduce meningeal irritation, however, there is no convincing evidence of a beneficial effect. As such, corticosteroids are no longer recommended.
Rebleeding - risk of rebleeding is highest in first 24 hours after initial SAH. Definitive prevention is done by repair via surgery or endovascular coiling. A large, prospective study found outcome was better with endovascular coiling.
Diringer MN. Managment of aneurysmal subarachnoid hemorrhage. Crit Care Med 2009;37:432-40.