ID Stroke Signs and Symptoms Activate EMS. Important Prehospital Interventions. Symptoms Indicate possible Ischemia or infarction. EMS and Prehospital Care Monitor support ABC’s. AHA ACLS Adult Suspected Stroke Algorithm. The perfect precourse assessment to help you pass your ACLS megacode. Important Schematic representation of ALS recommendations for use of advanced airways during CPR. ALS indicates advanced life support; CPR, cardiopulmonary resuscitation; and EMS, emergency medical services.