Researchers at the Medical College of Wisconsin are studying which type of advanced airway method is better for Emergency Medical Services (EMS) to use on a person having cardiac arrest. Cardiac Arrest is a major public health problem. There are about 300,000 cardiac arrest cases in the U.S. every year and only about 10% of people survive. This study will compare two commonly used Advanced Airway methods for adults having a cardiac arrest. The study will begin August 2016 in southeast Wisconsin and include Milwaukee County Emergency Medical Services and Flight for Life. Because cardiac arrest is an emergency, this study meets the U.S. Food and Drug Administration guidelines for exception from informed consent under emergency circumstances. Opting out of this study: Anyone who does not wish to be enrolled in this study may opt-out by wearing an opt-out bracelet or necklace. EMS providers are trained to not enroll anyone who is wearing this bracelet or necklace. An opt-out bracelet or necklace may be requested free of charge by either calling the Resuscitation Research Center at (414) 805-6493 or email at RRC@mcw.edu. For information about the study or if you do not want to be included, please call Dr. M. Riccardo Colella at (414)-805-6493, email at RRC@mcw.edu, or visit the website at www.mcw.edu/ROCPART.