Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation Using an Impedance Valve

The first treatment involves using a device called the Impedance Threshold Device (ITD). The ITD is a small hard plastic device about the size of a fist that is attached to the face mask or airway tube used during CPR (cardiopulmonary resuscitation). The ITD provides increased blood flow back to the heart during chest compressions until the heart starts beating on its own again. The other treatment involves the amount of CPR given before the emergency medical services (EMS) providers first look at the heart rhythm to determine if a shock is needed. A person would receive either about 30 seconds of chest compressions or about 3 minutes of compressions before checking the heart rhythm. Giving some compressions before checking the heart rhythm increases the blood being circulated to the body. Researchers do not know how many compressions before the rhythm check are necessary to save more lives. Depending on the circumstances of the cardiac arrest a person may receive only one of these treatments or both of these treatments. The purpose of the research study is to determine if more people live when either the real ITD is used or if additional CPR is given before looking at the heart rhythm the first time. This study is being conducted in 9 different areas throughout the United States and Canada by the Resuscitation Outcomes Consortium (ROC). About 15,000 patients will be enrolled in this research study.