The cardiopulmonary resuscitation (CPR) protocol consists of a set of maneuvers aimed at reversing cardiopulmonary arrest (CPA), a condition in which there is an imminent risk of death, and thus saving lives. This protocol is reviewed and updated regularly by the American Heart Association, an organization committed to scientific production on cardiopulmonary arrest (CPR). It is therefore essential that professionals who deal with this emergency keep their knowledge up to date, otherwise many lives would be lost. This book is based on a survey that aimed to identify first responders' knowledge of this protocol. The research was carried out with first responders at a Mobile Emergency Care Service (SAMU). The book contains notes on how up-to-date the knowledge of professional rescuers is on the current CPR guidelines and theoretical and practical considerations regarding the management of CPR. It is aimed at students and health professionals, as well as the general population, since anyone can be involved in situations where there is an imminent risk of death.