A nurse is caring for a client who has heart failure and respiratory arrest. Which of the following actions should the nurse take first?

Choice A rationale Establishing an open airway is the absolute first action in managing respiratory arrest, following the principles of Basic Life Support (BLS) or Advanced Cardiovascular Life Support (ACLS). Oxygenation is critical for tissue perfusion, especially to the brain and myocardium. Without a patent airway, ventilation and oxygen delivery are impossible, rapidly leading to irreversible organ damage and death. Choice B rationale Auscultating for breath sounds is a rapid assessment technique, but it is secondary to ensuring an open airway. While it confirms air movement, the primary, life-saving intervention is correcting the obstruction or position that prevents air entry. Airway patency must be addressed before full assessment of ventilation effectiveness in a respiratory arrest. Choice C rationale Establishing IV access is a critical step in resuscitation for administering emergency medications and fluids (e.g., epinephrine, antidysrhythmics). However, circulation and medication administration are secondary to establishing an airway and breathing. Oxygenation is the most immediate life requirement, per the "C-A-B" (Circulation, Airway, Breathing) or Airway-Breathing-Circulation (ABC) priority systems. Choice D rationale Feeling for a carotid pulse determines if the client is in cardiac arrest, dictating the need for chest compressions. However, in respiratory arrest with a pulse, the priority remains the airway and breathing. Furthermore, in current BLS/ACLS guidelines, establishing circulation (checking for pulse) is the first step in an unresponsive patient, but establishing an airway follows immediately, and is the key intervention for respiratory arrest.