What is the first step in the ACLS algorithm upon discovering a cardiac arrest?

Starting chest compressions is the first step in the Advanced Cardiovascular Life Support (ACLS) algorithm upon discovering a cardiac arrest. This action is critical because high-quality chest compressions are essential for maintaining blood flow to the heart and brain until more advanced interventions can be administered. Immediately beginning chest compressions enhances the chances of a positive outcome by promoting circulation during the critical moments of cardiac arrest.

While calling for help is an important component of the response to a cardiac arrest, it follows the initiation of compressions, as immediate action is necessary to preserve life. Defibrillation is crucial for treating certain types of cardiac arrest, specifically ventricular fibrillation or pulseless ventricular tachycardia, but it occurs after compressions have begun and the defibrillator is available. Medications also play a role in the advanced stages of treatment but are not the immediate priority upon discovering a cardiac arrest. Therefore, the correct focus is on initiating chest compressions first to maximize survival chances.