Final answer:
Perform CPR while waiting for the AED to arrive and be ready to use.
Step-by-step explanation:
When a 56-year-old man is found to be pulseless and apneic, it indicates a cardiac arrest. In such a situation, immediate action is required. While your partner gets the Automated External Defibrillator (AED) from the ambulance, you should start performing cardiopulmonary resuscitation (CPR).
CPR involves manually compressing the chest to push blood within the heart into the pulmonary and systemic circuits, which is crucial to keep the brain oxygenated. By applying pressure with the flat portion of one hand on the sternum, you should perform chest compressions at least 5 cm deep and at a rate of 100 compressions per minute. High-quality chest compressions are the priority at this stage.
Once the AED is available, it can be used to deliver an electrical shock to the heart to correct abnormal heart rhythm. AEDs are designed to be used by laypersons, and they automatically diagnose the patient's heart condition and apply the shock with appropriate energy and waveform.