A 58-year-old man collapses suddenly in the Emergency Department waiting area shortly after reporting dizziness and nausea. The resuscitation team has been called. On arrival, he is supine on the floor, pale, diaphoretic, and unresponsive to verbal command and central painful stimulus. He has intermittent gasping respiratory effort with no normal breathing pattern. A central pulse is not reliably palpable within 10 seconds. The resuscitation trolley is being brought to the area.

According to the Adult Advanced Life Support algorithm, what is the most appropriate immediate response?