Compressions early beat everything else

The single largest determinant of outcome, and it is time.

For cardiac arrest the evidence on what matters is unusually clear: immediate recognition, immediate chest compressions, and defibrillation as early as possible. Survival falls sharply with each minute of delay, which makes the organisational question a logistics question.

Recognition is where lay responders hesitate, particularly with agonal breathing, which looks like breathing and is not. Training covers it and confidence to act on it is what practice provides.

The organisational contribution is proximity of the defibrillator and knowledge of where it is. A device three minutes away is a substantially different asset from one thirty seconds away, and the placement decision is usually made on cost and tidiness rather than on retrieval time.

Locked cabinets, alarmed rooms and after-hours access arrangements regularly make devices unavailable at exactly the times coverage is thinnest. That is worth checking physically rather than on a plan.

Modern devices instruct the user aloud and are designed to be usable by an untrained person, which is worth communicating widely, because reluctance to touch one is common and costs time.

The other thing worth rehearsing is the handover. Paramedics arriving need a concise account: what happened, when, what was done, and anything known about the person. Responders under stress deliver that badly unless they have practised it, and the quality of the handover affects the care given.