CPR: Recognition, Compressions, and Rescue Breaths
When to Start CPR
The core recognition rule: if a person is unresponsive and not breathing normally (including gasping), start CPR and get an AED. Gasping is a common trap - it is not normal breathing and does not mean you should wait.
Compressions
Adult compressions are delivered on the lower half of the breastbone (center of the chest), at least 2 inches (5 cm) deep, at a rate of 100–120 per minute, with full recoil between compressions. Minimize interruptions. For a single rescuer trained in conventional CPR, the compression-to-breath ratio is 30:2. Hands-only CPR (continuous compressions, no breaths) is appropriate for untrained rescuers or when you are unwilling or unable to give breaths.
Rescue Breaths
Open the airway with a head-tilt/chin-lift, give each breath over about 1 second, and watch for chest rise. If the chest does not rise, reposition the head and try again. Avoid excessive volume - over-ventilation is a frequent distractor answer.
Child and Infant Differences
Children and infants receive the same 30:2 ratio for a single rescuer, but compressions are shallower (about one third the depth of the chest) and may be given with one hand (child) or two fingers (infant). For an unresponsive child or infant who collapsed suddenly and is not breathing, give about 2 minutes of CPR before leaving to call for help if you are alone and have no phone.
Worked Example
A coworker collapses and is gasping. Step order: check responsiveness and breathing, shout for help and send someone to call emergency services and fetch an AED, begin 30 compressions at 100–120/min, then 2 breaths, and apply the AED as soon as it arrives.