Basic Life Support and Cardiopulmonary Resuscitation
What the exam tests
This domain tests recognition of cardiac arrest, activation of the emergency response system, high-quality chest compressions, rescue breathing ratio, AED use, and pediatric differences.
Core rules
- Check responsiveness and breathing while checking the pulse for no more than 10 seconds. Agonal gasps are not normal breathing.
- Activate EMS and send for an AED. Start compressions immediately.
- Adult compressions: center of chest, 100–120 per minute, 5–6 cm deep, full recoil, minimize interruptions to under 10 seconds.
- Single-rescuer adult ratio is 30 compressions to 2 breaths. Use an AED as soon as available and follow its prompts.
- For children and infants, use two fingers or one hand as appropriate, compress at least one-third of chest depth, and use 15:2 with two rescuers or 30:2 with one rescuer if trained.
Worked example
An adult worker collapses in a warehouse. The first aider checks response and breathing, finds no normal breathing, and calls for the AED. A second responder begins compressions at 110 per minute while the first aider opens the airway and gives two breaths every 30 compressions. The AED arrives, pads are applied, and everyone clears before the shock. Compressions resume immediately after the shock.
Traps that cost marks
- Delivering breaths before starting compressions.
- Compressing too fast, too slow, or too shallow.
- Leaning on the chest and preventing full recoil.
- Waiting for the AED before starting CPR.
- Interrupting compressions for long pulse checks.
Key points
- Start compressions immediately when breathing is absent or abnormal.
- Adult rate is 100–120/min with 5–6 cm depth and full recoil.
- Use 30:2 for single-rescuer adult CPR.
- Apply the AED as soon as it arrives and follow prompts.
- Pediatric CPR uses proportionally deeper compressions and 15:2 with two rescuers.