Chain of Survival and High-Quality CPR
The Chain of Survival describes the sequence of actions that most improve survival from cardiac arrest, and it differs between adults and children. For adults, the out-of-hospital chain is: recognition and activation of emergency response, high-quality CPR, rapid defibrillation, advanced resuscitation, post-cardiac-arrest care, and recovery. For pediatric arrest, the emphasis shifts toward prevention: prevention of arrest, early high-quality CPR, rapid activation of emergency response, advanced resuscitation, post-arrest care, and recovery. A key trap is mixing the order of the adult and pediatric chains, or forgetting that prevention is the first pediatric link. Another trap is confusing the in-hospital chain with the out-of-hospital chain.
High-Quality CPR
Every link depends on the quality of compressions. The core parameters a candidate must know:
- Rate: 100–120 compressions per minute.
- Depth: at least 2 inches (5 cm) for adults; at least one third the depth of the chest for children (about 2 inches) and infants (about 1.5 inches).
- Full recoil: allow the chest to return to its normal position between compressions.
- Minimize interruptions: keep pauses under 10 seconds.
- Compression fraction: aim for at least 60% of resuscitation time spent compressing.
- Ventilation: avoid excessive ventilation; give just enough volume to make the chest rise.
- Switch compressors: rotate about every 2 minutes to limit fatigue.
A common question trap is a stem describing compressions that are too fast or too shallow but otherwise correct-those distractors are wrong. Another trap is the phrase "fully deflate" or "lean on the chest," which is the opposite of full recoil.
Rule of thumb: Push hard, push fast, allow full recoil, minimize interruptions. If a stem asks what most improves survival, the answer is high-quality CPR with minimal interruptions.