When to Start CPR
Start CPR immediately when a patient is unresponsive with no normal breathing (or only gasping) and no definite pulse felt within 10 seconds. 1, 2
Recognition Algorithm for Healthcare Providers
Simultaneous assessment (within 10 seconds maximum): 3, 1
- Check responsiveness by shouting and tapping the victim 1, 2
- Look for absent or abnormal breathing (only gasping counts as absent breathing) 3, 1
- Palpate for a pulse simultaneously—do not spend more than 10 seconds on this 3, 1
If uncertain about pulse presence after 10 seconds, start CPR immediately rather than continuing to search for a pulse, as delays worsen outcomes and pulse checks are unreliable. 3, 1
Decision Points Based on Assessment
Scenario 1: No pulse (or uncertain) + No normal breathing
Action: Start CPR immediately with chest compressions first 3, 1, 2
Scenario 2: Definite pulse present + No normal breathing
Action: Provide rescue breathing only (1 breath every 6 seconds in adults, 1 breath every 2-3 seconds in children), and recheck pulse every 2 minutes. 3, 2
Scenario 3: Pediatric-specific threshold
Action: Start CPR if heart rate <60 bpm AND signs of poor perfusion are present (mottled/pale skin, weak pulses, altered mental status). 4, 3
Critical Timing Considerations
Do not delay CPR beyond 10 seconds for pulse assessment. Healthcare providers have only 78% accuracy in detecting pulses, and prolonged pulse checks (averaging 20 seconds in practice) significantly delay life-saving compressions. 3, 5
Early CPR initiation (within 1.9 minutes) improves survival two-fold to three-fold compared to delayed CPR (5.7 minutes). The benefit exists within a narrow 4-6 minute window from collapse. 6
For Lay Rescuers (Simplified Criteria)
Lay rescuers should begin CPR for any victim who is unresponsive and not breathing normally—do not check for a pulse. 3 Pulse checks are unreliable for untrained rescuers (only 47% accuracy at 5 seconds), so the presence of unresponsiveness plus absent/abnormal breathing is sufficient. 3
Common Pitfalls to Avoid
- Do not perform prolonged pulse checks beyond 10 seconds—if uncertain, start compressions. 1, 2
- Do not mistake agonal gasping for normal breathing—gasping indicates cardiac arrest and requires immediate CPR. 3, 1
- Do not delay compressions to obtain history or establish IV access—chest compressions are the immediate priority. 1
- In pediatric bradycardia, do not start CPR if perfusion is adequate (heart rate <60 but good color, strong pulses)—provide rescue breathing only and reassess frequently. 4