What are the five steps of the adult chain of survival for cardiac arrest?

Adult Chain of Survival: Five Critical Links

The adult chain of survival consists of five sequential, time-sensitive links that must be rapidly executed to maximize survival and neurological recovery from cardiac arrest: (1) Recognition and activation of emergency response, (2) Immediate high-quality CPR, (3) Rapid defibrillation, (4) Advanced life support and post-cardiac arrest care, and (5) Recovery and rehabilitation. 1

The Five Links Explained

Link 1: Recognition and Activation of Emergency Response

• Immediate recognition that cardiac arrest has occurred (unresponsive patient with no normal breathing or only gasping)
• Simultaneous activation of the emergency response system (calling 9-1-1) while beginning resuscitation 1
• For laypersons: Use mobile phones to activate EMS without leaving the victim's side 2
• Dispatcher recognition and provision of CPR instructions to callers is increasingly emphasized 3

Link 2: Immediate High-Quality CPR

• Chest compressions are the most critical component and must be started immediately 1
• High-quality technique includes:
  • Adequate compression depth (at least 2 inches/5 cm) 1
  • Adequate rate (100-120 compressions per minute) 1
  • Full chest recoil between compressions 2
  • Minimizing interruptions in compressions 2
• For trained rescuers: Provide both compressions and rescue breaths (30:2 ratio) 1
• For untrained lay rescuers: Compression-only CPR is acceptable 1

Critical point: Only 39.2% of adults currently receive layperson-initiated CPR, representing a major gap in the chain 1

Link 3: Rapid Defibrillation

• Early defibrillation with concurrent high-quality CPR is critical to survival when cardiac arrest is caused by ventricular fibrillation or pulseless ventricular tachycardia 1
• Use of automated external defibrillators (AEDs) by the public occurred in only 11.9% of cases, indicating substantial room for improvement 1
• Defibrillation is the single most effective intervention and, when combined with early CPR, can result in survival rates approaching 50% for witnessed VF arrests 2

Link 4: Advanced Life Support and Post-Cardiac Arrest Care

• Administration of epinephrine with concurrent high-quality CPR improves survival, particularly in nonshockable rhythms 1
• Advanced airway management and intravenous medications 1
• Post-cardiac arrest care is a critical component requiring comprehensive, structured, multidisciplinary management 1
• Includes:
  • Targeted temperature management for all patients who don't follow commands after return of spontaneous circulation 1
  • Coronary angiography when indicated 4
  • Careful neurological prognostication to avoid premature withdrawal of care in patients with recovery potential 1

Evidence strength: Implementation of this link as a regionalized system (transporting to specialized centers) showed adjusted odds ratio of 7.8 for favorable neurological outcome 5

Link 5: Recovery and Rehabilitation

• This link was added in 2020 to acknowledge the enormous recovery journey after acute treatment 1
• Encompasses both short-term and long-term multimodal rehabilitation 1
• Includes recovery expectations and survivorship plans addressing:
  • Treatment surveillance
  • Physical, cognitive, and emotional rehabilitation
  • Family support needs 4
• Must be provided to cardiac arrest survivors and caregivers at hospital discharge to optimize transitions of care 1

Key Distinctions: Out-of-Hospital vs In-Hospital

The chain differs slightly based on setting:

Out-of-Hospital Chain 1:

• Depends heavily on community engagement and bystander response
• Requires public recognition, 9-1-1 activation, and citizen CPR
• EMS provides continuation and transport

In-Hospital Chain 1:

• Emphasizes surveillance and prevention as initial components
• Involves multidisciplinary teams responding immediately
• Generally achieves superior outcomes (25.8% survival vs 10.4% for OHCA) due to reduced delays 1

Common Pitfalls to Avoid

1. Delayed activation: Rescuers must activate emergency response immediately and simultaneously with starting CPR, not sequentially 1
2. Poor CPR quality: Inadequate compression depth, excessive interruptions, and hyperventilation all reduce survival 2
3. Delayed defibrillation: Every minute without defibrillation decreases survival; AED application must be immediate 1
4. Premature prognostication: Accurate neurological assessment requires time and multimodal evaluation to avoid withdrawing care from recoverable patients 1
5. Neglecting recovery planning: Discharge without comprehensive rehabilitation plans compromises long-term functional outcomes 1

The strength of this chain depends on each link being optimized and rapidly connected to the next—weakness in any single link dramatically reduces overall survival. 1