What are the new Advanced Cardiovascular Life Support (ACLS) guidelines for cardiac arrest management?

2020 American Heart Association Advanced Cardiovascular Life Support (ACLS) Guidelines for Cardiac Arrest Management

The 2020 American Heart Association guidelines for ACLS emphasize high-quality CPR as the foundation of cardiac arrest management, with chest compressions at a depth of at least 2 inches (5 cm) and a rate of 100-120/min as the cornerstone of successful resuscitation. 1

Core Components of High-Quality CPR

• Push hard (at least 2 inches/5 cm) and fast (100-120/min) while allowing complete chest recoil 1
• Minimize interruptions in compressions, with pauses kept as brief as possible 1
• Avoid excessive ventilation, which can impair cardiac output 1
• Rotate compressors every 2 minutes or sooner if fatigued to maintain compression quality 1
• Without advanced airway: maintain 30:2 compression-ventilation ratio 1
• With advanced airway: provide continuous compressions with 1 breath every 6 seconds (10 breaths/min) 1

Cardiac Arrest Rhythm-Based Management

Shockable Rhythms (VF/pVT)

• Immediate defibrillation for witnessed arrest 1
• For unwitnessed arrest, provide 2 minutes of CPR before first shock 1
• Antiarrhythmic medications for shock-refractory VF/pVT:
  • Either amiodarone (first dose: 300 mg bolus; second dose: 150 mg) OR lidocaine (first dose: 1-1.5 mg/kg; second dose: 0.5-0.75 mg/kg) can be used 1
  • The 2018 update no longer favors amiodarone over lidocaine as first-line therapy 1, 2

Non-shockable Rhythms (PEA/Asystole)

• Focus on high-quality CPR and identifying/treating reversible causes 1
• Early epinephrine administration is recommended 1
• Atropine is no longer recommended for routine use in PEA/asystole 3

Vascular Access and Medication Administration

• Intravenous (IV) access should be attempted first for drug administration 1
• Intraosseous (IO) access may be considered if IV attempts are unsuccessful or not feasible 1

Advanced Airway Management

• Endotracheal intubation or supraglottic airway placement should not cause prolonged interruptions in chest compressions 1
• Waveform capnography is recommended to confirm and monitor advanced airway placement 1
• PETCO₂ < 10 mm Hg suggests need to improve CPR quality 1
• Abrupt sustained increase in PETCO₂ (typically ≥40 mm Hg) may indicate return of spontaneous circulation 1

Monitoring CPR Quality

• Quantitative waveform capnography 1
• Arterial diastolic pressure (relaxation phase) < 20 mm Hg indicates need to improve CPR quality 1
• Continuous assessment of chest compression rate, depth, and recoil 1

Post-Cardiac Arrest Care

• The 2020 guidelines add a fifth link to the Adult Chain of Survival: "post-cardiac arrest care" 1, 3
• Consider therapeutic hypothermia (32-34°C for 12-24 hours) if the patient remains comatose after resuscitation 4
• For patients with VF/pVT arrest, prophylactic lidocaine may be considered in specific circumstances (such as during EMS transport) to prevent recurrence 1

Important Considerations and Pitfalls

• Double sequential defibrillation for refractory shockable rhythm has not been established as effective (Class 2b, LOE C-LD) 1
• No antiarrhythmic drug has been definitively shown to increase long-term survival or improve neurological outcomes 1
• The optimal sequence of ACLS interventions (vasopressors, antiarrhythmic drugs, timing of medication in relation to shock) remains unknown and may need to be adapted based on provider numbers and skill levels 1
• Recent evidence suggests lidocaine may be associated with higher rates of ROSC, 24-hour survival, survival to discharge, and favorable neurologic outcomes compared to amiodarone for in-hospital VF/VT cardiac arrest 2