What are the latest Advanced Cardiovascular Life Support (ACLS) guidelines for managing adult cardiac arrest?

ACLS Update: Latest Guidelines for Adult Cardiac Arrest Management

The 2025 American Heart Association Guidelines represent the most current evidence-based approach to adult cardiac arrest, building upon the foundational 2020 recommendations with critical refinements in vasopressor timing, advanced techniques, and post-arrest care. 1

Core Resuscitation Algorithm

The fundamental approach to cardiac arrest remains centered on immediate, high-quality CPR with minimal interruptions:

High-Quality CPR Parameters 2

• Compression depth: At least 2 inches (5 cm), but avoid exceeding 2.4 inches (6 cm)
• Compression rate: 100-120 per minute
• Complete chest recoil between compressions
• Minimize interruptions in compressions
• Avoid excessive ventilation
• Change compressors every 2 minutes or sooner if fatigued

Initial Response Sequence 2

Upon recognizing cardiac arrest, simultaneously activate emergency response and initiate CPR immediately—do not delay for any reason. In the modern era of mobile devices, both actions occur concurrently rather than sequentially.

Rhythm-Specific Management

Shockable Rhythms (VF/pVT) 2

Defibrillation Strategy:

• Biphasic: 120-200 Joules initially (follow manufacturer recommendations); if unknown, use maximum available
• Monophasic: 360 Joules
• Subsequent shocks should be equivalent or higher doses
• Resume CPR immediately after shock delivery for 2 minutes before rhythm check
• Early defibrillation with concurrent high-quality CPR is critical to survival 2

Antiarrhythmic Therapy for Refractory VF/pVT:

• Amiodarone: 300 mg IV/IO bolus first dose, then 150 mg second dose
• Lidocaine (alternative): 1-1.5 mg/kg first dose, then 0.5-0.75 mg/kg second dose

Non-Shockable Rhythms (PEA/Asystole)

Focus on high-quality CPR, early epinephrine administration, and identifying reversible causes.

Pharmacologic Management

Vasopressor Therapy 3

Epinephrine remains the cornerstone vasopressor:

• Dose: 1 mg IV/IO every 3-5 minutes
• Timing for non-shockable rhythms: Administer as soon as feasible after arrest recognition
• Timing for shockable rhythms: After initial defibrillation attempts (typically after 2nd shock)
• Epinephrine improves survival, particularly in non-shockable rhythms 2

Vasopressin: May be considered but offers no advantage over epinephrine alone 3

Vascular Access 4

Critical update: Attempt IV access first before resorting to IO access. New evidence suggests uncertainty about IO route efficacy compared to IV. If IV attempts are unsuccessful or not feasible, then proceed to IO access.

Advanced Airway Management 2

Options:

• Endotracheal intubation
• Supraglottic advanced airway

Once advanced airway is placed:

• Ventilation rate: 1 breath every 6 seconds (10 breaths/minute)
• Continue uninterrupted chest compressions (no pause for ventilations)
• Mandatory waveform capnography to confirm and monitor tube placement
• PETCO₂ ≥40 mmHg suggests return of spontaneous circulation (ROSC)

Reversible Causes: The H's and T's 2

Systematically evaluate and treat:

H's:

• Hypovolemia
• Hypoxia
• Hydrogen ion (acidosis)
• Hypo-/hyperkalemia
• Hypothermia

T's:

• Tension pneumothorax
• Tamponade (cardiac)
• Toxins
• Thrombosis (pulmonary)
• Thrombosis (coronary)

Recognition of ROSC 2

Signs indicating return of circulation:

• Palpable pulse and measurable blood pressure
• Abrupt sustained increase in PETCO₂ (typically ≥40 mmHg)—most reliable indicator
• Spontaneous arterial pressure waves on invasive monitoring

Post-Cardiac Arrest Care 2

Immediate priorities after ROSC:

1. Targeted Temperature Management: Initiate promptly for all patients who do not follow commands to optimize neurological outcomes 2

2. Hemodynamic Optimization: Maintain adequate perfusion pressure

3. Coronary Angiography: Consider for suspected cardiac etiology 5

4. Seizure Management: Monitor and treat appropriately 5

5. Neuroprognostication: Delay until adequate time has passed (typically ≥72 hours) to avoid premature withdrawal of care in patients with recovery potential 2

Special Considerations

Double Sequential Defibrillation 4

For refractory VF/pVT, double sequential defibrillation (two defibrillators delivering near-simultaneous shocks) may be considered, though evidence remains limited and its usefulness is not yet established.

Opioid-Associated Cardiac Arrest 2

The opioid epidemic has increased overdose-related arrests. Mainstay of care remains activation of EMS and high-quality CPR. Administer naloxone per protocol if opioid overdose is suspected.

Critical Pitfalls to Avoid

1. Excessive compression depth (>2.4 inches) can cause injury without improving outcomes
2. Excessive ventilation increases intrathoracic pressure and decreases venous return
3. Prolonged pulse checks interrupt compressions—limit to <10 seconds
4. Premature termination of resuscitation without considering reversible causes
5. Delayed epinephrine in non-shockable rhythms—administer as soon as feasible
6. Choosing IO over IV as first-line access—attempt IV first

Quality Metrics

Monitor CPR quality continuously:

• Compression depth and rate feedback
• Compression fraction (goal: >80% of arrest time)
• PETCO₂ monitoring (sustained values <10 mmHg suggest poor CPR quality)

The 2025 guidelines emphasize that cardiac arrest management is not one-size-fits-all—specialized management is necessary for specific conditions including electrolyte abnormalities, pregnancy, post-cardiac surgery, and toxicologic emergencies 2, 4. However, the core principles of immediate high-quality CPR, early defibrillation for shockable rhythms, appropriate vasopressor therapy, and comprehensive post-arrest care remain universal.