2025 AHA ACLS Guidelines - Key Updates

1. Unified Chain of Survival

• The 2020 guidelines had four separate chains of survival (adult OHCA, adult IHCA, pediatric OHCA, pediatric IHCA).
• 2025 change: A single, unified Chain of Survival framework now applies to all ages and settings (OHCA and IHCA combined).
• Each link now has a dedicated visual symbol; the symbol for high-quality CPR now includes lungs alongside chest compressions, reinforcing the role of breaths, particularly in pediatric and opioid-related arrests.

2. High-Quality CPR - Core Parameters (Unchanged but Reinforced)

3. Defibrillation - New Recommendations

• Standard defibrillation: Early defibrillation remains top priority for shockable rhythms (VF/pVT). Start at 200 J biphasic (or max energy).
• Double Sequential Defibrillation (DSED): The 2025 guidelines state the usefulness of DSED for adults with persistent VF/pVT after 3 or more consecutive shocks has not been established - this is an important update given the DOSE VF trial.
• Vector Change Defibrillation (VCD): A new 2025 recommendation - usefulness of vector change defibrillation for refractory VF/pVT also has not been established (new literature added this as a distinct consideration).
• Resume CPR immediately after each shock, even if ROSC appears to occur.

4. Pharmacology - Updated Guidance

Epinephrine

• Shockable rhythms (VF/pVT): Give epinephrine after the first failed defibrillation attempt, then every 3-5 minutes.
• Non-shockable rhythms (PEA/asystole): Administer epinephrine as early as possible - 2025 explicitly labels early timing as critical (the 2020 guideline did not emphasize this as strongly).
• Dose: 1 mg IV/IO every 3-5 minutes (unchanged).

Antiarrhythmics

• Amiodarone or lidocaine for shock-refractory VF/pVT - used after failed shocks + epinephrine.
• Amiodarone dose: 300 mg IV/IO first dose, then 150 mg if needed.
• Lidocaine alternative: 1-1.5 mg/kg IV/IO.
• Vasopressin has been removed from the cardiac arrest algorithm in prior updates and this remains in 2025.

Opioid-Related Cardiac Arrest

• Expanded emphasis on rapid naloxone administration.
• New recommendation for public access to opioid emergency kits.

5. Airway Management

• No single airway modality is superior: BVM, supraglottic airway (SGA), and endotracheal intubation (ETI) are all acceptable during CPR - evidence shows similar patient outcomes.
• Do not interrupt compressions to place an airway.
• Once advanced airway is in place: continuous compressions + 1 breath every 6 seconds (10 breaths/min).
• Waveform capnography (EtCO2) now plays a central role in monitoring CPR quality - low EtCO2 signals poor compressions or prolonged arrest; target EtCO2 >10-20 mmHg during resuscitation.
• Do not use EtCO2 alone to terminate resuscitation (2025 explicit caution).

6. Monitoring During CPR

• EtCO2 monitoring recommended throughout.
• Arterial diastolic pressure monitoring (when arterial line available): target ≥25 mmHg (infants), ≥30 mmHg (children).
• Point-of-care ultrasound (POCUS): now has explicit guideline support for use in ALS to identify reversible causes.

7. Reversible Causes - The 5 H's and 5 T's

8. Post-Cardiac Arrest Care (ROSC)

• Targeted temperature management (TTM): Preventing fever (>37.7°C) remains recommended. The benefit of active cooling to 32-36°C is less certain after the TTM2 trial - 2025 guidelines reflect this uncertainty.
• Coronary angiography: No longer routinely recommended immediately post-arrest without ST-elevation - selective approach based on clinical features.
• Hemodynamic optimization: Target MAP ≥65 mmHg, avoid hypoxia and hypocapnia.
• Neuroprognostication: Multimodal approach; do not make decisions earlier than 72 hours post-ROSC.

9. Team Dynamics and Human Factors

• Stronger focus on closed-loop communication.
• Enhanced guidance for the team leader role.
• Clinical debriefing: Both immediate ("hot") and delayed ("cold") debriefing after CPR events is now explicitly recommended.
• New recommendations on resuscitation team composition (in-hospital and out-of-hospital).

10. Terminology Updates

• "Rescue breaths" is no longer used - replaced with "breaths" (for assisted breathing during CPR).
• "Ventilation" is reserved for mechanical respiratory support by professionals.

ACLS Universal Algorithm Overview

Key References

• The full 2025 Adult ALS guidelines: Wigginton et al., Circulation 2025, PMID 41122884 (Part 9 of the 2025 AHA CPR/ECC guidelines)
• AHA 2025 Guidelines Highlights PDF - concise summary from the AHA
• Tintinalli's Emergency Medicine: A Comprehensive Study Guide, Chapter 24 (ACLS framework)