Jessica Nave, MD, vice president for middle revenue cycle at Emory Healthcare and assistant professor of medicine in Emory’s division of hospital medicine, both in Atlanta, summarized the updated 2025 American Heart Association Guidelines for Advanced Cardiac Life Support (ACLS), explaining the studies that informed those updates and offering evidence-based best practices for inpatient cardiac arrest management. Given the breadth of the guidelines (more than 760 recommendations), she focused on changes most likely to impact frontline clinical decision making in hospital medicine. Dr. Nave reviewed key practice‑relevant updates, emphasizing evidence‑based resuscitation, system‑level teamwork, and post‑arrest care.
Cardiac arrest is an ongoing public health crisis. Out‑of‑hospital cardiac arrest occurs at a rate of more than 80 per 100,000 people annually, with survival to hospital discharge remaining about 10%. In‑hospital cardiac arrest is more common than many clinicians appreciate, occurring in about one of every 100 hospitalized patients. While return of spontaneous circulation (ROSC) after in‑hospital arrest now approaches 70%, survival to discharge remains stagnant at around 24%. Encouragingly, among survivors, 85% achieve favorable neurological outcomes, reinforcing the importance of strategies that protect brain function, not merely restoring a pulse.
Dr. Nave highlighted several notable updates outside traditional ACLS that warrant awareness. In newborn resuscitation, the two‑finger chest compression technique has been removed due to inadequate compression depth; the two‑thumb encircling hands technique is now standard. In opioid overdose response, the guidelines strongly promote public access to naloxone and legal protections for lay rescuers. Another key change reverses pandemic‑era guidance for adult resuscitation, and adding rescue breaths to chest compressions rather than compression‑only cardiopulmonary resuscitation (CPR) is once again recommended.
Moving into adult ACLS, she noted that one major update concerns unstable atrial fibrillation and atrial flutter. When patients are hypotensive or unstable, immediate cardioversion remains the standard approach. However, the 2025 guidelines recommend higher initial energy levels (200 joules or more, rather than 120 joules) for cardioversion, particularly for atrial fibrillation and flutter, because lower initial shocks were associated with lower success rates and a higher risk of degeneration into ventricular fibrillation. Algorithms are otherwise largely unchanged for stable tachycardia.
For stable wide‑complex tachycardia, another important update is the removal of sotalol from recommended antiarrhythmic infusions. Evidence demonstrated no added benefit compared with procainamide or amiodarone, along with slower infusion times. As a result, procainamide and amiodarone are now the preferred agents when expert consultation is not immediately available.
Dr. Nave then discussed ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The guidelines now emphasize the concept of “persistent VF,” defined as VF or pulseless VT that continues after three or more defibrillation attempts. Within this category, clinicians may encounter either refractory VF (never terminating) or recurrent VF (briefly terminating but recurring).
For refractory VF, emerging data suggest potential benefit from defibrillation strategies beyond standard anterior‑lateral pad placement. These include vector change (switching pads to an anterior‑posterior position) and dual sequential external defibrillation using two defibrillators. Despite promising results, the American Heart Association (AHA) categorized these strategies as Class IIb recommendations due to limited and underpowered data. As such, they are not broadly endorsed but may be considered in experienced settings once standard measures are optimized. Dr. Nave emphasized that the AHA guidelines are intentionally conservative and designed for broad applicability, whereas international guidelines are somewhat more permissive.
Dr. Nave noted that point‑of‑care ultrasound (POCUS) is a supportive but limited tool during active resuscitation. The guidelines caution that ultrasound must never interrupt chest compressions or delay defibrillation. Its role during arrest is restricted to identifying potentially reversible causes such as cardiac tamponade, tension pneumothorax, massive pulmonary embolism, or profound hypovolemia, and only when performed quickly by an experienced operator. Importantly, ultrasound should not be used as the sole criterion to terminate resuscitation. In contrast, ultrasound becomes highly valuable after ROSC, allowing rapid bedside evaluation of cardiac function, volume status, and residual shock etiology.
Dr. Nave noted that the 2025 guidelines promote a more protocolized, intensive-care‑level approach beginning immediately after ROSC. Temperature management has shifted from strict hypothermia targets to a broader goal of fever prevention, allowing temperatures from 32°C to 37.5°C. Early coronary angiography is now more selectively recommended, reserved for patients with suspected ischemic etiology rather than performed universally. Neuroprognostication is delayed until at least 72 hours post‑arrest and must rely on a multimodal approach including clinical assessment, imaging, electrophysiology, and biomarkers.
Hemodynamic goals remain focused on maintaining mean arterial pressure greater than 65 mmHg, with greater attention to perfusion markers such as lactate clearance and consideration of mechanical circulatory support when indicated. Oxygenation targets now explicitly avoid both hypoxia and hyperoxia, favoring saturations between 90% and 98%.
Another major change involves vascular access during cardiac arrest. Intravenous access remains first‑line, but if IV access cannot be rapidly obtained, intraosseous access should be used to avoid delays in epinephrine administration, especially in non‑shockable rhythms such as pulseless electrical activity. Central venous lines are no longer recommended during active resuscitation, and endotracheal drug administration has been completely removed from ACLS due to unreliable absorption.
Dr. Nave noted the growing role of end‑tidal CO₂ monitoring during CPR, including during bag‑mask ventilation. End‑tidal CO₂ provides an objective measurement of compression quality, early detection of ROSC, and prognostic information. Persistently low values despite high‑quality CPR correlate strongly with poor outcomes, though the guidelines emphasize that this parameter should never be used alone to guide termination decisions.
Termination of resuscitation in the hospital remains a clinical judgment. Clinicians should consider rhythm evolution, duration of arrest, response to interventions, reversible causes, physiologic markers, and the patient’s baseline health and goals of care. Family presence during resuscitation is encouraged when feasible, as it can improve communication, understanding, and emotional closure for both families and care teams.
Team-based practices such as clear leadership, closed-loop communication, crowd control during codes, and structured debriefings are critical. These practices improve not only clinical outcomes but also healthcare worker resilience and system-wide quality improvement.
Key Takeaways
- Treatment pearls: For cardioversion, higher first shock energy (200 joules or more) matters. The tachycardia algorithm has been streamlined, and sotalol has been removed from the stable wide-QRS pathway. For persistent VF or pulseless VT, focus on fundamentals: high-quality CPR, changing pad vector from anterior-lateral to anterior-posterior, and cautious, selective use of dual sequential external defibrillation, which remains a Class IIb recommendation. Ultrasound is helpful only when it does not interrupt CPR and is targeted at identifying reversible causes. Access priorities are very clear: IV is first line, intraosseous is appropriate when IV is delayed, and endotracheal tube drug delivery has been removed from the guidelines.
- Judgment matters: In the hospital, termination of resuscitation decisions is a clinical and ethical judgment; emergency medical services rules do not apply. Post-ROSC care is more structured than ever. Temperature targets are now 32°C to 37.5°C, oxygenation has clear goals, etiologic evaluation is protocolized, and neurologic prognostication is delayed and multimodal.
- Successful ACLS depends on shared mental models across hospital and intensive care unit teams, consistent practice, and coordinated implementation.
Dr. Massart
Ms. Hall
Dr. Massart is an associate professor in the division of hospital medicine and associate vice chair of faculty development in the department of medicine at Emory University School of Medicine in Atlanta. Ms. Hall is the senior medical writer in the division of hospital medicine at Emory University School of Medicine in Atlanta.