What are the steps for Advanced Cardiovascular Life Support (ACLS) in a patient experiencing cardiac arrest or a life-threatening cardiovascular emergency?

Advanced Cardiovascular Life Support (ACLS) Summary

ACLS is a systematic algorithm for managing cardiac arrest that prioritizes immediate high-quality CPR (100-120 compressions/min at 5-6 cm depth), early rhythm identification and defibrillation for shockable rhythms, IV/IO access with epinephrine every 3-5 minutes, advanced airway management, and treatment of reversible causes. 1, 2

Initial Response and Recognition

• Immediately check for responsiveness by tapping the victim's shoulder and shouting "Are you all right?" 2
• Simultaneously assess breathing and pulse within 10 seconds—look for absent breathing or only gasping while checking for a definite pulse 2, 3
• Activate the emergency response system immediately if the patient is unresponsive with no breathing or only gasping 2, 3
• Retrieve the AED and emergency equipment or send someone to get them 1

High-Quality CPR: The Foundation

Push hard, push fast, allow complete recoil, minimize interruptions. 1

• Perform chest compressions at a rate of 100-120/min 1, 2, 3
• Compress at least 2 inches (5-6 cm) deep 1, 2, 3
• Allow complete chest recoil after each compression to permit cardiac refilling 1, 2, 3
• Minimize interruptions in compressions to less than 10 seconds 2
• Perform cycles of 30 compressions to 2 breaths until an advanced airway is placed 1, 2, 3
• Change compressor every 2 minutes or sooner if fatigued 1, 2
• Avoid excessive ventilation which increases intrathoracic pressure and decreases cardiac output 4

Common Pitfall: Healthcare providers often take too long checking for a pulse, delaying compressions. Incomplete chest recoil prevents full cardiac refilling and reduces effectiveness. 3

Rhythm Check and Defibrillation

• Check rhythm every 2 minutes during the resuscitation cycle 1, 3

For Shockable Rhythms (VF/pVT):

• Deliver 1 shock immediately when VF/pVT is identified 1, 2, 3
• Use biphasic energy at manufacturer recommendation (typically 120-200 Joules initially); if unknown, use maximum available 1
• Use 360 Joules for monophasic defibrillators 1
• Resume CPR immediately for 2 minutes after the shock without pausing to check rhythm 1, 2, 3
• For breakthrough VF or hemodynamically unstable VT, give 150 mg supplemental amiodarone infusions (mixed in 100 mL D5W over 10 minutes) 1

For Non-Shockable Rhythms (PEA/Asystole):

• Resume CPR immediately for 2 minutes 1
• Focus on identifying and treating reversible causes 1, 4

Drug Therapy

Epinephrine:

• Establish IV/IO access during CPR 1, 2, 3
• Administer epinephrine 1 mg IV/IO every 3-5 minutes throughout the resuscitation 1, 2, 4
• Epinephrine remains the primary vasopressor for post-arrest hemodynamic support 4
• Avoid high-dose epinephrine as it provides no benefit over standard dosing 4

Antiarrhythmics for Refractory VF/pVT:

• Amiodarone: First dose 300 mg IV/IO bolus, second dose 150 mg 1, 5
• Lidocaine (alternative): First dose 1-1.5 mg/kg IV/IO, second dose 0.5-0.75 mg/kg 1, 6

Evidence Note: A 2023 study of 14,630 in-hospital cardiac arrests found lidocaine associated with statistically significantly higher rates of ROSC, 24-hour survival, survival to discharge, and favorable neurologic outcomes compared to amiodarone (3.3% absolute improvement in survival to discharge). 7 However, both remain acceptable per AHA guidelines. 1

Advanced Airway Management

• Place endotracheal tube or supraglottic airway when feasible without prolonged interruption of compressions 2, 4
• Confirm placement with waveform capnography 1, 2
• ETCO₂ <10 mmHg suggests inadequate CPR quality and requires improved compressions 2
• Once advanced airway is placed, provide continuous chest compressions with 1 breath every 6 seconds (10 breaths/min)—no more cycles 1, 2, 4

Recognizing Return of Spontaneous Circulation (ROSC)

• Pulse and blood pressure return 1, 4
• Abrupt sustained increase in PETCO₂ (typically ≥40 mmHg) 1, 4
• Spontaneous arterial pressure waves with intra-arterial monitoring 1, 4

Post-ROSC Care

Airway and Ventilation:

• Maintain adequate oxygenation, targeting SpO₂ 94-98% to avoid both hypoxemia and hyperoxemia 2, 4
• Maintain normocapnia by adjusting ventilation and monitoring with waveform capnography 2, 4
• Avoid hyperventilation which decreases cerebral blood flow 4

Hemodynamics:

• Support hemodynamics, maintaining MAP ≥65 mmHg with vasopressors as needed 2, 4
• Monitor blood pressure continuously 4

Cardiac Evaluation:

• Obtain 12-lead ECG immediately to identify ST-elevation MI 2, 4
• Consider urgent coronary angiography for suspected cardiac etiology, particularly with ST-elevation 2, 4

Neuroprotection:

• Initiate targeted temperature management for all patients who don't follow commands after ROSC 2, 4

Laboratory and Monitoring:

• Obtain arterial blood gases, electrolytes, glucose, complete blood count, and cardiac biomarkers 4
• Implement continuous cardiac monitoring to detect recurrent arrhythmias 4
• Monitor for and treat seizures, which are common after cardiac arrest 4

Reversible Causes: The H's and T's

Systematically evaluate and treat these potential causes throughout the resuscitation: 1, 4

• Hypovolemia: Administer IV fluids 4
• Hypoxia: Ensure adequate oxygenation 4
• Hydrogen ion (acidosis): Correct with adequate ventilation 4
• Hypo-/hyperkalemia: Check and correct electrolytes 1, 4
• Hypothermia: Warm if accidental hypothermia was the cause 1, 4
• Tension pneumothorax: Perform needle decompression if suspected 1, 4
• Tamponade (cardiac): Consider pericardiocentesis 1, 4
• Toxins: Administer specific antidotes if available (e.g., naloxone for opioid overdose) 1, 3, 4
• Thrombosis (pulmonary): Consider thrombolytics or mechanical intervention 1, 4
• Thrombosis (coronary): Evaluate for acute coronary syndrome 1, 4

Critical Technical Considerations

• Use a volumetric infusion pump for amiodarone administration 5
• Administer amiodarone through a central venous catheter when possible; concentrations >2 mg/mL require central access 5
• Use an in-line filter during amiodarone administration 5
• For infusions >1 hour, do not exceed amiodarone concentrations of 2 mg/mL unless using central venous access 5
• Administer amiodarone in glass or polyolefin bottles containing D5W for infusions exceeding 2 hours 5