What are the initial steps in Advanced Cardiovascular Life Support (ACLS) for a patient in cardiac arrest?

Initial Steps in Advanced Cardiovascular Life Support (ACLS) for Cardiac Arrest

The initial steps in ACLS for a patient in cardiac arrest are to immediately verify scene safety, check responsiveness, activate the emergency response system, and begin high-quality CPR with minimal interruptions while preparing for rhythm analysis and defibrillation if indicated. 1

Immediate Actions

1. Verify scene safety
2. Check responsiveness
3. Shout for nearby help
4. Activate the emergency response system
5. Check for no breathing or only gasping and check pulse simultaneously (within 10 seconds)
6. Begin high-quality CPR if no pulse is detected

High-Quality CPR Components

• Push hard and fast: Compress at a depth of at least 2 inches (5 cm) at a rate of 100-120 compressions per minute 1
• Allow complete chest recoil after each compression
• Minimize interruptions in chest compressions (keep pauses under 10 seconds)
• Avoid excessive ventilation
• Change compressor every 2 minutes (or sooner if fatigued) to maintain quality
• Compression-to-ventilation ratio: 30:2 (before advanced airway placement) 1

Early Rhythm Analysis and Defibrillation

• Check rhythm as soon as a monitor/defibrillator is available
• If VF/pVT (shockable rhythm): Deliver one shock immediately, then resume CPR for 2 minutes 1
• If asystole/PEA (non-shockable rhythm): Continue CPR and proceed with medication administration

Medication Administration

• Establish IV/IO access as soon as possible without interrupting chest compressions
• Administer epinephrine: 1 mg IV/IO every 3-5 minutes 1
• For persistent VF/pVT: Consider antiarrhythmic medications after the second shock
  • Amiodarone: First dose 300 mg IV/IO bolus, second dose 150 mg
  • Lidocaine: First dose 1-1.5 mg/kg IV/IO, second dose 0.5-0.75 mg/kg

Advanced Airway Management

• Consider advanced airway placement after initial CPR and defibrillation attempts
• Use waveform capnography to confirm and monitor endotracheal tube placement
• After advanced airway placement: Provide 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions 1

Identify and Treat Reversible Causes

Consider and address potential reversible causes (the "H's and T's") 1:

• H's: Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia
• T's: Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary), Thrombosis (coronary)

Common Pitfalls to Avoid

• Interrupting compressions: Minimize all interruptions to less than 10 seconds
• Delayed defibrillation: Use the defibrillator as soon as it's available for shockable rhythms
• Hyperventilation: Avoid excessive ventilation which can decrease venous return
• Pulse checks: Limit to less than 10 seconds; if uncertain, resume CPR
• Protocol deviations: Studies show that deviations from ACLS protocols are associated with decreased rates of ROSC and survival to discharge 2

Signs of Return of Spontaneous Circulation (ROSC)

Monitor for 1:

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

The systematic approach outlined above maximizes the chance of survival by prioritizing the interventions that have been proven to improve outcomes: high-quality CPR and early defibrillation for shockable rhythms, followed by appropriate medication administration and addressing reversible causes.