What are the key interventions in Advanced Cardiovascular Life Support (ACLS) for cardiac arrest?

ACLS Pearls: Key Interventions for Cardiac Arrest

High-quality CPR with minimal interruptions and early defibrillation are the cornerstones of ACLS that actually improve survival—prioritize these over everything else, including medication administration. 1, 2

Foundation: The Primary Survey

Immediate Recognition and Response

• Check responsiveness, breathing, and pulse simultaneously within 10 seconds—if no pulse, start CPR immediately without delay 3
• Activate emergency response and attach monitor/defibrillator pads as soon as available to identify rhythm 3
• The key to successful ACLS is prompt initiation of correct BLS—survival will be poor if this foundation is inadequate 4

High-Quality CPR: The Non-Negotiables

Compression Technique

• Push hard (at least 2 inches/5 cm depth) and fast (100-120 compressions/minute) with complete chest recoil between compressions 2, 3
• Minimize interruptions—keep all pauses under 10 seconds, including during rhythm checks and defibrillation 2, 3
• Rotate compressors every 2 minutes to prevent fatigue and maintain quality 2

Ventilation Strategy

• Before advanced airway: 30 compressions to 2 ventilations 3
• After advanced airway placement: continuous compressions with 1 breath every 6 seconds (10 breaths/minute)—avoid excessive ventilation 2, 3
• Use waveform capnography to confirm airway placement and monitor CPR quality (target PETCO₂ >10 mmHg) 2, 3

Rhythm-Specific Management

Shockable Rhythms (VF/pVT)

• Deliver one shock immediately when defibrillator available—do not delay for medications 2, 3
• Use biphasic 120-200J (manufacturer recommendation) or monophasic 360J 2, 3
• Resume CPR immediately after shock for 2 minutes before rhythm reassessment 3
• Administer epinephrine 1 mg IV/IO every 3-5 minutes 2, 3

Refractory VF/pVT (After 2-3 Shocks)

• Consider either amiodarone OR lidocaine—both are acceptable first-line antiarrhythmics with no clear superiority for long-term survival or neurological outcome 1
• Amiodarone: 300 mg IV/IO first dose, then 150 mg second dose 2
• Lidocaine: 1-1.5 mg/kg IV/IO first dose, then 0.5-0.75 mg/kg second dose 2
• Critical caveat: Antiarrhythmic drugs facilitate defibrillation but have NOT been shown to improve survival to discharge or neurological outcomes—never delay CPR or defibrillation to establish vascular access 1

Medication Pearls

Epinephrine

• Give 1 mg IV/IO every 3-5 minutes throughout the arrest 2, 3
• Important warning: Monitor for hypertension, pulmonary edema, cardiac arrhythmias, and tissue necrosis with extravasation 5
• Paradoxically, observational data shows epinephrine use associated with decreased resuscitation success in some studies, though this likely reflects confounding by indication 6

Antiarrhythmic Evidence Nuance

• The ROC-ALPS trial (largest study) showed amiodarone and lidocaine improved survival to hospital admission compared to placebo, but neither improved survival to discharge or neurological outcomes 1
• Earlier ARREST and ALIVE trials showed amiodarone improved hospital admission rates but were not powered for discharge outcomes 1
• Bottom line: Use either amiodarone or lidocaine for shock-refractory VF/pVT, but understand their benefit is limited to facilitating defibrillation, not improving ultimate survival 1

Monitoring During Resuscitation

Quantitative Waveform Capnography

• Use to confirm advanced airway placement and monitor CPR quality 2, 3
• Target PETCO₂ >10 mmHg during CPR 2
• Critical pitfall: Do NOT use ETCO₂ alone to predict mortality or terminate resuscitation 2, 3

Intra-arterial Pressure (if available)

• Target relaxation phase (diastolic) pressure >20 mmHg for adequate coronary perfusion 2

Special Circumstances

Reversible Causes: The 4 Hs and 4 Ts

• Hypoxia, Hypovolemia, Hyper/hypokalemia, Hypothermia 7
• Thrombosis (coronary/pulmonary), Tamponade, Tension pneumothorax, Toxins 7
• Consider point-of-care ultrasound to identify reversible causes 7

Pregnancy

• Perform lateral uterine displacement to relieve aortocaval compression 2, 3

Hypothermia

• Continue resuscitation until patient is rewarmed 3

ECPR Consideration

• Consider extracorporeal CPR for select patients when conventional CPR failing, particularly witnessed arrests with shockable rhythms 3, 7

Common Pitfalls to Avoid

• Never delay defibrillation while preparing medications—shock first, drugs later 2
• Avoid excessive ventilation—this impedes venous return and decreases cardiac output 2
• Don't interrupt compressions for advanced airway placement—intubate during ongoing CPR 3
• Avoid prolonged pulse checks—if not definitely felt within 10 seconds, resume CPR 2
• Don't rely on ACLS drugs to "save the day"—no standard ACLS medication has proven benefit for ultimate survival in randomized trials 6
• Prevent extravasation of epinephrine—can cause tissue necrosis; treat with phentolamine 5-10 mg infiltrated locally 5

Post-ROSC Care

Immediate Priorities

• Maintain oxygenation avoiding both hypoxia and hyperoxia 3
• Maintain hemodynamic stability 3
• Consider emergent coronary angiography for ST-elevation or ongoing ischemia 3
• Implement therapeutic hypothermia for comatose patients 8