What is the step-by-step management algorithm for a patient in cardiac arrest?

Adult Cardiac Arrest Management Algorithm

Immediately begin high-quality chest compressions at 100-120 compressions per minute with a depth of at least 2 inches (5 cm) as soon as cardiac arrest is recognized—this is the single most critical intervention for survival. 1

Initial Recognition and Response

• Check for responsiveness while simultaneously assessing breathing and pulse within 10 seconds. 1, 2
• Look for absent breathing or only gasping respirations—agonal gasps are common and should NOT be mistaken for normal breathing. 3
• If pulse is not definitively palpated within 10 seconds, immediately start CPR, as pulse checks are notoriously unreliable even among trained providers. 2
• Activate the emergency response system immediately and retrieve the AED/defibrillator. 1

High-Quality CPR Technique

The foundation of successful resuscitation is uninterrupted, high-quality chest compressions:

• Push hard (at least 2 inches/5 cm depth) and fast (100-120/min), allowing complete chest recoil between compressions. 1, 2
• Position compressions centered over the mid-sternum with your body weight over the middle of the chest. 4
• Minimize interruptions in compressions—any pause reduces perfusion pressure and decreases survival. 1, 3
• Change compressor every 2 minutes or sooner if fatigued to maintain compression quality. 1, 2
• Use a 30:2 compression-to-ventilation ratio until an advanced airway is placed. 1, 2
• Avoid excessive ventilation as it impedes venous return and decreases cardiac output. 3

Rhythm Assessment and Defibrillation

Check rhythm after 2 minutes of CPR with minimal interruption:

For Shockable Rhythms (VF/Pulseless VT):

• Deliver one shock immediately using biphasic defibrillator at 120-200 Joules (or manufacturer recommendation) or monophasic at 360 Joules. 1, 2
• Resume CPR immediately after shock delivery WITHOUT a pulse check, beginning with chest compressions for 2 minutes. 1
• While charging the defibrillator, continue CPR to minimize hands-off time. 1
• Repeat rhythm check every 2 minutes. 1

For Non-Shockable Rhythms (PEA/Asystole):

• Resume CPR immediately for 2 minutes and search aggressively for reversible causes. 1
• Repeat rhythm check every 2 minutes. 1

Advanced Airway Management

Once advanced providers arrive, consider endotracheal intubation or supraglottic airway:

• Use waveform capnography to confirm correct tube placement—this is mandatory. 1, 2
• After advanced airway placement, deliver 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions WITHOUT pauses for ventilation. 1, 2
• Monitor PETCO₂ continuously—values <10 mmHg indicate poor CPR quality and require immediate improvement. 1, 3

Medication Administration

Establish IV or IO access as soon as feasible without interrupting compressions:

Epinephrine:

• Administer 1 mg IV/IO every 3-5 minutes throughout the resuscitation. 1, 2

For Refractory VF/Pulseless VT:

• Amiodarone: First dose 300 mg bolus, second dose 150 mg. 1, 3
• Lidocaine (alternative): First dose 1-1.5 mg/kg, second dose 0.5-0.75 mg/kg. 1, 3

Reversible Causes (H's and T's)

Systematically search for and treat reversible causes during resuscitation:

• Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia 1, 3
• Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary), Thrombosis (coronary) 1, 3

Recognition of ROSC

Recognize return of spontaneous circulation by:

• Palpable pulse and measurable blood pressure 1, 2
• Abrupt sustained increase in PETCO₂ to ≥40 mmHg (most reliable indicator) 1, 3
• Spontaneous arterial pressure waves on invasive monitoring 1, 2

CPR Quality Monitoring

Monitor and optimize CPR quality using:

• PETCO₂ monitoring—if <10 mmHg, immediately improve compression quality 1, 3
• Arterial line monitoring—if diastolic pressure <20 mmHg, improve compression quality 1
• Real-time feedback devices can improve guideline adherence, though not proven to improve survival 4

Critical Pitfalls to Avoid

• Never delay defibrillation to place an advanced airway—early defibrillation is the only intervention proven to increase survival to discharge for VF/VT. 1
• Do not mistake agonal gasps for normal breathing—these indicate cardiac arrest. 3
• Avoid excessive ventilation rates, which decrease venous return and cardiac output. 1
• Do not perform prolonged pulse checks—if uncertain about pulse presence, resume CPR immediately. 2

Special Considerations

For bystander-administered CPR by untrained rescuers, compression-only CPR (without rescue breaths) improves survival to hospital discharge by 2.4% compared to conventional CPR with interruptions for breaths. 5 This applies specifically to telephone-guided CPR for sudden collapse of non-asphyxial etiology. 6