What are the steps for cardiopulmonary resuscitation (CPR) in an adult with cardiac arrest?

Cardiopulmonary Resuscitation (CPR) for Adult Cardiac Arrest

Immediately begin high-quality chest compressions at 100-120 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, 2

Initial Recognition and Activation

• Check for responsiveness while simultaneously assessing breathing and pulse within 10 seconds 1, 2
• Look for absent breathing or only gasping respirations (agonal gasps should not be mistaken for normal breathing) 1, 2
• If pulse is not definitively palpated within 10 seconds, start CPR immediately—pulse checks are unreliable even among trained providers 1, 2
• Activate emergency response system first and get an AED/defibrillator immediately 1

High-Quality CPR Technique

Perform cycles of 30 compressions followed by 2 breaths until an advanced airway is placed. 1, 2

Compression Quality Parameters:

• Depth: At least 2 inches (5 cm) 1, 2
• Rate: 100-120 compressions per minute 1, 2
• Recoil: Allow complete chest recoil between compressions 1, 2
• Minimize interruptions: Any pause reduces coronary and cerebral perfusion pressure 1, 3, 2
• Change compressors every 2 minutes or sooner if fatigued to maintain quality 1, 3, 2

Defibrillation Protocol

Use the AED as soon as it arrives. 1

• For shockable rhythms (VF/pulseless VT), deliver one shock immediately 1, 2
• Resume CPR immediately for 2 minutes without checking pulse or rhythm after shock delivery 1, 3, 2
• Use biphasic defibrillator at 120-200 Joules (or manufacturer recommendation) or monophasic at 360 Joules 1, 2
• Check rhythm every 2 minutes only when prompted by AED 1, 3

Critical pitfall: Do not check pulse or rhythm immediately after shock—this wastes time when compressions should be ongoing. 3

Advanced Life Support (When Available)

Airway Management:

• Place endotracheal tube or supraglottic airway device 1, 2, 4
• Confirm placement with waveform capnography (PETCO2 monitoring) 1, 2, 4
• Once advanced airway is placed, give 1 breath every 6 seconds (10 breaths/minute) with continuous chest compressions—no pauses for ventilation 1, 2

Medication Administration:

• Establish IV or IO access without interrupting compressions 1, 2
• Epinephrine 1 mg IV/IO every 3-5 minutes throughout resuscitation 1, 2
• For refractory VF/pulseless VT: Amiodarone 300 mg bolus (second dose 150 mg) or Lidocaine 1-1.5 mg/kg (second dose 0.5-0.75 mg/kg) 1

Rhythm and Pulse Checks

Check rhythm every 2 minutes during CPR cycles. 1, 3

• Keep rhythm checks brief (less than 10 seconds) 3
• Only check pulse if an organized rhythm is observed—if any doubt exists, resume compressions immediately 3
• If waveform capnography shows sudden sustained increase in PETCO2 (≥40 mmHg), this may indicate ROSC and warrants immediate rhythm/pulse check 3, 4

Recognition of Return of Spontaneous Circulation (ROSC)

ROSC is indicated by: 1, 2, 4

• Palpable pulse and measurable blood pressure 1, 2, 4
• Abrupt sustained increase in PETCO2 ≥40 mmHg 1, 2, 4
• Spontaneous arterial pressure waves on invasive monitoring 1, 2, 4

Reversible Causes to Address

Search for and treat the H's and T's: 1, 4

• H's: Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia 1, 4
• T's: Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary), Thrombosis (coronary) 1, 4

Post-ROSC Care

Immediately after achieving ROSC: 4

• Obtain 12-lead ECG to identify ST-elevation requiring emergent coronary intervention 4
• Target mean arterial pressure ≥65 mmHg (preferably >80 mmHg) 4
• Titrate oxygen to achieve saturation 92-98% (avoid hyperoxia) 4
• Ventilate at 10-12 breaths/minute targeting PETCO2 35-40 mmHg (avoid hyperventilation) 4
• Consider targeted temperature management (32-36°C) for comatose patients 4

Key evidence: The 2020 American Heart Association guidelines provide the most current framework for adult cardiac arrest management, emphasizing that chest compressions are the most critical component and should be provided promptly with minimal interruptions. 1, 2