What is the treatment for cardiac arrest?

Treatment of Cardiac Arrest

Immediately begin high-quality chest compressions at a rate of 100-120 per minute with a depth of at least 2 inches (5 cm), allowing complete chest recoil between compressions, and minimize any interruptions in compressions—this is the foundation of cardiac arrest management. 1, 2

Immediate Recognition and Activation

• Check for responsiveness by tapping the victim and shouting; if unresponsive with no breathing or only gasping (agonal breaths), assume cardiac arrest 3
• Activate the emergency response system immediately 3
• Dispatcher-assisted CPR should be provided for all suspected out-of-hospital cardiac arrests, with dispatchers trained to recognize unconsciousness with abnormal breathing 1

High-Quality CPR Technique

• Compress the chest to a depth of 5 cm (2 inches) at a rate of 100-120 compressions per minute 1, 2
• Allow complete chest recoil after each compression without leaning on the chest 1, 2
• Switch compressors every 2 minutes to prevent fatigue and maintain compression quality 2, 4
• Minimize interruptions in chest compressions; aim for a chest compression fraction of at least 60% (ideally higher) 1
• For lay rescuers: perform compression-only CPR if untrained, or 30:2 compression-to-ventilation ratio if trained 1, 3
• For healthcare providers with basic airway: use 30:2 compression-to-ventilation ratio, keeping interruptions for ventilation under 10 seconds 1
• Once an advanced airway is placed: provide continuous chest compressions with 10 breaths per minute (1 breath every 6 seconds) 2, 4, 3

Defibrillation for Shockable Rhythms

• For ventricular fibrillation or pulseless ventricular tachycardia, defibrillate as quickly as possible 2, 3
• Use biphasic defibrillators at 120-200 joules per manufacturer recommendation, or 360 joules for monophasic devices 2
• Resume CPR immediately after shock delivery without pausing to check pulse 2, 3
• Administer epinephrine after the third shock for shockable rhythms (prioritize defibrillation and CPR first) 1
• Consider amiodarone 300 mg IV bolus for shock-refractory ventricular fibrillation/pulseless ventricular tachycardia, with a second dose of 150 mg if needed 1, 4, 5
• Lidocaine is an alternative antiarrhythmic if amiodarone is unavailable 1

Important caveat: Two recent randomized trials showed that performing 90 seconds to 3 minutes of CPR before defibrillation did not improve outcomes compared to immediate defibrillation, so prioritize rapid defibrillation over delayed shock 1, 6

Vasopressor Administration

• Administer epinephrine 1 mg IV/IO every 3-5 minutes during cardiac arrest 1, 4
• For non-shockable rhythms (asystole, pulseless electrical activity), give epinephrine as soon as IV/IO access is obtained 1
• Earlier epinephrine administration is associated with improved return of spontaneous circulation, particularly for non-shockable rhythms 1
• Standard-dose epinephrine is recommended; high-dose epinephrine has not shown improvement in survival or neurological outcomes 1
• Vasopressin combined with methylprednisolone after the first epinephrine dose may increase return of spontaneous circulation in in-hospital cardiac arrest, though survival benefit remains uncertain 1

Advanced Airway Management

• Either bag-mask ventilation, supraglottic airway, or endotracheal intubation are acceptable airway strategies 1
• Providers should master one advanced airway technique and have a backup strategy 1
• Use continuous waveform capnography to confirm proper tube placement and monitor CPR quality 1
• Avoid excessive ventilation (more than 10 breaths per minute), as hyperventilation decreases cardiac output and cerebral blood flow 1, 2
• Target ETCO2 of 35-40 mmHg or PaCO2 of 40-45 mmHg once return of spontaneous circulation is achieved 1

Critical consideration: Recent evidence shows no clear superiority of endotracheal intubation over supraglottic airways or bag-mask ventilation for overall survival, so choose the airway device based on provider skill and clinical context 1

Reversible Causes (H's and T's)

Systematically evaluate and treat reversible causes 1, 2:

H's:

• Hypovolemia
• Hypoxia
• Hydrogen ions (acidosis)
• Hypo/hyperkalemia
• Hypothermia

T's:

• Tension pneumothorax

• Cardiac tamponade

• Toxins

• Thrombosis (pulmonary embolism)

• Thrombosis (coronary—acute myocardial infarction)

• Correct electrolyte abnormalities (potassium, magnesium, calcium) before and during resuscitation, as these can prolong QTc and increase risk of torsades de pointes 1, 4

• Sodium bicarbonate is NOT recommended for routine use in undifferentiated cardiac arrest and may worsen outcomes; reserve for specific situations like severe hyperkalemia or tricyclic antidepressant overdose 1

Post-Cardiac Arrest Care

Once return of spontaneous circulation is achieved:

• Transport immediately to a hospital with percutaneous coronary intervention capability and comprehensive post-cardiac arrest care 1, 2
• Obtain a 12-lead ECG as soon as possible to identify ST-elevation myocardial infarction 1
• Activate the cardiac catheterization laboratory for ST-elevation or high suspicion of acute coronary syndrome, even in comatose patients 1, 7
• Initiate targeted temperature management at 32-34°C for 24 hours in all comatose survivors 1, 2, 4
• Avoid hyperthermia, which worsens neurological outcomes 4
• Maintain mean arterial pressure >80 mmHg or systolic blood pressure >100 mmHg to ensure adequate cerebral and coronary perfusion 4
• Titrate inspired oxygen to achieve arterial oxygen saturation of 94% to avoid oxygen toxicity (100% oxygen may be used initially during resuscitation) 1
• Avoid hyperventilation; maintain ETCO2 35-40 mmHg 1
• Elevate head of bed 30 degrees if tolerated to reduce cerebral edema and aspiration risk 1

Extracorporeal CPR (ECPR)

• Consider ECPR for patients with witnessed cardiac arrest from potentially reversible causes when conventional CPR is failing 1, 2
• ECPR should only be implemented in centers with established programs, experienced teams, and adequate resources 1, 2
• Maintain ECMO flow at 3-4 L/min after cannulation with mixed venous oxygen saturation target above 66% 2

Neurological Prognostication

• Do not prognosticate neurological outcome before 72 hours post-return of spontaneous circulation, especially when therapeutic hypothermia is used 4
• Use a multimodal approach including clinical examination, neurophysiology, imaging, and biomarkers after 72 hours 4

Common pitfall: Premature withdrawal of care based on early clinical examination can result in inappropriate cessation of treatment in patients who might otherwise recover with favorable neurological outcomes 4, 7