Cardiac arrest is an ‘arrest’ in the activity of the heart - the heart has stopped beating
Common Causes
Cardiac
- Acute myocardial infarction
- Severe electrolyte disturbances (K⁺, Mg²⁺)
- Drug toxicity (e.g., digoxin, cocaine)
Non-Cardiac
Reversible Causes – The H’s & T’s
H’s
- Hypovolemia
- Hypoxia
- Hydrogen ion (acidosis)
- Hypo-/Hyperkalemia
- Hypothermia
T’s
- Tension pneumothorax
- Tamponade (cardiac)
- Toxins/poisoning/drugs
- Thrombosis (coronary)
- Thrombosis (pulmonary)
Recognizable Features
- No breathing or only gasping (agonal respiration)
- No pulse (carotid or femoral)
Management (ACLS Algorithm)
Immediate Actions
- Check responsiveness and breathing
- Call for help/activate EMS
- Start CPR:
- Allow full recoil, minimize interruptions
- Ratio: 30 compressions : 2 breaths (if no advanced airway)
- Attach AED/defibrillator as soon as available
Shockable Rhythms (VF/pVT)
- Resume CPR for 2 min after shock
- Epinephrine 1 mg IV every 3–5 min
- Amiodarone 300 mg IV (first dose), then 150 mg (second dose)
- Consider reversible causes
Non-Shockable Rhythms (Asystole/PEA)
- Continue high-quality CPR
- Epinephrine 1 mg IV every 3–5 min
- No defibrillation indicated
- Identify and treat H’s and T’s
Return of Spontaneous Circulation (ROSC)
Post-resuscitation care
- Maintain oxygenation (SpO₂ 92–98%)
- Stabilize blood pressure (MAP ≥65 mmHg)
- Consider targeted temperature management (32–36°C for 24 h)
- Continuous cardiac monitoring