Advanced Cardiovascular Life Support (ACLS) Protocol
The ACLS protocol is a systematic approach to managing cardiac arrest that emphasizes high-quality CPR, early defibrillation for shockable rhythms, and addressing reversible causes, with the foundation of successful resuscitation being continuous, high-quality chest compressions at a rate of 100-120/min and a depth of at least 2 inches (5 cm). 1
Initial Assessment and Basic Life Support
- Recognition of Cardiac Arrest: Unresponsiveness with no breathing or abnormal breathing
- Activate Emergency Response System: Call for help and request defibrillator
- Begin High-Quality CPR immediately:
- Push hard (at least 2 inches/5 cm) and fast (100-120/min)
- Allow complete chest recoil after each compression
- Minimize interruptions in compressions (< 10 seconds)
- Avoid excessive ventilation
- Rotate compressor every 2 minutes to prevent fatigue 1
- For no advanced airway: 30:2 compression-ventilation ratio
- After advanced airway placement: continuous compressions with 1 breath every 6 seconds (10 breaths/min) 1
Rhythm Assessment and Management
Shockable Rhythms (VF/Pulseless VT)
- Defibrillation: Deliver one shock as soon as defibrillator is available
- Resume CPR immediately for 2 minutes
- Establish IV/IO access
- Epinephrine: 1 mg IV/IO every 3-5 minutes
- Antiarrhythmic after second shock:
- Reassess rhythm every 2 minutes; deliver shock if VF/VT persists
Non-Shockable Rhythms (Asystole/PEA)
- Continue CPR for 2 minutes
- Establish IV/IO access
- Epinephrine: 1 mg IV/IO every 3-5 minutes 2
- Reassess rhythm every 2 minutes
- Consider advanced airway placement
- Identify and treat reversible causes 2
Monitoring CPR Quality
- Quantitative waveform capnography:
- If PETCO2 < 10 mm Hg, attempt to improve CPR quality
- Abrupt sustained increase in PETCO2 (typically > 40 mm Hg) may indicate ROSC 1
- Intra-arterial pressure monitoring (when available):
- If relaxation phase (diastolic) pressure < 20 mm Hg, attempt to improve CPR quality 1
Advanced Airway Management
- Endotracheal intubation or supraglottic airway
- Confirm placement with waveform capnography
- After placement: Give 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions 1
Reversible Causes (H's and T's)
- H's: Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/Hyperkalemia, Hypothermia
- T's: Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary), Thrombosis (coronary) 2
Return of Spontaneous Circulation (ROSC)
Signs of ROSC:
- Pulse and blood pressure
- Abrupt sustained increase in PETCO2 (typically > 40 mm Hg)
- Spontaneous arterial pressure waves with intra-arterial monitoring 1
Special Considerations
Pregnancy
- For pregnant patients with uterus at or above umbilicus:
- Perform continuous manual left uterine displacement (LUD) during resuscitation
- Place patient supine for chest compressions
- Consider early perimortem cesarean delivery if no ROSC within 4 minutes 1
Post-Cardiac Surgery
- Consider early chest reopening and internal cardiac massage within 5 minutes if unresponsive to initial resuscitation efforts 3
Post-Resuscitation Care
- Optimize ventilation and oxygenation
- 12-lead ECG to identify STEMI or other cardiac pathology
- Targeted temperature management for comatose patients
- Hemodynamic optimization
- Treat the underlying cause of cardiac arrest
Common Pitfalls to Avoid
- Interrupting chest compressions for prolonged periods
- Hyperventilation which increases intrathoracic pressure and decreases venous return
- Delayed defibrillation for shockable rhythms
- Failure to identify and treat reversible causes
- Ineffective chest compressions (inadequate rate, depth, or recoil)
- Delayed administration of epinephrine in non-shockable rhythms
The 2018 ACLS guidelines update notes that CPR and defibrillation remain the only therapies associated with improved survival in patients with VF/pVT cardiac arrest, with antiarrhythmic drugs showing benefits primarily in short-term outcomes rather than long-term survival 1.