What is the algorithm for managing cardiac arrest in an adult patient?

Adult Cardiac Arrest Management Algorithm

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

Initial Recognition and Response

Step 1: Rapid Assessment (Within 10 Seconds)

• Check for responsiveness while simultaneously assessing breathing and pulse 1
• Look for absent or only gasping respirations (agonal gasps are common and should not be mistaken for normal breathing) 1
• Pulse check should not exceed 10 seconds - healthcare providers frequently take too long and have difficulty determining pulse presence accurately 1, 2
• If pulse is not definitively palpated within 10 seconds, immediately start CPR 1

Critical Pitfall: Pulse checks are notoriously unreliable even among trained providers, with studies showing only 55% specificity for detecting pulselessness and median delays of 24 seconds. 2 When in doubt, start compressions - the risk of harm from compressions in a non-arrested patient is minimal (only 1.7% bone fractures, 0.3% rhabdomyolysis, no visceral injuries). 1

Step 2: Immediate Activation

• Shout for help and activate emergency response system first (for lone rescuers) 1
• Send someone to retrieve AED/defibrillator and emergency equipment 1
• If multiple rescuers present, one begins CPR immediately while others activate and retrieve equipment 1

Basic Life Support Algorithm

High-Quality CPR Technique

Chest compressions are the foundation of resuscitation and should never be delayed. 1

• Compression depth: At least 2 inches (5 cm) 1
• Compression rate: 100-120 per minute 1
• Allow complete chest recoil between compressions 1
• Minimize interruptions - any pause reduces perfusion pressure 1
• Change compressor every 2 minutes or sooner if fatigued 1
• Compression-to-ventilation ratio: 30:2 until advanced airway placed 1

Defibrillation Protocol

When AED/defibrillator arrives, apply pads without interrupting compressions if possible, then immediately analyze rhythm. 1

For Shockable Rhythms (VF/Pulseless VT):

• Deliver one shock immediately 1
  • Biphasic: 120-200 Joules (or manufacturer recommendation; use maximum if unknown) 1
  • Monophasic: 360 Joules 1
• Resume CPR immediately for 2 minutes without pulse check 1
• Recheck rhythm after 2 minutes and repeat cycle 1
• Over 80% of successful defibrillations occur within first three shocks 3

For Non-Shockable Rhythms (Asystole/PEA):

• Continue CPR immediately for 2 minutes 1
• Recheck rhythm after 2 minutes 1

Advanced Life Support Components

Airway Management

Once advanced providers arrive:

• Consider endotracheal intubation or supraglottic airway 1
• Use waveform capnography to confirm tube placement (PETCO2 monitoring) 1
• After advanced airway placement: deliver 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions (no pauses for ventilation) 1

Critical Point: Avoid excessive ventilation, which impairs venous return and reduces cardiac output. 1

Vascular Access and Medications

Establish IV or IO access as soon as feasible without interrupting compressions. 1

Epinephrine Dosing:

• 1 mg IV/IO every 3-5 minutes throughout resuscitation 1
• Continue until ROSC or termination of efforts 1

Antiarrhythmics for Refractory VF/Pulseless VT:

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

Reversible Causes Assessment

Simultaneously search for and treat reversible causes (H's and T's): 1, 4

The 4 H's:

• Hypovolemia
• Hypoxia
• Hydrogen ion (acidosis)
• Hypo-/Hyperkalemia
• Hypothermia

The 4 T's:

• Tension pneumothorax
• Tamponade (cardiac)
• Toxins
• Thrombosis (pulmonary or coronary)

Point-of-care ultrasound can identify reversible causes such as tamponade, tension pneumothorax, or massive PE during pulse checks. 4

Return of Spontaneous Circulation (ROSC) Indicators

Recognize ROSC by: 1

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

When ROSC achieved, immediately transition to post-cardiac arrest care. 1

Special Circumstances

Pregnancy

• Immediate defibrillation takes priority over all other interventions including perimortem cesarean section 3
• Perform manual left lateral uterine displacement to relieve aortocaval compression 3
• Position compressions slightly higher on sternum to account for elevated diaphragm 3
• Use standard ACLS defibrillation doses without modification 3
• Consider perimortem cesarean section only if ROSC not achieved within 4-5 minutes 3

Duration of Resuscitation Efforts

• VF/pulseless VT arrests should be resuscitated for at least 45 minutes, especially if patient is gasping during CPR 5
• Asystole/PEA with pupillary light reflex present should receive at least 45 minutes of ALS 5
• Asystole/PEA without pupillary response and inefficient compressions have virtually no chance of survival and may warrant earlier termination 5

Quality Metrics During Resuscitation

Continuously monitor and optimize: 1

• Compression depth and rate
• Chest recoil completeness
• Minimization of interruptions (goal: <10% hands-off time)
• PETCO2 values (sustained <10 mmHg suggests poor quality CPR or futility)
• Team coordination and role clarity

The evidence strongly supports that early defibrillation combined with high-quality CPR can achieve survival rates up to 30% for witnessed VF arrests, making these the highest priority interventions. 6