Chapter 06. Advanced life support algorithm

 Key Principles of ALS Algorithm

The ALS algorithm follows a standardised process to:
✔ Ensure early recognition and intervention for cardiac arrest.
✔ Provide high-quality CPR to maintain circulation.
✔ Deliver rapid defibrillation for shockable rhythms.
✔ Administer appropriate medications and treat reversible causes.
✔ Optimise post-resuscitation care after ROSC (Return of Spontaneous Circulation).

The ALS process involves two main pathways based on rhythm classification:
1. Shockable rhythms – Ventricular Fibrillation (VF) and Pulseless Ventricular Tachycardia (pVT).
2. Non-shockable rhythms – Asystole and Pulseless Electrical Activity (PEA).

 Initial Approach to Cardiac Arrest

 Recognising Cardiac Arrest

• Assess for signs of life (unresponsiveness, abnormal or absent breathing).
• If cardiac arrest is suspected, call the resuscitation team (2222 in UK hospitals).
• Check for normal breathing and a carotid pulse (≤10 seconds).
• If no pulse or abnormal breathing → Start CPR immediately.

 Performing High-Quality CPR

• Chest compressions: Rate of 100-120 per minute, depth of 5-6 cm.
• Compression-to-ventilation ratio: 30:2 (until advanced airway is placed).
• Minimise interruptions in chest compressions (pauses should be <5 seconds).
• Use waveform capnography to monitor CPR quality.

 Attaching a Defibrillator & Rhythm Assessment

• Attach self-adhesive defibrillation pads as soon as possible.
• Determine the cardiac rhythm:
   Shockable (VF/pVT) – Immediate defibrillation required.
   Non-shockable (Asystole/PEA) – Continue CPR and give adrenaline.

🔹 Management of Shockable Rhythms (VF/pVT)

 1. Defibrillation Strategy

• Deliver first shock at 150-200J (biphasic) or 360J (monophasic).
• Resume CPR immediately after the shock (do not check rhythm).
• Continue 2-minute CPR cycles before reassessing the rhythm.

 2. Drug Therapy for Shockable Rhythms

• After the 3rd shock, give:
  • Adrenaline (1 mg IV/IO, every 3-5 minutes).
  • Amiodarone (300 mg IV/IO bolus, after 3rd shock).
• After the 5th shock, give an additional 150 mg Amiodarone.

 3. Consider Reversible Causes (4 Hs & 4 Ts)

• Hypoxia, Hypovolaemia, Hypo-/Hyperkalaemia, Hypothermia.
• Thrombosis (coronary/pulmonary), Tension pneumothorax, Tamponade, Toxins.

 Management of Non-Shockable Rhythms (Asystole/PEA)

 1. Immediate CPR & Adrenaline

• Start CPR immediately (30:2 ratio).
• Give adrenaline (1 mg IV/IO) as soon as possible, then repeat every 3-5 minutes.
• DO NOT give defibrillation for non-shockable rhythms.

 2. Reassess Rhythm Every 2 Minutes

• Continue CPR for 2-minute cycles, checking for signs of ROSC.
• If a shockable rhythm appears, switch to shockable pathway.

 3. Identify & Treat Reversible Causes (4 Hs & 4 Ts)

• Hypoxia – Provide 100% oxygen.
• Hypovolaemia – Give IV fluids or blood products.
• Electrolyte Imbalances – Treat hyperkalaemia/hypokalaemia.
• Thrombosis (MI or PE) – Consider thrombolysis or PCI.

 Monitoring & Adjuncts During ALS

 Waveform Capnography

• Used to confirm correct endotracheal tube placement.
• Helps assess CPR effectiveness (normal ETCO₂ = 10-20 mmHg during CPR).
• Sudden ETCO₂ rise may indicate ROSC.

 Mechanical CPR Devices

• May be used in long transport situations (e.g., in ambulances or catheter labs).

 Intraosseous (IO) Access

• Used when IV access is not feasible.

 Post-Resuscitation Care (After ROSC)

 Immediate Post-ROSC Management

1. Maintain oxygen saturation 94-98%.
2. Maintain blood pressure (MAP ≥65 mmHg).
3. Perform a 12-lead ECG to identify STEMI or arrhythmias.
4. Consider targeted temperature management (TTM, 32-36°C for 24 hours).

 Neurological Prognostication

• Wait at least 72 hours before making decisions on neurological recovery.

 ALS Key Takeaways

✔ Early defibrillation is crucial for VF/pVT.
✔ High-quality CPR with minimal interruptions improves survival.
✔ Adrenaline & Amiodarone are essential for shockable rhythms.
✔ 4 Hs & 4 Ts should be assessed in every cardiac arrest.
✔ Post-resuscitation care (oxygen, BP, ECG, TTM) is vital for improving outcomes.