ALS Algorithm

Amplified
Checklist

Advanced Life Support - Amplified

Quick Reference

Rhythm Recognition

RhythmECG AppearanceShockable?
VFChaotic, no QRSYes
Pulseless VTWide, regular, fast (>180)Yes
AsystoleFlat lineNo
PEAOrganised rhythm, no pulseNo

Drug Doses

DrugDoseWhen
Adrenaline1mg IVAfter 2nd shock (shockable) or immediately (non-shockable), then every 2nd cycle
Amiodarone300mg IVAfter 3rd shock, then 150mg after 5th shock
Calcium chloride10mL 10%Hyperkalaemia, Ca-blocker OD
Magnesium2g IVTorsades de pointes

Shockable (VF/pVT)

Shockable rhythms have the best prognosis - the heart is trying to beat but chaotically. Early defibrillation is key. Each minute without defib reduces survival by 10%.

Shock 200J biphasic

Pad placement (anterolateral): Right pad below clavicle, right sternal border. Left pad at V6 position (5th ICS, mid-axillary line). Ensure pads are flat with good contact.

Energy: 200J for biphasic defibrillators (most modern machines). If using monophasic, use 360J.

Before shocking: Use COACHED checklist (see below).

CPR 2 minutes (30:2)

Resume compressions immediately after shock - don't pause to check rhythm. High-quality CPR: rate 100-120/min, depth >5cm, full recoil, minimal interruptions.

Give 30 compressions then 2 breaths if no advanced airway. Once intubated: continuous compressions at 100-120/min with 10 breaths/min (not synchronised).

Rhythm check

After 2 minutes of CPR, pause briefly (<5 sec) to check the monitor:

  • Still VF/pVT → shock again
  • Organised rhythm → pulse check (10 sec max)
  • Asystole → switch to non-shockable algorithm

Drugs

Adrenaline 1mg IV after the 2nd shock (i.e., during the 3rd cycle of CPR), then every alternate cycle (every 3-5 minutes). Given for its α1 vasoconstriction - increases coronary and cerebral perfusion pressure.

Amiodarone 300mg IV after the 3rd shock if still in VF/pVT. Can give additional 150mg after the 5th shock. It's a class III antiarrhythmic that may help achieve ROSC.


Non-Shockable (Asystole/PEA)

Non-shockable rhythms have poorer prognosis. Focus on high-quality CPR and identifying reversible causes.

CPR 2 minutes (30:2)

Same as shockable - high-quality compressions are the priority. PEA may have some cardiac output (pseudo-PEA) so good CPR can support this.

Rhythm check

After 2 minutes, check the monitor:

  • Still asystole/PEA → continue CPR
  • Shockable rhythm develops → switch to shockable algorithm
  • Organised rhythm with pulse → ROSC!

Drugs

Adrenaline 1mg IV immediately (don't wait for a second cycle like in shockable), then every alternate cycle. No amiodarone in non-shockable rhythms.

Actively think about reversible causes - PEA especially often has a treatable cause. Check 4H and 4T.


COACHED (Safe Defibrillation)

Use this checklist every time you prepare to shock. It keeps everyone safe and minimises CPR interruptions.

C - Continue compressions

Keep doing compressions while the defib charges. Only stop when ready to shock.

O - Oxygen away (1m)

Move oxygen tubing at least 1 metre from patient's chest. Oxygen supports combustion - rare, but can cause burns/fire.

A - All others away

Look around and ensure nobody is touching the patient or bed. Announce "Charging, stand clear."

C - Charge defibrillator

Press charge button. Modern biphasic defibs charge to 200J. Watch the charge indicator.

H - Hands off (announce clear)

When charged, clearly announce "Oxygen away, everyone clear" and visually check everyone is clear. Compressor lifts hands.

E - Evaluate rhythm

Briefly confirm still VF/pVT on the monitor before shocking.

D - Defibrillate or disarm

Deliver shock if shockable rhythm confirmed. If rhythm has changed, disarm and reassess. Resume CPR immediately after shock.


Reversible Causes (4H 4T)

During any cardiac arrest, actively think about treatable causes. These are especially important in PEA.

CauseCluesTreatment
HypoxiaCyanosis, airway issues, SpO2Oxygenate, secure airway
HypovolaemiaTrauma, GI bleed, AAAIV fluids, blood, surgery
Hypo/hyperkalaemiaRenal failure, ECG changesCalcium, glucose-insulin, dialysis
HypothermiaCold, drowning, exposureWarm IV fluids, blankets, ECMO
Tension pneumothoraxTrauma, absent breath soundsNeedle thoracocentesis, chest drain
TamponadeTrauma, muffled heart soundsPericardiocentesis, thoracotomy
ToxinsHistory, pupils, seizuresSpecific antidote, supportive care
ThrombosisPE or MI history/riskThrombolysis, PCI, embolectomy

Hyperkalaemia clues on ECG: peaked T waves, flat P waves, wide QRS, sine wave.


Post-ROSC Care

When you get return of spontaneous circulation (pulse returns), the work isn't over.

Immediate priorities

  • 12-lead ECG: If STEMI, activate cath lab immediately
  • Oxygenation: Target SpO2 94-98%, avoid hyperoxia
  • Blood pressure: Keep MAP >65mmHg (vasopressors if needed)
  • Blood glucose: Treat hypo/hyperglycaemia
  • Ventilation: Aim normocapnia (EtCO2 35-40mmHg)

Targeted Temperature Management

For unconscious patients after ROSC, maintain temperature at 32-36°C for at least 24 hours. This reduces cerebral metabolic demand and prevents secondary brain injury.

Consider causes

The arrest happened for a reason. If not already identified, investigate:

  • ACS (troponin, echo, angiography)
  • PE (CTPA)
  • Electrolyte abnormalities
  • Drug toxicity