Makindo Medical Notes

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💔 Victims of sudden cardiac arrest presenting with asystole have an extremely poor prognosis. 📊 Around 10% survive to admission; only 0–2% survive to hospital discharge.

📖 About

• ⚡ Asystole accounts for ~40% of cardiac arrests.
• 🪫 It represents the terminal rhythm in most cases of cardiac arrest.

🦠 Aetiology

• ⏱️ Usually arises from prolonged untreated ventricular fibrillation.
• ⚡ May occur after unsuccessful defibrillation of VF/VT.
• Can follow profound hypoxia, massive haemorrhage, or metabolic derangements.

🔍 Clinical

• GCS 3, no pulse, not breathing.
• Telemetry/monitor: flat line tracing.

📉 ECG

• 📏 Rate: No ventricular activity (occasionally ≤6/min). “P-wave asystole” may occur with isolated atrial activity but absent QRS.
• 📏 Rhythm: No organised ventricular activity.
• ⛔ PR/QRS: Cannot be determined; no QRS complexes present.

⚠️ Differentials

• 🎛️ Check monitor/lead placement — exclude fine VF.

🚑 Management (UK Resus Council/ALS)

• 🔄 Immediate actions: Start CPR, give high-flow oxygen, apply monitoring/defibrillator pads.
• 💉 Secure IV/IO access.
• 💊 Adrenaline (epinephrine): 1 mg IV/IO every 3–5 minutes.
• ⚡ Not shockable: Defibrillation is not indicated unless rhythm changes to VF/VT.
• 🔍 Confirm asystole in ≥2 leads before decisions about terminating resuscitation.
• 🚫 Atropine is no longer recommended in asystole (AHA/ERC guidelines).

🛑 Reversible Causes (“4 Hs & 4 Ts”)

• 💧 Hypovolaemia – IV fluids, transfusion if bleeding.
• 🌬️ Hypoxia – 100% O₂, airway check, suction, confirm tube position.
• 🧪 Hydrogen ion (acidosis) – optimise ventilation; consider bicarbonate if severe.
• ⚡ Hypo/hyperkalaemia – give potassium (if low); if high, treat with calcium chloride + insulin/dextrose ± sodium bicarbonate.
• ❄️ Hypothermia – active rewarming, warmed IV fluids.
• 🫁 Tension pneumothorax – needle decompression then chest drain.
• ❤️ Cardiac tamponade – ultrasound, pericardiocentesis.
• 🧴 Toxins – consider overdose, stop infusions, antidotes as available.
• 🩸 Thrombosis (coronary/pulmonary) – consider thrombolysis, PCI, or thrombectomy if appropriate.

📚 References

• UK Resus Council – Adult ALS
• NCBI Bookshelf – Asystole

📝 Revision Notes

• 📌 Asystole = non-shockable. Immediate CPR + adrenaline are the only evidence-based interventions.
• 📌 Always exclude fine VF or equipment error before labelling a rhythm asystole.
• 📌 Survival depends on rapidly identifying and reversing an underlying cause.