Hypokalaemia ⬇️
Clinical guide for managing hypokalaemia. Potassium replacement calculator, causes, treatment protocols, and monitoring for on-call doctors.
🧠 Definition
- Serum potassium <3.5 mmol/L.
- Mild: 3.1–3.4 mmol/L, Moderate: 2.5–3.0 mmol/L, Severe: <2.5 mmol/L.
🧾 Causes
- GI loss: vomiting, diarrhoea, laxatives
- Renal loss: diuretics, hyperaldosteronism
- Redistribution: insulin, beta-agonists, alkalosis
- Poor intake (rare as sole cause)
🩺 Symptoms
- Often asymptomatic if mild
- Muscle weakness, cramps, palpitations
- Severe: arrhythmias, paralysis, respiratory failure
🔍 Investigations
- Repeat K+ to confirm, check for haemolysis
- ECG: U waves, flattened T waves, prolonged QT
- Mg2+ (replace if low), U&Es, glucose, ABG if needed
💊 Management Principles
- Identify and treat cause
- Mild: oral replacement preferred (e.g. Sando-K, Slow-K)
- Severe or symptomatic: consider IV replacement cautiously
- Monitor serum potassium and ECG closely
📈 Replacement Tool
- Use the below tool to guide potassium replacement based on serum levels.
Potassium Replacement
Calculate replacement strategy based on potassium levels
Instructions
Please check your local hospital guidelines before initiating potassium replacement. Enter the patient's potassium level (mmol/L) to get a suggested replacement strategy. Magnesium levels should also be checked and replaced as needed, as hypomagnesaemia can impair potassium repletion.
Note Template
Ready-to-use clinical note structure
🕒 16 / 10 / 2026 — 16:20 ATRP re: hypokalaemia Patient: [age] [sex] Admission Dx: [reason for admission] PMHx: [diuretics, diarrhoea, renal disease] 🧾 Hx: • Symptoms: weakness, cramps, palpitations • Recent vomiting, diarrhoea or diuretic use • Dietary intake and supplements 🩺 Exam: • Vitals: HR __ BP __ RR __ Temp __ SpO₂ __ • Cardiac exam: arrhythmias, pulse irregularity • Neurological exam: muscle strength, reflexes 📋 Impression: Likely cause of hypokalaemia: [GI loss / renal loss / redistribution] 📌 Plan: • ECG monitoring for arrhythmias • Serum potassium and magnesium levels • Replace potassium orally or IV as appropriate • Treat underlying cause • Monitor potassium and renal function regularly 👤 [Your Name], [Role] IMC: _______
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