Hyperkalaemia is defined as serum potassium concentration >5.5 mmol/L, representing a potentially life-threatening electrolyte disorder. It affects 1-10% of hospitalized patients and is particularly common in those with chronic kidney disease, heart failure, and diabetes. Severe hyperkalaemia (>6.5 mmol/L) is a medical emergency requiring immediate intervention to prevent fatal cardiac arrhythmias.

Clinical Pearls:

• Most common electrolyte emergency in hospitalized patients
• Pseudohyperkalaemia occurs in 20-30% of cases due to hemolysis or delayed processing
• ECG changes may precede symptoms and are critical for risk stratification
• Chronic hyperkalaemia often asymptomatic until severe
• Mortality rate: 2-5% in severe cases without prompt treatment

Red Flags:

• K+ >6.5 mmol/L: Immediate cardiac monitoring and treatment required
• ECG changes: Tall tented T waves, prolonged PR, widened QRS, sine wave pattern
• Muscle weakness or paralysis: Suggests severe hyperkalaemia
• Cardiac arrest: Ventricular fibrillation or asystole from hyperkalaemia
• Rapid onset: Acute hyperkalaemia more dangerous than chronic

Non-Modifiable Risk Factors:

• Chronic kidney disease: GFR less than 60 ml/min increases risk exponentially
• Age: Renal function decline with aging increases susceptibility
• Genetic factors: Pseudohypoaldosteronism type 1, Gordon syndrome
• Heart failure: Reduced renal perfusion and RAAS activation

Modifiable Risk Factors:

• Medications: ACE inhibitors, ARBs, spironolactone, NSAIDs
• Diet: High potassium intake in compromised patients
• Metabolic acidosis: Increases cellular potassium release
• Dehydration: Reduces renal perfusion and potassium clearance

High-Risk Medications:

• RAAS inhibitors: ACE inhibitors, ARBs, direct renin inhibitors
• Potassium-sparing diuretics: Spironolactone, eplerenone, amiloride, triamterene
• NSAIDs: Reduce renal blood flow and aldosterone
• Trimethoprim: Blocks epithelial sodium channels
• Heparin: Reduces aldosterone synthesis

Protective Factors:

• Adequate hydration: Maintains renal perfusion
• SGLT2 inhibitors: Increase potassium excretion
• Loop diuretics: Enhance potassium clearance
• Regular monitoring: Early detection and intervention

"What is hyperkalaemia?" Hyperkalaemia means you have too much potassium in your blood. Potassium is an important mineral that helps your nerves and muscles work, including your heart. When levels get too high, it can be dangerous, especially for your heart rhythm.

"What causes it?" Common causes include kidney problems, certain medications (like blood pressure pills), diabetes, and sometimes eating too many high-potassium foods. Your kidneys normally remove extra potassium, but if they're not working well, it can build up.

"What symptoms will I notice?" Many people have no symptoms, especially if it's mild. When it's more severe, you might feel weak, tired, or have heart palpitations. Very severe cases can cause muscle paralysis or dangerous heart rhythms. Your doctor will check your blood and do an ECG (heart tracing) to see how serious it is.

"How is it treated?" Treatment depends on how high your potassium is:

• Mild cases: Your doctor might adjust your medications or suggest dietary changes
• Moderate cases: You may need hospital treatment with medications to lower potassium
• Severe cases: Emergency treatment in hospital with IV medications and possibly dialysis

"Will I need to change my diet?" Yes, you'll likely need to limit high-potassium foods like bananas, oranges, potatoes, tomatoes, and certain salt substitutes. Your doctor or dietitian will give you a list of foods to avoid and alternatives to eat instead.

"What about my medications?" Your doctor may need to adjust or stop certain medications that can raise potassium, especially blood pressure pills. Don't stop any medications on your own - always talk to your doctor first.

"Is it dangerous?" Severe hyperkalaemia can be life-threatening because it can cause dangerous heart rhythms. That's why it's important to get treatment right away if your doctor says your potassium is very high. With proper treatment, most people do very well.

"Will it come back?" It can recur, especially if you have kidney problems or take certain medications. Your doctor will help you manage it long-term with regular blood tests, medication adjustments, and sometimes special medications called potassium binders.

"What should I watch for?" Call your doctor or go to the emergency room if you develop:

• Severe muscle weakness
• Heart palpitations or irregular heartbeat
• Chest pain or difficulty breathing
• Numbness or tingling

"Can I prevent it?" Yes! Take your medications as prescribed, follow your diet recommendations, stay well-hydrated, and keep all your doctor appointments for regular monitoring. If you have kidney problems, managing those well helps prevent hyperkalaemia.