Hyperkalemia is characterized by serum potassium above 5.5 mmol/L. Symptoms include muscular weakness, abnormal sensations and abnormal heart rate. Patients may present with cardiac arrhythmia, metabolic acidosis and will need urgent ECG to plan the treatment. ECG changes include absent P wave, tall T waves, wide QRS complex and blurring of ST into T waves.
Medications:
If serum potassium between 5.5 mEq/L to 6.4 mEq/L without ECG changes:
- Tab. Lasix (Furosemide 40 mg) 1 tablet stat. Repeat 40 mg after 6 hours if desired diuretic effect not obtained.
- Correct the cause – Look for clotted blood sample, renal failure, congestive heart failure, diabetes mellitus, NSAIDs, beta blockers, digitalis, blood transfusion, renal tubular acidosis, adrenal insufficiency, ACE inhibitors or ARBs (angiotensin receptor blockers), dialysis, spironolactone, lithium, heparin, cyclosporine or metabolic acidosis.
If serum potassium between 6.5 mEq/L to 6.9 mEq/L with ECG changes or above 7.0 mEq/L without ECG changes:
- Glucose Insulin drip – inj. Actrapid 10 units mixed with 50 ml Dextrose 50% i.v. over 10 minutes followed by Dextrose 5% one litre i.v. over 12 hours. Monitor blood glucose every 30 minutes. Repeat insulin only if blood glucose more than 180 mg/dl.
- Nebuliser Asthalin (Salbutamol 2.5 mg respule) 1 respule by nebulization over 5 to 15 minutes three to four times a day.
- Inj. Lasix (Furosemide 10 mg/ml) 20 mg i.v. as bolus and repeat after 2 hours if desired effect not obtained.
- Monitor serum electrolytes and renal function test every 2 hours.
If serum potassium level fails to correct, consider adding:
- Sachet K Lock (Polystyrene sulfonate 15 g) in water up to 4 times a day.
- Renal team review and consider early dialysis, if potassium is persistently high and if there are symptoms and signs of renal dysfunction.
- Monitor serum electrolytes and renal function test every 2 hours.
If serum potassium more than 7 mEq/L with ECG changes:
- Inj. Glumin (Calcium gluconate 10%) 10 ml i.v. over 5 to 10 minutes. Repeat the dose if ECG continues to show signs of cardiotoxicity due to hyperkalemia.
- Glucose Insulin drip – inj. Actrapid as explained above.
- Nebuliser Asthalin as explained above.
- Inj. Lasix (Furosemide 10mg/ml) 20 mg i.v. slowly over 2 minutes. Repeat inj. Lasix 20 mg i.v. after 2 hours if desired effect not obtained.
- If serum potassium level is still high, consider adding K Lock (Polystyrene sulfonate 15 g) sachet in water up to 4 times per day
- Renal team review and consider early dialysis, if potassium is persistently high and if there are symptoms and signs of renal dysfunction.
- Monitor serum electrolytes and renal function test every 2 hours.
General care:
- Maintain strict intake output chart.
- Fluid intake equals to 300-400 mls + urine output
- Avoid diet high in potassium – nuts, potatoes, banana, beans and legumes.
- Prefer low potassium diet – apples, cauliflower, broccoli, cabbage, peas.
Investigations:
- Complete blood count – to rule out sepsis as a cause of renal failure.
- Serum electrolytes – to assess and monitor for hyperkalemia, hyponatremia.
- Arterial blood gas – to rule out and monitor acidosis.
- Renal function test, urine output – to assess renal failure.
- ECG – to investigate and monitor for cardiac changes due to electrolyte imbalance and cardiac ischaemia.
Referral:
Urgent referral may be needed for nephrologist in cases of persistently high potassium with ECG changes.