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Dose and administration
- Oral replacement is the preferred method.
- Intravenous infusions - usual dose up to 0.2mmol/kg/hour.
- Solution must be diluted to 1mmol/25ml if given via a peripheral line, or 1mmol/12.5ml via central line.
Acute treatment of symptomatic hypokalaemia
- If renal function is adequate 0.5mmol/kg in an hour. Repeat as necessary.
- Adjust maintenance potassium. Correct hypocalcaemia.
- Prevention and treatment of hypokalaemia
- Bradycardia secondary to hypokalaemia
Contraindications and precautions
- Caution in babies with severe renal impairment and oliguria and renal disease.
- Caution in babies with severe haemolytic reactions.
- Caution in babies with cardiac disease.
- Caution in babies with systemic acidosis.
- Caution in babies with digoxin intoxication in presence of conduction disturbances.
- Caution in babies receiving potassium sparing diuretic.
Potassium is the major intracellular cation. Hypokalaemia in critically ill neonates is usually the result of diuretic therapy, inadequate intake or diarrhoea. Other causes include congenital adrenal hyperplasia and renal disorders. However, serum potassium levels are a poor marker of total body stores of potassium, and a low serum potassium more often reflects redistribution than true deficit. Alkalosis as well as insulin infusions will lower serum potassium concentrations by driving the ion intracellularly. Symptoms of hypokalaemia include neuromuscular weakness and paralysis, ileus, urine retention, and ECG changes, ST segment depression, low voltage T wave and appearance of U wave. Hypokalaemia increases digoxin toxicity. Renal mechanisms are of primary importance in maintaining both total body potassium and plasma concentration within narrow limits. Oral potassium preparations are completely absorbed.
Hyperkalaemia affects cardiac conduction. ECG changes include tall peaked T waves, heartblock with widening QRS complex, arrhythmia and cardiac arrest.
Potassium is excreted mainly by the kidneys and is secreted in the distal tubules where it is involved in the sodium-potassium exchange process. Some potassium is excreted in the stools and small amounts may also be excreted in the sweat, saliva, bile and pancreatic juice.
Possible adverse effects
- Venous irritation, pain, soft tissue injury at the injection site.
- Gastrointestinal disturbances common (diarrhoea, vomiting, bleeding, abdominal discomfort).
- Altered sensitivity to digoxin.
- Respiratory distress.
- Hyperkalaemia, indicated by weakness, listlessness, flaccid paralysis, hypotension, cardiac arrhythmias including heart block and cardiac arrest.
- Administer IV slowly, maximum infusion rate, 0.5mmol/kg/hour.
- Monitor electrolytes.
- Dilute potassium before intravenous administration. The literature recommends dilution to 40mmol/L, i.e, 1mmol/25ml.4 As this may cause volume overload, in infants with central line access dilute to 1mmol/12.5ml1,2 and piggyback with IV fluids to achieve further dilution.
- If nutritional or fluid restriction indications dictate, intravenous potassium may be given as a neat (1 mmol/mL) solution with the attending SMO's approval. This can only be done when the solution is piggy-backed with intravenous nutrition / 10% glucose solutions. The potassium infusion should be connected at a point distal to the site of venous access to maximise dilution. Neat potassium must always be administered via a central line only. The baby shall be on full cardiac monitoring
- Adequate renal function must be confirmed.
- Management of hyperkalaemia if K+>7mmol/L unhaemolysed. Refer to hyperkalaemia guideline.
Management of Potassium administration
IV preparation: Clear colourless solution
1mmol/ml (0.75 gm in 10ml).
Oral preparation: Clear and colourless 2 mmol/ml (osmolality 4000mOsm/kg/)
- For an infusion to correct symptomatic hypokalaemia, charted on stat page of prescription chart stating mmol/dose and fluid to be diluted in type and volume, time to be infused.
- For oral supplementation, charted on prescription chart stating ml/dose, frequency, and mmol/kg/day.
Volumetric infusion pump
Charted on fluid chart only stating 1 molar potassium chloride and volume to be added.
Charted on prescription chart stating ml/dose.
- For central line administration, dilute prior to use to 1 mmol in 12.5ml (80mmol/L) with NS, D5W or D10W. Stronger solutions are unacceptable. Mix well.
- For peripheral line administration, dilute prior to use to 1mmol in 25ml (40mmol/L) with NS, D5W or D10W. Mix well.
- Administer by slow IV infusion Y injection port of minibore tubing. Keep IV fluids running to ensure further dilution of potassium. Compatible for co-infusion with IVN at Y injection site.
- Do NOT mix with other drugs, blood or blood products.
- Shake well before use.
- Administer with feeds to decrease likelihood of gastro-intestinal reactions.
Observation and documentation
- Monitor for adverse reactions.
- Observe site closely for extravasation.
- Continuous cardiac monitoring during administration of slow IV infusion by syringe pump.
- Monitor K+ levels closely following slow infusions.
- Assess for gastrointestinal intolerance of oral potassium.
- At room temperature <30°C. Discard ampoule after use.
- Oral: Store in refrigerator. Discard after 1 week.
- Trissel LA. Handbook on Injectable Drugs (14th Ed), 2007. p1370-1
- Phelps SJ, Hak EB. Pediatric Injectable Drugs (7th Ed), 2004. p332-3.
- Tubman M, Majumadar SR, Lee D, Friesen C, Klassen TP. Best practices for safe handling of products containing concentrated potassium. BMJ 2005;331:274-7.
- Neonatal Formulary 5: Drug use in pregnancy and the first year of life. BMJ Books (Blackwell Publishing, Oxford) 2007. p205.
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- Date last published: 30 April 2012
- Document type: Drug Dosage Guideline
- Services responsible: ADHB Pharmacy, Neonatology
- Editor: Sarah Bellhouse
- Review frequency: 2 years