Hypokalemia in children
- Michael J Somers, MD
Michael J Somers, MD
- Associate Professor of Pediatrics
- Harvard Medical School
- Avram Z Traum, MD
Avram Z Traum, MD
- Instructor of Pediatrics
- Harvard Medical School
Hypokalemia is defined as a serum or plasma potassium that is less than the normal value. Most reference laboratories establish the lower pediatric limit of normal serum potassium between 3 and 3.5 mEq/L. However, symptoms are unlikely to occur in most healthy children until serum potassium is below 3 mEq/L.
The etiology, clinical findings, diagnosis, evaluation, and management of pediatric hypokalemia are reviewed here. Hypokalemia in adults is discussed separately. (See "Clinical manifestations and treatment of hypokalemia in adults" and "Causes of hypokalemia in adults" and "Evaluation of the adult patient with hypokalemia".)
Hypokalemia is relatively common among hospitalized pediatric patients, especially those who are critically ill [1-3]. In one study of 667 children cared for in a single-center pediatric intensive care unit in the United States during the calendar year 2006, 40 percent of the patients had a serum potassium level below 3.5 mEq/L . This included patients with severe hypokalemia, defined as potassium level less than 2.5 mEq/L (4 percent); moderate hypokalemia, defined as potassium level 2.5 to less than 3 mEq/L (12 percent); and mild hypokalemia, defined as potassium level from 3 to less than 3.5 mEq/L (24 percent). Hypokalemia was associated with diagnoses of cardiac disease, renal failure, or shock .
In developing countries, severe hypokalemia (potassium level <2.5 mEq/L) is often observed in children with diarrhea and severe acute malnutrition, and is associated with an increased risk of mortality .
POTASSIUM BALANCE AND LEVELS
Definition — Potassium is primarily an intracellular cation with cells containing approximately 98 percent of total body potassium. Hypokalemia is defined as serum level below the normal value, which is usually defined as 3.5 mEq/L.
- Cummings BM, Macklin EA, Yager PH, et al. Potassium abnormalities in a pediatric intensive care unit: frequency and severity. J Intensive Care Med 2014; 29:269.
- Singhi S, Marudkar A. Hypokalemia in a pediatric intensive care unit. Indian Pediatr 1996; 33:9.
- Thomas B. Electrolyte abnormalities in children admitted to pediatric intensive care unit. Indian Pediatr 2000; 37:1348.
- Talbert A, Thuo N, Karisa J, et al. Diarrhoea complicating severe acute malnutrition in Kenyan children: a prospective descriptive study of risk factors and outcome. PLoS One 2012; 7:e38321.
- Moore RD. Stimulation of Na:H exchange by insulin. Biophys J 1981; 33:203.
- Carlotti AP, St George-Hyslop C, Bohn D, Halperin ML. Hypokalemia during treatment of diabetic ketoacidosis: clinical evidence for an aldosterone-like action of insulin. J Pediatr 2013; 163:207.
- Fuentebella J, Kerner JA. Refeeding syndrome. Pediatr Clin North Am 2009; 56:1201.
- Habashy D, Lam LT, Browne GJ. The administration of beta2-agonists for paediatric asthma and its adverse reaction in Australian and New Zealand emergency departments: a cross-sectional survey. Eur J Emerg Med 2003; 10:219.
- Krebs SE, Flood RG, Peter JR, Gerard JM. Evaluation of a high-dose continuous albuterol protocol for treatment of pediatric asthma in the emergency department. Pediatr Emerg Care 2013; 29:191.
- Deepthiraju B, Varma PR. Barium toxicity a rare presentation of fireworks ingestion. Indian Pediatr 2012; 49:762.
- Glauser J. Cardiac arrhythmias, respiratory failure, and profound hypokalemia in a trauma patient. Cleve Clin J Med 2001; 68:401, 405.
- Melnikov P, Zanoni LZ. Clinical effects of cesium intake. Biol Trace Elem Res 2010; 135:1.
- Yanturali S, Aksay E, Demir OF, Atilla R. Massive hydroxychloroquine overdose. Acta Anaesthesiol Scand 2004; 48:379.
- Marquardt K, Albertson TE. Treatment of hydroxychloroquine overdose. Am J Emerg Med 2001; 19:420.
- Jordan P, Brookes JG, Nikolic G, Le Couteur DG. Hydroxychloroquine overdose: toxicokinetics and management. J Toxicol Clin Toxicol 1999; 37:861.
- McKenzie AG. Intensive therapy for chloroquine poisoning. A review of 29 cases. S Afr Med J 1996; 86:597.
- Molla AM, Rahman M, Sarker SA, et al. Stool electrolyte content and purging rates in diarrhea caused by rotavirus, enterotoxigenic E. coli, and V. cholerae in children. J Pediatr 1981; 98:835.
- Butler T, Islam M, Azad AK, et al. Causes of death in diarrhoeal diseases after rehydration therapy: an autopsy study of 140 patients in Bangladesh. Bull World Health Organ 1987; 65:317.
- Bianchetti MG, Kanaka C, Ridolfi-Lüthy A, et al. Persisting renotubular sequelae after cisplatin in children and adolescents. Am J Nephrol 1991; 11:127.
- Walsh TJ, Finberg RW, Arndt C, et al. Liposomal amphotericin B for empirical therapy in patients with persistent fever and neutropenia. National Institute of Allergy and Infectious Diseases Mycoses Study Group. N Engl J Med 1999; 340:764.
- Dutta A, Palazzi DL. Risk factors of amphotericin B toxicty in the nonneonatal pediatric population. Pediatr Infect Dis J 2012; 31:910.
- Scurati-Manzoni E, Fossali EF, Agostoni C, et al. Electrolyte abnormalities in cystic fibrosis: systematic review of the literature. Pediatr Nephrol 2014; 29:1015.
- Linshaw MA. Potassium homeostasis and hypokalemia. Pediatr Clin North Am 1987; 34:649.
- Schaefer TJ, Wolford RW. Disorders of potassium. Emerg Med Clin North Am 2005; 23:723.
- Chhapola V, Kanwal SK, Sharma R, Kumar V. A comparative study on reliability of point of care sodium and potassium estimation in a pediatric intensive care unit. Indian J Pediatr 2013; 80:731.
- Morimatsu H, Rocktäschel J, Bellomo R, et al. Comparison of point-of-care versus central laboratory measurement of electrolyte concentrations on calculations of the anion gap and the strong ion difference. Anesthesiology 2003; 98:1077.
- Moffett BS, McDade E, Rossano JW, et al. Enteral potassium supplementation in a pediatric cardiac intensive care unit: evaluation of a practice change. Pediatr Crit Care Med 2011; 12:552.
- Sanguinetti MC, Jurkiewicz NK. Role of external Ca2+ and K+ in gating of cardiac delayed rectifier K+ currents. Pflugers Arch 1992; 420:180.
- POTASSIUM BALANCE AND LEVELS
- Homeostatic mechanisms
- Pathogenesis of hypokalemia
- Decreased intake
- Increased intracellular uptake
- - Alkalosis
- - Increased insulin activity
- - Elevated beta-adrenergic activity
- - Hypokalemic periodic paralysis
- - Other drugs (besides beta-adrenergic agonists)
- Gastrointestinal losses
- Increased urinary losses
- - Increased distal delivery of sodium and water
- Nonreabsorbable ions
- Osmotic diuresis
- Genetic tubular disorders
- Tubular injury
- - Distal (type 1) renal tubular acidosis (RTA)
- - Increased mineralocorticoid activity
- Other etiologies
- - Other causes of urinary loss
- Amphotericin B nephrotoxicity
- Liddle syndrome
- Cystic fibrosis and skin losses
- CLINICAL MANIFESTATIONS
- Muscular weakness
- Cardiac findings
- Renal manifestations
- DIFFERENTIAL DIAGNOSIS
- EVALUATION TO DETERMINE UNDERLYING ETIOLOGY
- Physical examination
- Laboratory studies
- - Urinary potassium excretion
- - Further evaluation
- Potassium supplementation
- - Route
- - Formulation
- - Our approach based on severity
- Other interventions
- - Magnesium depletion
- - Potassium-sparing diuretics
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS