Canis ISSN: 2398-2942 Hyperkalemia Contributor(s): Kathleen P Freeman, Elisa Mazzaferro Introduction Pathogenesis Diagnosis Treatment Introduction Definition: serum potassium concentration > 5.5 mEq/L. Potassium balance is regulated by potassium intake, serum pH, serum insulin concentration, cell breakdown and potassium excretion. Acute increase in serum potassium > 7.5 mEq/L can become life-threatening due to negative cardiac effects. Serum potassium > 7.5 mEq/L is usually clinically significant. Pathogenesis Pathophysiology Variety of underlying causes. Decreased potassium excretion: Oliguric or anuric renal failure Kidney: acute kidney injury (AKI). Urinary tract trauma or obstruction Urinary obstruction. Angiotensin converting enzyme inhibitors ACE inhibitor: overview. Potassium-sparing diuretics Spironolactone. Primary hypoaldosteronism. Hypoadrenocorticism Hypoadrenocorticism. Increased potassium load: Iatrogenic (oral or parenteral potassium load). Heat-induced illness Heat stroke Hyperthermia. Crush injuries. Burn injuries Skin: burn / scald. Reperfusion after thrombolytic therapy Fluid therapy: for heat exhaustion. Increased potassium release or shifts from intracellular to extracellular location: Cell death or necrosis. Chemotherapy-associated cell death Chemotherapy: general principles. Acidosis Acid base imbalance. Trichuris vulpisinfection Trichuris vulpis. Ancylostoma caninuminfection Ancylostoma caninum. Third spacing such as chylothorax Chylothorax. Pseudohyperkalemia: Red blood cell lysis in Akitas Akita. Severe leukocytosis Hematology: platelet count. Thrombocytosis Hematology: platelet count. Decreased renal potassium excretion by renal tubules: Oliguric or anuric renal failure Kidney: acute kidney injury (AKI). Urethral obstruction Urinary obstruction. Aldosterone deficiency. Massive cell lysis, overwhelming renal tubular excretion capacity: Excessive exercise. Rhabdomyolysis. Heat-induced illness Heat stroke Hyperthermia. Burn injuries Skin: burn / scald. Snake envenomation Adder bite poisoning. Metabolic disturbances: Metabolic acidosis Acid base imbalance. Diabetic ketoacidosis Diabetic ketoacidosis. Ethylene glycol Ethylene glycol poisoning. Lactic acidosis. Decreased sodium intake Blood biochemistry: sodium : Increased sodium and water resorption causes dilutional effect, thus decreasing renal tubular potassium excretion. Diagnosis This article is available in full to registered subscribers Sign up now to purchase a 30 day trial, or Login Treatment This article is available in full to registered subscribers Sign up now to purchase a 30 day trial, or Login Further ReadingPublicationsRefereed papers Recent references from PubMed and VetMedResource. Rubin S I (1998) Trimethoprim-induced exacerbation of hyperkalemia in a dog with hypoadrenocorticism. J Vet Int Med 12 (3), 186 - 188 PubMed. Macintire D K (1997) Disorders of potassium, phosphorus and magnesium in critical illness. Comp Contin Educ Pract Vet 19 (1), 41 - 48 VetMedResource. Other sources of information The Veterinary ICU Book(2002) Eds W E Wingfield and M R Raffee. Teton New Media, Jackson Hole, WY. Veterinary Emergency Secrets, 2nd edn(2000) Ed W E Wingfield. Hanley and Belfus, Philadelphia. The ICU Book, 2nd edn(1997) Ed P L Marino. Williams and Wilkins, Baltimore.