Etiology
The most common cause of hyperkalemia is pseudohyperkalemia, which is not reflective of the true serum potassium levels. Pseudohyperkalemia is most commonly due to hemolysis of the sample, causing intracellular potassium to be measured in the serum. Hemolysis is more common when a syringe is used than a vacuum device. Using tourniquets and excessive fist-pumping during the blood draw also increase the risk. Specimens drawn from patients with leukocytosis or thrombocytosis are also frequently associated with falsely elevated potassium concentrations.
Increased Potassium Intake
Bạn đang xem: Bookshelf
Xem thêm : How Does Acetaminophen Work? Understanding This Common Ingredient Found in OTC Medications
Increased potassium intake from food is a very uncommon cause of hyperkalemia in adult patients with normal renal function but can be an important cause in those with kidney disease. Foods with high potassium content include dried fruits, seaweed, nuts, molasses, avocados, and Lima beans. Many vegetables that are also high in potassium include spinach, potatoes, tomatoes, broccoli, beets, carrots, and squash. High-potassium-containing fruits include kiwis, mangoes, oranges, bananas, and cantaloupe. Red meats are also rich in potassium. While generally safe to consume even in large quantities by patients with normal potassium homeostasis, these foods should be avoided in patients with severe renal disease or other underlying conditions or medications predisposing them to hyperkalemia. Intravenous intake through high potassium-containing fluids, particularly total parenteral nutrition, medications with high potassium content, and massive blood transfusions can significantly elevate serum potassium levels.
Intracellular Potassium Shifts
Cellular injury can release large quantities of intracellular potassium into the extracellular space. This can be due to rhabdomyolysis from a crush injury, excessive exercise, or other hemolytic processes. Metabolic acidosis may cause intracellular potassium to shift into the extracellular space without red cell injury. Metabolic acidosis is most frequently caused by decreased, effective circulating arterial blood volume. Sepsis or dehydration may lead to hypotension and decreased tissue perfusion leading to metabolic acidosis with subsequent potassium elevation.
Xem thêm : The Definitive Guide to ICD-10 Cellulitis Codes
Insulin deficiency and diabetic ketoacidosis may cause dramatic extracellular shifts causing measured serum potassium to be elevated in the setting of whole-body potassium depletion. Certain medications, such as succinylcholine, may cause severe, acute potassium elevations in patients with up-regulation of receptors, particularly in subacute neuromuscular disease. Tumor lysis syndrome, particularly in patients receiving chemotherapy for hematogenous malignancy, may cause acute hyperkalemia due to massive cancer cell death.[3] Hyperkalemic periodic paralysis is a rare, autosomal dominant condition that causes potassium to shift into the extracellular space due to impaired sodium channel function in skeletal muscle.
Impaired Potassium Excretion
Acute or chronic kidney disease is a common cause of hyperkalemia. Hyperkalemia is usually not seen until the glomerular filtration rate falls below 30 ml/min. This is commonly due to primary renal dysfunction but may be due to acute volume depletion from dehydration or bleeding or decreased circulating blood volume due to congestive heart failure or cirrhosis. Tubular dysfunction due to aldosterone deficiency or insensitivity can also cause hyperkalemia.
Nguồn: https://blogtinhoc.edu.vn
Danh mục: Info