Achieve Mastery of Medical Concepts

Study for medical school and boards with Lecturio

Hyperkalemia

Hyperkalemia is defined as a serum potassium (K+) concentration > 5.2 mEq/L. Homeostatic mechanisms maintain the serum K+ concentration between 3.5 and 5.2 mEq/L, despite marked variation in dietary intake. Hyperkalemia can be due to a variety of causes, which include transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifts, tissue breakdown, inadequate renal excretion, and drugs. Hyperkalemia is usually asymptomatic if minor in severity; however, acute elevations or severe hyperkalemia can lead to potentially fatal cardiac arrhythmias. Management is guided by severity and includes measures to stabilize the myocardial membrane potential Membrane potential The membrane potential is the difference in electric charge between the interior and the exterior of a cell. All living cells maintain a potential difference across the membrane thanks to the insulating properties of their plasma membranes (PMs) and the selective transport of ions across this membrane by transporters. Membrane Potential, transiently shifting K+ intracellularly, removing K+ from the body, and treating the underlying predisposing conditions.

Last updated: Jan 26, 2023

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

General considerations

K+ is the main intracellular cation in all cells and is distributed unevenly between the intracellular fluid Intracellular fluid The fluid inside cells. Body Fluid Compartments (98%) and extracellular fluid Extracellular fluid The fluid of the body that is outside of cells. It is the external environment for the cells. Body Fluid Compartments (2%). 

Sites of action in the kidney

  • Glomerulus: K+ is freely filtered.
  • Proximal tubule Proximal tubule The renal tubule portion that extends from the bowman capsule in the kidney cortex into the kidney medulla. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the u-shaped loop of henle. Tubular System: 65%–70% of filtered K+ is reabsorbed. 
  • Thick ascending limb Thick ascending limb Renal Sodium and Water Regulation of the loop of Henle Loop of Henle The U-shaped portion of the renal tubule in the kidney medulla, consisting of a descending limb and an ascending limb. It is situated between the proximal kidney tubule and the distal kidney tubule. Tubular System: 10%–25% of filtered K+ is reabsorbed. 
  • Principal cell (cortical collecting duct Collecting duct Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of bellini) which opens on the summit of the papilla. Renal Cell Carcinoma): K+ is secreted. 
  • 𝛼-intercalated cell ( collecting duct Collecting duct Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of bellini) which opens on the summit of the papilla. Renal Cell Carcinoma): K+ is reabsorbed (final fine-tuning mechanism).

Normal response to ingested K+

A normal Western diet contains approximately 70–150 mmol of K+ per day. This diet is unlikely to lead to the development of hyperkalemia from increased intake only, owing to the following mechanisms:

  1. Gut absorbs dietary K+ into the bloodstream.
  2. Transcellular shift prevents excessive increase in extracellular fluid (ECF) K+ concentration.
    1. Insulin- and β2-mediated
    2. K+ shifts primarily into muscle and liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy cells.
  3. Increased ECF K+ concentration triggers mechanisms for renal K+ excretion.  
  4. Transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifting into muscle/ liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy cells gradually reverses.
  5. Remainder of ingested K+ load is renally excreted.

Etiology

The etiologies of hyperkalemia can be grouped into 5 categories: transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifts, tissue breakdown, inadequate renal excretion, drug-induced, and pseudohyperkalemia.

Transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifts

  • Certain factors cause K+ to move transiently into or out of cells.
  • The effect of this shift can be significant enough to decrease or increase the measured serum K+.
  • The total body K+ does not change.
  • Factors that cause shifting out of the cell (→ raise of plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products K+):
    • Acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis: H+/K+ exchange maintains electroneutrality → moves H+ into cell to help balance extracellular pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance in exchange for K+ moving out of the cell
    • Hyperosmolality ( hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus, IV contrast, mannitol Mannitol A diuretic and renal diagnostic aid related to sorbitol. It has little significant energy value as it is largely eliminated from the body before any metabolism can take place. It can be used to treat oliguria associated with kidney failure or other manifestations of inadequate renal function and has been used for determination of glomerular filtration rate. Mannitol is also commonly used as a research tool in cell biological studies, usually to control osmolarity. Osmotic Diuretics):
      • High ECF osmolality Osmolality Plasma osmolality refers to the combined concentration of all solutes in the blood. Renal Sodium and Water Regulation → shift of water into ECF → decreases ECF K+ concentration → more favorable gradient for diffusion Diffusion The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially facilitated diffusion, is a major mechanism of biological transport. Peritoneal Dialysis and Hemodialysis of K+ out of cells
      • Solvent drag on K+ as water leaves the cell may also contribute.
      • Common mechanism in hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus (i.e., diabetic ketoacidosis Ketoacidosis A life-threatening complication of diabetes mellitus, primarily of type 1 diabetes mellitus with severe insulin deficiency and extreme hyperglycemia. It is characterized by ketosis; dehydration; and depressed consciousness leading to coma. Metabolic Acidosis ( DKA DKA Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious, acute complications of diabetes mellitus. Diabetic ketoacidosis is characterized by hyperglycemia and ketoacidosis due to an absolute insulin deficiency. Hyperglycemic Crises))
    • Exercise: K+ is intentionally released by muscle cells to act as a local vasodilator.
  • Factors that cause shifting into the cell (→ lowers the plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products K+):
    • Insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin: stimulates Na+/K+ ATPase → 3 Na+ move out of cell, 2 K+ move into cell
    • β2-Adrenergic agonist (i.e., albuterol Albuterol A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat asthma. Sympathomimetic Drugs; stimulates Na+/K+ ATPase)
    • Alkalosis Alkalosis A pathological condition that removes acid or adds base to the body fluids. Respiratory Alkalosis: H+/K+ exchanger moves H+ out of cell to help balance extracellular pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance in exchange for K+ moving into cell
Transcellular shift of k potassium

Transcellular shift of K+:
Extracellular shift of K+:
1. Acidosis (increased H+) causes blockage of the Na+/H+ exchanger, which causes a decrease in intracellular Na+, in turn blocking Na+/K+ ATPase. On the other hand, acidosis activates the H+/K+ exchanger. Both cause an increase in extracellular K+.
2. Increased osmolarity in extracellular space (hyperglycemia, IV contrast, mannitol) shifts water outside the cell, decreasing K+ concentration. Increased gradient causes K+ diffusion outside.
Intracellular shift of K+:
1. Alkalosis (decreased H+) causes activation of the Na+/H+ exchanger, which causes an increase in intracellular Na+, in turn activating Na+/K+ ATPase. On the other hand, alkalosis blocks the H+/K+ exchanger. Both cause a decrease in extracellular K+.
2. Insulin and β2 adrenergic agonists activate Na+/K+ ATPase, lowering plasma K+ concentration.

Image by Lecturio.

Tissue breakdown

  • Similar to transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shift, but the shift is not reversible
  • Damage to cell results in release of the highly concentrated intracellular K+:
    • Tumor lysis Tumor Lysis Tumor Lysis Syndrome syndrome (high-volume malignant cell death Cell death Injurious stimuli trigger the process of cellular adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury. If the stimulus is severe or persistent, injury becomes irreversible. Apoptosis is programmed cell death, a mechanism with both physiologic and pathologic effects. Cell Injury and Death after chemotherapy Chemotherapy Osteosarcoma)
    • Rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis (muscle cells; trauma, crush injuries, prolonged immobilization Immobilization Delirium)
    • RBC transfusion (if multiple units or old blood RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology lyse over time in storage)
    • GI bleeding (RBC metabolized by GI tract → intracellular K+ released)
    • Large hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception (RBC reabsorbed and metabolized → intracellular K+ released)
    • Burns Burns A burn is a type of injury to the skin and deeper tissues caused by exposure to heat, electricity, chemicals, friction, or radiation. Burns are classified according to their depth as superficial (1st-degree), partial-thickness (2nd-degree), full-thickness (3rd-degree), and 4th-degree burns. Burns ( skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions cells)

Inadequate renal excretion

Renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome:

  • Oliguria Oliguria Decreased urine output that is below the normal range. Oliguria can be defined as urine output of less than or equal to 0. 5 or 1 ml/kg/hr depending on the age. Renal Potassium Regulation → ↓ distal flow rate Flow rate maximum flow the ventilator will deliver a set tidal volume in liters per minute Invasive Mechanical Ventilation → ↓ K+ secretion Secretion Coagulation Studies 
  • Oliguria Oliguria Decreased urine output that is below the normal range. Oliguria can be defined as urine output of less than or equal to 0. 5 or 1 ml/kg/hr depending on the age. Renal Potassium Regulation plus excess K+ load or aldosterone blocker ( ACEi ACEi A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility. Renin-Angiotensin-Aldosterone System Inhibitors/ARB) will result in hyperkalemia.
  • Oliguria Oliguria Decreased urine output that is below the normal range. Oliguria can be defined as urine output of less than or equal to 0. 5 or 1 ml/kg/hr depending on the age. Renal Potassium Regulation by itself may not cause hyperkalemia.

Volume depletion Volume depletion Volume status is a balance between water and solutes, the majority of which is Na. Volume depletion refers to a loss of both water and Na, whereas dehydration refers only to a loss of water. Volume depletion can be caused by GI losses, renal losses, bleeding, poor oral Na intake, or third spacing of fluids. Volume Depletion and Dehydration:

  • Hypovolemia Hypovolemia Sepsis in Children → ↓ distal Na+ delivery → ↓ K+ secretion Secretion Coagulation Studies 
  • Also occurs in states of total body fluid overload, but with effective arterial blood volume Effective arterial blood volume Renal Sodium and Water Regulation depletion (congestive heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis)
  • Volume depletion Volume depletion Volume status is a balance between water and solutes, the majority of which is Na. Volume depletion refers to a loss of both water and Na, whereas dehydration refers only to a loss of water. Volume depletion can be caused by GI losses, renal losses, bleeding, poor oral Na intake, or third spacing of fluids. Volume Depletion and Dehydration can also cause AKI AKI Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury → hyperkalemia from oliguria Oliguria Decreased urine output that is below the normal range. Oliguria can be defined as urine output of less than or equal to 0. 5 or 1 ml/kg/hr depending on the age. Renal Potassium Regulation

Functional hypoaldosteronism Hypoaldosteronism Hypoaldosteronism is a hormonal disorder characterized by low levels of aldosterone. These low levels can be caused by decreased aldosterone production or a peripheral resistance to aldosterone. When hypoaldosteronism occurs as a result of an acquired decrease in renin production, the condition is more commonly referred to as renal tubular acidosis (RTA) type 4. Hypoaldosteronism:

  • Mineralocorticoid deficiency:
    • Primary adrenal insufficiency Primary adrenal insufficiency An adrenal disease characterized by the progressive destruction of the adrenal cortex, resulting in insufficient production of aldosterone and hydrocortisone. Clinical symptoms include anorexia; nausea; weight loss; muscle weakness; and hyperpigmentation of the skin due to increase in circulating levels of acth precursor hormone which stimulates melanocytes. Adrenal Insufficiency and Addison Disease
    • Hyporeninemic hypoaldosteronism Hyporeninemic hypoaldosteronism Reduced aldosterone synthesis due to decreased stimulation of Renin-angiotensin-aldosterone system. Hypoaldosteronism
  • Tubulointerstitial disease: sickle cell disease Sickle cell disease Sickle cell disease (SCD) is a group of genetic disorders in which an abnormal Hb molecule (HbS) transforms RBCs into sickle-shaped cells, resulting in chronic anemia, vasoocclusive episodes, pain, and organ damage. Sickle Cell Disease, urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy obstruction
  • Drugs (see table below) 

Drug-induced hyperkalemia

Drugs are a very common cause of hyperkalemia and cause it by a variety of the previously mentioned mechanisms. A key part of the diagnosis of hyperkalemia is to review all the recent drugs and medications that a patient has received.

Table: Drug-induced hyperkalemia
Medication class (examples) Mechanism
ACEi ACEi A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility. Renin-Angiotensin-Aldosterone System Inhibitors (e.g., lisinopril Lisinopril One of the angiotensin-converting enzyme inhibitors (ACE inhibitors), orally active, that has been used in the treatment of hypertension and congestive heart failure. Renin-Angiotensin-Aldosterone System Inhibitors, captopril Captopril A potent and specific inhibitor of peptidyl-dipeptidase a. It blocks the conversion of angiotensin I to angiotensin II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the renin-angiotensin system and inhibits pressure responses to exogenous angiotensin. Hypertension Drugs) Inhibits angiotensin II Angiotensin II An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the c-terminal by angiotensin converting enzyme. The amino acid in position 5 varies in different species. To block vasoconstriction and hypertension effect of angiotensin II, patients are often treated with ace inhibitors or with angiotensin II type 1 receptor blockers. Renal Sodium and Water Regulation formation → decreases aldosterone secretion Secretion Coagulation Studies → decreases renal K+ secretion Secretion Coagulation Studies
ARB (e.g., losartan Losartan An antagonist of angiotensin type 1 receptor with antihypertensive activity due to the reduced pressor effect of angiotensin II. Hypertension Drugs, valsartan Valsartan A tetrazole derivative and angiotensin II type 1 receptor blocker that is used to treat hypertension. Hypertension Drugs) Blocks angiotensin receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors → ↓ aldosterone secretion Secretion Coagulation Studies → ↓ renal K+ secretion Secretion Coagulation Studies
Direct renin inhibitors Direct Renin Inhibitors Renin-Angiotensin-Aldosterone System Inhibitors (e.g., aliskiren Aliskiren Renin-Angiotensin-Aldosterone System Inhibitors) Blocks renin Renin A highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system. Renal Sodium and Water Regulation from converting angiotensinogen to angiotensin l → decreases aldosterone secretion Secretion Coagulation Studies → ↓ renal K+ excretion
K+-sparing diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication (e.g., amiloride Amiloride A pyrazine compound inhibiting sodium reabsorption through sodium channels in renal epithelial cells. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with diuretics to spare potassium loss. Liddle Syndrome, triamterene Triamterene A pteridinetriamine compound that inhibits sodium reabsorption through sodium channels in renal epithelial cells. Potassium-sparing Diuretics, spironolactone Spironolactone A potassium sparing diuretic that acts by antagonism of aldosterone in the distal renal tubules. It is used mainly in the treatment of refractory edema in patients with congestive heart failure, nephrotic syndrome, or hepatic cirrhosis. Its effects on the endocrine system are utilized in the treatments of hirsutism and acne but they can lead to adverse effects. Potassium-sparing Diuretics) Block epithelial sodium channel Epithelial sodium channel Sodium channels found on salt-reabsorbing epithelial cells that line the distal nephron; the distal colon; salivary ducts; sweat glands; and the lung. They are amiloride-sensitive and play a critical role in the control of sodium balance, blood volume, and blood pressure. Liddle Syndrome ( ENaC ENaC Sodium channels found on salt-reabsorbing epithelial cells that line the distal nephron; the distal colon; salivary ducts; sweat glands; and the lung. They are amiloride-sensitive and play a critical role in the control of sodium balance, blood volume, and blood pressure. Liddle Syndrome) ( amiloride Amiloride A pyrazine compound inhibiting sodium reabsorption through sodium channels in renal epithelial cells. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with diuretics to spare potassium loss. Liddle Syndrome, triamterene Triamterene A pteridinetriamine compound that inhibits sodium reabsorption through sodium channels in renal epithelial cells. Potassium-sparing Diuretics) or the aldosterone receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors ( spironolactone Spironolactone A potassium sparing diuretic that acts by antagonism of aldosterone in the distal renal tubules. It is used mainly in the treatment of refractory edema in patients with congestive heart failure, nephrotic syndrome, or hepatic cirrhosis. Its effects on the endocrine system are utilized in the treatments of hirsutism and acne but they can lead to adverse effects. Potassium-sparing Diuretics, eplerenone Eplerenone A spironolactone derivative and selective aldosterone receptor antagonist that is used in the management of hypertension and congestive heart failure, post-myocardial infarction. Potassium-sparing Diuretics) → ↓ renal K+ excretion
Cardiac glycosides Cardiac glycosides Cardiac glycosides are a class of drugs reversibly inhibiting the sodium-potassium ATPase pump in myocardial cells and increasing vagal tone, which results in increased cardiac contractility and slowed conduction through the atrioventricular node. Cardiac Glycosides ( digoxin Digoxin A cardiotonic glycoside obtained mainly from digitalis lanata; it consists of three sugars and the aglycone digoxigenin. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. Cardiac Glycosides) Inhibits Na+/K+ ATPase pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols → less K+ moved into cells
NSAIDs NSAIDS Primary vs Secondary Headaches (e.g., ibuprofen Ibuprofen A nonsteroidal anti-inflammatory agent with analgesic properties used in the treatment of rheumatism and arthritis. Nonsteroidal Antiinflammatory Drugs (NSAIDs)) Decreases renin Renin A highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system. Renal Sodium and Water Regulation and aldosterone → ↓ renal K+ secretion Secretion Coagulation Studies
Calcineurin inhibitors Calcineurin Inhibitors Compounds that inhibit or block the phosphatase activity of calcineurin. Immunosuppressants (e.g., cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants, tacrolimus Tacrolimus A macrolide isolated from the culture broth of a strain of streptomyces tsukubaensis that has strong immunosuppressive activity in vivo and prevents the activation of T-lymphocytes in response to antigenic or mitogenic stimulation in vitro. Immunosuppressants) Multifactorial/incompletely understood: ↓ aldosterone release, ↓ aldosterone sensitivity, inhibition of Na+/K+ ATPase pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols, blocking of ENaC ENaC Sodium channels found on salt-reabsorbing epithelial cells that line the distal nephron; the distal colon; salivary ducts; sweat glands; and the lung. They are amiloride-sensitive and play a critical role in the control of sodium balance, blood volume, and blood pressure. Liddle Syndrome channel
Succinylcholine Succinylcholine A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for. Cholinomimetic Drugs Causes extracellular leakage of K+ through acetylcholine Acetylcholine A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. Receptors and Neurotransmitters of the CNS receptor-gated channels Channels The Cell: Cell Membrane
Antimicrobials (e.g., trimethoprim Trimethoprim The sulfonamides are a class of antimicrobial drugs inhibiting folic acid synthesize in pathogens. The prototypical drug in the class is sulfamethoxazole. Although not technically sulfonamides, trimethoprim, dapsone, and pyrimethamine are also important antimicrobial agents inhibiting folic acid synthesis. The agents are often combined with sulfonamides, resulting in a synergistic effect. Sulfonamides and Trimethoprim, pentamidine) Block ENaC ENaC Sodium channels found on salt-reabsorbing epithelial cells that line the distal nephron; the distal colon; salivary ducts; sweat glands; and the lung. They are amiloride-sensitive and play a critical role in the control of sodium balance, blood volume, and blood pressure. Liddle Syndrome channel

Pseudohyperkalemia

  • False positive False positive An FP test result indicates that a person has the disease when they do not. Epidemiological Values of Diagnostic Tests hyperkalemia, due to process of drawing and/or processing of a blood sample
  • Related to blood draw:
    • Damaged RBCs RBCs Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology lyse and release their intracellular K+.
    • Prolonged tourniquet
    • Excessive fist clenching
    • Venipuncture trauma
  • Related to blood sample processing:
    • Severe thrombocytosis or leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus 
    • More likely if blood sample analysis is delayed
    • Intracellular K+ is released from platelets Platelets Platelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology after clotting in the test tube.
    • WBCs lyse and release intracellular K+

Clinical Presentation

The most severe symptoms of hyperkalemia are impaired electrical conduction in the heart. Cardiac symptoms are more likely to occur with increasing severity and acuity of hyperkalemia; however, even relatively severe hyperkalemia can be asymptomatic. Muscular symptoms may be observed, and these include weakness and paralysis. 

Cardiac symptoms

Cardiac symptoms are the most important symptoms of hyperkalemia, as they can be rapidly fatal.

  • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes follow a characteristic progression with increasing K+:
    • Peaked T waves and short QT interval QT interval Electrocardiogram (ECG) PR interval PR interval Electrocardiogram (ECG) prolongation and QRS widening → loss of P waves → QRS widens to sine wave → asystole Asystole No discernible electrical activity, flatline on electrocardiogram (P waves and QRS complexes are not present). Cardiac Arrest
    • This classic progression is often not observed clinically.
    • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) findings are helpful if present but are not sensitive for hyperkalemia overall.
  • Arrhythmias:
    • Advanced atrioventricular block Atrioventricular block Atrioventricular (AV) block is a bradyarrhythmia caused by delay, or interruption, in the electrical conduction between the atria and the ventricles. Atrioventricular block occurs due to either anatomic or functional impairment, and is classified into 3 types. Atrioventricular block (AV block)
    • Sinus bradycardia Sinus bradycardia Bradyarrhythmias
    • Sinus arrest Sinus arrest The omission of atrial activation that is caused by transient cessation of impulse generation at the sinoatrial node. It is characterized by a prolonged pause without P wave in an electrocardiogram. Sinus arrest has been associated with sleep apnea (rem sleep-related sinus arrest). Bradyarrhythmias
    • Slow idioventricular rhythm
    • Ventricular tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children, ventricular fibrillation Ventricular fibrillation Ventricular fibrillation (VF or V-fib) is a type of ventricular tachyarrhythmia (> 300/min) often preceded by ventricular tachycardia. In this arrhythmia, the ventricle beats rapidly and sporadically. The ventricular contraction is uncoordinated, leading to a decrease in cardiac output and immediate hemodynamic collapse. Ventricular Fibrillation (V-fib), and/or asystole Asystole No discernible electrical activity, flatline on electrocardiogram (P waves and QRS complexes are not present). Cardiac Arrest if severe
  • Monitoring:
    • Important at all levels of hyperkalemia
    • Can be done with repeat ECGs and/or continuous cardiac monitoring 

Some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will not have ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes or arrhythmias, even with severe hyperkalemia.

Hyperkalemia ekg

ECG changes in hyperkalemia:
In reality, ECG changes in hyperkalemia are more variable and less predictable.

Image by Lecturio.

Muscular symptoms

  • Muscle weakness
  • Ascending flaccid paralysis (can resemble Guillain–Barré syndrome)
  • Unlikely to have respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure due to respiratory muscle weakness Respiratory muscle weakness Respiratory Acidosis

Management and Diagnosis

The management of hyperkalemia often takes precedence over the diagnosis because of the possibility of life-threatening arrhythmias and is guided by determining the level of urgency needed for treatment. Usually, the etiology of hyperkalemia is not difficult to determine and is not impeded by treating it first.

Management

  1. Hyperkalemic emergency?
    • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes, arrhythmia, or severe muscle weakness/paralysis
    • Serum K+ usually > 6.5 mEq/L 
    • Options for emergency treatment:
      • IV calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes to stabilize myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy
      • Insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin/ glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance +/– sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes +/– β2 agonist, to shift K+ into cells
      • Cation exchange resin +/– loop diuretic to remove K+
      • Hemodialysis Hemodialysis Procedures which temporarily or permanently remedy insufficient cleansing of body fluids by the kidneys. Crush Syndrome
    • Monitor serum K+ frequently
    • Continuous cardiac monitoring and/or repeat ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) while treating
    • Consult nephrology early
  2. Lab result accurate?
    • Hemolyzed specimen?
      • Very common type of pseudohyperkalemia
      • Most labs will routinely indicate if specimen is hemolyzed.  
      • Redraw lab prior to making treatment decisions.
    • Less common causes of pseudohyperkalemia?
      • Severe thrombocytosis (i.e., > 1000 × 109/L)
      • Severe leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus (i.e., > 50,000 × 109/L)
      • Measure plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products K+ (rather than routine serum K+) to obtain accurate level.
  3. Moderate hyperkalemia with high risk?
    • Generally asymptomatic and without ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes
    • Serum K+ 5.5–6.5 mEq/L with high-risk factor:
      • Sudden increase (e.g., 3.7 mEq/L to 6 mEq/L overnight) 
      • Ongoing K+ release (e.g., tumor lysis Tumor Lysis Tumor Lysis Syndrome, rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis)
      • Ongoing K+ absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption (e.g., GI bleeding) 
      • Kidney dysfunction
      • Metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis
    • Treat similarly to hyperkalemic emergency, but no need for IV calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes.
  4. Moderate hyperkalemia without high risk?
    • Generally asymptomatic and without ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes
    • Serum K+ 5.5–6.5 mEq/L without any of the above risk factors
    • Treat urgently:
      • Cation exchange resin +/– loop diuretic +/– hemodialysis Hemodialysis Procedures which temporarily or permanently remedy insufficient cleansing of body fluids by the kidneys. Crush Syndrome to remove K+
      • Differences with emergent treatment:
        • Do not need IV calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes 
        • Do not necessarily need shifting measures
    • Monitor serum K+ frequently
    • Continuous cardiac monitoring and/or repeat ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) while treating
  5. Mild hyperkalemia?
    • Generally asymptomatic and without ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes
    • Serum K+ < 5.5 mEq/L 
    • Does not require urgent treatment
    • Management is primarily risk-factor modification:
      • Dietary K+ restriction if renal dysfunction
      • Stop/adjust offending medications (e.g., ACEi ACEi A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility. Renin-Angiotensin-Aldosterone System Inhibitors/ARB, NSAIDs NSAIDS Primary vs Secondary Headaches, etc ETC The electron transport chain (ETC) sends electrons through a series of proteins, which generate an electrochemical proton gradient that produces energy in the form of adenosine triphosphate (ATP). Electron Transport Chain (ETC).).
      • Start/adjust loop or thiazide Thiazide Heterocyclic compounds with sulfur and nitrogen in the ring. This term commonly refers to the benzothiadiazines that inhibit sodium-potassium-chloride symporters and are used as diuretics. Hyponatremia diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication.
      • Start/adjust oral sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes.
      • Start/adjust cation exchange resin.
  6. Identify and treat any contributing underlying diseases.
Table: Acute therapeutic options for hyperkalemia
Goal Intervention Properties/indication
Stabilize the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy IV calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes
  • Antagonizes effect on membrane potential Membrane potential The membrane potential is the difference in electric charge between the interior and the exterior of a cell. All living cells maintain a potential difference across the membrane thanks to the insulating properties of their plasma membranes (PMs) and the selective transport of ions across this membrane by transporters. Membrane Potential
  • Indicated in hyperkalemic emergency
  • Onset within minutes, lasts 30–60 minutes
  • May require repeat doses if emergent symptoms remain
  • Worsens digoxin toxicity Digoxin Toxicity Cardiac Glycosides (use cautiously)
Shift K+ into cells Insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin
  • ↓ ECF K+ via transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shift
  • Most effective transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifting option
  • Onset 10–20 min, lasts 4–6 hours
  • Repeat every 2–4 hours, if needed.
  • Usually given with dextrose Dextrose Intravenous Fluids (D50W), to avoid hypoglycemia Hypoglycemia Hypoglycemia is an emergency condition defined as a serum glucose level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic patients. In nondiabetic patients, there is no specific or defined limit for normal serum glucose levels, and hypoglycemia is defined mainly by its clinical features. Hypoglycemia
  • Monitor fingerstick blood glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance closely.
Sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes (NaHCO3)
  • ↓ ECF K+ via transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shift
  • Onset 15–30 minutes
  • Lasts as long as serum bicarbonate Bicarbonate Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the ph of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Electrolytes remains improved
  • More effective if metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis is initially present
β2 agonist
  • ↓ ECF K+ via transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shift
  • Onset 30 minutes, lasts for 2 hours
  • Can cause tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children (caution in heart disease)
Remove K+ from the body Via urine
Via GI tract Cation exchange resins: bind BIND Hyperbilirubinemia of the Newborn K+ in exchange for Na+ or Ca CA Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts)2+
Dialysis Dialysis Renal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD). Peritoneal Dialysis and Hemodialysis
  • Primary option if patient is on long-term dialysis Dialysis Renal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD). Peritoneal Dialysis and Hemodialysis
  • Indicated for any patient with life-threatening hyperkalemia unresponsive to other measures
  • Hemodialysis Hemodialysis Procedures which temporarily or permanently remedy insufficient cleansing of body fluids by the kidneys. Crush Syndrome is preferred (removes K+ faster than peritoneal dialysis Peritoneal dialysis Dialysis fluid being introduced into and removed from the peritoneal cavity as either a continuous or an intermittent procedure. Peritoneal Dialysis and Hemodialysis)

Diagnosis

  1. AKI AKI Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury or CKD CKD Chronic kidney disease (CKD) is kidney impairment that lasts for ≥ 3 months, implying that it is irreversible. Hypertension and diabetes are the most common causes; however, there are a multitude of other etiologies. In the early to moderate stages, CKD is usually asymptomatic and is primarily diagnosed by laboratory abnormalities. Chronic Kidney Disease present?
  2. Recent process that could cause transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shift?
    • New or worsening metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis (including DKA DKA Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious, acute complications of diabetes mellitus. Diabetic ketoacidosis is characterized by hyperglycemia and ketoacidosis due to an absolute insulin deficiency. Hyperglycemic Crises)
    • Recent intense exercise
    • Recent surgery
  3. Other predisposing disease process present?
    • Hypovolemia Hypovolemia Sepsis in Children or other states of decreased effective arterial blood volume Effective arterial blood volume Renal Sodium and Water Regulation (congestive heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR), cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis)
    • High cell turnover ( tumor lysis Tumor Lysis Tumor Lysis Syndrome syndrome, rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis, burns Burns A burn is a type of injury to the skin and deeper tissues caused by exposure to heat, electricity, chemicals, friction, or radiation. Burns are classified according to their depth as superficial (1st-degree), partial-thickness (2nd-degree), full-thickness (3rd-degree), and 4th-degree burns. Burns)
    • RBC absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption (RBC transfusion, GI bleeding, large hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception reabsorption) 
  4. Review medication list carefully.
  5. Check plasma renin activity Plasma renin activity Renal Artery Stenosis and aldosterone if etiology is still not identified.

Differential Diagnosis

  • Rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis: large-scale muscle cell death Cell death Injurious stimuli trigger the process of cellular adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury. If the stimulus is severe or persistent, injury becomes irreversible. Apoptosis is programmed cell death, a mechanism with both physiologic and pathologic effects. Cell Injury and Death, which can result from many possible etiologies (trauma, drugs, toxins, infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease): Serum K+ can increase suddenly if rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis is unrecognized or inadequately treated or if AKI AKI Acute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury develops (common complication). Rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis is diagnosed by a serum CK level > 5 times the upper limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation of normal and treated with IV fluids IV fluids Intravenous fluids are one of the most common interventions administered in medicine to approximate physiologic bodily fluids. Intravenous fluids are divided into 2 categories: crystalloid and colloid solutions. Intravenous fluids have a wide variety of indications, including intravascular volume expansion, electrolyte manipulation, and maintenance fluids. Intravenous Fluids.
  • Tumor lysis Tumor Lysis Tumor Lysis Syndrome syndrome: large-scale malignant cell death Cell death Injurious stimuli trigger the process of cellular adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury. If the stimulus is severe or persistent, injury becomes irreversible. Apoptosis is programmed cell death, a mechanism with both physiologic and pathologic effects. Cell Injury and Death, often sudden and brought on by the initiation of chemotherapy Chemotherapy Osteosarcoma: Large amounts of intracellular K+, phosphate Phosphate Inorganic salts of phosphoric acid. Electrolytes, and uric acid Uric acid An oxidation product, via xanthine oxidase, of oxypurines such as xanthine and hypoxanthine. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals urate oxidase further oxidizes it to allantoin. Nephrolithiasis are released when malignant cells die. Treated with rasburicase Rasburicase Gout Drugs (for hyperuricemia Hyperuricemia Excessive uric acid or urate in blood as defined by its solubility in plasma at 37 degrees c; greater than 0. 42 mmol per liter (7. 0 mg/dl) in men or 0. 36 mmol per liter (6. 0 mg/dl) in women. Gout), calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes supplementation, and dialysis Dialysis Renal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD). Peritoneal Dialysis and Hemodialysis, if necessary.
  • Digoxin toxicity Digoxin Toxicity Cardiac Glycosides: Digoxin Digoxin A cardiotonic glycoside obtained mainly from digitalis lanata; it consists of three sugars and the aglycone digoxigenin. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. Cardiac Glycosides is the only commonly used cardiac glycoside. Toxicity Toxicity Dosage Calculation is common, as the therapeutic window Therapeutic Window Dosage Calculation is narrow and excretion is renal. Clinical presentation includes arrhythmias, hyperkalemia, and characteristic vision Vision Ophthalmic Exam changes, including increased yellow colors in vision Vision Ophthalmic Exam (xanthopsia). Treated with digoxin-specific antibody ( Fab Fab Univalent antigen-binding fragments composed of one entire immunoglobulin light chain and the amino terminal end of one of the immunoglobulin heavy chains from the hinge region, linked to each other by disulfide bonds. Fab contains the immunoglobulin variable regions, which are part of the antigen-binding site, and the first immunoglobulin constant regions. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme papain. Immunoglobulins: Types and Functions) fragments, which bind BIND Hyperbilirubinemia of the Newborn to and thereby inactivate the circulating drug. 
  • Malignant hyperthermia Malignant hyperthermia An important complication of anesthesia is malignant hyperthermia, an autosomal dominant disorder of the regulation of calcium transport in the skeletal muscles resulting in a hypermetabolic crisis. Malignant hyperthermia is marked by high fever, muscle rigidity, rhabdomyolysis, and respiratory and metabolic acidosis. Malignant Hyperthermia: a life-threatening syndrome characterized by hyperthermia, muscle rigidity Muscle rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Motor Neuron Lesions, and hyperkalemia (via rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis): Malignant hyperthermia Malignant hyperthermia An important complication of anesthesia is malignant hyperthermia, an autosomal dominant disorder of the regulation of calcium transport in the skeletal muscles resulting in a hypermetabolic crisis. Malignant hyperthermia is marked by high fever, muscle rigidity, rhabdomyolysis, and respiratory and metabolic acidosis. Malignant Hyperthermia is triggered by perioperative volatile anesthetic use in genetically predisposed patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship. Treatment includes dantrolene Dantrolene Skeletal muscle relaxant that acts by interfering with excitation-contraction coupling in the muscle fiber. It is used in spasticity and other neuromuscular abnormalities. Although the mechanism of action is probably not central, dantrolene is usually grouped with the central muscle relaxants. Spasmolytics (skeletal muscle reluctant) and supportive care.
  • Primary adrenal insufficiency Primary adrenal insufficiency An adrenal disease characterized by the progressive destruction of the adrenal cortex, resulting in insufficient production of aldosterone and hydrocortisone. Clinical symptoms include anorexia; nausea; weight loss; muscle weakness; and hyperpigmentation of the skin due to increase in circulating levels of acth precursor hormone which stimulates melanocytes. Adrenal Insufficiency and Addison Disease ( Addison’s disease Addison’s Disease Adrenal insufficiency (AI) is the inadequate production of adrenocortical hormones: glucocorticoids, mineralocorticoids, and adrenal androgens. Primary AI, also called Addison’s disease, is caused by autoimmune disease, infections, and malignancy, among others. Adrenal Insufficiency and Addison Disease): a rare, autoimmune type of destruction of the adrenal glands Adrenal Glands The adrenal glands are a pair of retroperitoneal endocrine glands located above the kidneys. The outer parenchyma is called the adrenal cortex and has 3 distinct zones, each with its own secretory products. Beneath the cortex lies the adrenal medulla, which secretes catecholamines involved in the fight-or-flight response. Adrenal Glands: Anatomy: Addison’s disease Addison’s Disease Adrenal insufficiency (AI) is the inadequate production of adrenocortical hormones: glucocorticoids, mineralocorticoids, and adrenal androgens. Primary AI, also called Addison’s disease, is caused by autoimmune disease, infections, and malignancy, among others. Adrenal Insufficiency and Addison Disease is diagnosed by measuring aldosterone (low), renin Renin A highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system. Renal Sodium and Water Regulation (high), serum cortisol Cortisol Glucocorticoids (low), and ACTH (low) and ACTH stimulation test. Addison’s disease Addison’s Disease Adrenal insufficiency (AI) is the inadequate production of adrenocortical hormones: glucocorticoids, mineralocorticoids, and adrenal androgens. Primary AI, also called Addison’s disease, is caused by autoimmune disease, infections, and malignancy, among others. Adrenal Insufficiency and Addison Disease leads to hyperkalemia primarily through hypoaldosteronism Hypoaldosteronism Hypoaldosteronism is a hormonal disorder characterized by low levels of aldosterone. These low levels can be caused by decreased aldosterone production or a peripheral resistance to aldosterone. When hypoaldosteronism occurs as a result of an acquired decrease in renin production, the condition is more commonly referred to as renal tubular acidosis (RTA) type 4. Hypoaldosteronism. The disease manifests acutely as adrenal crisis Adrenal crisis Adrenal crisis is the acute decompensation of adrenal function that can be triggered by another disease, surgery, stress, or increased glucocorticoid inactivation. Adrenal Insufficiency and Addison Disease, which is an emergency because of circulatory shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock. Acute treatment is high-dose glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids and supportive care. Long-term treatment is by substituting glucocorticoids Glucocorticoids Glucocorticoids are a class within the corticosteroid family. Glucocorticoids are chemically and functionally similar to endogenous cortisol. There are a wide array of indications, which primarily benefit from the antiinflammatory and immunosuppressive effects of this class of drugs. Glucocorticoids ( hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants) and mineralocorticoids Mineralocorticoids Mineralocorticoids are a drug class within the corticosteroid family and fludrocortisone is the primary medication within this class. Fludrocortisone is a fluorinated analog of cortisone. The fluorine moiety protects the drug from isoenzyme inactivation in the kidney, allowing it to exert its mineralocorticoid effect. Mineralocorticoids ( fludrocortisone Fludrocortisone A synthetic mineralocorticoid with anti-inflammatory activity. Mineralocorticoids).  
  • Diabetic ketoacidosis Ketoacidosis A life-threatening complication of diabetes mellitus, primarily of type 1 diabetes mellitus with severe insulin deficiency and extreme hyperglycemia. It is characterized by ketosis; dehydration; and depressed consciousness leading to coma. Metabolic Acidosis ( DKA DKA Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious, acute complications of diabetes mellitus. Diabetic ketoacidosis is characterized by hyperglycemia and ketoacidosis due to an absolute insulin deficiency. Hyperglycemic Crises): severe acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis caused by insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin deficiency, usually in the setting of type 1 Type 1 Spinal Muscular Atrophy diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus: Presents with total body K+ deficit (urinary losses from osmotic diuresis Osmotic diuresis Volume Depletion and Dehydration/ polyuria Polyuria Urination of a large volume of urine with an increase in urinary frequency, commonly seen in diabetes. Renal Potassium Regulation); however, serum K+ will be normal or high. Treatment is by insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin replacement followed by K+ supplementation once the plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products level falls. If there is even mild hypokalemia Hypokalemia Hypokalemia is defined as plasma potassium (K+) concentration < 3.5 mEq/L. Homeostatic mechanisms maintain plasma concentration between 3.5-5.2 mEq/L despite marked variation in dietary intake. Hypokalemia can be due to renal losses, GI losses, transcellular shifts, or poor dietary intake. Hypokalemia on presentation, this represents severe total body K+ deficit, and the plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products K+ will decrease even further once an insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin drip is started. In this situation, K+ must be replaced until the plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products level is at least 3.3 mEq/L prior to starting insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin
  • Hyperkalemic periodic paralysis Hyperkalemic Periodic Paralysis Ion Channel Myopathy: a rare genetic disease with autosomal dominant inheritance Autosomal dominant inheritance Autosomal Recessive and Autosomal Dominant Inheritance: Hyperkalemic periodic paralysis Hyperkalemic Periodic Paralysis Ion Channel Myopathy is characterized by acute attacks of muscle weakness and/or paralysis due to hyperkalemia from severe transcellular Transcellular The movement of one cell into, through, and out of another cell. Tubular System shifting of K+. Attacks are precipitated by cold temperatures, rest after exercise, and/or K+ ingestion. If recovery is not spontaneous, treatment is with inhaled β2 agonists and K+-removing therapies (e.g., furosemide Furosemide A benzoic-sulfonamide-furan. It is a diuretic with fast onset and short duration that is used for edema and chronic renal insufficiency. Loop Diuretics, cation exchange resins, dialysis Dialysis Renal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD). Peritoneal Dialysis and Hemodialysis).
  • Type IV renal tubular acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis ( RTA RTA Renal tubular acidosis (RTA) is an imbalance in physiologic pH caused by the kidney’s inability to acidify urine to maintain blood pH at physiologic levels. Renal tubular acidosis exist in multiple types, including distal RTA (type 1), proximal RTA (type 2), and hyperkalemic RTA (type 4). Renal Tubular Acidosis): a syndrome of decreased urinary secretion Secretion Coagulation Studies of K+ and H+ at the principal cell, resulting in a non– anion gap Anion gap Metabolic Acidosis metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis and hyperkalemia: Common causes include diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, NSAIDs NSAIDS Primary vs Secondary Headaches, calcineurin inhibitors Calcineurin Inhibitors Compounds that inhibit or block the phosphatase activity of calcineurin. Immunosuppressants, heparin, and Addison’s disease Addison’s Disease Adrenal insufficiency (AI) is the inadequate production of adrenocortical hormones: glucocorticoids, mineralocorticoids, and adrenal androgens. Primary AI, also called Addison’s disease, is caused by autoimmune disease, infections, and malignancy, among others. Adrenal Insufficiency and Addison Disease. Diagnosed by history and measuring serum cortisol Cortisol Glucocorticoids, renin Renin A highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system. Renal Sodium and Water Regulation, and aldosterone. Treatment is by mineralocorticoid replacement (e.g., fludrocortisone Fludrocortisone A synthetic mineralocorticoid with anti-inflammatory activity. Mineralocorticoids). Hyperkalemia is usually not severe unless concurrent predisposing factors are present.

References

  1. Gutmann, L., Conwit, R. (2021). Hyperkalemic periodic paralysis. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/hyperkalemic-periodic-paralysis
  2. Kasper, D. L., Fauci, A. S., Hauser, S. L., Longo, D. L., Jameson, J. L., Loscalzo, J. (2015). Harrison’s principles of internal medicine (19th ed..). New York: McGraw Hill Education.
  3. Levine, M.D., O’Connar A. (2020). Digitalis (cardiac glycoside) poisoning. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/digitalis-cardiac-glycoside-poisoning
  4. Mount, D.B. (2020). Causes and evaluation of hyperkalemia in adults. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/causes-and-evaluation-of-hyperkalemia-in-adults
  5. Mount, D.B. (2020). Clinical manifestations of hyperkalemia in adults. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/clinical-manifestations-of-hyperkalemia-in-adults
  6. Mount, D.B. (2020). Treatment and prevention of hyperkalemia in adults. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/treatment-and-prevention-of-hyperkalemia-in-adults
  7. Nieman, L. K. (2020). Causes of primary adrenal insufficiency (Addison’s disease). UpToDate.  Retrieved March 9, 2021, from  https://www.uptodate.com/contents/causes-of-primary-adrenal-insufficiency-addisons-disease
  8. Nieman, LK. (2020). Treatment of adrenal insufficiency in adults. UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/treatment-of-adrenal-insufficiency-in-adults
  9. Young, W. F., Jr. (2019). Etiology, diagnosis, and treatment of hypoaldosteronism (type 4 RTA). UpToDate. Retrieved March 9, 2021, from https://www.uptodate.com/contents/etiology-diagnosis-and-treatment-of-hypoaldosteronism-type-4-rta

Create your free account or log in to continue reading!

Sign up now and get free access to Lecturio with concept pages, medical videos, and questions for your medical education.

User Reviews

Details