Table of contents
Hypokalemia
Background
Overview
Definition
Hypokalemia refers to the presence of serum potassium levels < 3.6 mmol/L.
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Pathophysiology
Potassium depletion occurs due to inadequate dietary intake, increased renal excretion (e.g., due to diuretic therapy), or increased gastrointestinal losses in the context of diarrhea.
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Epidemiology
Hypokalemia is the most common electrolyte disorder encountered in clinical practice.
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Disease course
Manifestations of hypokalemia include muscle weakness, ileus, and cardiac arrhythmias. Typical electrocardiographic changes include flat or inverted T waves, ST-segment depression, and prominent U waves.
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Prognosis and risk of recurrence
Severe untreated hypokalemia can lead to rhabdomyolysis and malignant cardiac arrhythmias, such as VT and VF.
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Guidelines
Key sources
The following summarized guidelines for the evaluation and management of hypokalemia are prepared by our editorial team based on guidelines from the American Academy of Family Physicians (AAFP 2023,2015) and the National Council on Potassium in Clinical Practice (NCPCP 2000).
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Diagnostic investigations
Measurement of potassium levels
As per NCPCP 2000 guidelines:
Use serum potassium as the most convenient laboratory test to establish the diagnosis of hypokalemia, recognizing that it is not always an accurate indicator of total body potassium.
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Consider measurement of 24-hour urinary potassium excretion as a more appropriate indicator of total body potassium in patients who are at high risk of complications from hypokalemia, such as those with HF.
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Medical management
General principles
As per NCPCP 2000 guidelines:
Initiate potassium replacement in individuals who are subject to nausea, vomiting, diarrhea, bulimia, or diuretic/laxative abuse.
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Administer potassium supplements PO in a moderate dosage over a period of days to weeks to achieve full repletion of potassium.
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More topics in this section
Oral potassium replacement
Intravenous potassium replacement
Optimization of patient adherence
Inpatient care
Nonpharmacologic interventions
Specific circumstances
Patients with diabetes mellitus: as per NCPCP 2000 guidelines, monitor potassium levels closely in patients with diabetes mellitus, and initiate potassium replacement therapy when appropriate.
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More topics in this section
Patients with hypertension
Patients with heart disease
Patients with cardiac arrhythmias
Patients at risk of stroke