The cause of hypokalemia can often be suggested by considering clinical and laboratory findings.
potassium excretion rate low?
ECF volume contracted?
renin levels low?
• diet low in potassium
• shift of K+ into ICF
• GI loss potassium
• prior loss of K+ in urine
• Bartter's syndrome
• low magnesium
• hypertensive causes of hypokalemia
• endogenous or exogenous mineralocorticoids
• renal artery stenosis
• malignant hypertension
• tumor producing renin
after Figure 1, page 32 (Halperin, 1992)
• low potassium excretion present if < 15 mmol/day or TTKG < 2
• ECF is extracellular fluid
• ICF is intracellular fluid
Age in Years
Low end of reference range plasma renin activity in ng AI per mL per hour if supine with normal sodium diet
< 1 year
1 - 3
3 - 5
5 - 10
10 - 15
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Purpose: To identify the cause of hypokalemia based on clinical and laboratory findings.
Specialty: Endocrinology, Clinical Laboratory
Objective: clinical diagnosis, including family history for genetics