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For further information, see CMDT Part 21-20: Metabolic Alkalosis
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Essentials of Diagnosis
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High HCO3– with alkalemia
Evaluate effective circulating volume by physical examination
Urinary chloride concentration differentiates saline-responsive alkalosis from saline-unresponsive alkalosis
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General Considerations
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No characteristic symptoms or signs
Hypotension and orthostasis may occur
Weakness and hyporeflexia occur if serum K+ is markedly low
Tetany and neuromuscular irritability occur rarely
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Arterial blood pH and bicarbonate are elevated
With respiratory compensation, arterial PCO2 is increased
Serum potassium and chloride are decreased
There may be an increased anion gap
The urine chloride can differentiate between saline-response (< 25 mEq/L) and unresponsive (> 40 mEq/L) causes
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Correct the extracellular volume deficit with isotonic saline
Discontinue diuretics
H2-blockers or proton pump inhibitors may be helpful in patients with alkalosis from nasogastric suctioning
If pulmonary or cardiovascular disease prohibits adequate resuscitation, acetazolamide will increase renal bicarbonate excretion
Hypokalemia may develop because bicarbonate excretion may induce kaliuresis
Dialysis with low-bicarbonate dialysate may be required in severe cases, especially when reduced kidney function is present