From the Guidelines
Metabolic alkalosis is primarily caused by conditions that lead to excessive bicarbonate levels in the body, including vomiting, diuretic use, excessive alkali administration, severe potassium depletion, and certain endocrine disorders, as well as rare genetic disorders like Bartter syndrome, which is characterized by hypokalemic metabolic alkalosis 1. The main causes of metabolic alkalosis can be broken down into several key categories:
- Vomiting or nasogastric suction, leading to loss of hydrochloric acid from the stomach
- Diuretic use, particularly loop and thiazide diuretics, which increase renal bicarbonate reabsorption
- Excessive alkali administration, such as sodium bicarbonate or antacids containing calcium carbonate
- Severe potassium depletion, often defined as hypokalemia with potassium levels less than 3.5 mEq/L 1
- Certain endocrine disorders, including hyperaldosteronism and Cushing's syndrome
- Contraction alkalosis, which can occur with volume depletion as the kidneys retain bicarbonate along with sodium
- Milk-alkali syndrome, resulting from excessive intake of calcium and absorbable alkali
- Rare genetic disorders affecting kidney tubules, such as Bartter and Gitelman syndromes, which can lead to chronic metabolic alkalosis 1 It's essential to address the underlying cause of metabolic alkalosis, correct fluid and electrolyte imbalances, and consider potassium replacement, as hypokalemia frequently accompanies and perpetuates the condition.
From the FDA Drug Label
In patients with hepatic cirrhosis and ascites, ... Supplemental potassium chloride and, if required, an aldosterone antagonist are helpful in preventing hypokalemia and metabolic alkalosis
- Metabolic alkalosis can be caused by:
- Hepatic cirrhosis and ascites, particularly if not properly managed
- Hypokalemia, which can be precipitated by Furosemide tablets therapy, especially with brisk diuresis, inadequate oral electrolyte intake, when cirrhosis is present, or during concomitant use of corticosteroids, ACTH, licorice in large amounts, or prolonged use of laxatives 2
- Electrolyte imbalance, including hypochloremic alkalosis, which can occur with Furosemide tablets therapy, especially in patients receiving higher doses and a restricted salt intake 2
- Prevention of metabolic alkalosis may involve the use of supplemental potassium chloride and, if required, an aldosterone antagonist 2
From the Research
Causes of Metabolic Alkalosis
The causes of metabolic alkalosis can be divided into several categories, including:
- Loss of fixed acid or a net accumulation of bicarbonate within the extracellular fluid 3
- Chloride depletion alkalosis, mineralocorticoid excess syndromes, apparent mineralocorticoid excess syndromes, and excess alkali administration 4
- Alkali accumulation or acid loss, resulting in a primary increase in serum bicarbonate (HCO3 -) 5
Specific Causes
Some specific causes of metabolic alkalosis include:
- Vomiting 3
- Aldosterone or cortisol excess 3
- Licorice ingestion 3
- Chloruretic diuretics 3
- Excess calcium alkali ingestion 3
- Genetic diseases such as Bartter syndrome, Gitelman syndrome, and cystic fibrosis 3
Underlying Mechanisms
The pathogenesis of metabolic alkalosis involves either a loss of fixed acid or a net accumulation of bicarbonate within the extracellular fluid, and can be influenced by factors such as: