Treatment of Alkalosis
The treatment of alkalosis depends fundamentally on whether it is metabolic or respiratory in origin, with metabolic alkalosis requiring identification of chloride-responsiveness and correction of underlying volume depletion, hypokalemia, and hypochloremia, while respiratory alkalosis is best managed by treating the underlying cause of hyperventilation. 1, 2, 3
Metabolic Alkalosis Management
Initial Assessment and Immediate Interventions
Stop or reduce diuretic therapy immediately, as diuretics are the most common precipitating cause of metabolic alkalosis. 2 Review all medications that may contribute to chloride depletion and discontinue them if possible. 2
Measure urine chloride to distinguish chloride-responsive (<20 mEq/L) from chloride-resistant (>20 mEq/L) alkalosis, as this determines treatment strategy. 2 Most cases in hospitalized patients are chloride-responsive and related to volume depletion. 4, 5
Fluid and Electrolyte Replacement
For chloride-responsive alkalosis with volume depletion:
Administer normal saline (0.9% NaCl) to reverse volume contraction and provide chloride necessary for bicarbonate excretion. 2 This addresses the fundamental maintenance factor in most cases. 4
Give potassium chloride (20-60 mEq/day) to maintain serum potassium in the 4.5-5.0 mEq/L range. 1, 2 Hypokalemia is commonly present and perpetuates the alkalosis. 4
Never use potassium citrate or other non-chloride potassium salts, as these will worsen the metabolic alkalosis rather than correct it. 1, 2 The chloride component is essential for correction. 1
Pharmacologic Interventions
When fluid and electrolyte replacement alone is insufficient:
Amiloride is the first-line potassium-sparing diuretic for metabolic alkalosis, starting at 2.5 mg daily and titrating up to 5 mg daily. 1, 2 It provides the most effective correction while countering hypokalemia. 1
Spironolactone (25-100 mg daily) is particularly useful in heart failure patients with diuretic-induced alkalosis. 1, 2, 4 It addresses the aldosterone-mediated component of bicarbonate retention. 4
Acetazolamide can be used in patients with adequate kidney function, especially those with heart failure and diuretic-induced alkalosis. 1 However, potassium-sparing diuretics are generally preferred as first-line alternatives. 1
Avoid combining potassium-sparing diuretics with ACE inhibitors without close monitoring due to significant hyperkalemia risk. 1, 2
Severe or Refractory Cases
For severe metabolic alkalosis requiring rapid correction:
Dilute hydrochloric acid (0.1-0.2 N HCl) may be infused through a central venous catheter when conventional therapy cannot be tolerated or rapid resolution is needed. 6, 7 This directly titrates the base excess but carries risk of hemolysis. 7
Hemodialysis with low-bicarbonate/high-chloride dialysate is the treatment of choice in refractory cases, especially with concurrent renal failure. 1 This provides definitive correction when other measures fail. 7
Special Populations
In heart failure patients, appropriate management of the underlying circulatory failure is integral to treatment. 4 Consider adding an aldosterone antagonist to the diuretic regimen rather than simply stopping diuretics. 1, 4
In patients with Bartter syndrome or other salt-losing tubulopathies, sodium chloride supplementation (5-10 mmol/kg/day) is recommended along with potassium chloride and consideration of NSAIDs for symptomatic patients. 1 Use potassium-sparing diuretics cautiously as they may worsen volume depletion in these conditions. 2
Critical Pitfalls to Avoid
Never administer sodium bicarbonate or alkalinizing agents - these are absolutely contraindicated and will worsen the alkalosis. 1, 2
Do not use potassium-sparing diuretics in patients with significant renal dysfunction or existing hyperkalemia. 1, 2
Avoid non-chloride containing potassium supplements as they perpetuate rather than correct the alkalosis. 2
Monitoring Parameters
Monitor the following serially during treatment:
- Serum electrolytes (sodium, potassium, chloride, bicarbonate) 2
- Arterial blood gas to assess pH and compensatory changes 2
- Urine chloride levels 2
- Volume status through clinical examination and urine output 2
- In critically ill patients, consider central venous pressure monitoring to guide fluid therapy 2
Respiratory Alkalosis Management
Respiratory alkalosis is best corrected by treating the underlying etiology causing hyperventilation. 3 The condition produces multiple metabolic abnormalities including changes in potassium, phosphate, and calcium. 3
Hyperventilation syndrome is a diagnosis of exclusion in the emergency department setting after ruling out pulmonary and extrapulmonary disorders. 3
Special Context: Pulmonary Hypertension
In pediatric patients with pulmonary hypertension after cardiac arrest, short-term induced alkalosis through hyperventilation or alkali administration may be appropriate as part of multipronged therapy for pulmonary hypertensive crises. 8 However, this is a specific exception where alkalosis is therapeutically induced rather than treated. 8
Avoid forced alkalosis with prolonged hyperventilation in most settings, as it paradoxically worsens outcomes and can cause cerebral vasoconstriction. 2