Skip to Main Content

Source: Devlin JW, Matzke GR. Acid–Base Disorders. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. Accessed August 8, 2012.

  • Acid–base disorder characterized by increased pH and serum bicarbonate (HCO3) concentrations

  • Clinical situations resulting in loss of H+ or gain of HCO3 and impairment of renal HCO3 excretion (Table 1)
    • Volume-mediated (sodium chloride–responsive) or volume-independent (sodium chloride–resistant) processes

Table 1. Causes of Metabolic Alkalosis Differentiated on the Basis of Their Responsiveness to Sodium Chloride

  • Initiated by increased pH and HCO3 that can result from:
    • Loss of H+ via gastrointestinal (GI) tract (e.g., nasogastric suctioning, vomiting) or kidneys (e.g., diuretics, Cushing’s syndrome)
    • Gain of bicarbonate (e.g., administration of bicarbonate, acetate, lactate, or citrate)
  • Maintained by abnormal renal function that prevents kidneys from excreting excess bicarbonate.
  • Respiratory response: increases Paco2 by hypoventilation.

  • Hospitalized patients with acid–base disturbances due to many factors, including (but not limited to):
    • Vomiting
    • Nasogastric suctioning
    • Secretory diarrhea
    • Use of diuretics
    • Administration of bicarbonate or infusion of organic anions metabolized to bicarbonate

  • No unique signs or symptoms with mild to moderate alkalosis.

Signs and Symptoms

  • Mild to moderate alkalosis: symptoms may be related to underlying disorder.
    • Muscle weakness with hypokalemia
    • Postural dizziness with volume depletion
  • Severe alkalemia (pH >7.60) can be associated with cardiac arrhythmias and neuromuscular irritability.

Means of Confirmation and Diagnosis

  • Blood gases, serum electrolytes, medical history, and clinical condition are the primary tools for determining the cause of acid–base disorders and for designing therapy.

Laboratory Tests

  • Correction of acid–base disorder

  • Initial treatment: stabilizing acute condition, followed by identifying and correcting underlying cause(s) of acid–base disturbance.
  • Metabolic alkalosis persists until renal mechanism maintaining disorder is corrected.


Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.