From the Research
The values of pH 7.48, CO2 47 mmHg, and HCO3 34.7 mEq/L indicate a metabolic alkalosis with a compensatory increase in CO2, suggesting a primary elevation of serum bicarbonate and arterial pH, as described in the study by 1.
Interpretation of Blood Gas Values
- The elevated pH (normal range is 7.35-7.45) suggests alkalemia.
- The elevated CO2 level (normal range 35-45 mmHg) points to a compensatory increase in CO2, which is a common response to metabolic alkalosis, as noted in the study by 2.
- The significantly elevated bicarbonate (HCO3) level (normal range 22-26 mEq/L) represents a metabolic alkalosis, which is characterized by the gain of bicarbonate or the loss of nonvolatile acid from extracellular fluid, as described in the study by 3.
Pathogenesis and Maintenance of Metabolic Alkalosis
- The pathogenesis of metabolic alkalosis involves either a loss of fixed acid or a net accumulation of bicarbonate within the extracellular fluid, as noted in the study by 1.
- Factors that help maintain metabolic alkalosis include decreased glomerular filtration rate, volume contraction, hypokalemia, hypochloremia, and aldosterone excess, as described in the study by 4.
- The kidney plays a crucial role in maintaining acid-base balance, and its ability to excrete excess bicarbonate is impaired in metabolic alkalosis, as noted in the study by 5.
Management and Treatment
- Management should focus on addressing the underlying cause of metabolic alkalosis, which might include correcting volume depletion, discontinuing diuretics if appropriate, or addressing other causes of bicarbonate retention, as recommended in the study by 2.
- Close monitoring of electrolytes, especially potassium, is important as hypokalemia often accompanies metabolic alkalosis and can worsen the condition, as noted in the study by 3.
- Treatment of metabolic alkalosis is simple, once the pathophysiology of the cause is delineated, and therapy consists of reversing the contributory factors promoting alkalosis, as described in the study by 4.