A decrease in bicarbonate is most consistent with which disturbance?

A decrease in bicarbonate is most consistent with which disturbance?

• A. Decrease in HCO3
• B. Increase in HCO3
• C. Decrease in pCO2
• D. Increase in pCO2

Answer: (A)

A decrease in bicarbonate points to metabolic acidosis. Bicarbonate (HCO3-) is the base in the body's buffering system; when fixed acids accumulate or base is lost, bicarbonate is consumed, causing the pH to fall. The body tries to compensate by increasing ventilation to blow off CO2, so pCO2 drops in response. Among the options, the direct indicator of the disturbance is the decreased bicarbonate itself, since increasing bicarbonate would suggest metabolic alkalosis and changes in pCO2 describe respiratory disturbances rather than the primary acid-base problem.

A decrease in bicarbonate points to metabolic acidosis. Bicarbonate (HCO3-) is the base in the body's buffering system; when fixed acids accumulate or base is lost, bicarbonate is consumed, causing the pH to fall. The body tries to compensate by increasing ventilation to blow off CO2, so pCO2 drops in response. Among the options, the direct indicator of the disturbance is the decreased bicarbonate itself, since increasing bicarbonate would suggest metabolic alkalosis and changes in pCO2 describe respiratory disturbances rather than the primary acid-base problem.