Question

Ph7.2, \(H_{CO_3}\) - (10 or 12), \(p_{CO_2}\)- 35 , metabolic acidosis due to

• A. \(K^+\) excretion by the kidney
• B. \(CO_2\) expiration by lungs
• C. \(H^+\) excretion by the kidney
• D. \(HCO_3\) loss by kidney

Answer 1

The Correct Option is D

To determine the cause of metabolic acidosis in this scenario, we examine the given parameters:

• pH = 7.2, indicating acidosis (as normal pH is around 7.35-7.45).
• \(H_{CO_3}^-\) (bicarbonate) = 10 or 12 mEq/L, which is lower than the normal range of 22-26 mEq/L, suggesting a loss of bicarbonate.
• \(p_{CO_2}\) = 35 mmHg, which is within the normal range (35-45 mmHg); thus, respiratory compensation is not evident, ruling out lung-related issues.

Given these points, we need to identify a potential cause of the low bicarbonate levels, leading to metabolic acidosis:

• \(K^+\) excretion by the kidney: This typically affects electrolyte balance but is not directly related to bicarbonate loss or metabolic acidosis.
• \(CO_2\) expiration by the lungs: This would result in respiratory changes, rather than causing metabolic acidosis directly.
• \(H^+\) excretion by the kidney: This process helps maintain acid-base balance by removing excess hydrogen ions, not causing acidosis.
• \(HCO_3^-\) loss by kidney: Loss of bicarbonate through the kidneys could result in decreased bicarbonate levels, directly causing metabolic acidosis.

Therefore, the correct cause of metabolic acidosis in this scenario is \(HCO_3^-\) loss by kidney.