**Compensatory Mechanisms in Acid-Base Balance**
**Core Concept**
In the context of blood gas analysis, compensation refers to the physiological adjustments made by the body to maintain acid-base homeostasis. This is particularly relevant when there is an initial disturbance, such as respiratory alkalosis, which is characterized by a high pH, low pCO2, and elevated pO2.
**Why the Correct Answer is Right**
The given blood gas values - pH = 7.52, pCO2 = 30, and pO2 = 105 - indicate a respiratory alkalosis. The body compensates for this condition by increasing the excretion of bicarbonate ions (HCO3-) in the kidneys, thereby reducing the blood concentration of bicarbonate and mitigating the alkalotic effect. This process is mediated by the kidneys' ability to increase the production of ammonia, which is then excreted, allowing for the reabsorption of hydrogen ions and the subsequent reduction of bicarbonate levels.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the kidneys do not directly compensate for respiratory alkalosis by increasing the excretion of bicarbonate ions.
**Option B:** This option is incorrect because the respiratory system does not compensate for respiratory alkalosis by increasing the excretion of CO2.
**Option C:** This option is incorrect because metabolic alkalosis is characterized by an elevated pH, high HCO3- levels, and often an elevated pCO2, which is not consistent with the given blood gas values.
**Clinical Pearl / High-Yield Fact**
In cases of respiratory alkalosis, the kidneys play a crucial role in compensating by increasing the excretion of bicarbonate ions and reducing the blood concentration of bicarbonate.
**Correct Answer: C. Metabolic acidosis**
Free Medical MCQs Β· NEET PG Β· USMLE Β· AIIMS
Access thousands of free MCQs, ebooks and daily exams.
By signing in you agree to our Privacy Policy.