Name the following Arterial Blood Gas (ABG) values: pH 7.31, PaCO2 44, HCO3- 12

Choice A reason: Respiratory acidosis involves low pH and high PaCO2. Normal PaCO2 (44) and low HCO3- (12) point to metabolic acidosis, not respiratory, so this incorrect. Choice B reason: Metabolic alkalosis has high pH and HCO3-. Low pH (7.31) and low HCO3- (12) rule this out, indicating metabolic acidosis, so this is incorrect. Choice C reason: Low pH (7.31) and low HCO3- (12) with normal PaCO2 confirm metabolic acidosis, where acid accumulation lowers pH. This matches, making it the correct choice. Choice D reason: Respiratory alkalosis has high pH and low PaCO2. Low pH and normal PaCO2 exclude this, pointing to metabolic acidosis, so this is incorrect.