Which of the following arterial blood gas results could be caused by diarrhea?

a. pH = 7.15; PaCO2 = 20 mm Hg; and HCO3– = 7.4 mEq/L
b. pH = 7.20; PaCO2 = 65 mm Hg; and HCO3– = 26 mEq/L
c. pH = 7.57; PaCO2 = 22 mm Hg; and HCO3– = 20 mEq/L
d. pH = 7.49; PaCO2 = 49 mm Hg; and HCO3– = 38 mEq/L

ANS: A
Diarrhea can be caused by a metabolic acidosis. Arterial blood gas values in which the pH is 7.15 (acidosis), PaCO2 is 20 mm Hg, and the HCO3– is 7.4 mEq/L are indicative of a partially compen-sated metabolic acidosis. Answer B is an uncompensated respiratory acidosis. Answer C is a par-tially compensated respiratory alkalosis, and answer D is a partially compensated metabolic alka-losis.