ABG analysis of a patient on ventilator, shows decreased pCO2, normal pO2, pH 7.5, diagnosis is -: (A) Resp. acidosis, (B) Metabolic alkalosis, (C) Resp. alkalosis, (D) Metabolic acidosis
Answer is C. First step

Determine whether academia or alkalemia is present by observing the pH.
pH is increased, indicating alkalosis

Second step

Inspect HCO3- /CO2 to determine the cause of academia or alkalemia
pCO2 is decreased indicating respiratory alkalosis.