ABG analysis of a patient on ventilator,shows decreased pCO2, normal pO2, pH 7.5; diagnosis is:
Respiratory acidosis
Metabolic alkalosis
Resp alkalosis
Metabolic acidosis
Answer is C (Respiratory akalosis) : There is alkalosis (pH = 7.5) and CO2 is low (alkalosis). Change in CO2 is inkeeping with change in pH and thus the primary cause is respiratory. The acid base disturbance is thus primary respiratory alkalosis.