<prompt> ABG analysis of a patient on ventilator,shows decreased pCO2, normal pO2, pH 7.5; diagnosis is:Respiratory acidosisMetabolic alkalosisResp alkalosisMetabolic acidosis  <response>: 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. 