On an ABG, pH of 7.2, pO2 of 46, pCO2 of 80 are indicative of:
ABG shows severe hypoxia with hypercarbia with acidosis suggestive of type 2 respiratory failure. ARDS and acute asthma both have Type 1 Respiratory Failure and are ruled out. So we have to select between options A and C. Interstitial Pneumonitis on routine presentation will not have such low oxygen values but an acute exacerbation of chronic bronchitis will definitely present with low oxygen values.
Acute exacerbation of COPD
Adult respiratory distress syndrome
Interstitial pneumonitis
Acute asthma
Respiratory Failure