Blood gas measurements of a patient shows the following values pH 7.2, pCO2 80 mm Hg, p02 46 mm Hg. Which of the following could be the most probable diagnosis:

Answer is B (Acute exacerbation of COPD): The patient in question is presenting with type II Respiratory failure (Decreased PaO2 and increased PaCO2) which indicates an obstructive lung disease. Amongst the options provided Asthma and COPD, both are examples of obstructive lung diseases. Obstructive lung disease with elevated PCO2 is more characteristic and common in acute exacerbations of COPD than in Acute Asthma and hence acute exacerbation of COPD is the single best answer of choice. Acute Asthma and COPD are both examples of Obstructive lung diseases. Both conditions may present with the above picture but an elevated PCO2 is more characteristic of COPD than asthma