<prompt> A 68 year old man with a history of very severe COPD FEV11.0L, 25 predicted presents to the ER complaining of worsening dyspnea and an increase in the frequency and purulence of his sputum production over the past 2 days. His oxygen saturation is 78 on room air. Before he is placed on supplemental oxygen, a room air aerial blood gas is drawn and reveals: pH 7.25, PCO2 - 68, PO2 - 48, HCO3 -31. What is the diagnosis?Respiratory acidosis uncompensatedRespiratory acidosis paially compensatedMetabolic acidosis uncompensatedMetabolic alkalosis paially compensated  <response>: pH- 7.25 acidic PCO2 - 68 mm Hg respiratory acidosis HCO3 - 31 mm Hg elevated - but pH acidic - So paially compensated 