A 67-Year-Old Man with Chronic Obstructive Pulmonary Disease (COPD) Is

A 67-year-old man with chronic obstructive pulmonary disease (COPD) is seen in the emergency department for increasing dyspnea.  His most recent FEV1 was 0.8 L and he is on chronic oxygen therapy.  Two days ago, he began coughing up increased sputum and felt more short of breath.  One day ago, he noticed that his sputum became purulent and his shortness of breath worsened.  He denies chest pain, hemoptysis, fever, abdominal pain, or nausea.  He receives an annual influenza vaccination and obtained vaccination for S.  pneumoniae three years ago.  He denies any other new symptoms and does not have diarrhea, nausea, or vomiting.  He has hypertension, hyperlipidemia, and type 2 diabetes mellitus.  His current medications include albuterol, tiotropium, lovastatin, hydrochlorothiazide, and metformin.
On examination, he appears dyspneic.  His temperature is 36.7 C (98 F) , blood pressure is 130/90 mm Hg, pulse is 96 /min, and respirations are 20 /min.  He has difficulty speaking in complete sentences.  There is no asterixis.  Cardiac examination demonstrates a right ventricular lift, but is otherwise normal.  All breath sounds are decreased.  There is prolongation of the expiratory phase of respiration.  There are no rales or rhonchi.  Abdominal examination is normal.  Extremity examination shows 1+ pedal edema bilaterally to the mid-shin.
Fingerstick blood glucose is 90 mg/dL.  A metabolic panel shows that his serum creatinine is 1.0 mg/dL.
Which of the following arterial blood gases (ABG) would be most compatible with his clinical picture?

A) pH 7.30, bicarbonate 34 mEq/L, and anion gap of 8 mEq/L
B) pH 7.30, bicarbonate 24 mEq/L, and anion gap of 10 mEq/L
C) pH 7.30, bicarbonate 14 mEq/L, and anion gap of 17 mEq/L
D) pH 7.47, bicarbonate 24 mEq/L, and anion gap of 10 mEq/L
E) pH 7.47, bicarbonate 34 mEq/L, and anion gap of 8 mEq/L