A previously healthy 27-year-old man was involved in a motorcycle accident. He sustained a ruptured spleen, bilateral haemopneumothoraces, compound tibial fractures, and multiple lacerations, abrasions and contusions. He arrived in the ER comatose and was taken immediately to the OR. Blood chemistries: BUN 25 mg/dL, Cr 1.4 mg/dL, Na 145 mEq/L, K 5.9 mEq/L, HCO3 15 mEq/L, Cl 105 mEq/L, CK 2500 U/L. Arterial blood gases: pH 7.25, pCO2 35 mmHg, pO2 49 mmHg. Urinalysis: pH 5.0, protein 2+, RBC 20–30/HPF, WBC 5–10/HPF, specific gravity 1.018, many hyaline, granular and broad coarsely granular casts with epithelial cells. Urine Na 48 mEq/L, Cr 18 mg/dL, K 28 mEq/L. Which of the following best describes the acid–base status of this patient?