Describe and interpret this venous blood gas:
History: A 73-year-old woman with a background of COPD presents to the emergency department with a 2-day history of influenza-like symptoms, dyspnoea and drowsiness. She reports anorexia and reduced oral intake, but no other gastrointestinal symptoms.
| pH 7.35 | Na 114 mmol/L |
| pCO2 74 mmHg | K 3.0 mmol/L |
| pO2 56 mmHg | Cl 69 mmol/L |
| HCO3 40 mmol/L | Ca 0.98 mmol/L |
| Glucose 7.4 mmol/L | Mg 0.61 mmol/L |
| Lactate 0.8 mmol/L | PO4 0.46 mmol/L |
| Urea 3.2 mmol/L | Creatinine mmol/L 42 |
| Spot urine Na 59 mmol/L | hs-TnI 399 ng/L* |
| Plasma Osmolality 244 mmol/kg | Urine osmolality 59 mmol/kg |
*hs-TnI = high-sensitivity troponin
[expand title=”Interpretation”]