The following arterial blood gas (ABG) results indicate? pH-7.13 PaCO2-38.8 mmHg PaO2-83 mmHg HCO3-13.2 mEq/L BE-(-14.5) O2 Sat-95%

A. Metabolic acidosis: The patient’s pH of 7.13 indicates acidemia, and the HCO3- is significantly decreased at 13.2 mEq/L, showing a primary metabolic derangement. The PaCO2 of 38.8 mmHg is within normal limits (35–45 mmHg), suggesting that respiratory compensation has not yet fully occurred. The base excess of -14.5 further supports a significant metabolic acid load. These findings are consistent with metabolic acidosis. B. Respiratory acidosis: Respiratory acidosis is characterized by elevated PaCO2 (>45 mmHg) due to hypoventilation, which leads to a decreased pH. In this case, the patient’s PaCO2 is normal, indicating that CO2 retention is not the primary cause of acidemia. The primary disturbance is metabolic rather than respiratory. C. Normal ABG results: Normal arterial blood gas values include pH 7.35–7.45, PaCO2 35–45 mmHg, HCO3- 22–28 mEq/L, and PaO2 80–100 mmHg. In this ABG, the pH is acidotic, HCO3- is low, and base excess is markedly negative, which clearly deviates from normal ranges, indicating a pathological process. D. Respiratory alkalosis: Respiratory alkalosis is characterized by decreased PaCO2 (<35 mmHg) due to hyperventilation, resulting in an elevated pH. In this ABG, PaCO2 is normal and pH is low, which contradicts the pattern seen in respiratory alkalosis. The acidemia is therefore not caused by a respiratory mechanism.