The nurse assesses a client with acute renal failure. The laboratory findings show a decrease in pH, a decrease in bicarbonate, and a decrease in serum carbon dioxide. The client is experiencing Kussmaul breathing and acidic urine. Which acid base complication is this client experiencing?

Nursing assessment of a client with Acute renal failure requires careful interpretation of acid–base balance. The kidneys play a key role in regulating hydrogen ion excretion and bicarbonate reabsorption. When renal function declines, acid accumulates in the body, leading to metabolic disturbances. Clinical signs such as Kussmaul respirations and acidic urine reflect the body’s attempt to compensate for excess acid. Rationale: A. Respiratory alkalosis is incorrect because it is characterized by increased pH due to excessive carbon dioxide loss from hyperventilation. In this case, the pH is decreased, indicating acidosis rather than alkalosis. The respiratory pattern described (Kussmaul breathing) is compensatory for metabolic acidosis, not a primary respiratory disorder. B. Respiratory acidosis is incorrect because it results from hypoventilation and retention of carbon dioxide, leading to increased PaCO₂ and decreased pH. Although acidosis is present, the primary issue in this case is not respiratory in origin. Instead, the kidneys are failing to excrete acid, making it a metabolic problem. C. Metabolic acidosis is correct because the decreased pH, decreased bicarbonate, and compensatory Kussmaul respirations indicate excess acid accumulation due to impaired kidney function. The kidneys are unable to excrete hydrogen ions or regenerate bicarbonate, leading to systemic acid buildup. The respiratory system compensates by increasing ventilation to reduce carbon dioxide levels. D. Metabolic alkalosis is incorrect because it is characterized by increased pH and elevated bicarbonate levels. The client instead shows decreased pH and bicarbonate, which are consistent with acidosis. Therefore, this option does not match the laboratory findings or clinical presentation.