A client with acute renal failure has arterial blood gas results showing low pH and low bicarbonate with Kussmaul breathing and acidic urine. Which acid-base disturbance best fits this presentation?

A client with acute renal failure has arterial blood gas results showing low pH and low bicarbonate with Kussmaul breathing and acidic urine. Which acid-base disturbance best fits this presentation?

• A. Metabolic acidosis
• B. Respiratory alkalosis
• C. Metabolic alkalosis
• D. Respiratory acidosis

Answer: (A)

Renal failure disrupts the kidney’s ability to excrete hydrogen ions and regenerate bicarbonate, so hydrogen ions accumulate and bicarbonate falls. That combination—low pH with low bicarbonate on an arterial blood gas—indicates metabolic acidosis rather than a primary respiratory disturbance. Kussmaul breathing is the compensatory response to metabolic acidosis, with rapid, deep breathing trying to blow off CO2 to raise the pH. The presence of acidic urine aligns with the body’s attempt to excrete the excess acid load despite renal impairment. Taken together, this pattern fits metabolic acidosis.

Renal failure disrupts the kidney’s ability to excrete hydrogen ions and regenerate bicarbonate, so hydrogen ions accumulate and bicarbonate falls. That combination—low pH with low bicarbonate on an arterial blood gas—indicates metabolic acidosis rather than a primary respiratory disturbance. Kussmaul breathing is the compensatory response to metabolic acidosis, with rapid, deep breathing trying to blow off CO2 to raise the pH. The presence of acidic urine aligns with the body’s attempt to excrete the excess acid load despite renal impairment. Taken together, this pattern fits metabolic acidosis.