CKD - Acid-base imbalance

Question 1

A common disturbance in advanced CKD

Answer 1

Metabolic acidosis

Question 2

Why are CKD patients prone to metabolic acidosis?

Answer 2

The majority of patients can still acidify the urine, but they produce less ammonia and, therefore cannot excrete the normal quantity of protons

Question 3

____, if present, further depresses ammonia production

Answer 3

Hyperkalemia

Question 4

The combination of hyperkalemia and hyperchloremic metabolic acidosis is often present in what stage of CKD?

Answer 4

Earlier stages of CKD (stages 1–3), in patients with diabetic nephropathy or in those with predominant tubulointerstitial disease or obstructive uropathy

Question 5

With worsening renal function, the total urinary net daily acid excretion is usually limited to ____ mmol, and the anions of retained organic acids can then lead to an anion gap metabolic acidosis. Thus, the non-anion-gap metabolic acidosis seen in earlier stages of CKD may be complicated by the addition of an anion-gap metabolic acidosis as CKD progresses.

Answer 5

30–40

Question 6

Animal and human studies have suggested that even modest degrees of metabolic acidosis may be associated with the development of ____

Answer 6

Protein catabolism

Question 7

Alkali supplementation is recommended when the serum bicarbonate concentration is ____ for the purpose of ____

Answer 7

• Below 20–23 mmol/L
• Avoiding the protein catabolic state seen with even mild degrees of metabolic acidosis and to slow the progression of CKD
• Note:*
• The concomitant sodium load mandates careful attention to volume status and the need for diuretic agents