American Board of Internal Medicine (ABIM) Certification Practice Exam

Oral alkali therapy is aimed at maintaining serum bicarbonate levels between which values to reduce the risk of progression of chronic kidney disease?

1. 20 and 24 mEq/L

2. 23 and 29 mEq/L

3. 30 and 35 mEq/L

4. 15 and 19 mEq/L

The correct answer is: 23 and 29 mEq/L

Oral alkali therapy aims to maintain serum bicarbonate levels between 23 and 29 mEq/L to reduce the risk of progression of chronic kidney disease (CKD). This range is significant because it helps to mitigate the metabolic acidosis commonly seen in patients with CKD. As kidney function declines, the kidneys' ability to excrete acid diminishes, resulting in lower bicarbonate levels and an accumulation of acids in the body. Maintaining bicarbonate in the specified range is crucial because it can help neutralize excess acid, thereby alleviating the harmful effects of metabolic acidosis. This can improve metabolic health, potentially slow the progression of kidney disease, and enhance overall patient outcomes. In contrast, the other ranges do not offer the same protective benefits against the complications of metabolic acidosis in CKD. Levels below the recommended range would be insufficient to effectively counteract the acidosis, while levels above this range may not be necessary to achieve the desired therapeutic effect and could potentially lead to other imbalances or complications. Thus, maintaining serum bicarbonate levels in the range of 23 to 29 mEq/L is the most evidence-based approach for managing patients with CKD and preventing its progression.