D-lactic acidosis in short bowel syndrome

Hello everyone!

D-lactic acidosis is an unusual form of lactic acidosis.

Which patients develop D-lactic acidosis?
1. In patients with jejunoileal bypass, small bowel resection, or other causes of the short bowel syndrome.
2. Patient who receives or ingests a large amount of propylene glycol
3. Patients with diabetic ketoacidosis

In this post, I'm going to specifically talk about D-lactic acidosis in patients with small bowel syndrome.

How do patients with D-Lactic acidosis present?

Increased anion gap metabolic acidosis.
Neurologic findings of intermittent confusion, slurred speech, and ataxia.

Why does it happen in patients with small bowel syndrome?

Glucose and other carbohydrates are normally absorbed by the small bowel. If the small bowel is bypassed, removed, or diseased, then delivery of these substances to the colon increases.

Also, overgrowth of gram-positive anaerobes, such as Lactobacilli seen in small bowel syndrome contributes to lactic acidosis.

How is it metabolized?

D-lactate is not metabolized by L-lactate dehydrogenase, the enzyme that catalyzes the conversion of the physiologically occurring L-lactate into pyruvate. Thus, D-lactate is slowly metabolized in humans, accumulates in body fluids, and generates metabolic acidosis.

Diagnosis:
Laboratory studies show increased anion gap metabolic acidosis with normal plasma lactate levels, because the D-isomer is not measured by conventional laboratory assays for lactate. Diagnosis is confirmed by specifically measuring D-lactate.

Treatment:
Sodium bicarbonate if D-lactic acidosis and acidemia are severe.

Oral antimicrobial agents (such as metronidazole, neomycin, or vancomycin) can be used when D-lactic acidosis that decrease the number of D-lactate-producing organisms.
FYI: Although antimicrobials are sometimes helpful, they can occasionally precipitate D-lactic acidosis in susceptible subjects by causing an overgrowth of lactobacilli.

Low-carbohydrate diet (or the use of starch polymers rather than simple sugars) is also helpful because it diminishes carbohydrate delivery to the colon.

That's all!

-IkaN