An unusual cause of acute encephalopathy: D-lactic acidosis secondary to short bowel syndrome

Abstract

Background: Blood D-lactate levels increase in short bowel syndrome (SBS) and may lead to neurological manifestations. Clinical Description: A 5-year-old boy, postoperative case of SBS, presented with loose stools, generalized weakness, and lethargy for 2 days. The child had undergone significant intestinal resection in the past. On examination, he had some dehydration, and was drowsy, but arousable. Remaining examination was normal. Metabolic abnormalities detected included metabolic acidosis (pH of 7.1, HCO3 7 mmol/L), high anion gap (20 mmol/l), and normal lactate levels (2 mmol/L). Other baseline investigations were normal. He was treated as a case of acute gastroenteritis with some dehydration and metabolic acidosis and improved. He was discharged after 5 days. After 2 months, he was readmitted with drowsiness and unsteady gait. This time there was no diarrhea or dehydration. Investigations again revealed severe metabolic acidosis, high anion gap, and normal lactate levels. Management: We considered SBS induced D-lactate encephalopathy but were unable to prove it by assay due to unavailability of tests. The child was kept nil per orally and given bicarbonate infusion, on which he showed dramatic improvement. He was also given a low carbohydrate diet and oral metronidazole. The family was counseled at discharge 5 days later regarding dietary modifications and microsupplementation. The patient had 6 admissions for D-lactic encephalopathy over 4 years that coincided with dietary lapse. Conclusion: D-lactate acidosis is an underrecognized condition and its diagnosis and management is challenging. A high index of suspicion should be kept in patients with history of intestinal resection presenting with acute encephalopathy and unexplained metabolic acidosis.