Recurrent Anion Gap Metabolic Acidosis.

Abin Sajan,Noriyuki Murakami,Isabel M Mcfarlane,Judah Horowitz

doi:10.12691/ajmcr-7-9-5

Abstract

Background:Metabolic acidosis refers to any process that increases the hydrogen ions in the body and reduces the bicarbonate concentration. Metabolic acidosis is subdivided based on presence of anion gap (AG), and AG metabolic acidosis is most often due to ketoacidosis, lactic acidosis, renal failure, or toxic ingestions. AG metabolic acidosis is frequently encountered in the clinical practice. Rarely, the underlying cause of the AG metabolic acidosis is considered a diagnostic dilemma as the established algorithm allows the physicians to identify the etiology.Case presentation:A fifty-three-year-old Black woman with well-controlled human immunodeficiency virus (HIV), hypertension, and asthma presented with recurrent episodes of severe anion gap metabolic acidosis. The patient’s AG metabolic acidosis always corrected with the administration of intravenous normal saline. Laboratory studies were always negative for common causes of acidosis.Conclusion:Nucleoside reverse transcriptase inhibitors-associated lactic acidosis has been reported in the literature. The shift to anaerobic mitochondrial metabolism induced by the HIV medications used in this patient could be explain the recurrent severe metabolic acidosis.

Highlights

Acidosis refers to any process that leads to an increase in the serum hydrogen ion concentration while acidemia is defined as pH < 7.35 [1]
Recurrent cases of anion gap (AG) metabolic acidosis are rarely reported in the literature and the etiologies included episodic ethylene glycol ingestion, midazolam therapy, D-lactic acidosis secondary to short bowel syndrome, dialysis, pyroglutamic acid buildup associated with acetaminophen ingestion, and 5-oxoproline buildup secondary to glutathione synthetase deficiency [7,8,9,10,11,12]
AG metabolic acidosis is a commonly seen acid-base derangement and its etiology generally attributed to ketoacidosis, lactic acidosis, renal failure, or toxic ingestions

Summary

Introduction

Acidosis refers to any process that leads to an increase in the serum hydrogen ion concentration while acidemia is defined as pH < 7.35 [1]. Acidosis can be further classified as metabolic vs respiratory based on the underlying origin of insult. Respiratory and metabolic acidosis are related to changes in the carbon dioxide and bicarbonate respectively. Metabolic acidosis requires a bicarbonate level less than 24 and can be further subdivided based on the presence or absence of an anion gap [1,2]

Case Presentation

Discussion

Conclusion