Recognizing Pseudohypobicarbonatemia in Patients with Hypertriglyceridemia - A Case Report

Pseudohypobicarbonatemia is a laboratory artifact in which severe hypertriglyceridemia interferes with enzymatic bicarbonate measurements, leading to falsely low levels that can mimic metabolic acidosis. We present a case of a patient with diabetes and hyperlipidemia who was initially found to have profound hypobicarbonatemia and an elevated anion gap, raising concerns for metabolic acidosis. However, arterial blood gas analysis revealed a normal acid-base status, prompting further investigation and identification of severe hypertriglyceridemia (>1100 mg/dL) as the underlying cause. This case highlights the diagnostic challenges posed by hypertriglyceridemia-induced lab errors and underscores the importance of confirming suspected metabolic acidosis with arterial blood gas analysis. Awareness of pseudohypobicarbonatemia is crucial to prevent unnecessary interventions and ensure accurate clinical decision-making.