Severe Hypertriglyceridaemia Leading to Factitious Hypobicarbonataemia

Area of Science:

• Clinical Chemistry
• Acid-Base Physiology
• Laboratory Medicine

Background:

• Anion gap metabolic acidosis is a common laboratory finding in critical illnesses like sepsis and diabetic ketoacidosis.
• Serum blood chemistry is the standard method for detecting this acid-base disturbance.
• Elevated triglyceride levels can interfere with standard laboratory measurements.

Purpose of the Study:

• To highlight the impact of hypertriglyceridemia on anion gap metabolic acidosis assessment.
• To emphasize the need for accurate bicarbonate level determination in hospitalized patients.
• To prevent misdiagnosis and unnecessary investigations due to laboratory interference.

Main Methods:

• Review of laboratory principles of lipid interference in blood chemistry.
• Comparison of serum blood chemistry with arterial blood gas analysis and lipid panels.
• Clinical case analysis of patients with high anion gap metabolic acidosis and hypertriglyceridemia.

Main Results:

• High triglyceride levels can lead to falsely low bicarbonate measurements, mimicking other conditions.
• Lipid interference occurs through direct interference with bicarbonate assay and volume displacement.
• Arterial blood gas analysis and lipid panels are essential for confirming true bicarbonate levels.

Conclusions:

• Hypertriglyceridemia is a significant cause of spurious low bicarbonate levels, potentially masking or altering the interpretation of anion gap metabolic acidosis.
• Accurate assessment of acid-base status in patients with elevated triglycerides requires awareness of lipid interference.
• Correctly identifying falsely low bicarbonate levels prevents unnecessary diagnostic work-up and guides appropriate clinical management.