Abstract: TH-PO1119
Lactate Gap as an Early Diagnostic Clue in Ethylene Glycol Intoxication
Session Information
- Pathology and Lab Medicine
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1700 Pathology and Lab Medicine
Authors
- St Gilus, Rose H., Stamford Health, Stamford, Connecticut, United States
- Rosen, Raphael Judah, Stamford Health, Stamford, Connecticut, United States
Introduction
Ethylene glycol intoxication is a life-threatening medical emergency that requires rapid recognition and management to prevent accumulation of toxic metabolites and limit end-organ injury. We present a case of ethylene glycol poisoning in which the initial diagnostic clue was a lactate gap, defined as a marked discrepancy between lactate levels measured by point-of-care blood gas analyzers and standard laboratory assays.
Case Description
A 34-year-old man with no significant medical history presented with slurred speech, ataxia, nausea, and vomiting. Vital signs were stable. Neurologic exam showed marked asterixis without focal deficits. Laboratory studies revealed mild hyperkalemia (5.6), AKI (Cr 1.5 mg/dL; baseline 0.9), high anion gap metabolic acidosis (anion gap 17) and an elevated osmolar gap of 18. BHB, ethanol, salicylate, and acetaminophen levels were normal. Lactate level measured by arterial blood gas lactate was 17 mmol/L, while simultaneous venous lactate was 2.1 mmol/L, demonstrating a significant lactate gap and raising suspicion for ethylene glycol intoxication. The patient received fomepizole in consultation with poison control. Despite early therapy, kidney function worsened and he ultimately required dialysis. Kidney biopsy demonstrated tubular degenerative changes with prominent calcium oxalate deposition, confirming acute oxalate nephropathy from ethylene glycol poisoning. His renal function gradually improved, and he was discharged without dialysis with creatinine 8 mg/dL, later improving to 1.0 mg/dL at 4-month follow-up.
Discussion
This patient exhibited the “triple gap” – elevated osmolar gap (due to the uncharged parent alcohol), elevated anion gap (due to the charged metabolites) and an elevated lactate gap due to the presence of oxalate and glyoxylate. The lactate gap occurs because glycolate and glyoxylate, metabolites of ethylene glycol, may be falsely detected as lactate by point-of-care blood gas analyzers due to structural similarity.