A retrospective analysis of glycol and toxic alcohol ingestion: utility of anion and osmolal gaps

Matthew D Krasowski,Joel Miron,Rebecca M Wilcoxon

doi:10.1186/1472-6890-12-1

Matthew D Krasowski, Joel Miron + Show 1 more

Open Access

https://doi.org/10.1186/1472-6890-12-1

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Abstract

BackgroundPatients ingesting ethylene glycol, isopropanol, methanol, and propylene glycol ('toxic alcohols') often present with non-specific signs and symptoms. Definitive diagnosis of toxic alcohols has traditionally been by gas chromatography (GC), a technique not commonly performed on-site in hospital clinical laboratories. The objectives of this retrospective study were: 1) to assess the diagnostic accuracy of the osmolal gap in screening for toxic alcohol ingestion and 2) to determine the common reasons other than toxic alcohol ingestion for elevated osmolal gaps.MethodsElectronic medical records from an academic tertiary care medical center were searched to identify all patients in the time period from January 1, 1996 to September 1, 2010 who had serum/plasma ethanol, glucose, sodium, blood urea nitrogen, and osmolality measured simultaneously, and also all patients who had GC analysis for toxic alcohols. Detailed chart review was performed on all patients with osmolal gap of 9 or greater.ResultsIn the study period, 20,669 patients had determination of serum/plasma ethanol and osmolal gap upon presentation to the hospitals. There were 341 patients with an osmolal gap greater than 14 (including correction for estimated contribution of ethanol) on initial presentation to the medical center. Seventy-seven patients tested positive by GC for one or more toxic alcohols; all had elevated anion gap or osmolal gap or both. Other than toxic alcohols, the most common causes for an elevated osmolal gap were recent heavy ethanol consumption with suspected alcoholic ketoacidosis, renal failure, shock, and recent administration of mannitol. Only 9 patients with osmolal gap greater than 50 and no patients with osmolal gap greater than 100 were found to be negative for toxic alcohols.ConclusionsOur study concurs with other investigations that show that osmolal gap can be a useful diagnostic test in conjunction with clinical history and physical examination.

Highlights

Patients ingesting ethylene glycol, isopropanol, methanol, and propylene glycol (’toxic alcohols’) often present with non-specific signs and symptoms
In addition to the organ damage caused by metabolites of ethylene glycol and methanol, all three toxic alcohols are capable of producing central nervous system (CNS) depression that in and of itself may be life-threatening [1,4]
Serum/plasma concentrations of ethylene glycol, propylene glycol, methanol, isopropanol, and acetone were measured by gas chromatography (GC) (Agilent 6850 with 7683 injector, Agilent Technologies, Santa Clara, CA, USA), which served as the gold standard technique for diagnosis of toxic alcohol ingestion

Summary

Introduction

Isopropanol, methanol, and propylene glycol (’toxic alcohols’) often present with non-specific signs and symptoms. Definitive diagnosis of toxic alcohols has traditionally been by gas chromatography (GC), a technique not commonly performed on-site in hospital clinical laboratories. Methanol is likewise metabolized by a series of enzymatic reactions to formic acid, a toxic compound that can cause blindness from permanent injury to the optic nerve. Both ethylene glycol and methanol are capable of causing marked metabolic acidosis, mainly due to their metabolites. In addition to the organ damage caused by metabolites of ethylene glycol and methanol, all three toxic alcohols are capable of producing central nervous system (CNS) depression that in and of itself may be life-threatening [1,4]

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