Ethylene Glycol Poisoning: An Unusual Cause of Altered Mental Status and the Lessons Learned from Management of the Disease in the Acute Setting

Abstract

Ethylene glycol is found in many household products and is a common toxic ingestion. Acute ingestions present with altered sensorium and an osmolal gap. The true toxicity of ethylene glycol is mediated by its metabolites, which are responsible for the increased anion gap metabolic acidosis, renal tubular damage, and crystalluria seen later in ingestions. Early intervention is key; however, diagnosis is often delayed, especially in elderly patients presenting with altered mental status. There are several laboratory tests which can be exploited for the diagnosis, quantification of ingestion, and monitoring of treatment, including the lactate and osmolal gaps. As methods of direct measurement of ethylene glycol are often not readily available, it is important to have a high degree of suspicion based on these indirect laboratory findings. Mainstay of treatment is bicarbonate, fomepizole or ethanol, and, often, hemodialysis. A validated equation can be used to estimate necessary duration of hemodialysis, and even if direct measurements of ethylene glycol are not available, monitoring for the closure of the anion, lactate, and osmolal gaps can guide treatment. We present the case of an elderly male with altered mental status, acute kidney injury, elevated anion gap metabolic acidosis, and profound lactate and osmolal gaps.

Rapid Diagnosis of Ethylene Glycol Poisoning by Urine Microscopy

“…Furthermore, the value of this test to guide acute diagnostics is limited because obtaining the results often takes 24–48 h. Sankaralingam et al presented an enzymatic spectrophotometric assay for measuring ethylene glycol, but this method is not available in most hospitals [ 4 ]. As indirect tests, osmolar gap, anion gap, lactic acidosis, and hypocalcemia are used, but these analyses can only support the clinical suspicion of ethylene glycol poisoning, and none of these can serve as a definitive diagnostic test [ 1 , 11 ]. Microscopic visualization of COM crystals in the urine is not definitive, but it adds valuable information to support the diagnosis and thus facilitates early targeted treatment.…”

“…Ethylene glycol is a common ingredient in many household products such as household cleaners, cosmetics, and antifreeze coolant [ 1 , 2 ]. In the United States there are nearly 6000 yearly cases of ethylene glycol poisoning reported to poison control centers, with most cases of accidental poisoning occurring in children [ 3 , 4 ].…”

“…The treatment for ethylene glycol poisoning is often commenced based on clinical suspicion because diagnostic testing, such as measuring the ethylene glycol concentration in blood, is not available in emergency settings [ 3 , 7 ]. The suspicion of ethylene glycol poisoning is often supported by indirect findings in blood samples, such as an increased serum osmolal gap and severe unexplained anion gap metabolic acidosis [ 1 ].…”

Lactate Gap: A Diagnostic Support in Severe Metabolic Acidosis of Unknown Origin

“…Additionally, patients presenting late after intake may have normal ethylene glycol levels ( Figure 2 ). They could be critically ill, however, having metabolized ethylene glycol to its toxic metabolites already ( Figure 2 ) [ 9 ].…”

A Case of Ethylene Glycol intoxication with Acute Renal Injury: Successful Recovery by Fomepizole and Renal Replacement Therapy

“…According to a report by the American Association of Poison Control Centers, 809 cases of ethylene glycol poisoning were reported in 2014, and ethylene glycol poisoning was the third most common cause of poisoning-related deaths after ethanol and carbon monoxide poisoning 17) . However, the exact number of Korean cases is unknown owing to a lack of statistical data in Korea.…”