If a patient is suspected of ethylene glycol or propylene glycol toxicity, a series of laboratory blood tests are required, as reported by the Agency for Toxic Substances and Disease Registry. Some of these tests include testing blood glucose, arterial blood gases, serum electrolytes and blood ethanol.
Additionally, several other tests are useful in determining ethylene glycol and propylene glycol toxicity. These include serum BUN and creatinine tests, calcium and magnesium levels, acetaminophen and aspirin levels, liver function tests, and urinalysis, as listed by the Agency for Toxic Substances and Disease Registry. During a urinalysis, special attention should be given to crystalluria.
During a urinalysis test, several things are observed. The presence of calcium oxalate or hippurate crystals in the urine, combined with an elevated anion gap or osmolal gap, strongly suggests ethanol glycol poisoning. However, absence of urinary crystals does not rule out glycol poisoning. Reports indicate that renal damage can occur without deposits of calcium oxalate crystals in the kidneys, as reported by ATSDR.
Although not always considered to be a reliable diagnostic test, urine may be tested to see if it fluoresces under a Wood's lamp, explains ATSDR. It is established that ethylene glycol and propylene glycol are present in antifreeze. This particular test is administered because some antifreeze products also contain fluorescein.
A serum analysis of elevated ethylene glycol levels in the blood confirms ethylene glycol toxicity, according to ATSDR. An ethylene glycol level of greater than 25 milligrams per deciliter is considered to be elevated.