If untreated, death most commonly occurs during this period. Stage 3 (24 to 72 hours) kidney failure is the result of ethylene glycol poisoning. In cats, this stage occurs 12–24 hours after consuming antifreeze; in dogs, at 36–72 hours after consuming antifreeze. During this stage, severe kidney failure is developing secondary to calcium oxalate crystals forming in the kidneys. Severe lethargy, coma, depression, vomiting, seizures, drooling, and inappetence may be seen. Other symptoms include acute tubular necrosis, red blood cells in the urine, excess proteins in the urine, lower back pain, decreased or absent production of urine, elevated blood concentration of potassium, and acute kidney failure. If kidney failure occurs it is typically reversible, although weeks or months of supportive care including hemodialysis may be required before kidney function returns. Sources
The most common source of ethylene glycol is automotive antifreeze or radiator coolant, where concentrations are high. Other sources of ethylene glycol include windshield deicing agents, brake fluid, motor oil, developing solutions for hobby photographers, wood stains, solvents, and paints. Some people put antifreeze into their cabins toilet to prevent it from freezing during the winter, resulting in toxicities when animals drink from the toilet. Small amounts of ethylene glycol may be contained in holiday ornaments such as snow globes.The most significant source of ethylene glycol is from aircraft de-icing and anti-icing operations, where it is released onto land and eventually to waterways near airports experiencing cold winter climates. It is also used in manufacturing polyester products.
Hemodialysis is usually indicated in people with severe metabolic acidosis (blood pH less than 7.3), kidney failure, severe electrolyte imbalance, or if the persons condition is deteriorating despite treatment. Often both antidotal treatment and hemodialysis are used together in the treatment of poisoning. Because hemodialysis will also remove the antidotes from the blood, doses of antidotes need to be increased to compensate. If hemodialysis is not available, then peritoneal dialysis also removes ethylene glycol, although less efficiently. Prognosis
Treatment for antifreeze poisoning needs to be started as soon after ingestion as possible to be effective; the earlier treatment is started, the greater the chance of survival. Cats must be treated within 3 hours of ingesting of antifreeze to be effective, while dogs must be treated within 8–12 hours of ingestion. Once kidney failure develops, the prognosis is poor.Generally, if the person is treated and survives then a full recovery is expected. People who present early to medical facilities and have prompt medical treatment typically will have a favorable outcome. Alternatively, people presenting late with signs and symptoms of coma, hyperkalemia, seizures, or severe acidosis have a poor prognosis. People who develop severe central nervous system manifestations or stroke who survive may have long term neurologic dysfunction; in some cases they may recover, although convalescence may be prolonged. The most significant long-term complication is related to the kidneys. Cases of permanent kidney damage, often requiring chronic dialysis or kidney transplantation, have been reported after severe poisoning. Epidemiology
Ethylene glycol poisoning is a relatively common occurrence worldwide.