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.
In the EU classification of dangerous substances it is harmful (Xn) while more toxic substances are classified as toxic (T) or very toxic (T+). The U.S. Environmental Protection Agency generally puts substances which are lethal at more than 30 g to adults in Toxicity Class III.Ethylene glycol has a low vapor pressure; it does not evaporate readily at normal temperatures and therefore high concentrations in air or intoxication are unlikely to occur following inhalational exposures. There may be a slight risk of poisoning where mists or fogs are generated, although this rarely leads to poisoning as ethylene glycol causes irritation and coughing when breathed in, alerting victims to its presence. Ethylene glycol is not well absorbed through skin meaning poisoning following dermal exposure is also uncommon. Diagnosis
As many of the clinical signs and symptoms of ethylene glycol poisoning are nonspecific and occur in many poisonings the diagnosis is often difficult. It is most reliably diagnosed by the measurement of the blood ethylene glycol concentration. Ethylene glycol in biological fluids can be determined by gas chromatography. Many hospital laboratories do not have the ability to perform this blood test and in the absence of this test the diagnosis must be made based on the presentation of the person. In this situation a helpful test to diagnose poisoning is the measurement of the osmolal gap.