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I am very sorry to hear about your cousin, and that he drank anti freeze (ethylene glycol).
Much about his prognosis depends on the amount he drank, and when treatment was initiated.
That he is young is of course to his benefit, as he will recover more easily than an if an older person was exposed to this same poison.
If he waited a few days to seek help, rather than getting treatment immediately after ingesting then there may be permanent damage to his kidneys
If this was a suicide attempt, then the underlying depression will need treatment, and dealing with the results of the poisoning itself can sometimes result in depression. (It sounds like he may not have realized what he was drinking?) - If so that at least will help him from having to deal with as severe as a depression or a mood disorder which is likely if this were a suicide attempt.
There are considered to be 3 stages of poisoning from Ethylene glycol:
1: Neurological (30 minutes to 12 hours after ingestion) - inebriation and euphoria (similar to alcohol ingestion); then nausea & vomiting, metabolic acidosis and central nervous system depression. In severe cases coma & seizures can occur
2: Cardiopulmonary (12-24 hours after ingestion)
In the second stage of ethylene glycol poisoning, tachycardia and mild hypertension frequently occur (fast heart beat and high blood pressure) In serious cases, severe metabolic acidosis with compensatory hyperventilation can develop accompanied by multiple organ failure. Most deaths occur in this stage
Stage 3: Renal (24-72 hours after ingestion)
The symptoms of the third stage can include oliguria (lack of urine production by the kidneys) flank pain, renal failure and, in rare instances, bone marrow suppression. Recovery of renal function is often complete but may require several months of hemodialysis. Even when renal damage is severe, chronic hemodialysis or renal transplantation are rarely required. Serious damage to the liver is rare. (Reference: http://www.antizol.com/egpoisono.htm)
There are statistics about survival/effects are available:
Ethylene glycol is a relatively common cause of overdose in American emergency departments. In 2007, 4966 single exposure cases were reported to the American Association of Poison Control Centers;1 the 2008 incidence data remains much the same, with 4921 single exposures to ethylene glycol reported.2 Rapid intervention often makes an important difference in the outcome of ethylene glycol toxicity.
According to the annual report of the American Association of Poison Control Centers' National Poison Data System in 2007, 878 had minor outcomes, 365 had moderate outcomes, 135 had severe outcomes, and 16 deaths were documented.1 Similar data were reported in the 2008 American Association of Poison Control Centers' National Poison Data System annual report: 780 minor outcomes, 358 moderate outcomes, 140 major outcomes, and 7 deaths.2
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