What is the treatment for a patient with suspected brake fluid poisoning?

Brake Fluid Poisoning Treatment

Immediately contact a poison control center (1-800-222-1222 in the US) and initiate aggressive supportive care with airway protection, intravenous ethanol or fomepizole to block alcohol dehydrogenase, sodium bicarbonate for metabolic acidosis, and early hemodialysis for severe cases—brake fluid contains toxic glycol ethers that cause life-threatening metabolic acidosis, coma, and renal failure. 1, 2, 3

Immediate Stabilization and Toxicology Consultation

• Secure the airway immediately if the patient shows altered mental status, as coma can develop within 4 hours of ingestion and requires intubation for airway protection 2, 4
• Contact poison control immediately for specialized guidance, as brake fluid poisoning requires toxicological expertise that most clinicians rarely encounter 1
• Establish IV access and begin continuous cardiac monitoring, as systemic toxicity causes electrolyte disturbances and metabolic derangements 5

Toxin Identification and Clinical Assessment

Brake fluid contains multiple toxic glycol ethers (polyethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monomethyl ether, and others at varying concentrations) that are metabolized by alcohol dehydrogenase into acidic metabolites 2, 6. The key clinical features include:

• Rapid onset of CNS depression (somnolence to coma within 1-4 hours) 2, 3, 4
• Severe metabolic acidosis with increased anion gap (pH can drop to 7.03) 3, 4
• Renal impairment developing over hours to days 4
• Seizures and hypotension in severe cases 4

Decontamination

• Do NOT induce vomiting with ipecac or any other method, as this is explicitly contraindicated and causes harm 5, 7
• Do NOT perform gastric lavage, as it provides no benefit and increases risk of aspiration 5
• Do NOT administer activated charcoal unless specifically directed by poison control, as it has uncertain benefit for glycol ether poisoning 7
• For skin exposure, immediately remove all contaminated clothing and irrigate with copious running water for at least 15 minutes 5

Alcohol Dehydrogenase Inhibition (Critical Antidote)

The cornerstone of treatment is blocking alcohol dehydrogenase to prevent formation of toxic acidic metabolites:

First-Line: Fomepizole (Preferred)

• Administer fomepizole immediately without waiting for confirmatory testing if significant ingestion is suspected 2, 3
• Loading dose: 15 mg/kg IV, followed by 10 mg/kg every 12 hours 2
• Continue until glycol ether levels are undetectable and acidosis has resolved 2

Alternative: Intravenous Ethanol

• Use IV ethanol if fomepizole is unavailable, as ethanol competitively inhibits alcohol dehydrogenase 3, 6
• Loading dose: 600-800 mg/kg IV, then continuous infusion to maintain serum ethanol at 100 mg/dL 3
• Continue for at least 22 hours or until acidosis resolves and glycol levels are undetectable 3

Last Resort: Oral Ethanol

• Oral ethanol (whisky via nasogastric tube) can be used when neither fomepizole nor IV ethanol is available 6
• This is a viable alternative that has been successfully used in resource-limited settings 6

Metabolic Acidosis Management

• Administer sodium bicarbonate aggressively for pH <7.2 or severe acidosis (start with 100 mmol IV bolus) 3, 4
• Monitor serial arterial blood gases every 2-4 hours to guide bicarbonate therapy 3
• Correct electrolyte abnormalities including hypocalcemia, hypokalemia, and hyponatremia 5

Hemodialysis Indications

Initiate hemodialysis urgently for:

• Severe or refractory metabolic acidosis despite bicarbonate therapy 2
• Renal impairment or rising creatinine 2, 4
• Persistent CNS depression 2
• Large ingestion volume (>100 mL) even if initially stable 2, 6

Hemodialysis for 3 hours starting approximately 8 hours post-ingestion has resulted in complete symptom resolution 2

Critical Laboratory Monitoring

• Obtain immediately: Complete blood count, comprehensive metabolic panel, arterial blood gas, lactate, anion gap, serum creatinine 5, 3
• Serial monitoring every 2-4 hours for the first 24 hours: pH, bicarbonate, anion gap, creatinine 2, 3
• Serum ethanol, ethylene glycol, and methanol levels to rule out co-ingestions 3
• Continue monitoring for 48-72 hours minimum, as delayed effects can occur even in apparently stable patients 7

Supportive Care

• Benzodiazepines (diazepam or midazolam) for seizures if they occur 7, 4
• Vasopressor support (norepinephrine preferred) for hypotension refractory to fluid resuscitation 4
• Mechanical ventilation for respiratory failure or airway protection in comatose patients 4

Common Pitfalls to Avoid

• Do not delay antidote administration while waiting for confirmatory glycol ether levels—treat based on history and clinical presentation 7, 2
• Do not stop alcohol dehydrogenase inhibition prematurely—continue until acidosis resolves AND glycol levels are undetectable 2, 3
• Do not rely on initial clinical stability to rule out significant poisoning—severe toxicity can develop 4-8 hours post-ingestion 2
• Do not discharge patients before 48-72 hours of observation, even if they appear stable, as delayed renal and neurological effects can occur 7

Psychiatric Evaluation

• Mandatory psychiatric evaluation is required for all intentional ingestions before discharge, as these patients have high risk of repeat suicide attempts 5