Tox

Question 1

Wernickes triad

Answer 1

Nystagmus
Ataxia
Altered mental status

REVERSIBLE

Question 2

Ethylene glycol

what’s it in?
lethal dose?
what does it do?
Timeline of effects?

Answer 2

In - antifreeze, radiator coolants, solvents, brake fluids

Lethal dose >1mg/kg

Does -
HAGMA
Converted to oxalic acid which complexes with Ca - crystals

1-2h - CNS
Euphoria, drowsiness, N&V.
Increased osmolar gap.

4-12h - Cardio/ resp failure
HAGMA, high lactate
HypoCa (has crystalised)
Dyspnoea, tachypnoea
Tachycardia, hypotension, SHOCK
LOC, coma
Seizure 
Death

24-72h - CNS, renal failure
LOC
Seizure 
Death
Flank pain - ARF from ATN

5-20 days - late cranial neuropathy

Question 3

Ethylene glycol - clinical features

Answer 3

Does -
HAGMA
Converted to oxalic acid which complexes with Ca - crystals

1-2h - CNS
Euphoria, drowsiness, N&V.
Increased osmolar gap.

4-12h - Cardio/ resp failure
HAGMA, high lactate
HypoCa (has crystalised)
Dyspnoea, tachypnoea
Tachycardia, hypotension, SHOCK
LOC, coma
Seizure 
Death

24-72h - CNS, renal failure
LOC
Seizure 
Death
Flank pain - ARF from ATN

5-20 days - late cranial neuropathy

Question 4

Ethylene glycol management

Answer 4

ABC
Likely acidaemic - consider bicarb pre intubation
Risk seizures

ONLY correct HypoCa if
REFRACTORY SEIZURES
PROLONGED QT

HAEMODYIALYSIS is definitive Mx

Temporising -
Ethanol
Fomepizole

Question 5

HD for ethylene glycol - indications and end points

Answer 5

Indications:
Hx of EG ingestion with osmolar gap <10
pH <7.3
Acute Renal failure
Ethylene glycol level >8mmol/l

Endpoints:
Corection of acidosis
Osmolar Gap <10
Ethylene glycol level <3.2mmol/l

Question 6

Methanol

• what’s it in
• lethal dose
• what does it do

Answer 6

In home made alcohol, solvents

Lethal dose >0.5ml/kg

Does
Metabolised to formic acid
HAGMA
Direct cellular toxicity, increases lactate
Directly toxic retina - blindness
Directly toxic brain - subcortical white matter haemorrhage, putamental oedema

Question 7

Methanol - timeline

Answer 7

> 0.5ml/kg potentially lethal

1h - mild CNS depression, N&V

LATENT PERIOD

12-24h - headache, dizziness, vertigo, dyspnoea, blurred vision,photophobia
severe - drowsiness, blindness, coma/ seizure (cerebral oedema), tachypnoea (MA)

If recover - extrapyramidal movement disorders
1/3 irreversible visual complications

Question 8

Methanol - management

Answer 8

> 0.5ml/kg potentially lethal

HAGMA - hyperventillate if intubate, consider bicarb

pH<7.3 - 50mmol NaBicarb (acidosis worsens formic acid toxicity)

Seizures

Hypoglycaemia

FOLINIC ACID/ FOLIC ACID 50mg IV every 6h until toxicity resolved (cofactor)

Thiamine

HAEMODIALYSIS is DEFINITIVE

Ethanol/ fomepizole as temporising

Question 9

Methanol - indications for HD

End points of HD

Answer 9

Indications:
Any patient meeting criteria for ADH blockade
pH <7.3
Visual symptoms
Renal failure
Deterioration in vision/ electrolytes despite supportive care
Methanol level >16mmol/l

End points:
Correction of acidosis
Osmolar Gap <10
Methanol level <6mmol/l

Question 10

Isopropyl alcohol

Answer 10

hand sanitiser/ disinfectant

> 4ml/kg CNS effects

Rapid onset intoxication similar to ethanol
Resp depression, hypotension, CNS depression

Like ethanol but more potent and longer acting

Increased OG
NOT HAGMA (like EG/ Meth)

Managed by supportive care, HD rarely indicated