Toxic Alcohols

Question 1

What is the Ddx of an elevated Osmol Gap:

Answer 1

· The alcohols:
	o EtOH
	o Methanol
	o Ethenol
	o Isopropanolol
	o Propylene glycol (Ativan/diazepam/dilantin/dig/phenobarb/septra IV)
· Sugars + ketones:
	o Mannitol
	o Acetone (as seen in DKA/AKA/SKA)
· Ethyl ether
· Lipids:
	o Hyperlipidemia
· Protein:
	o Hyperprotemia à from sepsis, renal failure
· Contrast dyes
· Acidosis

Question 2

DDx double Gap (ie AG/Osm gap)

Answer 2

· Methanol / ethylene glycol
· DKA/AKA
· End stage renal Dz
· Paraldehyde / formaldehyde
· Acetonitrate
· Lactic acidosis
· Propylene glycol
Critical illness, multiorgan failure

Question 3

List products found in the home that contain methanol.

Answer 3

• Gasoline industrial Antifreeze
• Windshield washer fluid
• Carburator fluid
• Duplicator fluid
• Hobby (model airplane) engine fuel
• Embalming fluid & formalin
• MOONSHINE!!!
  Caterer gas for food heaters
• Gasohol
• Dry gas
• Sterno (silver polish)
• Glass cleaners
• Thinners
• Adhesives, inks

Question 4

What occupations are at high risk for inhalation of methanol?

Answer 4

• Painting
• Glazing
• Lithography
  Printing

Question 5

Describe the metabolism of methanol.

Answer 5

methanol oxidised by ADH to formaldehyde
converted th Aldehyde by aldehyde dehydrogenase (AD) to formic acid
then with folic acid converted to CO2 and water

Question 6

What are the two main complications of severe methanol toxcity?

Answer 6

• Optic neuropathy – Visual impairment and blindness

Putaminal necrosis – Parkinsonian motor dysfunction

Question 7

What urinary finding is associated with ethylene glycol toxicity?

Answer 7

• Calcium oxalate crystals

Question 8

What products contain ethylene glycol?

Answer 8

• Commercial antifreeze
• Commercial coolant
• Airplane deicing solutions
• Hydraulic brake fluid
• Industrial solvents/precursors
• Paints
• Cosmetics
  Lacquers

Question 9

Describe the metabolism of ethylene glycol.

Answer 9

Hepatic metabolism (70%)
- Hepatic oxidation by ADH and other oxidative enzymes to various organic toxic aldehydes and acids.
- Glycoxylic acid can be metabolized to non-toxic metabolites with thiamine and pyridoxine as co-factors

Renal clearance (30%)

Question 10

Describe the timing and clinical characteristics of each stage of ethylene glycol toxicity.

Answer 10

Stage I (30 min to 12hr): inebriation

Stage II (12-24hr): cardiopulmonary stage

Stage III (24-72hr) renal stage

stage IV (6-12d): delayed neuro sequelae

Question 11

What are the indications for ADH blockade in toxic alcohol ingestion

Answer 11

1. Hx with OG GT 10
2. Plasma concentration GT 3.2mmol/l EG or 6.2mmol/L methanol
3. suspected ingestion with:
   -pH LT 3
   -HCO3 LT 20
   -OG GT 10
   oxalate crystalutia

Question 12

List indications for hemodialysis in methanol or ethylene glycol toxicity?

Answer 12

pH  LT 7.1
pH drom 0.5+ despite HCO3 infusion
pH LT 7.3 despite HCO3 infusion
renal failure
deteriorating vitals despite care
visual or neuro impairement
methanol level GT 15.6

Question 13

List additional therapies that are indicated in methanol/EG toxicity?

Answer 13

- Methanol:
	o Folic acid  or Leucoviron (Folinic acid) 50mg iv q4h
- Ethylene glycol:
	o Thiamine 100mg x 1
	o Pridoxine 60mg x 1
Consider MgSO4 as well