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Flashcards in Toxic Alcohols Deck (13)
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1
Q

What is the Ddx of an elevated Osmol Gap:

A
· 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
2
Q

DDx double Gap (ie AG/Osm gap)

A
· Methanol / ethylene glycol
· DKA/AKA
· End stage renal Dz
· Paraldehyde / formaldehyde
· Acetonitrate
· Lactic acidosis
· Propylene glycol
Critical illness, multiorgan failure
3
Q

List products found in the home that contain methanol.

A
  • 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
4
Q

What occupations are at high risk for inhalation of methanol?

A
  • Painting
  • Glazing
  • Lithography
    Printing
5
Q

Describe the metabolism of methanol.

A

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

6
Q

What are the two main complications of severe methanol toxcity?

A
  • Optic neuropathy – Visual impairment and blindness

Putaminal necrosis – Parkinsonian motor dysfunction

7
Q

What urinary finding is associated with ethylene glycol toxicity?

A
  • Calcium oxalate crystals
8
Q

What products contain ethylene glycol?

A
  • Commercial antifreeze
  • Commercial coolant
  • Airplane deicing solutions
  • Hydraulic brake fluid
  • Industrial solvents/precursors
  • Paints
  • Cosmetics
    Lacquers
9
Q

Describe the metabolism of ethylene glycol.

A
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%)
10
Q

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

A

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

11
Q

What are the indications for ADH blockade in toxic alcohol ingestion

A
  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
12
Q

List indications for hemodialysis in methanol or ethylene glycol toxicity?

A
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
13
Q

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

A
- 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