Flashcards in Toxic Alcohols Deck (13):
What is the Ddx of an elevated Osmol Gap:
· The alcohols:
o Propylene glycol (Ativan/diazepam/dilantin/dig/phenobarb/septra IV)
· Sugars + ketones:
o Acetone (as seen in DKA/AKA/SKA)
· Ethyl ether
o Hyperprotemia à from sepsis, renal failure
· Contrast dyes
DDx double Gap (ie AG/Osm gap)
· Methanol / ethylene glycol
· End stage renal Dz
· Paraldehyde / formaldehyde
· Lactic acidosis
· Propylene glycol
Critical illness, multiorgan failure
List products found in the home that contain methanol.
- Gasoline industrial Antifreeze
- Windshield washer fluid
- Carburator fluid
- Duplicator fluid
- Hobby (model airplane) engine fuel
- Embalming fluid & formalin
Caterer gas for food heaters
- Dry gas
- Sterno (silver polish)
- Glass cleaners
- Adhesives, inks
What occupations are at high risk for inhalation of methanol?
Describe the metabolism of methanol.
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
What are the two main complications of severe methanol toxcity?
- Optic neuropathy – Visual impairment and blindness
Putaminal necrosis – Parkinsonian motor dysfunction
What urinary finding is associated with ethylene glycol toxicity?
- Calcium oxalate crystals
What products contain ethylene glycol?
- Commercial antifreeze
- Commercial coolant
- Airplane deicing solutions
- Hydraulic brake fluid
- Industrial solvents/precursors
Describe the metabolism of ethylene glycol.
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%)
Describe the timing and clinical characteristics of each stage of ethylene glycol toxicity.
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
What are the indications for ADH blockade in toxic alcohol ingestion
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
List indications for hemodialysis in methanol or ethylene glycol toxicity?
pH LT 7.1
pH drom 0.5+ despite HCO3 infusion
pH LT 7.3 despite HCO3 infusion
deteriorating vitals despite care
visual or neuro impairement
methanol level GT 15.6