S15C179 - Alcohols

Question 1

Isopropanol

Answer 1

• AKA: isopropyl alcohol, rubbing alcohol, paint thinner, de-icer
• peak blood 30-120min
• hepatic metabolism
• ketosis and osmolar gap w/o acidosis
• metabolite is acetone which is not toxic
• Sx: coma, resp dpn, HoTN, n/v, abdo pain, gastritis , fruity breath (acetone)
• Dx: serum levels
• Tx: supportive, giving fomepizole will just prolong everything so don’t give, acetone not harmful, HD if refractory HoTN

Question 2

Methanol

Answer 2

• windshield fluid, antifreeze
• peak levels in 30-60min
• lethal dose: 1g/kg or 1.25ml/kg, permanent blindness at 24g or 30ml
• toxic metabolite: formic acid causes toxicity, acidosis, lactic acidosis, and blindness (photphobia, blurred, snow field vision, papilledema)
• Sx: metabolic acidosis, visual changes, CNS depression
• tx: fomepizole prevents methanol degradation so that it can be cleared by the kidneys in it’s adult form, folate
• coingestion with EtOH worsens the toxicity b/c causes toxic metabolite bulid up

Question 3

Ethylene Glycol

Answer 3

• antifreeze, hydraulic brake fluid, sweet tasting
• toxic metabolite: glycolic acid
• glycolic acid binds calcium and precipitates out to oxalic acid in tissues and urine, hypocalcemia develops
• CNS depression, metabolic acidosis, renal failure
• abdo pain, n/v, meningismus, cerebral edema
• > 12h: tachy, HTN, CHF, ALI, myositis
• > 24h: reanl stage, renal fialure, HD
• Dx: ABG, acidosis (initially an osmolar gap that decreases and acidosis increases)
• Tx: fomepizole 15mg/kg IV over 30 min then 10mg/kg IV q12h, hemodialysis (HD), pyridoxine, thiamine, Mg
• HD for: refractory acidosis pH 50mg/dL