Isopropyl alcohol toxicity

Background

• Main component of rubbing alcohol
• Hallmark is osmolar gap without acidosis
  • Metabolized to acetone, not to an acid
• Takes 30-60min for acetone to appear in blood; 3hr to appear in urine
• Lethal Dose: 4-8 g/kg or 250mL in average adult

Clinical Features

• CNS depression
  • Similar to ETOH intoxication, but longer-lasting
  • Usually peaks in first hour of ingestion
• GI
  • Nausea/vomiting / abdominal pain / hemorrhagic gastritis
• Respiratory depression
• Hypotension
• Hypoglycemia (in malnourished pts)

Differential Diagnosis

• Starvation ketoacidosis
• Diabetic Ketoacidosis
• Inborn errors of metabolism
• Salicylate Toxicity
• Acetone ingestion

Sedative/hypnotic toxicity

• Absinthe
• Barbiturates
• Benzodiazepines
  • Flunitrazepam (Rohypnol)
• Chloral hydrate
• Gamma hydroxybutyrate (GHB)
• Baclofen toxicity
• Opioids
  • Lomotil toxicity
  • Loperamide toxicity
• Toxic alcohols
  • Ethanol
  • Ethylene glycol
  • Isopropyl alcohol
  • Methanol
• Xylazine toxicity

Diagnosis

Work-Up

• Fingerstick glucose
• Complete metabolic panel
• Serum ketones
• Serum Osmolality
• Uinarlysis
• VBG
• Aspirin/Tylenol levels
• ECG
• Serum isopropyl alcohol level (if available)
• Total CK

Evaluation

• Osmolal gap > 10; see Osmolal or Osmolar Gap
• Absence of anion gap
• Absence of metabolic acidosis
• Absence of serum beta hydroxybutyrate
• Presence of serum and urine ketones
  • Consider other diagnosis if absent 2hr after ingestion
• Creatinine may be falsely elevated d/t acetone interference w/ laboratory measurement of Cr

Toxic Alcohols Anion/Osmolar Gaps

	Osmolar gap	Anion gap	Management
Ethanol	+	+ if ketoacidosis	Mainly supportive
Ethylene glycol	+	+	Fomepizole, Thiamine, Pyridoxine, +/- Dialysis
Methanol	+	+	Fomepizole or ethanol, Folinic acid, +/- Dialysis
Isopropyl alcohol	+	-	Mainly supportive

Management

• Treatment is supportive.
• No role for fomepizole or ethanol

Disposition

• Generally may be discharged once clinically sober.