Isopropyl alcohol toxicity: Difference between revisions

 
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==Background==
==Background==
*Main component of rubbing alcohol
*Main component of rubbing alcohol
*Hallmark is osmolar gap without acidosis
*Hallmark is osmolar gap, ketosis, that is without acidosis
**Metabolized to acetone, not to an acid
**Metabolized to acetone, not to an acid
*Takes 30-60min for acetone to appear in blood; 3hr to appear in urine
*Takes 30-60 min for acetone to appear in blood; 3 hr to appear in urine
*Lethal Dose: 4-8 g/kg or 250mL in average adult
*Lethal Dose: 4-8 g/kg or 250 mL in average adult (calculated using volume of pure isopropyl alcohol)
**Typical store bought rubbing alcohol is 70% isopropyl alcohol by volume, so lethal dose is ~ 350 mL


== Clinical Features ==
==Pharmacology<ref>Kraut JF, Kurtz I. Clin J Am Soc Nephrol 2008. PMID: 18045860</ref>==
*Unlike other toxic alcohols (methanol, ethylene glycol), toxic effects caused by parent agent (IA) rather than metabolite (acetone)
*Metabolized to acetone by alcohol dehydrogenase
*Maximal distribution in ≤ 2 hours
*Lethal dose > 200 mg/dL, although variable literature
 
==Clinical Features==
*CNS depression
*CNS depression
**Similar to ETOH intoxication, but longer-lasting
**Similar to ETOH intoxication, but longer-lasting
**Usually peak in first hour of ingestion
**Usually peaks in first hour of ingestion
*GI
*GI
**N/V / abd pain / hemorrhagic gastritis
**[[Nausea/vomiting]] / [[abdominal pain]] / hemorrhagic gastritis
*Respiratory depression
*Respiratory depression
*Hypotension
**Fruity breath from acetone
*Hypoglycemia (in malnourished pts)
*[[Hypotension]], [[hypothermia]] from peripheral vasodilation
*[[Hypoglycemia]] (in malnourished patients)


== Differential Diagnosis ==
==Differential Diagnosis==
*[[Ethanol Toxicity]]
*[[Starvation ketoacidosis]]
*[[Methanol Toxicity]]
*[[Ethylene Glycol Toxicity]]
*Starvation ketoacidosis
*[[Diabetic Ketoacidosis]]
*[[Diabetic Ketoacidosis]]
*Inborn errors of metabolism  
*Inborn errors of metabolism  
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*Acetone ingestion
*Acetone ingestion


==Diagnosis==
{{Sedatve/hypnotic toxicity types}}
=== Work-Up ===
 
==Evaluation==
===Work-Up===
*Fingerstick glucose
*Fingerstick glucose
*Complete metabolic panel
*Complete metabolic panel
*Serum ketones
*Serum ketones
*Serum Osmolality
*Serum Osmolality
*Uinarlysis
*Urinalysis
*VBG
*VBG
*Aspirin/Tylenol levels
*Aspirin/Tylenol levels
*ECG
*[[ECG]]
*Serum isopropyl alcohol level (if available)
*Serum isopropyl alcohol level (if available)
*Total CK
*Total CK


=== Evaluation ===
===Evaluation===
*Osmolal gap > 10; see [[Osmolal or Osmolar Gap]]
*Osmolal gap > 10; see [[Osmolal or Osmolar Gap]]
*Absence of anion gap
*Absence of anion gap
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*Presence of serum and urine ketones
*Presence of serum and urine ketones
**Consider other diagnosis if absent 2hr after ingestion
**Consider other diagnosis if absent 2hr after ingestion
*Creatinine may be falsely elevated d/t acetone interference w/ laboratory measurement of Cr
*Creatinine may be falsely elevated due to acetone interference with laboratory measurement of Cr
 
{{Toxic Alcohols Anion/Osmolar Gaps}}


==Treatment==
==Management==
*Mechanical ventilation may be necessary
*Treatment is supportive.
*Hypotension
*No role for fomepizole or ethanol
**Usually responsive to IVF; pressors may be necessary
**Blockade of alcohol dehydrogenase (ADH) will prolong intoxication
*Hemodialysis
*Hemodialysis indications:
**Consider for:
**Hypotension
***Hypotension refractory to conventional therapy
**Comatose
***Isopropanol level >400
**Consider if IA serum level >200mg/dL


===Contraindicated===
==Disposition==
*Fomepizole
*Generally may be discharged once clinically sober.
**Metabolite, acetone, is no more toxic than the parent compound
**Use may lead to prolonged CNS toxicity
*GI decontamination
**Activated charcoal ineffective (absorbed too quickly)


== Disposition ==
==See Also==
*Consider discharge if asymptomatic x 4-6hr
*[[Toxic alcohols]]
*[[In-Training Exam Review]]


== References ==
==References==
<references/>


[[Category:Tox]]
[[Category:Toxicology]]

Latest revision as of 18:52, 20 February 2021

Background

  • Main component of rubbing alcohol
  • Hallmark is osmolar gap, ketosis, that is without acidosis
    • Metabolized to acetone, not to an acid
  • Takes 30-60 min for acetone to appear in blood; 3 hr to appear in urine
  • Lethal Dose: 4-8 g/kg or 250 mL in average adult (calculated using volume of pure isopropyl alcohol)
    • Typical store bought rubbing alcohol is 70% isopropyl alcohol by volume, so lethal dose is ~ 350 mL

Pharmacology[1]

  • Unlike other toxic alcohols (methanol, ethylene glycol), toxic effects caused by parent agent (IA) rather than metabolite (acetone)
  • Metabolized to acetone by alcohol dehydrogenase
  • Maximal distribution in ≤ 2 hours
  • Lethal dose > 200 mg/dL, although variable literature

Clinical Features

Differential Diagnosis

Sedative/hypnotic toxicity

Evaluation

Work-Up

  • Fingerstick glucose
  • Complete metabolic panel
  • Serum ketones
  • Serum Osmolality
  • Urinalysis
  • 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 due to acetone interference with 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
    • Blockade of alcohol dehydrogenase (ADH) will prolong intoxication
  • Hemodialysis indications:
    • Hypotension
    • Comatose
    • Consider if IA serum level >200mg/dL

Disposition

  • Generally may be discharged once clinically sober.

See Also

References

  1. Kraut JF, Kurtz I. Clin J Am Soc Nephrol 2008. PMID: 18045860