Isopropyl alcohol toxicity: Difference between revisions

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== Background ==
==Background==
*Isopropyl alcohol acts directly as CNS depressant and is broken down by alcohol dehydrogenase to acetone, which further compounds effect
*Main component of rubbing alcohol
*Lethal Dose: 4-8 g/kg or 250mL in average adult
*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


== Clinical Features ==
==Pharmacology<ref>Kraut JF, Kurtz I. Clin J Am Soc Nephrol 2008. PMID: 18045860</ref>==
*Symptoms of inebriation, disinhibition, sedation, and coma usually peak in the first hour of ingestion
*Unlike other toxic alcohols (methanol, ethylene glycol), toxic effects caused by parent agent (IA) rather than metabolite (acetone)
*"Fruity breath" can be seen as a result of acetone production
*Metabolized to acetone by alcohol dehydrogenase
*Maximal distribution in ≤ 2 hours
*Lethal dose > 200 mg/dL, although variable literature


== Work-Up ==
==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
**Fruity breath from acetone
*[[Hypotension]], [[hypothermia]] from peripheral vasodilation
*[[Hypoglycemia]] (in malnourished patients)
 
==Differential Diagnosis==
*[[Starvation ketoacidosis]]
*[[Diabetic Ketoacidosis]]
*Inborn errors of metabolism
*[[Salicylate Toxicity]]
*Acetone ingestion
 
{{Sedatve/hypnotic toxicity types}}
 
==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


== Diagnosis ==
===Evaluation===
*Positive serum isopropyl alcohol level (if available)
*Osmolal gap > 10; see [[Osmolal or Osmolar Gap]]
*Osmolal gap > 10, see [[Osmolal or Osmolar Gap]]
*Absence of anion gap
*Absence of anion gap
*Absence of metabolic acidosis
*Absence of metabolic acidosis
*Absence of serum beta hydroxybutyrate
*Absence of serum beta hydroxybutyrate
*Presence of serum and urine ketones
*Presence of serum and urine ketones
**Consider other diagnosis if absent 2 hours after ingestion
**Consider other diagnosis if absent 2hr after ingestion
*Elevated creatinine may be falsely elevated as a result of acetone interference with laboratory measurement of creatinine
*Creatinine may be falsely elevated due to acetone interference with laboratory measurement of Cr
 
{{Toxic Alcohols Anion/Osmolar Gaps}}


== DDX ==
==Management==
*Ethanol ingestion
*Treatment is supportive.
*Methanol or ethylene glycol ingestion
*No role for fomepizole or ethanol
*Starvation ketoacidosis
**Blockade of alcohol dehydrogenase (ADH) will prolong intoxication
*Diabetic ketoacidosis
*Hemodialysis indications:
*Inborn errors of metabolism
**Hypotension
*Salicylate ingestion
**Comatose
*Acetone ingestion
**Consider if IA serum level >200mg/dL


== Treatment ==
==Disposition==
*Airway
*Generally may be discharged once clinically sober.
*Breathing
**Consider intubation to secure airway
*Circulation
**Fluid rehydration
*Minimal role in GI decontamination due to rapid absorption
**May consider nasogastric aspiration if done within 1 hour of ingestion
*Hemodialysis should be considered in persistently hypotensive patient after aggressive fluid hydration and vasopressor support or for Siopropyl levels greater than 400 mg/dL


== Disposition ==
==See Also==
*Unintentional ingestions may be safely discharged if asymptomatic after 2 hours of observation
*[[Toxic alcohols]]
*Any intentional ingestions should be screened for suicidal ideation and alcohol addiction
*[[In-Training Exam Review]]


== Source ==
==References==
*Uptodate
<references/>
*Rosen


[[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, 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