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GHB Poisoning, Emergency Medicine

Basics

Description

- Naturally occurring analog of Оі-aminobutyric acid (GABA) - Used medically for narcolepsy - Nonmedical uses: - Bodybuilding agent - Euphoric agent - Date-rape/predatory agent

- Pulmonary: - Respiratory depression - Apnea - Laryngospasm (rare)

- ABCs: - Airway control essential - Administer supplemental oxygen - Intubate if indicated

- Supportive care - Bradycardia: - Hypotension: - 0.9% NS IV fluid bolus - Trendelenburg - Dopamine titrated to pressure

  • Naturally occurring analog of Оі-aminobutyric acid (GABA)
  • Used medically for narcolepsy
  • Nonmedical uses:Bodybuilding agentEuphoric agentDate-rape/predatory agent
  • Оі-Hydroxybutyrate (GHB) precursors (Оі-butyrolactone [GBL], 1,4 butanediol [1,4-BD], GHV [Оі-hydroxyvalerate], and GVL) have same effects as GHB.
  • Onset of activity: 15-30 min after ingestion
  • Duration of effect: 2-6 hr

Etiology

Deliberate or accidental ingestion of GHB пїЅ

Diagnosis

Signs and Symptoms

  • CNS:CNS depressionAtaxia/dizzinessImpaired judgmentAggressive behaviorClonic movements of the extremitiesComaSeizures
  • Pulmonary:Respiratory depressionApneaLaryngospasm (rare)
  • GI:
  • Cardiovascular:BradycardiaAtrioventricular blockHypotension
  • Other:
  • Withdrawal symptoms:HTNTachycardiaHyperthermiaAgitationDiaphoresisTremorsNausea, vomiting, and abdominal crampingHallucinations, delusions, and psychosis

Essential Workup

  • Diagnosis based on clinical presentation and an accurate history
  • Exclude coingestants if signs and symptoms inconsistent with GHB intoxication

Diagnosis Tests & Interpretation

Lab

  • Confirmatory GHB screen is typically a send-out lab and does not change ED management.
  • Urine toxicology screen to exclude coingestants
  • Serum alcohol level
  • Urinalysis and creatine kinase (CK) if suspected rhabdomyolysis from prolonged immobilization or agitation

Imaging

  • ECG:Sinus bradycardiaAtrioventricular block
  • CXR:
  • Head CT if suspected occult head trauma

Differential Diagnosis

  • Alcohol intoxication
  • Barbiturate overdose
  • Benzodiazepine overdose
  • Neuroleptic overdose
  • Opiate overdose
  • Withdrawal:Alcohol withdrawalSedative-hypnotic withdrawal

Treatment

Pre-Hospital

Transport all pills/bottles and drug paraphernalia involved in overdose for identification in ED. пїЅ

Initial Stabilization/Therapy

  • ABCs:Airway control essentialAdminister supplemental oxygenIntubate if indicated
  • Administer thiamine, dextrose (or Accu-Chek), and naloxone for depressed mental status.

Ed Treatment/Procedures

  • Supportive care
  • Bradycardia:
  • Hypotension:0.9% NS IV fluid bolusTrendelenburgDopamine titrated to pressure
  • Seizures:Treat initially with benzodiazepine.Treat refractory seizures with phenobarbital.
  • Withdrawal:Treat aggressively with benzodiazepine.Treat with phenobarbital or propofol if large doses of benzodiazepines unsuccessful.

Medication

  • Dextrose: 50-100 mL D50 (peds: 2 mL/kg of D25 over 1 min) IV; repeat if necessary
  • Diazepam: 5-10 mg (peds: 0.2-0.5 mg/kg) IV q10-15min
  • Dopamine: 2-20 Ојg/kg/min with titration to effect
  • Lorazepam: 2-4 mg (peds: 0.03-0.05 mg/kg) IV q10-15min
  • Naloxone: 0.4-2 mg (peds: 0.1 mg/kg; neonatal: 10-30 Ојg/kg) IV or IM
  • Phenobarbital: 10-20 mg/kg IV (loading dose) monitor for respiratory depression with IV administration
  • Propofol: 0.5-1 mg/kg IV (loading dose), then 5-50 Ојg/kg/min (maintenance dose)
  • Thiamine (vitamin B1): 100 mg (peds: 50 mg) IV or IM

Follow-Up

Disposition

Admission Criteria

  • Intubated patient
  • Patient with hypothermia or other hemodynamic instability
  • Coingestion prolonging duration of intoxication

Discharge Criteria

  • Asymptomatic after 6 hr of observation
  • No clinical evidence of withdrawal syndrome

Withdrawal from GHB is life-threatening and appears similar to alcohol withdrawal. Prolonged inpatient treatment may be indicated. пїЅ

Follow-Up Recommendations

  • Substance abuse referral for patients with recreational drug abuse.
  • Patients with unintentional (accidental) poisoning require poison prevention counseling.
  • Patients with intentional (e.g., suicide) poisoning require psychiatric evaluation.

Pearls and Pitfalls

  • Consider nontoxicologic causes for persistent altered mental status
  • Routine hospital drug testing will not confirm GHB or other common recreational drugs of abuse

Additional Reading

  • Gahlinger пїЅPM. Club drugs: MDMA, gamma-hydroxybutyrate (GHB), Rohypnol, and ketamine. Am Fam Physician. 2004;69(11):2619-2926.
  • Schep пїЅLJ, Knudsen пїЅK, Slaughter пїЅRJ, et al. The clinical toxicology of Оі-hydroxybutyrate, Оі-butyrolactone and 1,4-butanediol. Clin Toxicol (Phila). 2012;50(6):458-470.
  • van Noorden пїЅMS, van Dongen пїЅLC, Zitman пїЅFG, et al. Gamma-hydroxybutyrate withdrawal syndrome: Dangerous but not well known. Gen Hosp Psychiatry. 2009;31(4):394-396.
  • Wood пїЅDM, Brailsford пїЅAD, Dargan пїЅPI. Acute toxicity and withdrawal syndromes related to Оі-hydroxybutyrate (GHB) and its analogues Оі-butyrolactone (GBL) and 1,4-butanediol (1,4-BD). Drug Test Anal. 2011;3(7-8):417-425.
  • Zvosec пїЅDL, Smith пїЅSW, Porrata пїЅT, et al. Case series of 226 Оі-hydroxybutyrate-associated deaths: Lethal toxicity and trauma. Am J Emerg Med. 2011;29(3):319-332.

Codes

ICD9

968.4 Poisoning by other and unspecified general anesthetics пїЅ

ICD10

  • T41.291A Poisoning by oth general anesthetics, accidental, init
  • T41.293A Poisoning by other general anesthetics, assault, init encntr
  • T41.294A Poisoning by oth general anesthetics, undetermined, init
  • T41.292A Poisoning by oth general anesthetics, self-harm, init

SNOMED

  • 269268004 Central nervous system depressants and anesthetic agent poisoning (disorder)
  • 295591002 Central nervous system depressants and anesthetic overdose (disorder)