Barbiturate toxicity
Background
- Death most commonly due to respiratory arrest and cardiovascular collapse
- Assume severe poisoning if >10x hypnotic dose has been ingested
Clinical Features
Mild-moderate toxicity
- Resembles ETOH intoxication
Severe toxicity
- Respiratory depression
- Hypothermia
- Hypotension (decreased vascular tone)
- Coma, absence of corneal reflex
Differential Diagnosis
Sedative/hypnotic toxicity
- Absinthe
- Barbiturates
- Benzodiazepines
- Chloral hydrate
- Gamma hydroxybutyrate (GHB)
- Baclofen toxicity
- Opioids
- Toxic alcohols
- Xylazine toxicity
Evaluation
Management
- Airway assessment and stabilization
- Mechanical ventilation often required
- Hypotension
- IVF
- Dopamine or norepinepherine
- Hypothermia
- Rewarming measures
- GI Decontamination
- Activated charcoal x1 if present within 1hr of ingestion
- Multi-dose activated charcoal
- Consider only if patient has ingested life-threatening amount of phenobarbital
- Give 50-100gm PO initially; follow by 12.5-25gm PO q4hr
- Urinary alkalinization
- Less effective than multi-dose activated charcoal
- Dialysis
- Only effective for phenobarbital (long-acting barb)
- Reserved for patients who are deteriorating despite aggressive supportive care
Disposition
- Consider discharge if improvement in neuro status / vital signs over 6-8hr
- Evidence of toxicity after 6hr requires admission