Signs and Symptoms
- Neurologic:
- Lethargy
- Agitation
- Coma
- Hallucinations
- Seizures
- Respiratory:
- Tachypnea, bradypnea, apnea
- Inability to protect airway
- Cardiovascular:
- Dysrhythmias
- Conduction blocks
- Vital signs:
- Varies depending on toxic substance
- Hyperthermia, hypothermia
- Tachycardia, bradycardia
- Hypertension, hypotension
Selected Toxidromes
- Anticholinergic:
- Altered mental status (confusion, delirium, lethargy)
- Dry skin and mucous membranes
- Fixed dilated pupils
- Tachycardia
- Hyperthermia
- Flushing
- Urinary retention
- Cholinergic:
- Secretory overdrive (salivation, lacrimation, urination, diaphoresis)
- Miosis
- Bronchospasm, wheezing
- Opiate:
- CNS and respiratory depression
- Miosis
- Sympathomimetic:
- CNS excitation
- Seizures
- Tachycardia
- Hypertension
- Diaphoresis
Essential Workup
- A complete set of vital signs, including core temperature
- A complete physical exam, including eyes, skin, odors
Diagnostic Tests & Interpretation
Lab
- Electrolytes, BUN/creatinine, glucose
- Calculate anion gap: Na + (Cl + HCO3):
- Normal anion gap: 8-12
- Use mnemonic A CAT MUD PILES for elevated anion gap acidosis:
- Alcoholic ketoacidosis
- Cyanide, carbon monoxide
- Aspirin, other salicylates
- Toluene
- Methanol, metformin
- Uremia
- Diabetic ketoacidosis
- Paraldehyde, phenformin
- Iron, isoniazid
- Lactic acidosis from other causes
- Ethylene glycol
- Starvation ketosis, SGLT2 inhibitor
- Serum osmol gap:
- Calculate osmol gap if elevated anion gap acidosis from potential toxic alcohol
- Most sensitive early in poisoning
- Normal osmol gap does not completely rule out toxic alcohol ingestion
- Calculated osmolality = 2(Na+) + glucose/18 + BUN/2.8 + ethanol (in mg/dL)/4.6
- Osmol gap = measured osmolality - calculated osmolality
- Use mnemonic ME DIE A when osmol gap >10:
- Methanol
- Ethanol
- Diuretics (mannitol, glycerin, sorbitol)
- Isopropyl alcohol
- Ethylene glycol
- Acetone
- Pregnancy test
- Acetaminophen level for suicidal ingestions
- Toxicology screen
Imaging
- ECG for dysrhythmias or QRS/QT changes
- CT of head for altered mental status not clearly due to toxin
- CXR if suspected aspiration or pneumonia
Differential Diagnosis
- Causes of altered mental status
- Intracranial mass, bleeding
- Infection, sepsis
- Endocrine abnormalities
- Hypothermia
- Hypoxia
- Metabolic abnormalities
- Psychogenic
Prehospital
- Search for clues at scene:
- Pills/pill bottles
- Drug paraphernalia
- Witnesses
- Transport all drugs and pill bottles for identification
- Restrain uncooperative patients for patient and health care giver protection
- Consider comorbid conditions:
- Trauma
- Medical illness
- Environmental exposure
- Prehospital administration of activatedcharcoal may optimize decontamination if prolonged transport time
Initial Stabilization/Therapy
- ABCs:
- Endotracheal intubation as needed for airway protection, oxygenation, ventilation, and orogastric lavage
- Supplemental oxygen for hypoxia
- Pulse oximetry
- Cardiac monitor
- IV access
- Hypotension:
- Administer 0.9% normal saline IV fluid bolus
- Trendelenburg
- Vasopressors for persistent hypotension
- Bradycardia:
- If altered mental status, administer coma cocktail: Thiamine, D50W (or Accu-Chek), naloxone
ED Treatment/Procedures
- Decontamination:
- Orogastric lavage:
- Consider in potentially lethal ingestions without known antidote within 1 hr of ingestion
- Protected airway essential prior to lavage
- Activated charcoal:
- Most effective within a few hours of most toxic ingestions
- Contraindicated if caustic ingestion, unprotected airway, or bowel obstruction
- Drugs not effectively bound to charcoal: Metals (borates, bromide, iron, lithium), alcohols, potassium
- Whole-bowel irrigation:
- Polyethylene glycol (Colyte, GoLytely) evacuates bowel without causing electrolyte disturbances
- Consider in toxins not well adsorbed by charcoal (e.g., iron and lithium) or body packers/stuffers
- Contraindicated if bowel obstruction, perforation, or hypotension
- Enhanced elimination:
- Enhances removal of systemically absorbed toxin
- Multiple-dose activated charcoal:
- Urinary alkalinization:
- Hemodialysis/hemoperfusion:
- Lithium
- Salicylates
- Theophylline
- Toxic alcohols
- Valproate
- Seizures:
- Treat initially with diazepam or lorazepam
- For persistent seizures, consider phenobarbital
- Phenytoinnot indicated in toxicologic seizures:
- Antidotes:
Medication
- Activated charcoal slurry: 1-2 g/kg PO
- Dextrose: D50W 1 amp: 50 mL or 25 g (peds: D25W 2-4 mL/kg) IV
- Diazepam: 5-10 mg (peds: 0.2-0.5 mg/kg) IV every 10-15 min
- Lorazepam: 2-6 mg (peds: 0.05-0.1 mg/kg) IV every 10-15 min
- Naloxone (Narcan): 0.4-2 mg (peds: 0.1 mg/kg) IV/IM initial dose
- Thiamine (vitamin B1): 100 mg (peds: 50 mg) IV/IM
Disposition
Admission Criteria
- Altered mental status
- Cardiopulmonary instability
- Suicidal
- Lab abnormalities
- Potential for decompensation from delayed acting substance
Discharge Criteria
- Psychiatrically clear
- Detoxified
- Hemodynamically stable
Issues for Referral
- Patients with unintentional (accidental) poisoning require poison prevention counseling
- Patients with intentional (e.g., suicide) poisoning require psychiatric evaluation
- Substance abuse referral (e.g., SBIRT) for patients with recreational drug abuse
Pregnancy Prophylaxis |
| In general, treating the mother is also the best treatment strategy for the fetus |
Follow-up Recommendations
- Consider 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
- CalelloDP, HenretigFM. Pediatric toxicology: Specialized approach to the poisoned child . Emerg Med Clin North Am. 2014;32(1):29-52.
- MycykMB. Poisoning and drug overdose. In: JamesonJ, FauciA, KasperD, et al., eds. Harrison's Principles of Internal Medicine. 20th ed.New York: McGraw Hill; 2018.
- ThompsonTM, TheobaldJ, LuJ, et al. The general approach to the poisoned patient . Dis Mon. 2014;60(11):509-524.
- WelkerKL, MycykMB. Pharmacology in the geriatric patient . Emerg Med Clin North Am. 2016;34(3):469-481.
See Also (Topic, Algorithm, Electronic Media Element)