Toxicology (main): Difference between revisions
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*Ethanol or other alcohols
*Ethanol or other alcohols
*Digoxin, digitalis
*Digoxin, digitalis
===Pupil size===
MIOSIS (COPS)
*Cholinergics, clonidine, carbamates
*Opioids, organophosphates
*Phenothiazines, pilocarpine, pontine hemorrhage
*Sedative-hypnotics
MYDRIASIS (SAW)
*Sympathomimetics
*Anticholinergics
*Withdrawal syndromes
===Coma===
LETHARGIC
*[[Lead]], [[lithium]]
*[[Ethanol]], ethylene glycol
*[[TCA]], [[thallium]], [[toluene]]
*[[Heroin]], hemlock, [[hepatic encephalopathy]], [[heavy metals]], [[hydrogen sulfide]], hypoglycemics
*[[Arsenic]], antidepressants, anticonvulsivants, antipsychotics, antihistamines
*[[Rohypnol]], risperidone
*GHB
*[[Isoniazid]], [[insulin]]
*[[Carbon monoxide]], [[cyanide]], clonidine 


===Seizures===
===Seizures===
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*[[Lead]], [[lithium]]
*[[Lead]], [[lithium]]
*Lidocaine, lindane (pesticide, scabies)
*Lidocaine, lindane (pesticide, scabies)
===Skin findings===
DIAPHORETIC SKIN (SOAP)
*Sympathomimetics
*Organophosphates
*Acetylsalicylic acid and other salicylates
*PCP
DRY SKIN
*Antihistamines, anticholinergics
BULLOUS LESIONS/BLISTERS
*Barbiturates
*Mustard gas
*Snakes and spiders
FLUSHED/RED APPEARANCE
*Anticholinergics, niacin
*Boric acid
*Carbon monoxide
*Cyanide
CYANOSIS
*Aniline dyes
*Dapsone
*Ergotamine
*Nitrates
*Nitrites
*Phenazopyridine
ACNEIFORM RASH
*Bromides
*Chlorinated aromatic hydrocarbons


==Evaluation==
==Evaluation==

Revision as of 15:14, 31 August 2019

Background

Epidemiology

  • In 2014, ~2.2million human exposures reported to US poison control centers
  • Top 5 substance classes:
    • analgesics (11%)
    • cosmetics/personal care products (8%)
    • household cleaning substances (8%)
    • sedatives/hypnotics/antipsychotics (6%)
    • antidepressants (4%)
  • 1,835 human exposures resulted in death

Autonomic Nervous System Receptors and Their Effects

  • Parasympathetic - ACh is transm
    • Muscarinic
      • receptors in heart, eye, lung, GI, skin and sweat glands
      • Bradycardia
      • Miosis
      • Bronchorrhea / Bronchospasm
      • Hyperperistalsis (SLUDGE)
      • Sweating
      • Vasodilation
    • Nicotinic
  • Sympathetic
    • Alpha effects (vessels, eye, skin)
    • Beta effects (heart, lungs)

Clinical Features

Toxidrome Chart

Finding Cholinergic Anticholinergic Sympathomimetic Sympatholytic^ Sedative/Hypnotic
Example Organophosphates TCAs Cocaine Clonidine ETOH
Temp Nl Nl / ↑ Nl / ↑ Nl / ↓ Nl / ↓
RR Variable Nl / ↓ Variable Nl / ↓ Nl / ↓
HR Variable ↑ ↑ (sig) Nl / ↓ Nl / ↓
BP ↑ ↑ ↑ Nl / ↓ Nl / ↓
LOC Nl / Lethargic Nl, agitated, psychotic, comatose Nl, agitated, psychotic Nl, Lethargic, or Comatose Nl, Lethargic, or Comatose
Pupils Variable Mydriatic Mydriatic Nl / Miotic
Motor Fasciculations, Flacid Paralysis  Nl Nl / Agitated Nl
Skin Sweating (sig) Hot, dry Sweating Dry
Lungs Bronchospasm / rhinorrhea Nl Nl Nl
Bowel Sounds Hyperactive (SLUDGE) ↓ / Absent Nl / ↓ Nl / ↓
^Consider Sympatholytic when looking at Sedative OD or someone who doesn't respond to Narcan
Withdrawal from substances have the opposite effect

Differential Diagnosis for Specific Signs

Hyperthermia

Hypothermia

Increased Respiratory Rate

Respiratory Depression

Bradycardia

PACED

  • Propranolol/ beta-blockers, poppies (opiates), propoxyphene,

physostigmine

  • Anticholinesterases, antiarrhythmics
  • Clonidine, calcium channel blockers
  • Ethanol or other alcohols
  • Digoxin, digitalis

Pupil size

MIOSIS (COPS)

  • Cholinergics, clonidine, carbamates
  • Opioids, organophosphates
  • Phenothiazines, pilocarpine, pontine hemorrhage
  • Sedative-hypnotics

MYDRIASIS (SAW)

  • Sympathomimetics
  • Anticholinergics
  • Withdrawal syndromes

Coma

LETHARGIC

Seizures

OTIS CAMPBELL

Skin findings

DIAPHORETIC SKIN (SOAP)

  • Sympathomimetics
  • Organophosphates
  • Acetylsalicylic acid and other salicylates
  • PCP

DRY SKIN

  • Antihistamines, anticholinergics

BULLOUS LESIONS/BLISTERS

  • Barbiturates
  • Mustard gas
  • Snakes and spiders

FLUSHED/RED APPEARANCE

  • Anticholinergics, niacin
  • Boric acid
  • Carbon monoxide
  • Cyanide

CYANOSIS

  • Aniline dyes
  • Dapsone
  • Ergotamine
  • Nitrates
  • Nitrites
  • Phenazopyridine

ACNEIFORM RASH

  • Bromides
  • Chlorinated aromatic hydrocarbons

Evaluation

Toxicological Exam

  • All vital signs (Temp, RR, HR, BP)
  • Neurologic exam
    • Level of consciousness
    • Pupillary exam
    • Motor response
    • DTRs
  • Skin Exam - moisture, temp, evidence of injection drug abuse
  • Lung Exam
  • Bowel Sounds
  • ECG (ie. look for QT prolongation, QRS prolongation, etc)

Management

  • Depends on agent
  • See antidotes
  • "Coma cocktail" when suspecting toxic ingestion (mnemonic = "DONT")
    1. Dextrose (50mg IV)
    2. Oxygen
    3. Naloxone (0.2-0.4mg IV/IM, repeat dose 1-2mg)
      • Empiric opioid ingestion treatment
    4. Thiamine (50-100mg)
      • Treat or avoid Wernicke encephalopathy
      • Though some suggest giving thiamine prior to dextrose, do NOT let this delay treatment of hypoglycemia!
      • Case reports of dextrose precipitating Wernicke's involved thiamine-deficient patients receiving prolonged course of IV glucose, NOT with single bolus[1][2]

Disposition

  • Depends on agent

See Also

References

  1. ↑ Donnino MW, Vega J, Miller J, Walsh M. Myths and misconceptions of Wernicke's encephalopathy: what every emergency physician should know. Ann Emerg Med. 2007;50(6):715-21.
  2. ↑ Gussow, L. Myths of Toxicology: Thiamine Before Dextrose. Emergency medicine news. 2007;29(4):3-11.
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