Toxicology (main): Difference between revisions
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*1,835 human exposures resulted in death
*1,835 human exposures resulted in death


===Autonomic Nervous System===
{{Autonomic nervous system receptors}}
*Parasympathetic - ACh is transm
**Muscarinic
***receptors in heart, eye, lung, GI, skin and sweat glands
***Bradycardia
***Miosis
***Bronchorrhea / Bronchospasm
***Hyperperistalsis (SLUDGE)
***Sweating
***Vasodilation
**Nicotinic
***receptors in both sympathetic and parasympathetic nervous systems
***fasciculations, flaccid paralysis
***?Mild bradycardia, hypotension
*Sympathetic
**ALPHA EFFECTS - vessels, eye, skin
***Mydriasis, hypertension, Sweating
**BETA EFFECTS - heart, lungs
***Tachycardia, Bronchodilation


==Clinical Features==
==Clinical Features==
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**botulinis
**botulinis
**Mojave rattlesnake, Cobra
**Mojave rattlesnake, Cobra
===Bradycardia===
PACED
*Propranolol/ beta-blockers, poppies (opiates), propoxyphene,
physostigmine
*Anticholinesterases, antiarrhythmics
*Clonidine, calcium channel blockers
*Ethanol or other alcohols
*Digoxin, digitalis
===Seizures===
OTIS CAMPBELL
*[[Organophosphates]], oral hypoglycemics
*[[TCA]], [[theophylline]], tramadol
*Isoniazid, Insulin
*[[Sympathomimetics]], [[salicylates]], strychnine
*Camphor, [[carbon monoxide]], [[cyanide]], chlorinated hydrocarbons, [[cocaine]]
*[[Anticholinergics]] (antihistamines), amphetamines, antidepressants (citalopram, TCAs, buproprion)
*[[Methanol]], Methylxanthines (theophylline, caffeine), [[MAOI]]
*[[PCP]], propranolol
*Benzo withdrawal, buproprion, botanicals (hemlock, nicotine), GHB
*EtOH withdrawal, ethylene glycol
*[[Lead]], [[lithium]]
*Lidocaine, lindane (pesticide, scabies)


==Evaluation==
==Evaluation==
===Toxicological Exam===
===Toxicological Exam===
*All vital signs (Temp, RR, HR, BP)
*All vital signs (Temp, RR, HR, BP)
*Neuro Exam
*[[Neurologic exam]]
**Level of consciousness
**Level of consciousness
**Pupillary exam
**Pupillary exam
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*Lung Exam
*Lung Exam
*Bowel Sounds
*Bowel Sounds
*EKG (ie. look for QT prolongation, QRS prolongation, etc)
*[[ECG]] (ie. look for [[QT prolongation]], QRS prolongation, etc)


==Management==
==Management==
*Depends on agent
*Depends on agent
*See [[Antidote]]
*See [[antidotes]]
*"Coma cocktail" when suspecting toxic ingestion:
*"Coma cocktail" when suspecting toxic ingestion (mnemonic = "DONT")
**[[Dextrose]] (50mg IV)
*#[[Dextrose]] (50mg IV)
**Oxygen
*#[[Oxygen]]
**[[Thiamine]] (50-100mg) - treat or avoid Wernicke encephalopathy
*#[[Naloxone]] (0.2-0.4mg IV/IM, repeat dose 1-2mg)  
**[[Naloxone]] (0.2-0.4mg IV/IM, repeat dose 1-2mg) - treat opioid ingestion
*#*Empiric opioid ingestion treatment
*#[[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<ref>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.</ref><ref>Gussow, L. Myths of Toxicology: Thiamine Before Dextrose. Emergency medicine news. 2007;29(4):3-11.</ref>


==Disposition==
==Disposition==
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*[[Drug_levels|Drug Levels]]
*[[Drug_levels|Drug Levels]]
*[[Antidote]]
*[[Antidote]]
*[[Camphor toxicity]]


==References==
==References==

Revision as of 03:27, 26 March 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

Seizures

OTIS CAMPBELL

Evaluation

Toxicological Exam

  • All vital signs (Temp, RR, HR, BP)
  • Neurologic exam
    • Level of consciousness
    • Pupillary exam
    • Motor response
    • DTRs
  • Skin Exam - moisture, temp
  • 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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