Toxicology (main): Difference between revisions

No edit summary
Line 109: Line 109:
*Depends on agent
*Depends on agent
*See [[Antidote]]
*See [[Antidote]]
*"Coma cocktail" when suspecting toxic ingestion: Remember "DONT"
*"Coma cocktail" when suspecting toxic ingestion (mnemonic = "DONT")
**[[Dextrose]] (50mg IV)
*#[[Dextrose]] (50mg IV)
**[[Oxygen]]
*#[[Oxygen]]
**[[Naloxone]] (0.2-0.4mg IV/IM, repeat dose 1-2mg) - treat opioid ingestion
*#[[Naloxone]] (0.2-0.4mg IV/IM, repeat dose 1-2mg)  
**[[Thiamine]] (50-100mg) - treat or avoid Wernicke encephalopathy
*#*Empiric opioid ingestion treatment
***Though some suggest giving thiamine prior to dextrose, do NOT let this delay treatment of hypoglycemia!
*#[[Thiamine]] (50-100mg)
***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>
*#*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==

Revision as of 09:14, 3 November 2016

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

  • 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

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

Evaluation

Toxicological Exam

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

Management

  • Depends on agent
  • See Antidote
  • "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.