Toxicology (main)

Background

Autonomic Nervous System

1. Parasympathetic - ACh is transm
   1. Muscarinic
      1. receptors in heart, eye, lung, GI, skin and sweat glands
      2. Bradycardia
      3. Miosis
      4. Bronchorrhea / Bronchospasm
      5. Hyperperistalsis (SLUDGE)
      6. Sweating
      7. Vasodilation
   2. Nicotinic
      1. receptors in both sympathetic and parasympathetic nervous systems
      2. fasciculations, flaccid paralysis
      3. ?Mild bradycardia, hypotension
2. Sympathetic
   1. ALPHA EFFECTS - vessels, eye, skin
      1. Mydriasis, HTN, Sweating
   2. BETA EFFECTS - heart, lungs
      1. Tachycardia, Bronchodilation

Diagnosis

Toxicological Exam

1. All VS (Temp, RR,HR, BP)
2. Neuro Exam
   1. Level of consciousness
   2. Pupillary exam
   3. Motor response
3. Skin Exam - moisture, temp
4. Lung Exam
5. Bowel Sounds

Toxidromes

	Cholinergic (Organophosphates)	Anticholinergic (TCAs, antihist, phenothiazines)	Sympathomimetic^ (Cocaine, Amphetamines, Ketamine)	Sympatholytic^^ (Clonidine)	Sedative/Hypnotic (ETOH)
Temp	Nl	Nl/Inc	Nl/Inc	Nl/Dec	Nl/Dec
RR	Variable	Nl/Dec	Variable	Nl/Dec	Nl/Dec
HR	Variable	Inc	Inc (sig)	Nl/Dec	Nl/Dec
BP	Inc	Inc	Inc	Nl/Dec	Nl/Dec
LOC	Nl/Lethargic<	Nl, agitated, psychotic, comatose	Nl, agitated, psychotic	Nl, Lethargic, or Comatose	Nl, Lethargic, or Comatose
Pupils	Varriable	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)	Dec/Absent	Nl/Dec	Nl/Dec

^^Consider Sympatholytic when looking at Sedative OD or someone who doesn't respond to Narcan

DDx for Specific Signs

Hyperthermia

1. Altered Metabolism
   1. Aspirin (Salicylate) Toxicity
   2. withdrawal states
   3. thyroid hormones
   4. dinitrophenols
2. Increased Muscle Activity
   1. withdrawal, sympathomimetics
   2. MAOI Toxicity
   3. PCP, LSD
   4. Lithium
   5. Amoxapine
   6. Serotonin Syndrome
3. Impaired Heat Dissipation
   1. anticholinergics
   2. antihistamines
   3. antipsychotics (TCAs)
4. Malignant Hyperthermia
   1. anesthestics
5. Neuroleptic Malignant Syndrome
   1. phenothiazines, Lithium, LevoDopa

Hypothermia

1. Exposure
   1. Ethanol Toxicity
   2. Sedative hypnotics
   3. Narcotics
   4. TCAs
   5. Phenothiazines
   6. Insulin (Hypoglycemia)

Increased Respiratory Rate

1. Direct Stimulation
   1. Aspirin (Salicylate) Toxicity
   2. Metabolic Acidosis
   3. dintirophenol, pentachlorophenol
   4. hepatorenal failure
   5. CNS stimulants (cocaine, amphet, theophylline)
2. Tissue Hypoxia
   1. CO
   2. Cyanide
   3. Hydrogen Sulfide
   4. Methemoglobinemia

Respiratory Depression

1. Central Depression
   1. antipsychotics
   2. Chlorinated hydrocarbons
   3. Sedative/hypnotics (Ethanol Toxicity, glycols)
   4. Tricyclic (TCA) Toxicity
   5. Lomitil
2. Muscle Failure
   1. Organophosphates
   2. Marine Toxins
   3. nicotine
   4. strychnine
   5. botulinis
   6. Mojave rattlesnake, Cobra

See Also

Altered Mental Status (AMS)

Source

Originally adapted from BIRNBAUMER