View source for Organophosphate toxicity

==Background==
*[[Organophosphates]] found in:
**Pesticides (e.g. malathion, diazinon)
**[[Chemical weapons]] (e.g. Sarin,  nerve agents has been used as chemical weapon)
**medications (e.g. [[neostigmine]], [[edrophonium]]
*Highly lipid soluble: absorbed via dermal, gastrointestinal or respiratory routes
*Colorless, odorless, low volatility, and high lipophilicity
*These compounds act as [[Acetylcholinesterase inhibitors]]
**Block acetylcholinesterase, resulting in excess accumulation of acetylcholine at the neuromuscular junction and [[cholinergic crisis|cholinergic toxicity]]
*LD50 of 0.04mg/kg (10 mg). Death can occur within 15 minutes after absorption

{{Autonomic nervous system receptors}}

==Clinical Features==
*Symptoms caused by acetylcholine buildup in CNS and PNS.
*CNS symptoms = [[headache]], [[confusion]], [[vertigo]], [[seizures]], [[coma]]
*Muscarinic Receptors
**SLUDGE(M) = '''S'''alivation, '''L'''acrimation, '''U'''rination, '''D'''iarrhea, '''G'''I pain, '''E'''mesis, '''M'''iosis
**DUMBELLS = '''D'''iarrhea, diaphoresis, '''U'''rination, '''M'''iosis, '''B'''radycardia, '''B'''ronchorrea, '''E'''mesis, '''L'''acrimation, '''L'''ethargic, '''S'''alivation
*Nicotinic Receptors (NMJ)
**MTWThF (days of week) = '''M'''ydriasis/Muscle cramps, '''T'''achycardia, '''W'''eakness, '''T'''witching, '''H'''ypertension/Hyperglycemia, '''F'''asciculations, '''S'''eizures, '''S'''omnolent 
*Common causes of death in [[organophosphate]] toxicity
**Killers B's = '''B'''radycardia, '''B'''ronchorrhea, '''B'''ronchospasm

===Intermediate Syndrome===
*Syndrome that occurs 24-96 hours after acute [[cholinergic crisis]]
*Proximal muscle weakness, [[cranial nerve palsies]]
*Can last for days - weeks 
*May require mechanical ventilation

==Differential Diagnosis==
{{SLUDGE DDX}}
{{Weakness DDX}}
{{Chemical weapon DDX}}
{{Symptomatic bradycardia}}

==Evaluation==
===Work-up===
*CBC
**May show leukocytosis
*Comprehensive Metabolic Panel
*[[CXR]]
**[[Pulmonary edema]] in severe cases
*[[ECG]]
**[[Ventricular dysrhythmias]], [[torsades]], [[QT prolongation]], [[AV block]]

===Diagnosis===
*Clinical diagnosis
*Blood tests such as RBC and plasma pseudocholinesterase levels are available, but little clinical utility

==Management==
{{Cholinergic Toxicity Treatment}}

==Disposition==
*Minimal exposure + asymptomatic at least 12 hours after exposure can likely be discharged.
*Admit all symptomatic patients!
*If evidence of deliberate self harm, place on hold and consult psychiatry

==See Also==
*[[Toxidromes]]

==References==
<references/>

[[Category:Toxicology]]