ED Management on “Toxidromes” poisoningBy Shama Rani PaulYear 4MAHSA University

Definition and Types

group drugs together according to the signs and symptoms they generally produce in patients (so when you encounter a patient presenting a certain way, you will be able to recognize the toxidrome)

What are the major toxidromes? Anticholinergics Sympathomimetics / Withdrawal Opiate / Sedative Cholinergic / Anticholinesterase

1. Anticholinergics

interfere with the binding of acetylcholine to muscarinic receptors Hyperthermia Dilated pupils (mydriasis) Dry skin Vasodilation causing flushed skin Agitation / Hallucinations Tachycardia and possibly dysrhythmiasTricylic antidepressants, antihistaminics, tegretol(carbamazepine), antipschyotics, antispasmodics, jimson seed, atropine

Treatment for overdose

Pre-hospital - focus on safe, rapid transport with oxygen administration and cardiac monitoring, and staying alert for complications such as vomiting, seizures or violent behaviour

In-hospital - supportive measures in most cases. A rarely used option is the administration of physostigmine, a short-acting cholinesterase inhibitor

2. Sympathomimetrics

mimics the sympathetic nervous system effects Alcohol and drug withdrawal present the same way as sympathomimetics, which is

why they are grouped together Tachycardia, Dysrhythmias Hypertension Diaphoresis Goosebumps Delusions, Paranoia, Seizures Increased temperature Dilated pupilsCaffeine, cocaine, amphetamine, theophylline, ecstasy

Treatment for ovedose

Pre-hospital - same as that for an anticholinergic overdose In-hospital - administration of a benzodiazepine to calm agitated patients.

3. Opioids

o Pin-point pupils (Miosis)o Respiratory depression – Due to decreased sensitivity of the respiratory center to

CO2 (slow as 2-4 breaths/min)o Sedation – Often GCS 3o Nausea and vomiting – Due to stimulation of the chemoreceptor trigger zoneHypothermia Heroin, Morphine, Hydromorphone, Codeine, Porpoxyphene, Hydrocodone, Oxycodone, Fentanyl, MeperidineAlways consider an opiate overdose when assessing elderly patients with altered LOC who have been prescribed an opiate for pain control - Increasing pain or confusion can cause accidental overdoses

Treatment for overdose

Pre-hospital - focus on supporting the ABC’s. Often significantly require suctioning, placement of an airway adjunct and supported ventilations with a BVM. Even if the patient can be roused, monitor the respiratory effort carefully. Sometimes patients need to be told to ‘take a few deep breaths’ to maintain adequate ventilations

sedation exhibited by opiate overdose patients are often due to a combined effect of the drug itself, as well as high carbon dioxide levels

In-hospital - administration of Naloxone . Always use with caution - you can very quickly go from having an easily managed and sedate patient, to a combative individual in full withdrawal

Combine heroin with amphetamine or cocaine, “speed balling”

4. Cholinergics

elevated levels of acetylcholine, either through direct ‘cholinergic’ effects or by inhibiting the enzyme responsible for the breakdown of acetylcholine (cholinesterase)

DUMBELS Diaphoresis, Diarrhea, Decreased blood pressure Urination Miosis Bronchorrhea, Bronchospasm, Bradycardia Emesis, Excitation of skeletal muscles Lacrimation (tearing) Salivation, Seizures

Cholinergic: Nicotine, MushroomsAnticholinesterases: Organophosphate insecticides, Nerve gas (sarin)

o SLUDGE o Salivationo Lacrimationo Urinationo Defecationo GI Stresso Emesis

Treatment for overdose

pre-hospital - focuses on the ABC’s and vigorous monitoring. Be prepared for seizures ALS and in-hospital - administration of Atropine, an anticholinergic.

Diagnosis of poisoning Ask patient or relatives/friends what drugs or poison have been taken (not always

accurate) Self-poisoning –

under the influence of alcohol may not know which tablets he/she took check any bottles or packets for the names and quantities of drugs/poisons that were

available unconscious or severely poisoned, look in hospital notes for details of previous

overdosesed. Record the time of ingestion of the drug or poison Examine the patient all over for signs of poisoning, injection marks or self-injury mimicking poisoning (eg head injury, meningitis) traditional Chinese medicines or herbs can cause signifcant toxicity

Toxidromes: features suggesting a particular poison

o Coma with dilated pupils, divergent squint, tachycardia, increase muscle tone, increase reflexes and extensor plantars tricyclic antidepressant or orphenadrine poisoning

o Coma with hypotension, respiratory depression and decrease muscle tone barbiturates, clomethiazole, benzodiazepines with alcohol, or severe tricyclic antidepressant poisoning

o Coma with slow respiration and pinpoint pupils is typical of opioid poisoningo Tinnitus, deafness, hyperventilation, sweating, nausea and tachycardia are typical of

salicylate poisoningo Agitation, tremor, dilated pupils, tachycardia amphetamines, ecstasy, cocaine,

sympathomimetics, tricyclic antidepressants, or selective serotonin re-uptake inhibitors

Assessment and Monitoring

• Assess and record conscious level, Observe frequently.• Check blood glucose in patients with confusion, coma or fiits.• Monitor breathing and record respiratory rate. Use a pulse oximeter, but note that SpO 2 may be misleadingly high in carbon monoxide (CO)poisoning • Check ABG if patient is deeply unconscious or breathing abnormally.• Record and monitor the ECG if a patient is unconscious, has tachy- or bradycardia or has taken drugs or poisons with risk of arrhythmias.• Record BP and temperature.

Investigations

most useful : paracetamol and salicylate levels, blood glucose, ABG, and urea & electrolytes (U&E)

Measure paracetamol if there is any possibility of paracetamol poisoning (this includes all unconscious patients). Record the time of the sample on the bottle, and in the notes.

Many labs can measure salicylate, iron and lithium and also check for paraquat if necessary.

Comprehensive drug screening is rarely neededand is only available in specialist centres

References

https://www.lakeridgehealth.on.ca/en/ourservices/resources/Toxidromes%20Self%20Study%20Package.pdf

Oxford Hanbook of Emergency Medicine

HOPE IT WASN’T

THAT BORING

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