Toxidrome's Flashcards
What is a toxidrome?
Signs and symptoms associated with a specific toxin
Which drug groups are associated with miosis?
Opiates
Cholinergic drugs e.g. organophosphates
Which drug groups are associated with mydriasis (dilated pupils)?
Sympathomimetic drugs e.g. cocaine, amphetamines
Anticholinergic drugs e.g. tricyclic antidepressants, antihistamines, atropine, antipsychotics (first generation)
What may you be looking for when exposing a suspected poisoned patient?
Medic alert bracelet
IV marks, sores around the mouth from chemical inhalation, burns from caustic substances,
Drug paraphernalia
Signs of self harm, suicide note
How should you manage a poisoned patient who is vomiting?
Recovery position and suction.
Suction unit can be set up in advance vomiting is likely
When should poisoning be suspected?
Altered conscious level Symptoms atypical of age group Context fitting e.g. nightclub Patient is reluctant to provide information Bizarre presentation
What are the key
a) metabolic
b) traumatic
c) neurological
differential diagnoses of poisoning
Metabolic
Electrolyte imbalance
Hypoxia
Hypoglycaemia
Traumatic
Head injury
Hypotension and haemorrhage
Neurological
Stroke
SAH
Post-ictal state
Which drug groups would you suspect in a patient with tachycardia, hypertension and tachypnoea?
Sympathomimetic- Cocaine, amphetamines
Anticholinergics- TCAs, sleeping pills, antihistamines
Which drug groups would you suspect in a patient with bradycardia, hypotension and bradypnea ?
Sedatives/hypnotics- BDZs
Opiates- Heroin, codeine
Cholinergic- Organophosphates, mushrooms
Describe the clinical features of a patient overdosed on their tricyclic antidepressants
Anticholinergic
RED as a beet- flushed from peripheral vasodilation
HOT as a hare- fever
DRY as a bone- dry skin, mouth
FULL as a flask- urinary retention
MAD as a hatter- hallucinations, confusion
Plus tachycardia, lethargy, coma, FITS, ataxia, dilated pupils.
Describe the typical signs and symptoms of a patient who has overdosed on pesticide
Cholinergic
Salivation Lacrimation Urinary incontinence Defeacation Gastric emesis E
Bradycardia
Bronchospasm
Bronchorrhea
What would be the typical vital signs of a morphine overdose?
Shallow breath sounds
Bradycardia
Hypotension
Hypothermia
Examples of Anticholinergic drugs?
AAAAA
Atropine Antihistamines, Antipsychotics, Anti-Parkinsons drugs Anti-depressants
How would you manage a suspected anticholinergic overdose?
A-> E
Treat fever
Main risks: fits and/or arrhythmias-> cardiac arrest.
Maintain cardiac monitoring
and transfer to hospital
Fits are normally transient and dysrhythmias don’t normally need treatment (unless VT->lignocaine)
Examples of sedative/hypnotic drugs
BDZ- Nitrazepam, loprazolam, temazepam, diazepam
Barbiturates (rare) e.g. phenobarbitone
What are the clinical features of sedative overdose?
CNS depression which can vary from drowsiness to coma Respiratory depression Confusion/delrium Ataxia Dysarthria
(like a very drunk person)
How should sedative overdose be managed?
Supportive maintaining open airway
Do not give flumazenil (now not recommend as can cause seizures)
What is the pharmacology of amphetamines?
Amphetamines are sympathomimetics which means they stimulate the sympathetic nervous system. They do this by blocking the reuptakes of catecholamines, dopamine and serotonin.
When do the clinical features of amphetamines present?
normally 1 hour after ingestion
What are the clinical features of amphetamine ingestion?
Sympathomimetic effects Tachycardia and cardiac arrhythmia Dilated pupils and blurred vision Excessive sweating Hypertension (can result in a CVA) Pallor, dry mouth
Central effects
Agitation, talkative,
paranoia, visual hallucinations
Drowsiness, convulsions- severe poistoning
Hyperpyrexial syndrome can develop
How should hyperthermia be managed in an amphetamine patient?
Damp sponging, cold IV fluids if transfer is going to be delayed
When might you consider giving an amphetamine patient diazepam?
Fitting/psychotic/agitated
What are the clinical features of cocaine overdose?
a) mental status
b) physical exam
c) vital signs
Clinical features are more rapid with inhaled vs. smoked cocaine
Mental status
in mild-moderate intoxication
restless/euphoric/agitated/aggressive/distracted w/hallucinations
severe intoxication
drowsiness/coma
Physical exam
mild/moderate
Slurred speech, ataxia, tremor, pallor, cold sweats, pupillary dilation
severe
hyperreflexia, convulsions, incontinence
Pneumothorax may occur due to repeated valsalva manoeuvre to increase the absorption of inhaled cocaine.
Vital signs
mild-moderate- tachycardia, hypertension, tachypnea, arrhythmia
severe- hyperthermia
Why is cocaine life-threatening?
Circulatory and respiratory failure- hypotension, hypoxia, arrhythmias
Severe HTN- stroke, ICH
Artery spasm- myocardial and intestinal ischaemia and acute mesenteric ischaemia.
Hyperthermia
