Others Flashcards
Carotid massage
Eliminate carotid bruit before carotid massage
Tilting test
SL GTN can be used to provoke response
60-70 degreee
For vasovagal or orthostatic syncope
Opioid toxicity e.g. heroin
Pin-point pupil, respiratory depression, bradycardia, reduced bowel motility, sedation
hypotension but bradycardia, ddx: beta-blocker, cradiogenic, autonomic neuropathy, adrenal insufficiency
Principles of toxicology
Principles of toxicology
- reduce exposure
- Reduce absorption
- Increase elimination
- Know when to intervene
- Give supportive care
- Give specific therapy and antidotes when appropriate
Usually monitoring, then supportive treatment, then decontamination, then antidote or specific treatment
History and PE for suspected poisoning
Suspected poisoning
History
M: medication/toxin exposed to
A: Amount ingested or exposed to
T: time of ingestion/since exposure
T: therapy that has been instituted
E: emetics
R: reason for/ route of exposure
S: symptoms
Vitals signs (BP, rate, RR, Temp) , include blood glucose and pulse oximetry
Eyes: pupil size, nystagmus
Neuro: GCS, tone, seizure
Skin
Odor: alcohol
Anticholinergic toxidrome (e.g. atropine, scopolamine, antihistamines)
• Antagonism at the muscarinic cholinergic receptors
• Tachycardia, hyperthermia, psychosis, dry flushed skin,
mydriasis, urinary retention, ↓ bowel sound
• Hot as a hare, Mad as a hatter, Dry as a bone, Blind as a bat,
Full as a Flash
Sympathomimetic toxidrome
E.g. cocaine, ephedrine
- hypertension, tachycardia, psychomotor agitation, hyperthermia, diaphoresis, mydriasis
Cholinergic toxidrome e.g. organophosphate
- Excessive activation of muscarinic cholinergic system but also generally include activation of the nicotinic system
- diarrhoea
- urination
- Miosis
- Bradycardia, bronchospasm, bronchorrhea
- emesis
- lacrimation
- lethargy
- salivation
Serotonin syndrome
- Clinical spectrum of mental status changes, autonomic hyperactivity and neuromuscular abnormalities
- tremor, agitation, hyperthermia, hyperreflexia, myoclonus, seizures
- usually cause by a combination of drugs
examples of drugs that asso with SS
- monoamine oxidase inhibitors
- SSRI
- Clomipromine
- Clonazepam
- MDMA, cocaine
Ix of suspected poisoning
- h’stix
- electrolytes, urea, creatinine, LFT, RFT
- ABG/ VBG
- paracetamol level (at least 4 hours after exposure)
- ECG
- CXR
Important ECG pattern in poisoning
- Terminal 40ms R axis deviation (TCA overdose)
- Widen QRS (Na channel blockade - TCA, cocaine, carbamazepine, citalopram, antiarrhythmics, amantidine, propranolol, phenothiazine, dolozene, venlafaxine, diphenhydramine)
- Prolonged QTc (hypo K, hypo Ca, hypo Mg —> antiarrhythmia, antidepressants, antipsychotics, antihistamine, anti microbial, cisapride, Lithium, arsenic trioxide, methadone)
- digitalis pattern —> heart block
Gut decontamination in poisoning
- Gastric lavage —> not commonly used now (come in within 1 hour and ingest fatal amount
- Activated charcoal
- Whole bowel irrigation —> 2L of PEG every hour —> large amount of drug not absorbed by charcoal such as lithium and iron, body packers
C/I: bowel obstruction - Multi dose activated charcoal (MDAC)
Paracetamol overdose
- use nomogram for plasma paracetamol level (check after 4 hour)
- give IV N-acetylcysteine within 8 hours
- may have anaphylactoid reaction (wheeze, rash) —> temporary withdrawal, restart at a slower rate after IC antihistamine +_ hydrocortisone
Paracetamol poisoning
- use nomogram for plasma paracetamol level (check after 4 hour)
- give IV N-acetylcysteine within 8 hours
- may have anaphylactoid reaction (wheeze, rash) —> temporary withdrawal, restart at a slower rate after IC antihistamine +_ hydrocortisone
TCA overdose
- within 6 hour, if no signs of toxicity, can safely discharge
- ECG pattern is important
- QRS duration longer, more severe toxicity
- gastric lavage and activated charcoal within 1-2hr
- IV sodium carbonate as first line agent, monitor blood gases for metabolic alkalosis
