Toxicology Flashcards
Peak time for poisoning in childhood
Toddlers peak time
Adolescents 2nd peak self harm
Childhood poisoning
Not usually self harm
History is difficult
Different types of materials ingested eg plant soil paint pesticides drugs
Usually very small amounts are NOT toxic
BUT one pill can kill
Smaller oesphagus and stomach limit the effectiveness of some decontamination
Always consider could this be Child abuse
One pill can kill
Amphetamines B blockers CCB Digoxin Suphonlureas Tricyclics antidepressant
Other potential killers
Pesticides
Kerr /eucalyptus oil
Campho/ napthalin
Poisoning history and examination
History is unreliable
Suspicious
Time of the ingestion unknown (when was the child last well)
Calculate the max possible dose ingested
If >1 child with meds assume all children could have ingested or one did max ingestion
Management of poisoning
Resuscitate Risk assessment Poisoning info Ongoing management Supportive care and monitoring DEAD decontamination/ increasing elimination / antidotes/ disposition
Examination of poisoning patient
Id and treat immediate threats to life Establish the baseline of clinical status Corroborate the history Consider toxin VS non Toxin causes Id complications of poisons
Full Neurological examination mental state pupils reflexes clonus focal signs
Evidence of trauma
Skin color sweating
Urine retention ? Full bladder ( anticholinergics)
Risk assessment in Posioning
What substance eg paradox/ B blocker Dose When time since ingestion Clinical features Ix ECG ( TCA) / Sr Paracetamol
DD coma /altered state
Non toxic vs toxic
Head injury CNS infection Hypo/hyperthermia Ictal / post Ictal Drugs Metabolic BSL /ARF
2ary complications of posioning
Aspiration Rhabdomyalysis ARF Pressure areas Hypoxic brain injury
Drug levels when are they helpful
Paracetamol levels 4 hours after ingestion helpful
Others only when clinically indicated eg phenytoin carbamazepine
Digoxin aspirin lithium
NOT HELPFUL cocain benzo Cocain opiates
ACE/ B Blockers CCB clonidine
Anticholinergic toxidromes
Blind as a bat / mad as a hatter /red as beet/ hot as a hare/dry on the bone the bowel and the bladder lose their tone
The heart races alone
Antihistamines TCA / Phenothiazines / Benstropine ( give for maxolon) Agitated delirium Dilated pupils Full bladder ileus IDC Tachycardia
Cholinergic Toxidromes
Seen with organophosphate
Chemical attack Vx gas
Carbamates
DUMBELS Diarrhoea Urinartion Miosis Bronchorrhoea Bradycardia (this is what kills you) Emesis Lacrimation Salivation
Sympathomimetics. Cocaine exctasy MDMA TCA
Hypertension Tachycardia Dilated pupils Agitation Sweating Hyperthermia do poorly treat aggressively
Pale sweaty patients
Serotonin toxicity SSRI SNRI and usually in combination or changes in meds
Neuromuscular examination
Hyper reflexive clonus eyes and ankle examination
Confusion, agitation, dilated pupiles sweating raised BP
Tachycardia
Opioid toxicity
Respiratory depression ( use Naloxone for resp depression NOT CNS depression) Sedation Pinpoint pupils
Management of poisoning
Resuscitate ABC
Supportive care
DEAD
Supportive care
Metabolic glucose and control the pH Sedation IV benzodiazepine Seizures IV benzodiazepine DONT use phenytoin Na+ channel blocker Body temp cool/ warm Renal function. Hydration/ haemodialysis
DEAD
Decontamination GIT ( do when the drug is still in the GI tract) Activated charcoal Whole body irrigation. Colonic prep Endoscopy
Activated charcoal
Don’t use in ileus / pt decreased loc
1gm/kg
Taken orally or NG (CXR to check position)
Greatest benefit <=1 hour
Complications of activated charcoal
Vomiting
Charcoal aspiration
Absorb the oral antidote
Bowl obstruction/ileu
Indications for charcoal
Risk assessment suggests drug ingested would be toxi
Give <= 1hour
Longer if SR meds or LOTS of meds
Co operative pt
Pt has to be alert or the airway protected
Contraindications to charcoal
Not for metals alcohol, corrosives , hydrocarbons MATCH
Low GCS
Ileus
Whole body irrigation
Metals
Body packers
SR or enteric coated EC CCB
Contraindicated. Bowel obstruction, ileus, / unprotected airway
Enhanced Elimination
1 multidose activated charcoal ( enterohepatic circulation) carbamazepine mushrooms
2 urinary alkalization. Salicylate ion trapping
3 heamodialysis use in antifreeze lithium/valproate/ carbamazepine
Paracetamol overdose
Toxic ingestion >200mg/kg Nomogram SINGLE ingestion Known time of ingestion Level >4hours to ensure peak point IV N acetylcystein antidote
Chronic paracetamol overdose and SR overdose over 24-48 hours
Complex consult guidelines and toxicologist
Clonodine
Clonodine used for ADD
CNS depression and bradycardia
IV fluids and iv Atropine
Naloxine controversial
Red back spider bite
Commonest spider bite
Local effect pain redness swelling sweating piloerection
SYSTEMIC regional pain hypertension sweatiness
Treatment is ANALGESIA ++ note the pain can come back
Anti venom
Not effective
Controversial
Funnel web spider. FWS ( needs pressure immobilizing and splinting)
Most venomous spider in the world
Uncommon to bite 1% of all bites
Anti venom works
Clinically facilitation of the tongue Tremor parasites Secretions ++ Piloerection N/V/BP pr up cardiac arrhythmia Management ABC IV access Anti venom Admit to icu
Brown snakes
Commonest cause of snake bite death in Australia
All over Australia NOT TASmania
Features
Collapse a few mins later CPR
Consumptive coagulopathy VICC ( coag profile )
Tiger snakes and Taipans
Neurotoxic /eyes ptosis and opthamoplegia
VICC coagulopathy
Give anti venom
Death adders
Neurotoxic
NO Coagulopathy
First aide for snake bite
Do remove from danger Keep still Apply pressure bandage Immobilize the whole limb Splint the limb ( leave the PIB on till A/E and bloods collected and ? AV given if necessary
Pressure immobilization bandage indications
For ALL snake bites in Australia ( including the sea snake)
For Funnel web spider bites
Blue ringed octopus
Cone shell sting
Describe the technique for pressure immobilization bandage
Firm bandage to the bitten site
Bandage the entire limb
Splint /immobilization of the limb
Clinical diagnosis
Geography
Circumstances of the bite
Symptoms and signs
Lab results
Anti venoms
Raised in horses
Given iv over 30mins ( diluted in NS)
Adverse reactions are common Anaphlaxis
Sr sickness
After one vial given cant take of the bandage and then get lots of blood tests
Snake venom detection kids
NOt used much
Box jelly fish
Tropical areas often remove
Can lead to child deaths
Cardiac arrest
Remove the testicles and apply vinegar and use Anti venom
Blue bottles
Pain responds to HEAT
Put both limbs in hot water to avoid burns
