Poisoning Flashcards
(45 cards)
what is the definition o these 3 words ?
1. Poison
2. Toxin
3. Venom
- Poison: Substance that causes disturbances to an organism when a sufficient amount is absorbed
- Toxin: produced biologically
- Venom: toxin injected by bite or sting
poisoning
any illness that is caused by exposure to toxic substance
Toxicity
inherent capacity of a chemical, including drugs, to cause injury
routes for poisoning
- Skin contact
2.Inhalation
3.Ingestion
what are the common target tissues ? and what type of substabce affect that organ ?
- Lungs (vapors or toxic gases)
- Liver (ingested drugs)
- Brain (bcoz of high blood flow )
- Kidneys (bcoz of high blood flow )
5.Heart (ionic gradient disturbances)
What is Toxicology?
The characterization of potentially adverse effects of foreign chemicals, including dose-response relationships, aimed at public health protection.
What are nonselective toxic actions of chemicals?
- Local irritation/ caustic effects( Local irritation or caustic effects at the site of exposure/application, causing injury by denaturing macromolecules.)
- Strong alkali or acids
these do not select ,they damage anything they are in contact with .e.g
What are selective toxic actions of chemicals?
- Interferes with specific biochemical pathways
- Chemical has to be absorbed and distributed
to a specific pathway
Give examples of selective toxic actions of a chemical and how are they selective
- Rattex (rodenticide/”superwarfarins”) contains
warfarin and interferes with the Vitamin K pathway - Paracetamol – depletion of glutathione needed for
conjugating the toxic metabolite NAPQI
- they have to e bdistributed toa specofic pathway.
Rattex
rodenticide/”superwarfarins
what are the 2 toxic actions that leads to symptoms quickly following the exposure ?
- Organophosphate poisoning
- Acetylcholinesterase inhibition can cause immediate
symptoms - Severe iron poisoning
What are the phases of severe iron poisoning?
-Early phase (0.5-2hrs)
-Quiescent phase (up to 12 hours)
-life-threatening phase
What are the key steps in the management of poisoning?
A-Airway
B-Breathing and oxygenation
C-Circulation and cardiac monitoring
D-Diagnosis and Decontamination
E-Enhancing drug clearance
F-Frequent re-evaluation and Further
symptomatic care
G-Give antidote
H-Help
What are important factors to consider during diagnosis of poisoning?
1.History from the patient and relatives about the toxic substance, time of ingestion, amount ingested,
2. On examination there might be clinic syndromes ( dilated or constricted pupils together with other signs )
3.Special investigations :arterial blood gas, electrolytes, liver and kidney function tests, FBC, urinalysis, ECG, and plasma poison concentration.
special investigations for suspected poisoning /poisoning
1.arterial blood gas
2.Electrolytes
3.Liver and kidney function tests
4.FBC
5.Urinalysis
6.ECG
7.Plasma poison concentration e.g paracetamol
Describe the decontamination methods for poisoning.
1.Skin decontamination
2.eye decontamination
3.airway decontamination
4.gastric decontamination
remove the pt contaminanted cloths ( put in the biohazard babgs ) and make sure you have your own PPE
what way can gastric decontamination be done ?
1.Gastric emesis/lavage
2. Activated charcoal
3.Whole bowel irrigation
When is emesis indicated ?
emesis= vomiting /throwing up
1. Time since ingestion < 1 hour
2.Children
3.If charcoal not indicated
what are the contraindications of emesis?
1.Impaired level of consciousness
2.Corrosive substances
3.Hydrocarbons
4.Risk of seizures
name ans explain the the 2 methods of emesis
1.Stimulation of pharynx=Mechanically stimulating the back of the throat to induce vomiting
2.Ipecacuanha=Administering ipecacuanha syrup, which is a plant extract that induces vomiting through its action on the stomach lining and the brain’s vomiting center.
what is gastric lavage ?
Gastric lavage, also commonly called stomach pumping, is an invasive procedure involving cleaning and removing stomach contents. A large tube is inserted through the mouth or nose into the stomach. Stomach contents are subsequently aspirated, and the stomach is later flushed with copious amounts of water or normal saline. During this procedure, the individual may be awake or under general anesthesia.
What is the role of gastric lavage in poisoning?
1.Useful if the time since ingestion is < 1-2 hours and a large amount of toxic solid substance has been ingested (2)
a substance that takes long to be absorbed
How is gastric lavage done done ?
A large tube is inserted through the mouth or nose into the stomach. Stomach contents are subsequently aspirated, and the stomach is later flushed with copious amounts of water or normal saline.
- Use LARGE-bore catheter (32-40)
◼ 200 – 300ml tap water in adults
◼ 10ml/kg body temperature saline in kids
- protect the airway (ETtube and position sightly on their side )
monitor the decontamination
what are the contractraindication of gastric lavage ?
- Corrosive substances and hydrocarbons
2.Risk of GI haemorrhage
3.Unprotected airway
