Lecture 19 - Poisons Flashcards
Describe carbon monoxide
- gas
- colorness
- odorless
- tastless
- slightly lighter than hair
sources of carbon monoxide
- endogenous
- incomplete combustion of fossil fuels and carbon-containing compounds (car exhaust from older cars or fires)
- exposure to methyl chloride (solvent in paint stripper)
- some drug therapy (phenobarbital)
metabolism/elimination of carbon monoxide
primarily eliminated unchanged by the lungs
carbon monoxide poisoning causes ____ ______
tissue hypoxia
Describe carbon monoxide levels (percent saturation)
1-10%: no detrimental effect (common esp if you live in urban centre)
5-9%: smoker level
10-20%: slight headache
20-30%: throbbing temples
30-40%: severe headache, weakness, dizziness, n/v, collapse
40-50%: retinal hemorrhages, increased respiration
Over 50%: convulsions, coma, death
What 3 spots are most sensitive to oxygen deprivation?
CNS, brain, lungs
Who is most susceptible to CO poisoning?
- infants
- those with lung disease
- those with CV disease
- elderly
- those with anemia
What is the treatment of carbon monoxide poisoning?
- remove person from source of carbon monoxide
- hyperbaric oxygen
- 100% oxygen, their CO2 level will drop by 1/2 within 40 minutes
- Air has 20% oxygen - will take about 4 hours to get the level to drop by 1/2
What can we use for analysis of carbon monoxide?
whole blood: need RBC’s
liver or kidney can also be used bc they have hemoglobin
What is the lethal dose of cyanide?
2mg/kg
What forms does cyanide come in?
- Hydrogen cyanide (HCN)
- colorless gas or blue-white liquid
- Cyanide salts ex. KCN, NaCN
- white crystalline powder
sources of cyanide?
- normal metabolism
- cigarette smoking
- fumigants, insecticides
- electroplating industry
- dying, printing, photography
- combustion of N-containing compounds
- cyanogenic glycosides
Describe the toxicity of cyanide
- an enzymatic poison
- attacks the cytochrome system
- prevents oxygen utilization at the cellular level (cytotoxic anoxia)
- results in metabolic asphyxiation
Describe the symptoms of acute toxicity of cyanide
- giddiness
- stiffness in lower jaw
- rapid, slow, irregular breathing
- muscle twitching
- palpitations
- cyanosis
- convulsions
- coma
- death due to respiratory arrest
____ and ____ are most sensitive to cyanide toxicity
brain and heart
Describe the chronic toxicity of cyanide
- dizziness
- weakness
- congestion of lungs
- conjunctivitis
- loss of appetite
- weight loss
- mental deterioration
Describe the max ppm of cyanide that you can get in an 8 hour work day and the ppm’s that cause death
Max 10 ppm over an 8 hour day
110 ppm = death in 1 hour
135 ppm = death in 30 min
180 ppm = death in 10 min
270 ppm = immediately fatal
Ingestion of cyanide: death may be delayed as long as ___ hour
1
What is the treatment for cyanide poisoning?
- Body can detoxify CN on it’s own
- Cn –> SCN- (via the rhodanese enzyme)
- cyanide –> thiocyanide
- this is an inefficient system; can be sped up by adding an exogenous source of sulfur
- 3 agents used: amyl nitrite; sodium nitrite; sodium thiosulfate
- thiocynate is water soluble and excreted in urine
if a house fire happens, what produces CO2 and what produces cyanide
wood: CO2
synthetic furniture: cyanide
What do we need to interpret cyanide?
-whole blood
What are inhalants?
What does that include?
defined as breathable chemical vapours that produce psychoactive (mind altering) effects
Includes: 1-volatile solvents 2-aerosols 3-anesthetics 4-volatile nitrates
What are some examples of volatile solvents?
Common sources?
- toluene
- methylethyl ketone
- acetone
- benzene
- naptha
- trichloroethane
- methylene chloride
Common sources:
- paint or paint thinner
- cement/glue
- lacquer thinner
- nailpolish remover
- lighter fluid
- dry cleaning fluids
- gasoline
Examples of aerosols and common sources
Ex. fluorocarbons
Common sources:
- hairspray
- cooking spray
- deodorant sprays
- glass chillers
- spray paint
