Gases and Oils Flashcards
Does CO have a greater or lesser affinity for Hb than O2?
240x greater
What two organs are most sensitive to oxygen depletion?
Brain and myocardium
How are CO and CO2 different as far as the type of combustion that produces them?
CO - incomplete combustion of fuels
CO2 - complete combustion of fuels
How does the toxicity of CO differ from CO2?
CO - highly toxic
- Binds Hb, making carboxyhemoglobin –> Hb cannot carry O2 –> tissue anoxia –> affects brain, myocardium, etc.
CO2 - much less toxic
- It reduces the amount of breathable O2
- It results in decreased CO2 removal from the blood in the alveoli
What tissues/organs does ammonia gas target in animals?
MM, esp. in the eyes and respiratory system (lungs, nasal passages, trachea)
How does the toxicity of anhydrous ammonia differ from that of ammonia generated from manure in confinement situations?
Ammonia
- Conjunctivitis (poultry) and tearing
- Nasal discharge
- Coughing, shallow breathing
- Increased tracheitis and bronchopneumonia
Anhydrous ammonia
- Severe necrosis of skin and conjunctiva
- Pulmonary edema
- Severe inflammation
- Death
What does hydrogen sulfide smell like?
Rotten eggs
What is the target organ for hydrogen sulfide?
MM of eyes and respiratory tract
Why doesn’t removal of an animal to fresh air reverse the toxic effects of an animal overcome with hydrogen sulfide intoxication?
Paralyzes there respiratory center at high enough concentrations; they will need full respiratory gear with oxygen to give artificial respiration until the hydrogen sulfide decreases
Why don’t animals and/or people try to escape from high concentrations of hydrogen sulfide gas, as they would with low concentration?
It paralyzes their olfactory tract, so they do not realize they are inhaling high concentrations (they cannot smell it)
How does excess sulfate/sulfur in cattle diets cause polioencephalomalacia?
Hydrogen sulfide gas is produced in the rumen when sulfate and sulfur are found in the water and/or feed
- some plants can have significant amounts of sulfur
- distiller’s grain can be high in sulfates
- may come from high sulfur molasses
What is the target organ for intoxication by smoke inhalation?
Lungs
What typically kills animals in house fires?
CO and smoke inhalation
What gas is generated and liberated from silage that is high in nitrates?
Nitrogen dioxide gas
What is the characteristic smell of nitrogen dioxide gas?
Bleach
Why are birds more susceptible to the toxic effects of Teflon fumes than mammals?
Birds are very efficient at gas exchange
What is the source of oil related ingestion by cattle?
Oil pools and waste around oil well on farms
What is the source of oil related to direct pulmonary damage?
Intubation of mineral oil into the lungs (instead of GI tract, as it was intended by the animal)
What is the source of oil related to wildlife exposure?
Dermal exposure –> dermatitis –> loss of insulation/thermoregulation
What oil causes aspiration pneumonia?
Volatile (light) oils
Ingestion of which oils can cause diarrhea
Crude oil high in gasoline, naphtha, and/or kerosene
How do you diagnose oil ingestion?
- History
- Oil on the muzzle
- Oil in the feces
- Necropsy
- Oil in the lungs
- Oil in the rumen or GI tract
- Analysis for petroleum hydrocarbons
What is the treatment for oil ingestion?
- Remove oil from the GI tract (rumenotomy, activated charcoal/vegetable oil to increase viscosity)
- Supportive care
- Wash of skin (if dermal)
What is a common source of exposure of Teflon?
Nonstick pans heated on a high temperature
what is a common exposure of CO?
incomplete combustion of fuels (space heaters or furnaces not working right)
what is a source of CO2?
complete combustion of fuels (decomposition of manure)
what is a source of ammonia?
decomposition of animal wastes, ammonia gas as a fertilizer
what is a common source of hydrogen sulfide?
natural gas deposits, coal, oil, volcanic gases, sulfur springs/lakes
what is a source of nitrogen dioxide?
rapid decomposition of nitrate containing plant materials (from silos)
what is a source of methane gas?
flatulence
What is the MOA for smoke?
burns from superheated particles
what is the MOA of CO?
binds Hb to form carboxyhemoglobin –> unable to carry O2 –> tissue anoxia
what is the MOA of CO2?
- high CO2 in air reduces the amount of O2
- decreased removal of CO2 from the blood –> respiratory acidosis –> compensatory tachypnea
what is the MOA of NH3?
- respiratory irritant that is highly water soluble, which allows it to easily come into contact with MM, causing irritation
- when it reacts with tissue water, it forms a strong irritating and potentially necrotizing alkaline solution (NH4OH) –> the reaction producing this is exothermic and capable of causing thermal injury in addition to irritation and necrosis
what is the MOA of NO2?
forms nitric acid with water in the lungs and MM –> irritation and tissue damage
what is the MOA of mathane?
displaces oxygen in air, combustible
what clinical signs are expected with Teflon gas?
death due to respiratory failure, acute pulmonary distress with dyspnea, ataxia, and depression –> hemorrhagic pulmonary necrosis
