Cardiac and Pulmonary Flashcards
cardiac glycosides
steroids that have a lactone group attached to the steroid nucleus
Cardiac Glycoside Sources (4)
- Cardiac medications (ex: digoxin)
- Plants (Oleander, Foxglove, Lily-of-the-Valley, Milkweed),
- Bufo Toads
- Fireflies
Cardiac Glycoside MOA
inhibits the sodium-potassium pump in cardiac muscle
Cardiac Glycoside Clinical Signs
ARRYTHMIAS, GI upset (a lot of vomiting), hyperkalemia, lethargy, uneasiness, SUDDEN DEATH
Cardiac Glycoside Antidote?
yes - Digibind
Digibind
human antidote for digoxin, very expensive (but patient would go home quickly)
Grayanotoxin MOA
binds to sodium channels in nerves, heart, and skeletal muscle, so cells are in prolonged depolarization
Cardiac Glycoside Treatment
ACTIVATED CHARCOAL (decreases absorption by 96%), NO calcium-containing fluids, symptomatic tx (especially for arrythmias)
Grayanotoxin Sources (4)
Rhododendron
Azalea
Laurel
Japanese pieris
Grayanotoxin Clinical Signs
negative chronotropic action (sinus arrest)
also bloat/abdominal pain, vomiting, anorexia, teeth grinding, depression, ataxia, convulsions
Do grayanotoxins have an antidote?
no
Grayanotoxin Tx
decontaminate, monitor heart, symptomatic/supportive care
What is the only part of the Yew plant that isn’t toxic?
the ripe fleshy fruit part
Yew MOA
directly toxic to the cardiac myocyte ion channels
Yew Clinical Signs
basically sudden death, can give AC but otherwise minimize stress and provide supportive care
White Snakeroot Cardiovascular Signs
CHF and arrythmias; cause cardiac necrosis in horses and if recovered can have residual circulatory dysfunction
Avocado Clinical Signs
cardiac arrythmias, myocardial necrosis, pulmonary congestion and edema
Are all parts of an avocado toxic?
yes
Toxin in Avocados?
persin
Avocados can affect cardiac and _______ tissue
mammary
Gossypol
from pigment gland in cottonseed and causes “thump” (pigs)
Gossypol Clinical Signs
CHF, weakness, cyanosis, “thumping”
What species is most susceptible to cardiac failure due to ionophores?
horses
Albuterol TOXICOSIS MOA
beta-1 and 2 agonist (normally only 2)
Albuterol Toxicosis Clinical Signs
tachycardia (200+ bpm and hypokalemia)
Albuterol
commonly used to treat bronchospasm associated with asthma
Albuterol Tx
propranolol (non-selective beta blocker for tachycardia)
decontaminate, symptomatic/supportive
Phenylpropanolamine (PPA)
sympathomimetic agent withdrawn from human market but still used in vet med for controlling urinary incontinence in dogs (Proin)
PPA Clinical Signs
tachycardia, agitated, and hypertension (very high), then later reflex bradycardia, depressed, and hypertensive
PPA Tx
decontamination, heart/blood pressure drugs (ace or nitroprusside), fluids
Why do you NOT give atropine to bradycardic PPA patients??
this will WORSEN the already awful hypertension - so make sure to take blood pressure before administering atropine
Paraquat
bipyridylium herbicide for restricted use; used in malicious poisonings
Paraquat MOA
forms a free radical and eventually lipid peroxides will stimulate a self-perpetuated damaging rxn; pulmonary specific toxin
Paraquat Clinical Signs
oral and dermal burns, GI damage, renal failure and hepatocellular necrosis, but most importantly progressive pulmonary fibrosis
Should you ever induce emesis with Paraquat?
YES even though it’s so corrosive, it is also incredibly deadly so this is where the risk needs to be taken
pulmonary fibrosis
damage to lungs repaired by fibrosis but then the lung can’t expand so there’s no oxygen exchange and then your patient suffocates
Should you give oxygen to Paraquat patients?
NO this increases free radicals therefore increasing pulmonary damage!
Acute Bovine Pulmonary Emphysema and Edema (4 sources)
Type 1 pneumocytes
main oxygen exchanger in lung that’s damaged when acute bovine pulmonary edema and emphysema occur
Hydrogen Sulfide Signs
colorless gas (rotten eggs) that causes loss of smell, loss of consciousness, and death d/t direct paralysis of the respiratory center
Hydrogen Sulfide Source?
pits! and apparently Yellowstone
Fumonisin Pigs
heart failure is first but also causes pulmonary edema
Teflon aka Polytetrafluoroethylene (PTFE)
nonstick cookware that release toxic particles upon heating that causes seizures and death in birds!
Petroleum Distallates
remember these “defat” so if they’re aspirated they’ll do this to the lungs and you get chemical pneumonitis
