Respiratory Flashcards
what are the three systems of the airway?
conucting, transitional, and exchange
do bronchioles have cartilage?
no! they have smooth muscle
it is the airways in the ____ zone that are subject to autonomically regulated bronchoconstriction and bronchodilation
transition
what makes up the gas blood barrier?
a type I penumocyte, the basement membrane, and the endothelial cell of the capillary
when a patient has allergies and inflammation, what are our therputic goals and what drug category should we use?
goals: decrease inflammation, improve mucociliary clearance, promote gas exchange
drug: steroids
if a patient has pulmonary edema, what are our theraputic goals and what kind of drug should we give?
goals: decrease fluid and improve gas exchange
drug: diuretics
if a patient is coughing, what should our theraputic goals be and what drugs should we consider?
goals: decrease the cough, improve mucus removal, suppress inflammation
drugs: cough suppressants, sometimes steroids
if an animal has a productive cough, should you give them a cough suppressant?
no! coughing is helping them clear their systems in this case. if it is not productive, you can consider a suppressant
if you have a patient with exercise induced pulmonary hemorrhage, what is our theraputic goal and what drugs should we consider?
goal: decrease trans-pulmonary capillary pressure
drug: diuretics aka furosemide
if a patient has penumonia, what are our theraputic goals and what drugs should we consider?
goals: treat infection, reduce inflammation, improve gas exchange
drugs: antibiotics, steroids, NSAIDS, bronchodilators, expectorants and mucolytics
what is an antitussive? name some diseases commonly treated with this
a cough suppressant
kennel cough, tracheal collapse, in horses for diagnostic procedures
list 4 antisussives
butorphanol, codeine, hydrocodone, and dextromethorphan (not an opiod but an opiod derivative without the analgesic or additive properties)
briefly describe the cough reflex
afferent fibers in the vagus nerve send signals to the medulla where the cough center is, then efferent system triggers the respiratory muscles to generate a cough
what are the 3 phases of a cough?
inspiratory (to generate the volume needed for a cough)
compression (diaphram contracts, intercostal muscles, and abdominal wall contracts putting pressure on a closed glottis)
expiratory (the pressure opens the glottis letting out rapid air and a cough sound)
how do antitussives work?
they act directly on the cough center in the brain to decrease it’s sensitivity to stimulation by afferent signals. this results in a lower frequency of coughing
what antitussive is safest for cats and is better for chronic use (not additive)?
Dextromethorphan (dex-troh-meh-thor-fan)
who is more sensitive to opiods: dogs or cats
cats, they are more sensitive to the CNS effects and can become sedated or excited when give butorphenol or codeine
briefly explain what expectorants and mucolytics do?
expectorants: increase bronchial secretions, enhance mucociliary clearance, promote productive coughing
mucolytics: break down mucus secretions, make mucus more watery
what kind of drug is acetylcysteine (mucomyst). how does this drug work? how is this drug administered?
it is a mucolytic
the drug has a free sulfhydryl group that breaks down disulfide bonds in mucoproteins
it is administered by nebulizer
what drug is used to break down chondroids in guttural pouches of horses?
acetylcysteine
what drug is used as an enema in foals with refractory muconium impactions?
acetylcysteine
what kind of drug is dembrexine (sputolysin?) how does this drug work? how is it administered?
a mucolytic
the proposed effect is alteration of the constituents and viscosity of abnormal resp mucus and improved efficiency of clearance
it is administered in feed as a powder
what drug can be given to dogs with otitis media (inner ear mucus plug)
dembrexine (sputolysin)
what kind of drug is (Guaifenesin)(gwai-fen-assun). How does it work? How is it administered?
expectorant and centrally acting muscle relaxant
it affects respiratory secretions via parasympathetic mechanisms stimulated by gastric mucosal irritation. it is given orally
which drug is commonly used as an IV field anesthetic in LA?
guaifenesin
briefly describe what saline expectorants and volatile oils are and how they are supposed to work
saline expectorants: proposed to stimulate bronchial mucus secretion possibly via vagal stimulation from gastric mucosal irritation with little evidence
volatile oils: believed to directly increase resp secretions
list 3 examples of saline expectorants
ammonium chloride
potassium iodide
ethylenediamine dihydroiodide (EDDI)
why are bronchodilators so useful in terms of physics?
because of poiseuille’s law; if you double the length of the tube you double resistance, BUT if you decrease radius by half, resistance increases 16 fold so diamater is the largest factor in air flowing through a tube with little resistance
bronchdilation and bronchconstriction happens at the level of the _____
bronchioles
what receptor types innervate/control bronchiolar smooth muscle?
muscarinic receptors (parasympathetic) is the main one
some beta 2 as well
stimulation of the M3 receptors will do what to bronchioles?
constrict them
stimulation of beta 2 receptors will do what to bronchioles?
dilate them (remember beta 2 receptors are adrenergic aka sympathetic)
what else can cause bronchoconstrition besides M3 stimulation?
inflammation
anticholinergics have what effects on the resp system? list some examples of anticholinergics
they are bronchodilators since they prevent parasymp stimulation
ex: atropine, glycopyrrolate, N-butylscopolamine bromide
equine asthma can be quickly treated to give the horse fast relief with what drug?
hyoscine butylbromide (buscopan)
what effects do beta 2 agonists have on the resp system? list some examples of beta 2 agonists
they are bronchodilators
ex: salbutamol, clenbuterol, epinepherine (non selective)
what kind of drug is salbutamol/albuterol? what is it used to treat?
a beta 2 agonist (short acting bronchodilator)
used to treat asthma in horses and cats for ACUTE treatment
you go visit a horse that is having trouble breathing and it seems to be having a flare up of equine asthma. this has happened before in this horse and it now seems to be a chronic problem. What drug(s) should you give the horse?
salbutamol/alberterol for acute treatment of asthma and for any flare ups and then steroids for chronic use
what kind of drug is clenbuterol? what is it used to treat?
a beta 2 agonist
labelled use is for airway obstruction in horses like recurrent airway obstruction/heaves, not the drug of choice anymore
it must be combined with environmental changes to see full effects
for which drug is tachyphylaxsis often seen within 21 days od continuous administration?
Clenbuterol(ventipulmin)
what is the most commonly used inhaled nasal steroid?
Fluticasone
list general categories of drugs that can cause respiratory depression
any CNS depressant
anesthetics, opiods, benzodiazepines
list general categories that act as respiratory stimulants
any CNS stimulant
doxapram, almitrine, caffeine
very few drugs ______ without other effects
specifically stimulate respiration
what is doxapram used for?
in emergency settings during anesthesia or to decrease resp depressant effects of opiods and barbituates. use is controversial
it can also be used to stimulate respiration in apneic neonates
what kind of drug is doxapram? how does it work?
general CNS stimulant, direct stimulant of the respiratory centers in the brain. it increases the resp rate and volume but arterial partial pressure of oxygen does not increase
