Respiratory - EMILY Flashcards
What comprises the mucociliary apparatus?
Ciliated cells and goblet cells that line the the conducting portion of the tracheobronchial tree
What is the site of airway constriction and dilation?
Bronchioles and terminal bronchioles because they are made of smooth muscle and no cartilage
What disappears in the transitional zone of the resp system?
Cilia and goblet cells
What are the therapeutic goals of treating allergies/inflammation?
-Decrease inflammation
-Improve mucociliary clearance
-Promote gas exchange
What kinds of drugs are used to treat allergies/inflammation?
-Steroids*
-Expectorants and mucolytics
-Bronchodilators
What type of drug is used to treat pulmonary edema and why?
Diuretics; reduces fluid content in lungs to improve gas exchange
What kind of drugs are used for treating coughing?
-Cough suppressants (antitussives)
-Expectorants and mucolytics
-Steroids
What type of drug would be used to treat exercise-induced pulmonary hemorrhage?
Diueretics
What kinds of drugs could be used to treat pneumonia?
-Antimicrobials
-Steroids/NSAIDS
-Expectorants and mucolytics
-Bronchodilators
What are the 3 main type of drugs used to treat respiratory conditions?
-Antitussives
-Expectorants and mucolytics
-Bronchodilators
What are the primary uses of cough suppressants in vet med?
-Tracheal collapse (dogs)
-Kennel cough (dogs)
-Cough suppression during diagnostic procedures (horses)
What are the 4 drugs commonly used to suppress coughing and what are they?
-Butorphanol (opioid)
-Codeine (opioid)
-Hydrocodone (opioid)
-Dextromethorphan (opioid derivative)
How is the cough reflex triggered?
Afferent pathways in the vagus nerve are stimulated and trigger the cough center in the medulla which stimulates respiratory muscles for coughing
What do antitussives do to the cough center in the medulla?
They make it less sensitive so it’s less likely to be activated
When should you NOT give an antitussive?
If the cough is productive (animal swallows after coughing). This could reduce helpful clearance of mucous and stuff which would be bad
What is the safest antitussive product for use in cats long-term?
Dextromethorphan. It does not act on opioid receptors so it is not physically addictive
What do expectorants do?
-Increase bronchial secretions
-Enhance mucociliary clearance
-Promote productive cough
What do mucolytics do?
Break down mucous secretions
Which 3 drugs are mucolytics?
-Acetylcysteine
-Dembrexine (sputolysin)
-Guaifenesin
Which 2 things are expectorants?
-Saline expectorants
-Volatile oils
How does acetylcysteine work?
The free sulfhydryl group on the drug breaks down disulfide bonds in mucoproteins
What are two situations where acetylcysteine could be used?
- Infused into gutteral pouch of horses to break down chondroids (mucous concretions)
- Enema in foals for refractory meconium impactions
What can acetylcysteine be given IV for?
Treating toxicities to acetaminophen and xylitol
What can happen in some patients if acetylcysteine is given in the inhaled version?
Can induce hypersensitivity reactions and bronchoconstriction in some patients
What does dembrexine (sputolysin) do?
Alters the viscosity of mucous to make it easier to clear
How is dembrexine (sputolysin) given?
Orally administered so it has systemic effects. May also have some antitussive effects
What is dembrexine (sputolysin) used to treat?
Horses: RAO, IAD, pneumonia
Dogs: Otitis media with effusion (mucous plug in middle ear)
What is guaifenesin?
Primarily a muscle relaxant, but also an expectorant/mucolytic
How does guaifenesin work?
-Affects respiratory secretions via parasympathetic mechanisms stimulated by gastric mucosal irritation
-Enhances mucociliary apparatus function
The _______ of a tube is much MORE important than its _______ in determining resistance to airflow
Radius; length
Bronchioles consist of:
Smooth muscle only!!
Bronchiolar smooth muscle innervation is primarily _______________
Parasympathetic
What are the primary receptors in bronchiolar smooth muscle?
M3 (muscarinic/cholinergic)
Stimulation of M3 receptors in the bronchioles will cause:
Bronchoconstriction
What other receptors are also present in bronchiolar smooth muscle?
beta-2 receptors
Stimulation of beta-2 receptors in bronchiolar smooth muscle will cause:
Bronchodilation
What are effective bronchodilators?
Anticholinergics (muscarinic antagonists)
Anticholinergics will prevent what?
Parasympathetic bronchoconstriction
What are 3 anticholinergic drugs that are bronchodilators?
-Atropine
-Glycopyrrolate
-N-butylscopolamine bromide (Hyoscine butylbromide)
What are 2 drugs that are beta-2 agonists?
-Clenbuterol
-Albuterol/salbutamol
What are 3 methylxanthines that cause bronchodilation?
-Aminophylline
-Theophylline*
-Caffiene
Beta-2 agonists are Broncho-__________
Dilators
Epinephrine is also a bronchodilator. What kind of drug is it?
Non-selective adrenergic agonist
What is salbutamol/albuterol usually given as treatment for?
Asthma in horses and cats - generally for acute treatment
Salbutamol/albuterol is a _______-acting bronchodilator
Short
Why is salbutamol/albuterol given in an inhaled form?
-Rapid onset of action
-Reduced risk of adverse effects and drug interactions
Why shouldn’t salbutamol/albuterol be given for extended periods?
-Tolerance can occur (tachyphylaxis)
-May be pro-inflammatory in cats
Clenbuterol should NOT be given to which animals?
FOOD ANIMALS!!
Clenbuterol is labelled for what?
Management of airway obstruction due to respiratory disease in horses (RAO, IAD)
Clenbuterol must be combined with ____________ __________ to achieve desired effects
Environmental changes
Clenbuterol is usually given as an adjunctive treatment with what other type of drug?
Steroids (inhaled or systemic)
When does the maximum benefit of clenbuterol usually occur?
After 14 days of administration
What can occur within 21 days of continuous administration of clenbuterol in horses?
Tachyphylaxis
What is the most commonly used inhaled nasal steroid?
Fluticasone
What is ciclesonide?
A steroid pro-drug used in the treatment of equine asthma
What are the drug classes that can cause respiratory depression?
-General anesthetics
-Opioids
-Benzodiazepines
What is doxapram?
A drug with specific respiratory stimulatory effects on the CNS
What is a useful but controversial use of doxapram?
Using it to stimulate respiration in apneic neonates
Doxapram _________ respiratory rate and volume, but arterial PaO2 may not __________
Increases; increase
