Respiratory System Flashcards
respiratory system function
brings oxygen from the air into the body for delivery to the cells via the blood
respiration
exchange of gases between the atmosphere and the cells of the body
ventilation
bringing of fresh air into the lungs
what does the upper respiratory tract consist of?
nostrils, nose, nasal cavities, pharynx, larynx
what lines the upper respiratory tract?
epithelial cells containing cilia and goblet cells
goblet cells
secrete mucus which traps foreign particles that are then moved out of the respiratory tract via cilia movement
what does the lower respiratory tract consist of?
trachea, bronchi, bronchioles, alveoli
bronchioles are lined with smooth muscles which allows them to constrict and dilate
alveoli
small, terminal, saclike structures where oxygen and carbon dioxide diffuse across a thin membrane
upper respiratory tract conditions
mainly caused by infectious agents
CS: coughing, sneezing, congestion
lower respiratory tract conditions
asthma, bronchitis, pneumonia, recurrent airway obstruction (ROA)
productive cough
expels mucus and foreign material
don’t suppress
non-productive cough
doesn’t expel mucus or foreign material
ok to suppress
can become a productive cough
respiratory drugs function
work to keep airways open and gases moving efficiently
what types of drugs treat upper airway conditions?
expectorants, mucolytics, antitussives, decongestants
what types of drugs treat lower airway conditions?
bronchodilators and antihistamines
what type of drug is used to enhance ventilation?
stimulants
what type of drug is used to treat infections?
antimicrobials
expectorants respiratory drugs
debris clearing
increase the flow of respiratory secretions to allow material such as pathogens and inflammatory debris to be coughed up from lungs, reduce stickiness of mucus
Guaifenesin
cough tablets
expectorant
used orally to increase secretions from the airway and clear it of fluid
used in horses as a muscle relaxant as part of anesthesia
mucolytics respiratory drugs
decrease the viscosity or thickness of respiratory secretions
Acetylcysteine
mucolytic
breaks up thick mucus secretions in the airway to promote better respiration
can be po, IV, or aerosol through nebulization
antitussives
suppress coughing
can be centrally or locally acting
centrally acting antitussives
work on cough centers of the brain
locally acting antitussives
soothes irritation that initiates cough
syrup or lozenges
not used often in vet
narcotic antitussives
Butorphanol, Hydrocodone, codeine
non-narcotic antitussives
Dextromethorphan, Trimeprazine and prednisolone combo
Butorphanol
narcotic antitussive
opioid
controlled substance C-IV
injectable or oral tablets
FDA approved for dogs
Hydrocodone
narcotic antitussive
opioid
controlled substance C-II
used for harsh, non-productive coughs
tablet and syrup forms
may contain anticholinergic drug homatropine (to discourage human abuse)
may contain acetaminphen
codeine
narcotic antitussive
opioid
centrally acting
controlled substance C-II
may be combined with: Guaifenesin, aspirin, acetaminophen
injectable, syrup, and tablets
Trimeprazine and prednisolone (Temaril-P)
non-narcotic antitussive
centrally acting antitussive and glucocorticoid combination
has antipruritic effects
tablet and spansules
Dextromethorphan
non-narcotic antitussive
centrally acting
chemical similar to codeine
over the counter
may be used in combo with other drugs
syrup form
no evidence that it’s effective in vet
decongestants
decrease swelling of nasal passages
forms: sprays, oral (liquid, tablet)
limited use in vet
have been used to treat feline upper respiratory tract disease
Phenylephrine
decongestant
cardio stimulant properties
don’t use in hypertension or tachycardia patients
Pseudoephedrine
decongestant
controlled substance C-IV
cardio stimulant properties
don’t use in hypertension or tachycardia patients
combined with pyrilamine maleate to treat ROA
bronchodilators
widen the lumen of the bronchioles and counteract bronchoconstriction
decrease airway resistance and increase airflow
beta-2 adrenergic agonist bronchodilators
relax smooth muscle
should not be used during gestation
Epinephrine, Isoproteronol, Terbutaline, Albuterol, Clenbuterol
Methylxanthine bronchodilators
inhibit enzymes in smooth muscle cells resulting in bronchodilation
Aminophylline, Theophylline
epinephrine bronchodilator
beta-2
short term effects
ER use
increases work of heart
produces bronchodilation
used in CPR
treats anaphylactic shock
Isoproterenol
beta-2 bronchodilator
short term effects
ER use
Terbutaline
beta-2 bronchodilator
selective, more respiratory effects than cardiac
po, IM, SQ in dogs and cats
IV in horses
used extra-label in dogs with bronchitis and cats with asthma
albuterol
beta-2 bronchodilator
selective, more respiratory effects than cardiac
oral or inhaled with a metered dose inhaler
Torpex approved for use in horses with ROA
used extra-label in dogs with bronchitis and cats with asthma
Clenbuterol
beta-2 bronchodilator
Ventipulmin: oral syrup approved for horses with airway obstructions
over time it has repartitioning effect in which body composition becomes more muscular and less fat (associated with weakness and decreased athletic performance)
abused to enhance horse muscles
what other drug can methylxanthines not be given with?
fluoroquinolones
Aminophylline
methylxanthine bronchodilator
metabolized into theophylline after administration
used for respiratory disease
not available in US
Theophylline
methylxanthine bronchodilator
used for respiratory disease
extended release tablet
what common foods are methylxanthines?
caffeine and theobromine (found in chocolate)
antihistimines
block the effects of histamine
histamine
chemical released from mast cells that combines with receptors on bronchiolar smooth muscle, increases heart rate, causes vasodilation, sedation, and inflammatory response
Pyrilamine
antihistamine
combined with pseudoephedrine for treatment of ROA in horses
Diphenhydramine
Benadryl
most commonly used
fast acting
po, IM, IV
Chlorpheniramine
antihistamine
longer onset of action
respiratory stimulants
drugs that stimulate the animal to increase its ventilating activity
Doxapram
respiratory stimulant
CNS stimulant
used in neonates to stimulate respiration after C-section or dystocia (can be administered through umbilical vein or sublingually)
approved for use in dogs, cats, and horses
used to restore reflexes after anesthesia
injectable
feline asthma
chronic, noninfectious inflammatory disease of the lower airways characterized by intermittent airway obstruction and heightened airway sensitivity
triggered by allergens
CS: wheezing, dry hacking cough, can lead to open mouth breathing and dyspneas
feline asthma
chronic, noninfectious inflammatory disease of the lower airways characterized by intermittent airway obstruction and heightened airway sensitivity
triggered by allergens
CS: wheezing, dry hacking cough, can lead to open mouth breathing and dyspnea
asthma treatments
metered dose inhaler (MDI): albuterol, glucocorticoids (oral then inhaled), fluticasone
oral: prednisolone, terbutaline, albuterol, theophylline
adjunct therapies: cyroheptadine, cyclosporine (Atopica)
equine RAO or heaves
chronic, noninfectious respiratory disease in which inflammation in the small airways of the lung leads to impaired ventilation secondary to chronic generalized bronchiolitis and destruction of airspaces
horses at risk of RAO
seen often in horses in cold climates, horses kept in barns for prolonged periods of time, and horses kept where hay is moldy
other triggers: dust, pollens, chemicals, microorganisms
clinical signs of RAO
coughing, tachypnea, labored breathing, yellow nasal discharge
severe signs: listlessness, dyspnea, muscular “heave line” along their barrel
treatments of RAO
medical: prednisone, dexamethasone, clenbuterol, albuterol
other treatments: improving management practices (keep horses outside as much as possible, reduce dust, store hay in dry place away from horses, improve ventilation where horses are stabled
infectious tracheobronchitis
kennel cough
caused by: bacterial infection (Bordetella bronchiseptica), viral infection
highly contagious, usually self limiting
CS: hacking, nonproductive cough
infectious tracheobronchitis treatment
antimicrobial drugs in severe cases (Doxycycline)
opioids (Butorphanol, codeine, hydrocodone)
bovine respiratory disease (BRD)
presents as lower respiratory tract infection (pneumonia) caused by viral and/or bacterial pathogens
common and costly in beef cattle
seen in times of stress (such as during weaning or transport)
bovine respiratory disease treatment
antibiotics with NSAIDs
Hexasol (oxytetracycline + flunixin meglumine)
ResFlor Gold (florfenicol + flunixin meglumine)
