Chapter 6 - Respiratory Flashcards
List some of the respiratory tracts protective mechanisms
- Coughing
- Retching gag
- Laryngospasm
- Sneezing
- Excessive mucous secretion
- Mucociliary apparatus
- Bronchoconstriction
- Macrophages
Mucociliary Apparatus
Apparatus that moves mucus and trapped materials up the bronchi and trachea via sheets of sticky mucus that trap particles, it is then swept upward by microscopic, hairlike cilia that line the respiratory tract so the mucus and trapped materials are coughed up and expelled
Bronchoconstriction
Ring of smooth muscle that surrounds the small terminal bronchioles and can narrow or close off the airway, preventing foreign materials from entering and damaging the alveoli
Cor Pulmonale
When protective mechanisms become overstimulated or act when they are nor needed for protection they are now contributing the the signs of clinical disease itself, causing changes in the lungs and leading to heart problem
Antitussive Drugs
Block the cough reflex coordinated through the cough center
Tachypnea
Rapid breathing
Productive Cough
Produces mucus
Nonproductive Cough
Dry and hacking with no significant mucus brought up
Insipissated
Dry
(True/False)
Antitussives are indicated for use in very productive coughs
FALSE.
Antitussives are contraindicated with a productive cough. In such cases the body may be relying on the cough itself to prevent obstruction of the airways or accumulation of excessive mucus/debris
Centrally Acting Antitussives
Reduces coughing by suppressing the cough center neurons in the brainstem
List 1-2 centrally acting antitussives
- Hydrocodone
- Codeine
Locally Acting Antitussives
Reduces coughing by directly soothing the irritated respiratory mucosa that is initiating the cough (cough lozenge)
(True/False)
Locally acting antitussives are not used in Veterinary medicine
TRUE.
Animal patients are unwilling to hold lozenges in their moth long enough to be effective
What are antitussives commonly used to treat in veterinary medicine?
Dry, nonproductive coughs generated by inflammation in the trachea or bronchi (or both)
Butorphanol (Torbutrol)
- Centrally acting opioid cough suppressant (IV best route of admin - oral dose 10x higher)
- Only FDA approved cough suppressant for Veterinary use
- Class IV controlled substance
Hydrocodone (Hycodan)
- Orally administered potent Mu opioid receptor agonist antitussive that is synthesized from codeine but is much more potent.
- Human drug - all Veterinary use is extra-label
- Class II controlled substance
Codeine
- Relatively weak Mu-opioid receptor agonist antitussive
- Found in a variety of oral cough and cold preparations (acetaminophen often included in these)
- Not typically used in the dog because it is not well absorbed
- Contraindicated for use in cats
Dextromethorphan
- Antitussive
- Considered a non-narcotic because it does not combine with opioid receptors to produce its effects
- Common in OTC preparations
- Caution should be used since they often contain acetaminophen
- Not recommended for use to control coughing in dogs/cats
Mucolytic Agents
Designed to break up or lyse mucus and reduce its viscosity so the cilia can more readily move it out of the respiratory tract
Reverse Sneezing
Can be caused by any irritation in the nasal cavity (allergic response, inhaled antigens, nasal polyps, tumors)
Acetylcysteine (Mucomyst)
- Mucolytic Agent - Decreases viscosity of mucus by breaking apart the disulfide bonds contributed to the mucus by DNA strands and that contribute significantly to the viscosity of the mucus
- Also used PO or IV as the antidote for acetaminophen toxicosis