Unit 3 - Dyspnea and Abnormal Breathing Flashcards
What zone makes up the majority of the lung volume?
the respiratory zone
What structures are in the respiratory zone?
respiratory bronchioles, alveolar ducts, and alveolar sacs
What structures are in the conducting zone?
trachea, bronchi, bronchioles, and terminal bronchioles
What are the anatomical disease divisions of the respiratory system?
nasal and sinuses, upper airway, lower airway, parenchymal, and pleural space
What structures make up the upper airway?
pharynx, larynx, trachea, bronchi, and bronchioles
What structures make up the lower airway?
respiratory bronchioles and alveoli
It is best to auscultate the lungs in a _____ ____.
quiet room
How should a patient be positioned for auscultation?
standing, with the mouth closed
How do bronchial sounds sound?
harsh, hollow, and blowing
Where are bronchial sounds loudest?
over the trachea
Are bronchial sounds inspiratory or expiratory?
both
How do vesicular sounds sound?
rustling
Where are vesicular sounds made?
airflow through lobar bronchi - peripheral
Are vesicular sounds inspiratory or expiratory?
primarily inspiratory
What are the types of abnormal breath sounds?
crackles, wheezes, stertor, and stridor
What do crackles sound like?
discontinous popping sounds
What is the cause of crackles?
snapping open of small airways that have collapsed or accumulated fluid/debris
When is the timing of crackles?
during inspiration
How are crackles characterized?
moist vs. dry, and fine vs. course
What are the differentials for crackles?
pulmonary edema, pneumonia, or fibrosis (dry, stiff airways)
What do wheezes sound like?
continous, whistling musical sounds
What is the cause of wheezes?
airflow through constricted or narrowed airways
When is the timing of wheezes?
during expiration
What are the differentials for wheezes?
lower airway inflammatory disease or an anaphylactic reaction
What do stertor sounds sound like?
snoring, snorting, and snuffling noise that can be heard without a stethoscope
What is the cause of stertor?
upper airway obstruction of airflow due to excess tissue or secretions
When is the timing of stertor?
variable
Stertor suggests that diseases is located where?
in the nasal cavity and/or the nasopharynx
What are the differentials for stertor?
Brachycephalic syndrome, nasal congestion/infiltration, nasopharyngeal polyps, nasal/nasopharyngeal neoplasia, inflammatory/infectious rhinitis, and nasal/nasopharyngeal foreign body
What do stridor sounds sound like?
intense, high-pitched wheeze - shouldn’t need a stethoscope
What is the cause of stridor sounds?
extrathoracic upper airway collapse and/or narrowing
When is the timing of stridor sounds?
virtually always inspiratory
When stridor is present with voice change, what should you suspect?
laryngeal involvement
What are the differentials for stridor?
laryngeal paralysis, laryngeal collapse, tracheal collapse, and laryngeal/tracheal obstruction
What can cause intraluminal laryngeal/tracheal obstruction?
foreign body or mass
What can cause extraluminal laryngeal/tracheal obstruction?
mass or soft tissue swelling
What is dyspnea?
difficult or labored breathing due to hypoxemia or hypercapnia
What is hypoxia?
a state in which the oxygen in the blood, lung, and/or tissues is abnormally low
What is hypoxemia?
oxygenation of the blood that is too low to meet tissue demands - PaO2 <80mmHg
What is hypercapnia?
a state in which the amount of CO2 in the blood is increased above normal
Where does dyspnea typically localize?
upper airway, lower airway, parenchymal, and pleural space
Characterize obstructive dyspnea.
Due to obstruction of airway, normal to increased respiratory rate, increased depth of breathing
Characterize obstructive inspiratory dyspnea.
Slow, deep inhalation - +/-stridor, the obstruction moves in front of the airway due to pressure
What is obstructive inspiratory dyspnea due to?
a dynamic extra-throacic obstruction (tracheal or laryngeal)
Characterize obstructive expiratory dyspnea.
slow prolonged expiration - the airways condense during expiration
What is obstructive expiratory dyspnea due to?
due to intra-throacic airway disease (large airway obstruction or small airway disease)
Characterize restrictive dyspnea.
Increased respiratory rate, variable depth depending on the disease state
What is restrictive dyspnea due to?
It is due to a disease process that restricts lung inflation
What is tachypnea?
increased respiratory rate at rest
What is the normal respiratory rate of dogs?
18-34 rpm
What is the normal respiratory rate of cats?
16-40 rpm
What is the normal FiO2?
approximately 21% - the percent of air composed of oxygen
What is the normal PaO2?
97-100 mmHg - partial pressure of oxygen dissolved in arterial blood
What is the normal SaO2?
98-100% - saturation of Hb binding sites with O2
What is pulse oximetry(SpO2) equivalent to?
SaO2
What does a pulse ox measure?
It emits red and infared lights and measured unabsorbed light (oxygenated blood absorbs the light, deoxygenated blood absorbs red light)
If SpO2 is 97.5%, PaO2 is what?
100 mmHg
If SpO2 is 93%, PaO2 is what?
80 mmHg
If SpO2 is 90%, PaO2 is what?
60 mmHg
What is the PaO2 if a patient is hypoxemic?
less than 80 mmHg
Why does O2 supplementation help?
It incrases FiO2 which increases PAO2, which increases PaO2, which thus increases tissue oxygenation
What percentage FiO2 does an oxygen cage reach?
40-60%
What are the pros to an oxygen cage? Cons?
Pros: non-invasive, non-stressful
Cons: takes time, expensive, isolation
What percentage of FiO2 does nasal oxygen achieve?
40-50%
What are the pros to nasal oxygen? Cons?
Pros: Good for large dogs, easy to care for the patient
Cons: Uncomfortable, nasal bleeding, inadvertent removal
What FiO2 level does face mask oxygen reach?
approximately 50%
What are the pros to face mask oxygen? Cons?
Pros: convenient
Cons: need a tight seal, can be stressful
What FiO2 level does hood oxygen reach?
40-60%
What are the pros of using hood oxygen? Cons?
Pros: easy and economical
Cons: Gets hot/humid, variable FiO2, and may need sedation
What FiO2 does flow-by oxygen reach?
30-40%
What are the pros to flow-by oxygen? Cons?
Pros: easy, convenient
Cons: high flow rates, not long-term solution
