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Flashcards in Lecture 1 Deck (38):
1

The mucociliary escalator clears dust/pathogens from which areas of the respiratory tract?

Trachea and Bronchi

2

Why does dust tend to settle in the terminal bronchioles?

There is a rapid decrease in air velocity in the terminal bronchioles, so dust tends to settle here!

3

Does the respiratory zone or the conducting zone have a greater surface area?

Respiratory zone

4

If the mucociliary escalator clears dust/debris from the trachea and bronchi, what clears debris from the respiratory zone (respiratory bronchioles, alveolar ducts, alveolar sacs)?

Macrophages clear debris out of the respiratory zone

5

What type of cell produces surfactant in the lungs?

Type II pneumocyte

6

What comprises the upper airway?

Pharynx, Larynx, Trachea, Bronchi, Bronchioles

7

What comprises the lower airway?

Respiratory bronchioles and alveoli

8

Is the smooth muscle in the respiratory tract in the upper airway or the lower airway?

Upper air way. The bronchi and bronchioles are surrounded by smooth muscle.

9

What do normal bronchial sounds sound like?

Harsh, hollow, blowing
- airflow through trachea/mainstem bronchi
- loudest over trachea
- both inspiratory and expiratory

10

What do normal vesicular sounds sound like?

Rustling
- Airflow through lobar bronchi
- Peripheral
- Primarily inspiratory (can be hard to hear!)

11

Name 4 abnormal breath sounds.

1. Crackles
2. Wheezes
3. Stertor
4. Stridor

NOTE: 1 &2: typically heard w/ stethoscope on chest
3&4: more upper resp. issues, audible

12

What are "crackles"?

Discontinuous "popping" sounds
- Cause: snapping open of small airways that have collapsed or accumulated fluid/debris
- Timing: mostly INSPIRATORY

13

What are some differentials if you were to hear crackles?

1. Pulmonary edema (cardiogenic vs. non-cardiogenic)
2. Pneumonia (esp. aspiration)
3. Fibrosis

14

What are wheezes?

A continuous, whistling musical sound (hear w/ stethoscope)
- Cause: airflow through constricted or narrowed airways
- Timing: EXPIRATORY

15

Wheezes: Differentials

1. Lower airway inflammatory disease
- Feline asthma/feline lower airway disease
- Canine chronic bronchitis
2. Anaphylactic reaction

16

Stertor?

Snoring, snorting, snuffling noise
- Cause: upper airway obstruction of airflow due to excess tissue or secretions
- Timing: VARIABLE (usually BOTH insp. and expir.)

Overtly audible sound, like snoring..

17

Where does stertor sugges disease is localized to?

Stertor suggests disease is localized to the nasal cavity and/or nasopharynx
- anything filling nasal cavity or nasopharynx can cause stertor

18

Stertor: differentials

1. Brachycephalic syndrome
2. Nasal congestion/infiltration
3. Nasopharyngeal polyps
4. Nasal/Nasopharyngeal neoplasia
5. Inflammatory/infectious rhinitis
6. Nasal/nasopharyngeal foreign body

19

Stridor

Intense, high-pitched wheeze
- Cause: extra-thoracic UPPER airway collapse and/or narrowing
- Timing: virtually always INSPIRATORY (opposite of wheezes!)
- Overtly audible sound
- When stridor is present w/ choice change, suspect laryngeal involvement (ie. dog has less of a bark)

20

Stidor: differentials

1. Laryngeal paralysis
2. Laryngeal collapse
3. Tracheal collapse
4. Laryngeal/tracheal obstruction
- intraluminal (foreign body, mass)
- Extraluminal (mass, soft tissue swelling)

21

Dyspnea

Respiratory distress - labored breathing in response to:
1. Hypoxemia
2. Hypercapnia

22

Top 4 localizations of Dyspnea

1. Upper airway
2. Lower airway
3. Parenchymal
4. Pleural space

23

Dyspnea patterns

1. Obstructive (inspiratory and expiratory)
2. Restrictive

24

Obstructive Dyspnea

Obstruction of airway
- normal to increased respiratory rate
- increased depth of breathing (hyperpnea)
ITS LIKE A MAN UNDERWATER BREATHING THROUGH A STRAW

25

Obstructive Inpiration

Slow, deep inhalation
+/- stridor

Due to a dynamic EXTRA-THORACIC obstruction
- tracheal or laryngeal obstruction (ie. laryngeal paralysis)

26

Obstructive expiratory

Slow, prolonged expiration
- Due to INTRA-THORACIC airway disease
- large airway obstruction (intra-thoracic tracheal collapse)
- small airway disease (bronchitis, feline asthma)

27

Restrictive Dyspnea

Occurs due to disease process that restricts lung INFLATION
- increased respiratory rate
- variable depth, depending on disease state
Example: pleural space disease
PICTURE A BEAR SQUEEZING A MAN - RESTRICTIVE

28

Does tachypnea equal panting?

NO.

29

Normal resting respiratory rates

Canine: 18 - 34 brpm
Feline: 16 - 40 brpm

30

Pulse Oximtry (SpO2)

Emits red and infrared lights
- Detector measures unabsorbed light
- Oxygenated blood ABSORBS infrared light
- Deoxygenated blood absorbs red light
Place on ear, lip, tongue, prepuce/vulva
- a dark pigmented animal may make it difficult to get a reading!

31

Can the pulse ox differentiate between carboxyhemoglobin and monoxyhemoglobin from oxygenated hemoglobin?

NO!!!

32

Oxygen supplementation?

1. Hypoxemia
- PaO2 < 80 mmHg
2. Oxygen desaturation
- SPO2 < 94%
3. Respiratory distress/arrest

33

FiO2 w/ intubaction

intubated FiO2 = 100% oxygen

34

FiO2 w/ Oxygen Cage

FiO2 oxygen cage = 40-60%
- takes time, expensive, isolation of animal
- non-invasive and non-stressful

NOTE: at 60% we are have a risk of explosion.. Start at 40%

35

Nasal Oxygen FiO2

Nasal oxygen FiO2 = 40-50%
- quite effective; place in ventral nasal meatus

Pros = good for large dogs; easy to care for patient
Cons = uncomfortable, nasal bleeding (not good in thrombocytopenic patients), inadvertent removal

36

Face mask FiO2

Face mask FiO2 = 50%
- very practical if it's NOT long term

Pros = convenient
Cons = need tight seal, can be stressful

37

Hood oxygen FiO2

Hood oxygen FiO2 = 40-60%

Pros = easy and economical (saran wrap the front of an E-collar)
Cons = gets hot/humid, variable FiO2, may need sedation

38

Flow-by-oxygen FiO2

Flow-by-oxygen FiO2 = ~30-40%
- hold tube 2-4 cm from nose

Pros = easy, convenient
Cons = high flow rates (waste), not long-term solution