Respiratory Distress

Question 1

What are the 5 basic mechanisms by which hypoxemia can occur?

Answer 1

Decreased FiO2, hypoventilation, diffusion barriers, anatomic shunting, and ventilation/perfusion (V/Q) mismatch

Question 2

How do you determine that hypoxemia is due to decreased FiO2?

Answer 2

Generally due to a complication of anesthesia or assisted ventilation

Question 3

How do you determine that hypoxemia is due to hypoventilation?

Answer 3

Can use the Alveolar-arterial (A-a) gradient; will typically have concurrent hypercapnia

Question 4

How do you determine that hypoxemia is due to diffusion abnormalities?

Answer 4

Diffusion abnormalities rarely are the sole cause of clinically significant hypoxemia, they often exacerbate other problems

Question 5

How do you determine that hypoxemia is due to an anatomic shunt?

Answer 5

Typically these are congenital disorders

Question 6

Describe how hypoxemia can occur due to a V/Q mismatch

Answer 6

Can occur if there are regions in the lung of high (reduced perfusion) or low (reduced ventilation) V/Q; the ventilation and perfusion of all regions of the lungs must be appropriately matched for all blood leaving the lungs to be fully oxygenated

Question 7

Extrathoracic airway obstruction most commonly leads to ________ distress in addition to a prolonged ______________ phase

Answer 7

Inspiratory; inspiratory (e.g. cervical tracheal collapse and lar par)

Question 8

Intrathoracic airway obstruction most commonly leads to ________ distress in addition to a prolonged ______________ phase

Answer 8

Expiratory; expiratory (e.g. intrathoracic tracheal collapse, chronic bronchitis)

Question 9

True respiratory distress implies what?

Answer 9

Involvement at or below the level of the oropharynx (cats can be the exception)

Question 10

Late-inspiratory crackles can be auscultated in patients that have what?

Answer 10

Pulmonary edema, lung, pleural or chest wall tumors, or interstitial pneumonia

Question 11

Early inspiratory or expiratory crackles may be heard with what?

Answer 11

Obstructive lung disease, bronchopneumonia, or conditions resulting in tracheobronchial fluid

Question 12

Inspiratory wheezes are associated with what?

Answer 12

Extrathoracic airway obstruction (e.g. masses, stenosis, or collapse of upper airways or extrathoracic trachea)

Question 13

Late inspiratory wheezes may be auscultated with what conditions?

Answer 13

Atelectasis or consolidation of lung lobes (need to localize at site of max intensity)

Question 14

Expiratory wheezes are associated with what?

Answer 14

Intrathoracic airway obstructions (COPD, intrathoracic airway collapse, stenosis, or mass obstruction)

Question 15

When might you hear a fluid line?

Answer 15

In patients with pleural effusion (ventral) or pneumothorax (dorsal)

Question 16

What should you be prepared to when while giving a patient in respiratory distress an oropharyngeal exam?

Answer 16

Incubate - typically these are done under minimal sedation, but animal may become stressed

Question 17

What would seeing normal appearing lung fields on thoracic radiographs of a patient in respiratory distress suggest?

Answer 17

A defect in oxygen transport or perfusion of lungs/tissue

Question 18

PaO2 and PaCO2 in ____ specimens provide useful info about pulmonary function

Answer 18

Arterial; venous blood is less useful b/c affected by cardiac function and peripheral circulation

Question 19

What are arterial blood gas measurements indicated to document?

Answer 19

Pulmonary failure, to differentiate pulm dz from hypoventilation, to determine the need for intervention, and to monitor response to therapy; respiratory compromise must be SEVERE for abnormalities to be detectable

Question 20

What parameter should always be measured at the same time as taking an arterial sample?

Answer 20

Body temp

Question 21

If the PaO2 is very low and they PaCO2 is low, normal, or mildly elevated, and the dog is breathing relatively normally, what type of sample do you probably have?

Answer 21

Venous or mixed

Question 22

A PaO2 of less than ___ mmHg is considered dangerous and treatment should be initiated urgently

Answer 22

60

Question 23

A PaO2 of less than 50 mmHg and/or a PaCO2 of greater than 50 mmHg in the face of O2 therapy generally indicates what?

Answer 23

Current or impending pulmonary failure and patients often need assisted ventilation

Question 24

T or F: Cyanosis develops more quickly in animals with polycythemia than anemia

Answer 24

True; cyanosis is a result of the increased concentration of non-oxygenated Hb in the blood.

Question 25

Which two values are commonly used to make rough assessments of pulmonary function and to monitor the course of disease or response to treatment?

Answer 25

A-a gradient and FIO2:PaO2

Question 26

Pulse oximetry measures what value?

Answer 26

Oxygen saturation (SpO2)

Question 27

T or F: A normal value on a Pulse Ox does not rule out hypoxia.

Answer 27

True; could have anemia, CO poisoning, cyanide toxicity

Question 28

An 8 year old Lab presents to you in respiratory distress. You note stridor, and his tongue is purple upon physical exam. The owner mentioned his bark has changed over the past 2 months, and he has been having periodic episodes of ‘collapse’ and exercise intolerance. What’s your primary differential?

Answer 28

Lar par

Question 29

What diagnostic test must be performed to confirm a lar par diagnosis?

Answer 29

Laryngoscopy

Question 30

What are the abnormalities associated with brachycephalic syndrome?

Answer 30

Stenotic nares, hypoplastic trachea, everted laryngeal saccules and laryngeal collapse, elongated soft palate

Question 31

Early routine surgical correction of which two known brachycephalic syndrome-associated abnormalities can potentially prevent eversion of laryngeal saccules and laryngeal collapse?

Answer 31

Elongated soft palate and stenotic nares

Question 32

Name a few primary disease processes associated with PTE

Answer 32

Cushing’s, hypothyroidism, PLN, IMHA, cardiac dz, HWD, sepsis, DIC, pancreatitis, neoplasia

Question 33

What is the clinical presentation of feline asthma?

Answer 33

Typically young adult to middle aged cat with progressively worsening sudden episodes of labored breathing, and increased expiratory effort/time, expiratory wheezes, +/ crackles

Question 34

What is the only condition causing respiratory distress where bronchodilators are indicated?

Answer 34

Feline asthma

Question 35

What medications should you always give with some type of anti-inflammatory?

Answer 35

Bronchodilators