Respiratory System

Question 1

What is the definition of hypoxemia?

Answer 1

A PaO2 of less than 80 mmHg (decreased oxygen content in the blood)

Defined as: when metabolic demand EXCEEDS oxygen delivery

Question 2

What constitutes severe hypoxemia?

Answer 2

A PaO2 of 60 mmHg or less (decreased oxygen content in the blood)

Defined as: when metabolic demand EXCEEDS oxygen delivery

Question 3

The atmosphere is made up of what percentage of oxygen?

Answer 3

21%

Question 4

The atmosphere is made up of what percentage of nitrogen?

Answer 4

78%

Question 5

The volume of gas normally inspired with a given breath is known as what?

Answer 5

Tidal volume (Vt)

Question 6

What is a patients appropriate tidal volume?

Answer 6

Between 10-20mL/kg (slightly less with a cat)

Question 7

What does the following equation represent?

Ve = Vt x Vf

Answer 7

Minute volume (total ventilation) equals the patients tidal volume times their frequency (rate of breathing)

Question 8

What diseases can be associated with dull or absent lung sounds?

Answer 8

Pleural space disease; severe lung consolidation of lung parenchyma, pleural effusion, pneumothorax

Question 9

What are possible causes of increased breath sounds, wheezes or crackles?

Answer 9

Pulmonary parenchymal diseases: aspiration pneumonia, ALI, ARDS, fluid overload, congestive heart failure, and pulmonary thromboembolism.

Parenchyma is made up of alveoli, interstitial tissue and fibers and is involved in gas exchange.

Question 10

Risks factors for the development of ALI or ARDS include:

Answer 10

SIRS, sepsis, infection, smoke inhalation, near drowning, severe trauma.

Question 11

What percentage on an SpO2 constitutes hypoxemia?

Answer 11

An SpO2 of less than 95% or a partial pressure of oxygen (PaO2) of less than 80 mm Hg

Question 12

Acute lung injury or ARDS can be identified using what formula?

Answer 12

PaO2 to FiO2 ratio (P/F ratio)

*controlled oxygen?

Question 13

ALI may be suspected in patients with a PaO2 to FiO2 ratio of what?

Answer 13

< 300

Question 14

ARDS may be suspected in patients with a PaO2 to FiO2 ratio of what?

Answer 14

< 200

Question 15

How is a shock index calculated?

Answer 15

Heart rate divided by blood pressure

Question 16

What shock index result can identify shock in both dogs and cats?

Answer 16

Shock index of > 1 in dogs and > 1.6 in cats.

Question 17

What is the normal inspiration to expiration ratio?

Answer 17

1:2 meaning a patient exhales twice as long as it inhales in normal breathing

Question 18

Increased inspiration time can be an indication of what?

Answer 18

Upper airway obstruction or extrathoracic pathology

Question 19

Increased expiration time can be an indication of what?

Answer 19

Lung pathology like pneumonia or intrathoracic pathology

Question 20

What type of breathing is associated with the chest and abdomen moving together?

Answer 20

Synchronous breathing

Question 21

What type of breathing is associated with the chest and abdomen moving opposite of one another?

Answer 21

Asynchronous breathing

Question 22

Asynchronous breathing is often a sign of pathology located where?

Answer 22

In the pleural space

Question 23

Synchronous breathing is often a sign of pathology located where?

Answer 23

Inside the lungs

Question 24

Define restrictive breathing patterns and when you might see it.

Answer 24

Short and shallow breaths indicating pleural space disease

Poor excursions

Question 25

Define Kussmaul breathing and when you might see it.

Answer 25

Rapid and very deep breathing pattern. May see this in diseases causing severe metabolic acidosis like DKA or renal disease.

Question 26

Define stridor

Answer 26

A high pitched sound produced by turbulent airflow through the UPPER airway (partial airway obstruction).

Question 27

Define stertor

Answer 27

Abnormal low pitched sound produced lower in the airway (partial airway obstruction)

Question 28

How much hemoglobin is required in the body to show physical signs of cyanosis?

Answer 28

5g/dL

Question 29

What is the oxygen flow rate range for nasal cannulas?

Answer 29

50-150mL/kg/min

Question 30

Under normal circumstances, a patient that has an EtCO2 of 40 mmHg is expected to have a PaCO2 of approximately:

Answer 30

42-47 mmHg. EtCO2 will be 2-5 mmHg less than PaCO2.

Question 31

What are common causes of HYPOcapnia?

Answer 31

Hyperventilation, decreased cardiac output and carbon dioxide production, and metabolic acidemia resulting in respiratory alkalosis.

Question 32

What are causes of HYPERcapnia?

Answer 32

Hypoventilation, rebreathing of carbon dioxide, or increased carbon dioxide production.

Question 33

What are consequences of HYPERcapnia?

Answer 33

Systemic vasodilation, increased cardiac output, increased heart rate, increased blood pressure, respiratory acidemia, metabolic alkalosis, electrolyte changes, neurological dysfunction, cerebral vasodilation, increased cerebral blood flow and increased intracranial pressure, narcosis and death.

Question 34

What are consequences of HYPOcapnia?

Answer 34

Vasoconstriction of cerebral blood vessels resulting in decreased intracranial pressure (can be positive). If too low, can also compromise cerebral blood flow and cerebral oxygen delivery.

Question 35

What is the name of the acupuncture point that’s attempting to be stimulated to encourage respiration called?

Answer 35

Governing Vessel 26 (GV 26) located between the nares at the top of the nasal philtrum.

Question 36

Expired carbon dioxide is directly proportional to what?

Answer 36

Pulmonary blood flow. Capnograph: Ideal monitor for measuring effectiveness of chest compressions during CPR.

Question 37

List 3 major things ETCO2 can determine.

Answer 37

1. Rate of tissue perfusion 2. Cardiovascular - rate of exchange from blood to alveoli 3. Ventilation - rate of removal by alveolar ventilation ^provides information on metabolism, circulation and ventilation

Question 38

What are 5 types of HYPOXIA

Answer 38

1. Hypoxemic hypoxia: inadequate oxygen-carrying capacity if blood (CaO2) 2. Hypemic hypoxemia: “anemic hypoxia” occurring when anemia causes a decrease in circulating hemoglobin 3. Stagnant or circulatory hypoxia caused by decreased cardiac output and poor perfusion 4. Histiotoxic hypoxia resulting when tissues are unable to extract and utilize oxygen 5. Metabolic hypoxia when the is an increased cellular consumption of oxygen (VO2)

Question 39

What is the definition of HYPOXIA

Answer 39

When there is inadequate oxygen delivery (DO2) to meet tissue metabolic demand (VO2) causes by inadequate tissue perfusion, metabolic disturbances, or lack of oxygen supply.

Question 40

What are the 5 causes of HYPOXEMIA

Answer 40

1. Decreased FiO2 2. Hypoventilation 3. Ventilation/perfusion (V/Q) mismatch 4. Diffusion impairment 5. Right to left shunt

Question 41

During the Bohr effect, or states with increased CO2, lower pH and increased temperatures, the oxygen-hemoglobin dissociation curve will shift in what direction? What does that mean?

Answer 41

There will be a shift to the right, meaning oxygen has less affinity with hemoglobin and more oxygen becomes unbound for delivery to tissue. *Think higher CO2, need more O2.

Question 42

During the Haldane effect, or states with decreased CO2, higher pH and decreased temperatures, the oxygen-hemoglobin dissociation curve will shift in what direction? What does that mean?

Answer 42

The curve shifts to the left resulting in oxygen being more tightly bound to hemoglobin and less oxygen offloading. *Think less CO2 means the need for less oxygen.

Question 43

What is the carbonic anhydrase reaction formula?

Answer 43

CO2 + H2O <—> H2CO3 <—> HCO3- + H+ This is why pH is directly affected by the ratio of CO2 and HCO3- *CO2 is a major bi-product of internal cellular respiration and has a significant role in maintaining acid base status, and is not just a waste product.

Question 44

What are the 4 phases that a breath can be broken down into?

Answer 44

1. Initiation of inspiration 2. Inspiration 3. Termination of inspiration 4. Expiration