L&J Chp 27 Phys, Pathophys, Ax Management of Patients with Respiratory Dz

Question 1

Normal changes in resp fxn seen in anesthetized animal compared to conscious, awake, spont breathing animal

Answer 1

• PaO2 often lower than observed with same species for same FiO2
• PaCO2 usually above conscious resting values if anesthetized patient spontaneously breathing
• Increased airway resistance unless intubated

Question 2

What are some other things that affect resp function in our anesthetized patients?

Answer 2

• Positioning
• Concurrent drug use
• Magnitude of preax cardiorespiratory dysfunction

Question 3

What are three important considerations of respiratory function as it pertains to GA?

Answer 3

1. Neural control of resp, its effect on alveolar ventilation (VA)
2. Influence of GA on airway, lung volumes, chest wall
3. Alterations in vent-perfusion relationships during GA

Question 4

What are the two respiratory function parameters that can be measured in conscious animals?

Answer 4

1. TV
2. FRC
   (others require patient cooperation, GA)

Question 5

Respiration

Answer 5

Total process whereby oxygen is supplied to, used by body cells; CO2 eliminated by means of gradients

Question 6

Ventilation

Answer 6

Movement of gas into, out of alveoli

-Ventilation requirement for homeostasis varies with body size, level of activity, body temp, ax depth

Question 7

Pulmonary Ventilation

Answer 7

Accomplished by expansion, ctx of the lungs

Question 8

Eupnea

Answer 8

Quiet, ordinary breathing

Question 9

Dyspnea

Answer 9

Labored breathing

Question 10

Tachypnea

Answer 10

Increased RR

Question 11

Hyperpnea

Answer 11

Fast +/- deep respiration, indicating “over respiration”

Question 12

Polypnea

Answer 12

Rapid, shallow, panting type of respiration

Question 13

Bradypnea

Answer 13

Slow, regular respiration

Question 14

Hypopnea

Answer 14

Slow +/- shallow breathing –> under respiration

Question 15

Apnea

Answer 15

Transient (or longer) cessation of breathing

Question 16

Cheyne-Stokes respirations

Answer 16

Increase rate, depth then become slower followed by brief periods of apnea

Question 17

Biot’s respirations

Answer 17

Sequences of gasps, apnea and several deep gasps

Question 18

Kussmaul’s respirations

Answer 18

Regular, deep respirations without pause

Question 19

Apneustic Respirations

Answer 19

Animal holds an inspired breath at the end of inhalation for short period of time before exhaling

Question 20

Tidal volume (VT or TV)

Answer 20

Volume of air inspired or expired in one breath

Question 21

Inspiratory reserve volume (IRV)

Answer 21

Volume of air that can be inspired over, above normal tidal volume

Question 22

Expiratory Reserve volume (ERV)

Answer 22

amount of air that can be expired by forceful expiration after N expiration

Question 23

Residual volume (RV)

Answer 23

Air remaining in the lungs after most forceful expiration

Question 24

Minute ventilation (VEmin) or minute respiratory volume

Answer 24

VT x RR

Question 25

Inspiratory capacity (IC)

Answer 25

TV + IRV

Amount of air that can be inhaled starting after a normal expiration and distending the lungs to maximum amount

Question 26

Functional residual capacity (FRC)

Answer 26

ERV + RV
Amount of air remaining in the lungs after normal expiration
-At FRC, inward ‘pull’ of lungs due to their elasticity equals outward ‘pull’ of chest wall

Question 27

Vital Capacity (VC)

Answer 27

IRV + TV + ERV

Maximum amount of air that can be expelled from the lungs after first filling them to maximum capacity

Question 28

Total lung capacity (TLC)

Answer 28

IRV + TV + ERV + RV
maximum volume to which the lungs can be expanded with the greatest possible inspiratory effort (or by full inflation to 30cm H20 airway pressure when patient anesthetized)

Question 29

Main differences btw managing resp in human med vs vet med

Answer 29

• IV anesthetics used without supplemental O2
• Less use of peripheral muscle relaxants
• IPPV sometimes, not always
• Carrier gas = 100% O2 whereas in ppl, 2:1 mixture of air, N2, N2O, O2

Question 30

4 major components of the resp system

Answer 30

1. Neural control
2. Bellows mechanism (chest wall, diaphragm)
3. Upper and lower airway
4. Parenchyma

Question 31

Control of respiration

Answer 31

• Central respiratory center
• Central peripheral chemoreceptors
• Pulmonary reflexes
• Non-resp neural input