Respiratory Failure

Question 1

Define hypoxemia:

Answer 1

failure of oxygenation

Question 2

What is the Pa02 value associated with type I respiratory failure?

Answer 2

Pa02< 60 mmHg

Question 3

Define type I respiratory failure:

Answer 3

processes impair oxygen transfer in the lung causing hypoxemia

Question 4

What factors lead to hypoxemia?

Answer 4

low pressure of inspired air
impaired diffusion
V/Q mismatch
shunt
hypoventilation

Question 5

Impaired diffusion is primarily a result of:

Answer 5

increased thickness of alveolar membrane due to pulmonary fibrosis

Question 6

How would exercise or increased CO effect diffusion?

Answer 6

Increased flow of blood through capillary beds means less time available for gas exchange to occur

Question 7

What is normal V/Q ratio?

Answer 7

~0.8

Question 8

What happens to blood flow with the presence of a shunt?

Answer 8

either the alveolar capillary membrane or the lungs are bypassed due to cardiac defect (patent foramen ovale).

Question 9

Hypoventilation leads to depression in _____ and overall leads to hypercapnia.

Answer 9

central respiratory centers

Question 10

Define type II respiratory failure:

Answer 10

inadequate ventilation leads to C02 retention with hypercarbia

Question 11

What is the PaC02 value associated with type II respiratory failure?

Answer 11

PaC02 > 55mmHg

Question 12

What factors lead to failure of ventilation?

Answer 12

central hypoventilation
neuromuscular weakness
airway obstruction
chest wall deformities
marked abdominal interference with diaphragm descent

Question 13

How should your body respond if you are hypercapnic?

Answer 13

ventilation increases as PC02 rises (eliminate excess C02)

Question 14

What are the indications or mechanical ventilation?

Answer 14

elevated cost of breathing
inadequate oxygenation or ventilation
retention of pulmonary secretions
airway protection

Question 15

Can a V/Q mismatch lead to a shunt?

Answer 15

yes.

Question 16

Respiratory _____ is associated with hypercapnia.

Answer 16

acidemia

Question 17

Which type(s) of respiratory failure are associated with gas exchange impairment?

Answer 17

Type I

Question 18

Which type(s) of respiratory failure are associated with ventilatory pump impairment?

Answer 18

Type II

Question 19

Which type(s) of respiratory failure are associated with airway clearance impairment?

Answer 19

Type I and II

Question 20

What NIF, negative inspiratory force, is needed for MV?

Answer 20

< -20 to -25 cm H2O

Question 21

What Pa02 is needed for MV?

Answer 21

PaO2 < 50 mmHg

Question 22

What PaC02 is needed for MV?

Answer 22

PaCO2 > 60 mmHg

Question 23

What is A-a gradient?

Answer 23

Alveolar-arterial oxygen tension difference

difference between PAO2 and PaO2 in pulmonary arteries

Question 24

High A-a gradient tells us:

Answer 24

there is diffusion problem or V/Q shunt

Question 25

What VC is needed for MV?

Answer 25

< 10-20 ml/kg (~ 30% predicted FVC)

Question 26

If A-a is normal then hypoxemia is explained by:

Answer 26

either hypoventilation to increase PaCo2 | or altitude

Question 27

Is MV controlled by volume or pressure?

Answer 27

Varies depending on patient population, MD preference, Pathology

Question 28

When MV is controlled by volume, what is set?

Answer 28

Tidal volume is set so inspiration terminated when reach pre-set volume (Pressure varies with resistance and elasticity of respiratory system)

Question 29

When MV is controlled by pressure, what is set?

Answer 29

Pressure levels are set so inspiration terminated when reach pre set pressure level (Tidal volume varies with elasticity or compliance, airway resistance and tubing)

Question 30

What is PEEP?

Answer 30

positive end-expiratory pressure

Question 31

What is PEEP usually set at?

Answer 31

5cm H2O to prevent atelectasis

Question 32

What does PEEP setting influence?

Answer 32

Keeps alveoli from collapsing by increasing end-expired lung volume

Question 33

Risks of too much Fi02?

Answer 33

Absorption atelectasis Increased hypercapnia Airway or parenchymal injury

Question 34

What is an endotracheal tube?

Answer 34

- Tube inserted into trachea through patient’s mouth when patient in respiratory failure - Allows air to easily pass in and out of lungs - Short-term use

Question 35

What is a tracheostomy tube?

Answer 35

- Surgical procedure where incision made in tracheal rings and tube inserted - Placed in acute & chronic conditions for more permanent airway

Question 36

What does CPAP stand for?

Answer 36

Continuous Positive Airway Pressure

Question 37

What does BiPAP stand for?

Answer 37

Bilevel Positive Airway Pressure

Question 38

What does CPAP do?

Answer 38

Maintains constant airway pressure; Analogous to PEEP

Question 39

What does BiPAP do?

Answer 39

Delivers preset inspiratory positive airway pressure (IPAP) and preset expiratory positive airway pressure (EPAP) such that IPAP > EPAP

Question 40

What are the names of non-invasive ventilation?

Answer 40

CPAP and BiPAP

Question 41

Goals of PT management:

Answer 41

- Maximize V/Q matching - Maximize airway clearance - Improve strength/endurance of ventilatory muscles to enhance airway protection and assist with weaning - Prevent deconditioning - Maintain functional mobility

Question 42

Which type of respiratory failure is most common?

Answer 42

type I

Question 43

How should your body respond if you are hypoxemic?

Answer 43

vasoconstriction use of accessory respiratory muscles elevate HR inc. AV02 diff

Question 44

What does respiratory academia lead to?

Answer 44

``` dec cardiac contractility dec resp. muscle endurance arterial vasodilation inc cerebral blood flow induces loss of consciousness raises seizure threshold ```

Question 45

What are the Pa02 and Sp02 goals for MV?

Answer 45

Pa02 > 60 mmHg | Sp02 > 90%