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1

Describes amt of O2 bound to hemoglobin in arterial blood

Normal value =

SaO2 (saturation)

Normal = 95-100%

2

Amt of O2 dissolved in arterial blood plasma
Partial pressure of O2 in arterial blood

Normal value =

PaO2

Normal = 80-100mmHg

3

Blood oxygen saturation level

Normal =

Mild respiratory disease =

Supplementary O2 should be used if falls below ________

SpO2

Normal = 94-99%

Mild respiratory disease > 90%

Supplemental O2 if falls below 90%

4

2 conditions of respiratory failure

Hypercarbia
Hypoxemia

5

What is hypercarbia?

Condition of abnormally elevated levels of CO2 levels in blood

Ex: COPD with acute exacerbation

6

What is hypoxemia?

Low O2 in blood

Ex: severe bilateral pneumonia

7

What type of receptor detects too much O2 or too little CO2?

Chemoreceptors (detect changes in chemical concentrations)

8

Where does O2 diffuse from alveoli to arterial blood and CO2 exits?

Alveolar-Capillary Membrane (AC membrane)

9

What is the partial pressure of CO2 called?
(Ventilation & ________)

Normal =

PaCO2 (in artery)

"Little a = artery, big A = alveolar"

Normal = 35-45 mmHg

10

If bulk of O2 is carried bound to hemoglobin, _________ (larger/smaller) amount is what is dissolved in plasma.

What is this called?

Smaller

PaO2

11

Patient not ventilating enough- not blowing off enough CO2

Respiratory acidosis (CO2 goes up, pH goes down)

12

Pt hyperventilating because of pain or anxiety, blowing off too much CO2

Respiratory alkalosis (pH goes up)

13

Too little blood =

Too little oxygen =

Hypoxemia

Hypoxia

14

Carotid arteries and aorta are ___________receptors that respond to changes in blood __________ in normal breathing

Chemoreceptors

Blood chemicals

15

Signals are sent to ________ as PaCO2 and PaO2 change in normal breathing

Medulla

16

Medulla sends signal to respiratory muscles to contract with the _________ nerve in normal breathing

C3-5 phrenic nerve (innervated diaphragm)

17

As thorax expands, the diaphragm ___________ in normal breathing

Contracts

18

Basic pulmonary abnormalities of ventilation (2)

Restrictive defect (neuromuscular, morbid obesity, circumferential burns)
Obstructive defect (asthma, copd)

19

Basic pulmonary abnormalities of oxygenation (2)

Diffusion deficit (pulmonary fibrosis- idiopathic)
Shunt (atelectasis, ARDS)

20

Indications for PFT (5)

1. Measuring lung volumes/capacities/flows (vs baseline and normal values)
2. Quantify level of lung dysfunction
3. Pt response to treatment protocols
4. Pre-op screening
5. Disability evaluation

21

Lung volumes and capacities are a measure of A/W and lung ___________

RESTRICTION

22

Two or more volumes = capacity
What are the 4 volume measures?

1. Tidal volume (VT)
2. Inspiratory reserve volume (IRV)
3. Expiratory reserve volume (ERV)
4. Residual volume (RV)

23

What is tidal volume

normal breath = 500 mls

24

What is inspiratory reserve volume

Volume above normal inhalation = approx 3 L

25

What is expiratory reserve volume

Additional volume exhaled after normal exhalation = 1.2 L

26

What is residual volume

Volume remaining in lungs after complete exhalation = 1.2 L

27

What are the capacities? (4)

1. Total lung capacity (TLC)
2. Vital capacity (VC/FVC/SVC)
3. Inspiratory capacity
4. Functional residual capacity

28

What is total lung capacity (TLC)

IRV + VT + ERV + RV = 5 L (to 6)

29

What is vital capacity (VC/FVC/SVC)

IRV + VT + ERV = 4.8 L

30

What is inspiratory capacity

IRV + VT = 3.5 L

31

What is functional residual capacity

Amt left in lungs after normal respiration = 2.4 L

32

Flows measure __________

OBSTRUCTION

33

Flow = ______/______

Volume/time

34

What does PFT Flow Measure (3)

1. Peak expiratory flow rate (PEFR)
2. % of FVC exhaled in 1 second (FEV1%) = 75-80%
3. Forced expiratory flow (FEF) 25-75% (smaller A/Ws)

35

________ is used to estimate the residual volume (1.2 L) that remains in lungs to keep alveoli open

Body plethysmograph

36

What is a peak flow measurement and what is it for?

Maximum flow during forced expiration, used to monitor asthma patients' airway tone

37

This is a good leading indicator of condition and can help keep pt out of the hospital

Peak flow measurement

38

General pattern of dysfunction for obstructive disorders-

_______ (inc/dec) flows and ______(inc/dec) volumes/capacities

Decreased flows (obstruction) and increased volumes/capacities (air trapping)

39

General pattern of dysfunction for restrictive disorders-

_______ (inc/dec) volumes/capacities and _______ or _______ flows

Decreased volumes/capacities and normal or increased flows

40

True/false

VT, RV, FRC, TLC increase with restrictive pattern

FALSE they DECREASE

41

Why is residual volume in an obstructive disease increased?

B/c increased compliance (COPD- lung loses elasticity)- inability to exhale normally (obstructive pattern has flattened costal angles)

42

What is DLCO and what is normal value?

Diffusion capacity of CO

25-30 mL CO/min/mmHg

43

True/false

Hemoglobin and surface area affect DLCO

TRUE

44

A low diffusion capacity with destruction of alveolar capillary membrane is found in _____ (2)

Emphysema
Pulmonary fibrosis

45

Moderate to severe emphysema- less healthy alveolar capillary membrane = _______ surface area (less/more)

less

46

Does emphysema increase or decrease diffusing capacity

Decrease

47

what is a bleb?

Cavity/hollow

48

Percent change: pre/post bronchodilator --> 15% or more improvement on post-tx suggests ______ (reversible/irreversible) component

Reversible

49

Obstructive sleep apnea, tracheal stenosis, and extrinsic airway compression (tumor) are examples of _____ airway obstruction

Upper/large

50

Kyphoscoliosis and obesity are examples of restrictive diseases of ______________ whereas pulmonary fibrosis and sarcoidosis are restrictive __________ diseases

Chest wall/pleura
Lung

51

What is a low/obstructive FEV1 suggestive of?

Air trapping

52

Indications for ABGs (3)

1. Determine adequacy of ventilation
2. Determine adequacy of oxygenation
3. Determine metabolic status

53

Physics of ABGs involves this physics law

Dalton's Law of Partial Pressures

54

Site from which to draw an ABG

Radial artery (adults)
Near surface, easy to palpate, collateral circulation through ulnar artery, not near large veins

55

What is the Modified Allen's Test for?

Pass/fail- <15 seconds to flush is good indication of collateral circulation (hand should turn pink again in 3-5 seconds)

56

What is the representation of the following numbers? (What ABGs)

7.40/41/92/23/1

PH/PCO2/PO2/HCO3/BE

57

What are the normal ABG values?

PH = 7.35-7.45
PCO2 = 35-45 torr
PO2 = 80-100 torr
HCO3 = 22-26 meq
BE = -2 --> +2
SO2 = 95-100%

58

Order to evaluate ABGs

1st- pH: normal, acidosis, alkalosis
2nd- PCO2: normal, acidosis, alkalosis
3rd- HCO3 and BE: normal, acidosis, alkalosis
4th- oxygenation status: normal, hypoxemia, hyperoxygenated

59

Values for pH acidosis and alkalosis

< 7.35 acidosis
>7.45 alkalosis

60

Values of PaCO2 acidosis and alkalosis

>45 respiratory acidosis
<35 respiratory alkalosis

61

HCO3 acidosis/alkalosis values

<22 metabolic acidosis
>26 metabolic alkalosis

62

Base Excess (BE) acidosis/alkalosis

< -2 metabolic acidosis
> +2 metabolic alkalosis

63

Assessment of PCO2-
If > 45 torr, what is happening with patient?

Acidosis- CO2 retention, hypoventilation

64

If PCO2 < 35 torr, what is happening with pt?

Hyperventilation (alkalosis)

65

What is compensatory response in respiratory acidosis?

Increase PCO2, Increase HCO3

66

What is compensatory response in respiratory alkalosis?

Decrease PCO2, decrease HCO3

67

What is compensatory response in metabolic acidosis?

Decreased HCO3, decreased PCO2

68

What is compensatory response in metabolic alkalosis?

increased HCO3, increased PCO2

69

Hypoxemia if PO2 is _______ torr

<75-80

70

Mild hypoxemia
Moderate hypoxemia
Severe hypoxemia

Mild: 67-75 torr on room air
Moderate: 50-65 torr
Severe: <50 torr

71

Hyperoxia

PO2 > 100-120 torr

72

Interpret the following:

7.28- PCO2 58- HCO3 26- BE +2- PO2 65

Uncompensated respiratory acidosis w/ mild hypoxemia

73

Interpret the following-

7.22- PCO2 36- HCO3 17- BE -6- PO2 98

Uncompensated metabolic acidosis w/ normal oxygenation

74

What is FRC and what is its purpose?

- Equilibrium point between lung and chest recoil
- Maintains ABGs to normal level

75

In obstructive diseases, FVC ______.

In restrictive diseases, FVC _______.

Obstructive- Normal or decreased

Restrictive- Decreased

76

In obstructive diseases, FEV1/FVC% ______.

In restrictive diseases, FEV1/FVC% ________.

Obstructive- decreases

Restrictive- normal/increases

77

How are capacity values determined?

By age, sex, and height

78

What is a normal PFT value?

80-110% of predicted

79

Does the PFT provide specific diagnosis?

NO- mainly IDs pattern of impairment