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942 > Test 4 > Flashcards

Test 4 Flashcards

1
Q

FRC:

2 primary physiologic functions

A
  1. determines point for resting ventilation
  2. determines O2 reserve
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2
Q

can this lung volume measurement to detect small airway diseases before symptoms appear

A

closing volume

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3
Q

sum of closing volume and residual volume

A

closing capacity

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4
Q

volume of gas in excess of RV at time when small airways in the dependent portions of the lungs close during maximal exhalation

-measured by breath nitrogen washout test

A

closing volume

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5
Q

volume below which small airways begin to close during expiration

A

closing volume

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6
Q

normal FEV 25-75% for healthy 70 kg male

A

4.7 L/sec

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7
Q

what does Maximum voluntary ventilation (MVV) measure

A

endurance of ventilatory muscles

-indirectly reflects lung thoracic compliance & airway resistance

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8
Q

best ventilatory endurance test

A

MVV

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9
Q

avg MVV in young healthy adult

A

170 L/min

lower in females

dec with age (both sexes)

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10
Q

Collectively measures all factors that affect diffusion of gas across alveolar-capillary membrane

A

Carbon monoxide diffusion capacity

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11
Q

CO affinity for Hg in comparison to O2

A

CO 200x more affinity for Hg than O2

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12
Q

partial pressure of carbon monoxide in blood

A

nearly zero

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13
Q

DLCO is recorded in _______ @ STPD

A

DLCO is recorded in ml of CO/min/mmHg @ STPD

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14
Q

Person with normal hgb and V ̇/Q ̇ - main factor limiting diffusion is _____ _____ ______.

A

Person with normal hgb & V ̇/Q ̇ - main factor limiting diffusion is alveolar-capillary membrane

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15
Q

CO diffusion capacity: Avg value resting subjects single-breath method is ____ml CO/min/mm

A

CO diffusion capacity: Ave value resting subjects single-breath method is 25ml CO/min/mm

inc 2-3x w/ exercise

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16
Q

CO diffusion capacity

Influencing Factors:

A
  1. Hgb (direct relationship)
  2. alveolar pco2 (direct)
  3. supine position (inc DC)
  4. pulmonary capillary blood volume
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17
Q

CO Diffusing Cap:↓ in alveolar fibrosis asso with:

A

CO Diffusing Cap: ↓ in alveolar fibrosis asso with:

  1. sarcoidosis
  2. asbestosis
  3. berylliosis
  4. oxygen toxicity
  5. pulmonary edema
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18
Q

CO Diffusing Cap

↓ in COPD due to what 4 thing:

A

CO Diffusing Cap

↓ in COPD due to

  1. V ̇/Q ̇ mismatch
  2. ↓ alveolar surface area
  3. loss of capillary bed
  4. ↑ distance from terminal bronchiole to alveolar-capillary bed
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19
Q

chronic allergic type lung response that is caused by exposure to berilium and its compounds. occuptionalhazard in the 1950s, treatable but not curable

A

berylliosis

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20
Q

measurement of pulmonary volume over time

A

spirometry

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21
Q

exams performed to evaluate lung volumes along with inspiratory & expiratory flow of gas

Many of these measurements are derived from having patient breathe through a closed circuit with measurement of gas flow & composition

A

PFT

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22
Q

Change in absolute volume of IC parallels change in __.

A

VC

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23
Q

Balance of inward (lung) forces with & outward (chest wall) forces

A

FRC

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24
Q

2 primary functions of FRC

A

1) Determines point for resting ventilation
2) Determines oxygen reserve

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25
Q

2 reasons FRC important

A

1) Inflating an opened lung is easier than inflating deflated lung
2) Prevents major desaturation after exhalation

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26
Q

Factors affecting FRC

A

1) Body habitus
2) Sex
3) Posture
4) Lung disease
5) Diaphragmatic tone

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27
Q

Total amount of new air into respiratory passages each minute

Equal to TV x RR

Averages 6 L/min

A

Minute Resp Volume

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28
Q

Volume of gas in the lungs in excess of RV at the time when small airways in the depended portions of the lungs close during maximal exhalation, measured by:

A

single breath nitrogen washout test

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29
Q

FVC: Values ____ ml/kg associated with ↑ incidence of postoperative pulmonary complications (PPCs) – poor cough

A

FRC: Values < 15 ml/kg associated with ↑ incidence of postoperative pulmonary complications (PPCs) – poor cough

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30
Q

Most important is its comparison to patient’s FVC

A

Forced Expiratory Volume (FEVT)

Normally can expire ¾ of FVC in 1st sec

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31
Q

most commonly reported PFT

Normal values

A

FEV1

Normal value ≥ 75% FVC (FEV1/FVC ≥ 0.75)

  1. 0.5 sec - expire 50-60 %
  2. 1 sec - 75-80%
  3. 2 sec - 94%
  4. 3 sec - 97% (volume is @ least 80% of VC)
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32
Q

FEV1

Validity highly dependent on __ & __

A

FEV1

Validity highly dependent on cooperation & effort

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33
Q

Ave forced expiratory flow during middle half of FEV

(what test is this)

A

FEF 25-75%

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34
Q

FEF 25-75% test

aka

A

maximum mid-expiratory flow rate

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35
Q

FEF 25-75% test

Normal value is___ % of predicted

more reliable and reproducible than what PFT

A

FEF 25-75% test

Normal value is 100 ± 25 % of predicted

> Reliable & reproducible than FEV1/FVC

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36
Q

what test is this

  • Largest volume of gas that can be breathed in 1 min voluntarily
  • Breathe deeply & rapidly as possible for 10, 12, or 15 sec
  • Results are extrapolated to 1 min
  • Subject sets rate & moves > VT but < VC
  • Measures endurance of ventilatory muscles
  • Indirectly reflects lung-thorax compliance & airway resistance
A

Maximum Voluntary Ventilation (MVV)

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37
Q

Flow generated during forced expiratory maneuver followed by forced inspiratory maneuver

Plotted against volume of gas expired

A

flow volume loop

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38
Q

flow volume loop:

_____ of loop most informative part

A

FVL

Configuration of loop most informative part

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39
Q

Flow volume loops

Zero point on x-axis is ___ ______

Lungs cannot empty due to __

A

Flow volume loops

Zero point on x-axis is full inspiration

Lungs cannot empty due to RV

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40
Q

Flow volume loops

Most important part is ____ flow (insp or exp)

A

Flow volume loops

Most important part is expiratory flow

Volume begins@ this point

Ends when loop reaches x-axis again

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41
Q

Flow volume loops:

Obstructive disease characterized by:

A

Flow volume loops:

Obstructive disease characterized by:

  1. reduced peak flow rates
  2. sloping of expiratory limb
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42
Q

Flow volume loops:

Restrictive disease characterized by:

A

Flow volume loops:

Restrictive disease characterized by:

  1. normal or heightened peak expiratory flows
  2. very narrow loop (reduced VC)
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43
Q

which type of restrictive disease?

Abnormal movement of intravascular fluid into interstitium & alveoli

Due to ↑ PVR from LVF, fluid overload, or ↑ pulm cap permeability

EX: pulmonary edema, aspiration pneumonia, & ARDS

A

acute intrinsic

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44
Q

which type of restrictive disease?

Diseases with pulmonary fibrosis

EX: IPF, radiation injury, cytotoxic and noncytotoxic drug exposute, oxygen toxicity, autoimmune disorders, sarcoidosis

A

chronic intrinsic

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45
Q

which type of restrictive disease?

Disorders that inhibit lung expansion

EX: flail chest, pneumothorax, pleural effusions,

Limit chest-expansion: ascites, obesity, pregnancy, skeletal & neuromuscular disorders

A

chronic extrinsic

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46
Q

Supine position ↓ FRC __ % in healthy person

worse in sick pt

GA decreases this further by

A

Supine position ↓ FRC 10-15%

GA another 5-10%

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47
Q

ventilator settings (tv and RR)

reduce risk of barotrauma

A

lower TV

inc RR

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48
Q

FRC restores after ___ hrs postop

A

FRC restores after 12 hr postop

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49
Q

American Thoracic Society & European Respiratory Society “’preventable and treatable disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases…” defines what disease

A

Obstructive Pulmonary Disease

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50
Q

Which obstructive disease:

Destruction of parenchyma leading to loss of surface area, elastic recoil & structural support

A

Emphysem’er

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51
Q

Which obstructive disease:

Narrowing of small airways by inflammation and mucous production

A

Chronic bronchitis

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52
Q

Which obstructive disease?

  • Numerous chronic conditions
  • Not mutually exclusive
  • May precede emphysema & chronic bronchitis
A

Peripheral airways disease

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53
Q

dominant clinical feature of obstructive disease

A

impaired expiratory airflow

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54
Q

condition of the lung characterized by abnormal permanent enlargement of the air spaces distal to the terminal bronchiole, accompanied by destruction of their walls and without obvious fibrosis

A

emphysema

Changes are irreversible

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55
Q

subclass of ephysema: 2 with definitions

A
  • Centrilobular: dilation affects respiratory bronchioles upper lobes
  • Panlobular: tissue destruction is widespread, involves acinus (16-17th gen)
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56
Q

4 primary alterations in pulmonary function of emphysema

A

4 primary alterations in pulmonary function

  • ↑ in size acini
  • Consolidation of alveoli
  • V/Q mismatch
  • Loss of alveolar walls
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57
Q

What obstructive disease?

Chronic or recurring excess mucous secretion on most days for at least 3 months of the year for at least 2 successive years

Critical element: airway obstruction of expiratory airflow

A

Chronic bronchitis

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58
Q

What obstructive disease?

Inflammation of all terminal & respiratory bronchioles, fibrosis, narrowing of airway walls, & goblet cell metaplasia

EX: sarcoidosis, Wegener granulomatosis, mineral dust-associated airways disease, disease from exposure to fumes and toxins, and bronchocentric granulomatosis

A

Peripheral airway disease

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59
Q

now list tell me about peripheral airway disease?

characteristics:

A

Peripheral airway disease:

  • Inflammation of all terminal & respiratory bronchioles, fibrosis, narrowing of airway walls, & goblet cell metaplasia
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60
Q

now tell me more about peripheral airway disease?

give examples:

A
  • sarcoidosis
  • Wegener granulomatosis
  • mineral dust-associated airways disease
  • disease from exposure to fumes and toxins
  • bronchocentric granulomatosis
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61
Q

Principal factor for development of COPD

A

smoking

environmental effects - minimal

some due to imbalance btw protease vs antiprotease activity

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62
Q

Dominant feature: COPD

why is FEV1 reduced?

A

Progressive airflow obstruction

↓ FEV1

  • 1) decrease of intrinsic size of bronchial lumen
  • 2) increase in collapsibility of bronchial walls
  • 3) decrease in elastic recoil of lungs
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63
Q

COPD: Airway narrowing primarily due to:

A

COPD: Airway narrowing primarily due to thickening of airway walls

(not due to inc muscle tone like in asthma)

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64
Q

Major difference btw asthma and COPd:

Airway hyperreactivity affects which airways segments primarily in COPD:

A

Airway hyperreactivity affects small airways more than large (in COPD)

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65
Q

COPD: single best variable for predicting airflow obstruction? (related to smoking)

A

patient smokes 40 pack per year (PPY)

66
Q

highly indicative (almost gauranteed) of severe COPD of airflow and dx of COPD.

Related to smoking

A

Patient smokes 50 PPY

current wheezing

67
Q

hallmark of obstructive disease

A

reduction of FEV1

(can also indicate restrictive disease - reduced FEV1 but ratio is normal)

68
Q

FEV1/FVC % indicates COPD

FEV1 % = mild

FEV1 % = moderate

FEV1 % = severe

FEV1 % = very severe

A

FEV1/FVC < 0.7 indicates COPD

  • FEV1 > 80% = mild
  • FEV1 50-79% = moderate
  • FEV1 30-49% = severe
  • FEV1 < 30% = very severe
69
Q

goals of vent mngt in obstructive diz (5)

A
  • vadequate oxygenation
  • eliminate CO2
  • avoid barotrauma
  • avoid tissue injury from repeated airway opening and closure
  • avoid volutrauma
70
Q

Obstructive dz:

Oxygenation is managed with what firstly:

A

Oxygenation is managed with FIO2

but avoid absorptive atelectasis from too much fiO2!

71
Q

pure memorization question:

Patients with marked obstructive pulmonary disease are at increased risk for both ___ and __.

A

Patients with marked obstructive pulmonary disease are at increased risk for both intraoperative and PPCs

72
Q

Management obstructive dz:

Preop FEV1 ____ correlates with ↑ in ___ during GA

A

Management obstructive dz:

Preop FEV1 reduction correlates with ↑ in CO2 during GA

73
Q

ETT issues related with COPD: (3)

A
  1. inc airway resistance
  2. reflex bronchoconstriction
  3. limits ability to clear secretions
74
Q

indication for possibly doing ABG on obstructive dz

A
  1. arterial hypoxemia
  2. severe enough COPD
  3. CO2 retention
  4. currently on O2
  5. struggling to breathe
75
Q

contraction of diaphragm causes these several changes (lungs, abd contents, ribs, chest)

A
  • Pulls lower surfaces of the lung down
  • Abdominal contents move downward and forward
  • Lower ribs rise; chest widens
76
Q

accessory muscles of inspiration (4)

A
  • Internal Intercostals (parasternal portion)
  • Sternocleidomastoid – Lifts sternum
  • Scaleni – Lifts 1st 2 ribs
  • Anterior serrati
77
Q

Most important muscles that elevate the chest cage

Increase A-P diameter of chest by 20%

A

external intercostals

78
Q

Pleural pressure:

Slightly negative pressure ~ -5cm of H2O @ begin of inspiration due to what?

A

Pleural pressure:

Slightly negative pressure ~ -5cm of H2O @ begin of inspiration due to opposition of lung tissue contraction & chest wall expansion

79
Q

by convention we use this pressure as a measure of intrathoracic pressure

A

pleural pressure

intrapleural pressure

(same thing)

80
Q

Difference between that in alveoli & outer surfaces of the lungs (outer surface = pleural pressure)

A

TPP

81
Q

what is transpulmonary pressure the difference of?

A

TPP

alveolar press - intrapleural press (outer surface of lungs or pl pressure)

82
Q

Chest and lungs elastic properties

A

Chest & lungs have elastic properties

  • Chest expands outward
  • Lungs collapse
83
Q

2 Elastic forces of lung tissue

A

Elastic forces of lung tissue

Elastin

Collagen

84
Q

Elastic forces caused by what tension?

A

Elastic forces caused by surface tension

85
Q

alveolar collapse is directly proportional to

A

alveolar collapse is directly proportional to surface tension

86
Q

Formula for surface tension related to law of laplace

A

(P = 2T/r)

or

Pressure = 2 x Surface tension/radius

87
Q

definition of lung compliance

A

Lung Compliance

Definition: change in volume divided by the change in pressure (V/P)

C = ∆V/∆P

88
Q

Extent lungs will expand for each unit ↑ in transpulmonary pressure

A

Total compliance of both lungs normal adult ≈ 200 ml/cm H2O transpulmonary press.

OR

When transpulmonary press ↑ 1cm H2O, lung volume expand 200 ml after 10-20 sec

89
Q

lung compliance formula

and normal value

A

CL = Change in lung volume/change in TPP

≈ 150-200 mL/cm H2O

90
Q

chest wall compliance formula

and normal value

A

CW = change in chest volume/change in TTP

Where transthoracic pressure =

atmospheric pressure – pleural pressure

≈ 200 mL/cm H2O

91
Q
A
92
Q
  • Describes pressure-volume relationship for lung when air is not moving
  • Reflects compliance of lung & chest wall alone
  • ↓ by conditions that make the lung abnormally stiff or difficult to inflate
  • ↑ by emphysema which destroys elastic tissue of lung
A

static effective compliance

93
Q

static effective compliance

↓’d by conditions that make the lung abnormally stiff or difficult to inflate

what are some examples of these conditions?

A
  • fibrosis
  • obesity
  • vascular engorgement
  • edema
  • ARDS
  • external compression of chest
94
Q
  • Compliance of lung while air is moving
    • Affected by same factors as static compliance plus airway resistance
  • and .. how is it calculated?
A

dynamic compliance

TV/(PIP – PEEP)

95
Q

Opposes inflation of lungs

(besides static elastic recoil, there are 2 more factors)

A

Opposes inflation of lungs

  1. Frictional resistance of lung tissues
  2. Resistance to airflow
96
Q

Resistance is _____\_ proportional to gas density

Resistance is _____\_ proportional to 5th power of the radius

A

Resistance is directly proportional to gas density

Resistance is inversely proportional to 5th power of the radius

97
Q

___ number is predictive of turbulent or laminar airflow

what is the formula?

A

Reynold’s number is predictive of turbulent or laminar airflow

Re = ρνd/η

98
Q

Re = ρνd/η

what do all those mean?

A
  • Re is Reynold’s number
  • ρ is density of the fluid
  • ν is velocity of fluid flow
  • d is diameter of the vessel
  • η is viscosity of the fluid

or

Re = (linear velocity x diameter x gas density)/

gas viscosity

99
Q

Low Re _amnt?_ (Nagelhout) – (lam or turb)

High Re_amnt?_ (Nagelhout) - (lam or turb)

what is the range for transitional area for resistance?

A

Low Re < 2000 (Nagelhout) – laminar

High Re > 4000 (Nagelhout) - turbulent

Transitional Area of Resistance (2000-4000)

100
Q

True laminar flow occurs in ___ airways

Turbulence found in ____ airways

(answer in size)

A

True laminar flow occurs in smaller airways

Turbulence found in larger airways

101
Q

40% of total airway resistance in ___ airways?

A

40% of total airway resistance in upper airways

(nasal cavity, pharynx, larynx)

102
Q

Greatest resistance to airflow in ____-sized bronchi

(small, medium, large)?

A

Greatest resistance to airflow in medium-sized bronchi

103
Q
  1. work needed to expand lungs against elastic forces of ulngs and chest
  2. work needed to overcome the viscocity of lung and chest wall
  3. work needed to overcome AW resistance to movement of air into lungs
A
  1. compliance work = work needed to expand lungs against elastic forces of ulngs and chest
  2. Tissue “frictional//resistance” work = work needed to overcome the viscocity of lung and chest wall
  3. “Frictional” AW resistance work = work needed to overcome AW resistance to movement of air into lungs
104
Q

Compliance work

Tissue “frictional//resistance” work

“Frictional” AW resistance work

(see what i did there… :) what are the definitions bc ur gonna have to memorize word for word.

A

compliance work = work needed to expand lungs against elastic forces of lungs and chest

Tissue “frictional//resistance” work = work needed to overcome the viscocity of lung and chest wall

“Frictional” AW resistance work = work needed to overcome AW resistance to movement of air into lungs

105
Q

Respiratory muscles use ___% of total body energy normal quiet breathing

what is the increase during exercise?

A

Respiratory muscles use 3-5% of total body energy

normal quiet breathing

inc 50-fold with exercise

106
Q

respiratory changes with aging

A

Dilation of alveoli

↓ lung recoil (reduce elastin/collagen)

↓ chest wall compliance → ↑ work of breathing

Respiratory muscle strength decreases

Expiratory flow rates decrease

Respiratory centers in nervous system show ↓ sensitivity to hypoxemia & hypercapnia

107
Q

reduced FRC due to alveolar collapse & compression causes these 3 changes:

A
  1. Loss of inspiratory tone
  2. Change in chest wall rigidity
  3. Upward shift of diaphragm
108
Q

Supine position ↓ FRC ____ L

Induction of GA ↓ FRC by another ____ L

A

Supine position ↓ FRC 0.8-1.0 L

Induction of GA ↓ FRC by another 0.4-0.5 L

109
Q

FRC and closing capacity reduced to same extent under GA

Risk of shunting greatest in these patients: (list 3)

A

Risk of shunting greatest in:

  1. elderly
  2. obese
  3. pulmonary disease
110
Q

Effects of Anesthesia on Resistance

A
  • Increased if obstruction (tongue, laryngospasm)
  • Bronchoconstriction – if light anesthesia
  • Secretions or blood in airway
  • Equipment – ETT, connectors, malfunction of valves
  • Increases not seen due to bronchodilating properties of volatile agents
111
Q

Age dependent formula/estimate for PO2 (A-a gradient)

A

0.21 x (Age + 2.5)

*room air, adjust to FiO2 as needed*

112
Q

Normal A-a gradient

A

<10-15 mm Hg

113
Q

Work of Breathing

Increased by:

A

Work of Breathing

Increased by:

  • Reduced lung & chest wall compliance
  • Rarely by airway resistance

Effects usually overcome by controlled mechanical ventilation

114
Q

PIO2 is reduced from ____ to _____ as it enters the alveoli

A

160 mm Hg to 149 mm Hg

115
Q

PAO2 formula?

A

PAO2= FiO2 x (PB-PH20) - (PaCO2/RQ)

0.21 x (760-47) - (PaCO2/RQ)

116
Q

Large increases in arterial CO2 (>75) will produce ________

A

Hypoxia (arterial O2 <60) if patient is on RA; supplement with FiO2 to prevent this

117
Q

How to estimate PAO2?

A

FiO2 x 6

118
Q

The decrease in PaO2 (O2 tension) as the body ages is due to what factor?

A

Progressive increase in closing capacity relative to FRC

119
Q

The most common mechanism for hypoxemia is?

A

Increased A-a gradient

120
Q

A-a gradient for O2 depends on 3 things:

A
  1. amount of R to L shunt (directly proportional)
  2. amount of VQ scatter
  3. mixed venous O2 tension (indirectly proportional)
121
Q

The tracheobronchial tree has an increase in total _______ pathways and total _______ _______ areas with each successive generation toward the periphery.

A

Parallel

cross sectional

122
Q

Airflow velocity is increased/decreased at the lower generations of the tracheobronchial tree.

A

Decreased compared to the upper airways.

Velocity d/c from the trachea to peripheral distal airways.

123
Q

Airflow at convective airways is mostly _______

A

laminar

124
Q

At what level of bronchioles does diffusion begin?

A

Terminal bronchioles (16th generation); diffusion is primary mode of transport and occurs b/c of kinetic motion of molecules in the respiratory gases

125
Q

Hypercapnia is NEVER due to what?

A

Defective diffusion

CO2 is 20X more diffusible than O2 and thus hypercapnia is related to inadequate alveolar ventilation and not diffusion.

126
Q

Whose law allows us to calculate partial pressures of gases?

A

Henry’s Law

127
Q

Solubility of O2, CO2, and Nitrogen?

A

O2 0.024

CO2 0.57

Nitrogen 0.012

128
Q

Vapor pressure depends entirely on _______?

A

Temperature

129
Q

With normal alveolar ventilation, 1/2 of alveolar air is removed in __________ seconds?

A

17

130
Q

Benefits of slow exchange of alveolar and atmospheric air?

A
  1. Prevents rapid change of gas concentration in blood
  2. Prevents excessive increase and decrese in tissue oxygenation
    - tissue CO2 concentration
    - tissue pH during apneic periods
131
Q

Which two factors determine the diffusion coefficient of a gas?

A

Solubility

Molecular Weight

132
Q

Diffusion coefficients for respiratory gases?

A

O2 1

CO2 20.3

CO 0.81

N 0.53

Helium 0.95

133
Q

Alveolar capillary membrane layers from inside alveolus to capillary?

A
  1. fluid and surfactant layer
  2. alveolar epithelium
  3. epithelial basement membrane

4 interstitial space

  1. capillary basement membrane
  2. capillary endothelium
134
Q

Average diameter of pulmonary capillary?

A

5-10 micrometers

135
Q

Mean pulmonary transit time

A

4-5 seconds

136
Q

How much time does blood spend in pulmonary capillary?

A

0.75 seconds

With exercise and increased CO, this can be reduced to 0.25 sec.

137
Q

How much time does it it take before a RBC is saturated w/ O2 in a pulmonary capillary?

A

0.25 seconds

This is also the time that equilibriation occurs b/w alveolar air and capillary blood.

138
Q

During exercise the reduced circulatory time has a greater effect on O2 or CO2?

A

O2 because CO2 diffuses 20x faster than O2

139
Q

Normal O2 absorption rate

A

250 mL/min

Increases up to 1000mL/min during moderate exercise

140
Q

Normal alveolar ventilation rate

A

4.2 L/min

Increases by 4x during exercise

141
Q

What is the max PO2 of humidified air?

A

149 mmHg

142
Q

Solubility coefficient of O2 in plasma?

A

0.003

so 0.003 mL of O2/1 mmHg partial pressure of PO2 in 100 mL of plasma

143
Q

What is arterial blood PO2?

A

95 mm Hg

144
Q

What is interstitial fluid PO2?

A

40 mm Hg

*same as venous blood PO2*

145
Q

What is the range for intracellular PO2?

A

5-40 mmHg

23 is the average

146
Q

How much O2 in mmHg is required for full support of chemical processes in the cells?

A

1-3 mm Hg

*So PO2 of 23 mm Hg which is average is more than enough*

147
Q

What pressure gradient is required for CO2 to diffuse from tissues to capillaries and from capillaries to alveoli?

A

5 mmHg

148
Q

An average of ___ mL of CO2 is transported from tissues to lungs per 100 mL of blood?

A

4 mL

149
Q

Carbonic anhydrase catalyzes what reaction? Accelerates it by how much?

A

Catalyzes CO2 and H20 to form carbonic acid

Accelerates it by 5000x so that equilibrium is reached w/in a fraction of a second

150
Q

Carbonic acid dissasociates into what?

A

Hydrogen and Bicarbonate ions

151
Q

H2CO3 is what? And it disassociates into what?

A

Carbonic acid

H+ and HCO3-

152
Q

______ diffuses from the RBC in exchange for ______ ion

A

HCO3

Chloride ion

*Chloride or Hamburger shift*

153
Q

CO2 binding with Hgb forms what?

A

Carbaminohemoglobin

CO2Hgb

154
Q

How is CO2 carried in plasma? %?

A

7% dissolved in plasma

23% bound to Hgb

70% carried as bicarb

155
Q

closing volume increase with:

A

inc Closing Volume with:

age

obstructive dz

(used to detect small airway disease)

156
Q

normal FEV1

  1. 0.5 sec
  2. 1 sec
  3. 2 sec
  4. 3 sec
A

normal FEV1

  1. 0.5 sec 50 - 60%
  2. 1 sec 75 - 80%
  3. 2 sec 94%
  4. 3 sec 97%
157
Q

examples of restrictitve dz:

acute intrinsic

A

pulm edema

asp pneumon’ier

ARDS

158
Q

examples of restrictitve dz:

Chronic intrinsic

A

Fibrosis

  1. IPF
  2. radiation injury
  3. cytotoxic/noncytotoxic drug exposure
  4. O2 toxicity
  5. autoimmune dz
  6. sarcodosis
159
Q

examples of restrictitve dz:

chronic extrinsic

A

inhibit excursion:

  1. obesity
  2. ascities
  3. prego
  4. RA
  5. Neuromuscular dz
  6. Flail chest
  7. pneumothorax
  8. pleural effusions
160
Q

Not considered part of Obstructive Disease process

A

TB

cystic fibrosis

bronchiectasis

161
Q

relationship of muscle paralysis to FRC

A

MP does not change FRC significantly

162
Q
A

942 (7 decks)

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