Spirometry and Related Tests

1
Spirometry and Related Tests

• RET 2414
• Pulmonary Function Testing
• Module 2.0

2
SPIROMETRY AND RELATED TESTS

• Learning Objectives
• Determine whether spirometry is acceptable and
  reproducible
• Identify airway obstruction using forced vital
  capacity (FVC) and forced expiratory volume
  (FEV1)
• Differentiate between obstruction and restriction
  as causes of reduced vital capacity

3
SPIROMETRY AND RELATED TESTS

• Learning Objectives
• Distinguish between large and small airway
  obstruction by evaluating flow-volume curves
• Determine whether there is a significant response
  to bronchodilators
• Select the appropriate FVC and FEV1 for reporting
  from series of spirometry maneuvers

4
Predicted Values

• Laboratory Normal Ranges
• Laboratory tests performed on a large number of
  normal population will show a range of results

5
Predicted Values

• Laboratory Normal Ranges

6
Predicted Values

• Laboratory Normal Ranges
• Most clinical laboratories consider two standard
  deviations from the mean as the normal range
  since it includes 95 of the normal population.

7
PFT Reports

• When performing PFTs three values are reported
• Actual what the patient performed
• Predicted what the patient should have
  performed based on Age, Height, Sex, Weight, and
  Ethnicity
• Predicted a comparison of the actual value to
  the predicted value

8
PFT Reports

• Example
• Actual Predicted Predicted
• VC 4.0 5.0 80

9
SPIROMETRY

• Vital Capacity
• The vital capacity (VC) is the volume of gas
  measured from a slow, complete expiration after a
  maximal inspiration, without a forced effort.

10
SPIROMETRY

• Vital Capacity

11
SPIROMETRY

• Vital Capacity
• Valid VC measurements important
• IC and ERV used to calculate
• RV and TLC
• Example
• RV FRC - ERV
• TLC IC FRC

12
SPIROMETRY

• VC Criteria for Acceptability
• End-expiratory volume varies by less than 100 ml
  for three preceding breaths
• Volume plateau observed at maximal inspiration
  and expiration

13
SPIROMETRY

• VC Criteria for Acceptability
• Three acceptable VC maneuvers should be obtained
  volume within 150 ml.
• VC should be within 150 ml of FVC value

14
SPIROMETRY

• VC Selection Criteria
• The largest value from at least 3 acceptable
  maneuvers should be reported

15
SPIROMETRY

• VC Significance/Pathophysiology
• Decreased VC
• Loss of distensible lung tissue
• Lung CA
• Pulmonary edema
• Pneumonia
• Pulmonary vascular congestion
• Surgical removal of lung tissue
• Tissue loss
• Space-occupying lesions
• Changes in lung tissue

16
SPIROMETRY

• VC Significance/Pathophysiology
• Decreased VC
• Obstructive lung disease
• Respiratory depression or neuromuscular disease
• Pleural effusion
• Pneumothorax
• Hiatal hernia
• Enlarged heart

17
SPIROMETRY

• VC Significance/Pathophysiology
• Decreased VC
• Limited movement of diaphragm
• Pregnancy
• Abdominal fluids
• Tumors
• Limitation of chest wall movement
• Scleraderma
• Kyphoscoliosis
• Pain

18
SPIROMETRY

• VC Significance/Pathophysiology
• If the VC is less than 80 of predicted FVC can
  reveal if caused by obstruction

19
SPIROMETRY

• VC Significance/Pathophysiology
• If the VC is less than 80 of predicted Lung
  volume testing can reveal if caused by restriction

20
SPIROMETRY

• Forced Vital Capacity (FVC)
• The maximum volume of gas that can be expired
  when the patient exhales as forcefully and
  rapidly as possible after maximal inspiration
  (sitting or standing)

21
SPIROMETRY

• FVC (should be within 150 ml of VC)

22
SPIROMETRY

• FVC Criteria for Acceptability
• Maximal effort no cough or glottic closure
  during the first second no leaks or obstruction
  of the mouthpiece.
• Good start-of-test back extrapolated volume lt5
  of FVC or 150 ml, whichever is greater

23
SPIROMETRY

• FVC Criteria for Acceptability
• Tracing shows 6 seconds of exhalation or an
  obvious plateau (lt0.025L for 1s) no early
  termination or cutoff or subject cannot or
  should not continue to exhale

24
SPIROMETRY

• FVC Criteria for Acceptability
• Three acceptable spirograms obtained two largest
  FVC values within 150 ml two largest FEV1 values
  within 150 ml

25
SPIROMETRY

• FVC Selection Criteria
• The largest FVC and largest FEV1 (BTPS) should
  be reported, even if they do not come from the
  same curve

26
SPIROMETRY

• FVC When to call it quits !!!
• If reproducible values cannot be obtained after
  eight attempts, testing may be discontinued

27
SPIROMETRY

• FVC Significance and Pathophysiology
• FVC equals VC in healthy individuals
• FVC is often lower in patients with obstructive
  disease

28
SPIROMETRY

• FVC Significance and Pathophysiology
• FVC can be reduced by
• Mucus plugging
• Bronchiolar narrowing
• Chronic or acute asthma
• Bronchiectasis
• Cystic fibrosis
• Trachea or mainstem bronchi obstruction

29
SPIROMETRY

• FVC Significance and Pathophysiology
• Healthy adults can exhale their FVC within 4 6
  seconds
• Patients with severe obstruction (e.g.,
  emphysema) may require 20 seconds, however,
  exhalation times gt15 seconds will rarely change
  clinical decisions

30
SPIROMETRY

• FVC Significance and Pathophysiology
• FVC is also decreased in restrictive lung disease
• Pulmonary fibrosis
• dusts/toxins/drugs/radiation
• Congestion of pulmonary blood flow
• pneumonia/pulmonary hypertension/PE
• Space occupying lesions
• tumors/pleural effusion

31
SPIROMETRY

• FVC Significance and Pathophysiology
• FVC is also decreased in restrictive lung disease
• Neuromuscular disorders, e.g,
• myasthenia gravis, Guillain-Barre
• Chest deformities, e.g,
• scoliosis/kyphoscoliosis
• Obesity or pregnancy

32
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• The volume expired over the first second of an
  FVC maneuver

33
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• May be reduced in obstructive or restrictive
  patterns, or poor patient effort

34
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• In obstructive disease, FEV1 may be decreased
  because of
• Airway narrowing during forced expiration
• emphysema
• Mucus secretions
• Bronchospasm
• Inflammation (asthma/bronchitis)
• Large airway obstruction
• tumors/foreign bodies

35
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• The ability to work or function in daily life is
  related to the FEV1 and FVC
• Patients with markedly reduced FEV1 values are
  more likely to die from COPD or lung cancer

36
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• FEV1 may be reduced in restrictive lung processes
• Fibrosis
• Edema
• Space-occupying lesions
• Neuromuscular diseases
• Obesity
• Chest wall deformity

37
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• FEV1 is the most widely used spirometric
  parameter, particularly for assessment of airway
  obstruction

38
SPIROMETRY

• Forced Expiratory Volume (FEV1)
• FEV1 is used in conjunction with FVC for
• Simple screening
• Response to bronchodilator therapy
• Response to bronchoprovocation
• Detection of exercise-induced bronchospasm

39
SPIROMETRY

• Forced Expiratory Volume Ratio (FEVT)
• FEVT FEVT/FVC x 100
• Useful in distinguishing between obstructive and
  restrictive causes of reduced FEV1 values

40
SPIROMETRY

• Forced Expiratory Volume Ratio (FEVT)
• Normal FEVT Ratios for Health Adults
• FEV 0.5 50-60
• FEV 1 75-85
• FEV 2 90-95
• FEV 3 95-98
• FEV 6 98-100
• Patients with obstructive disease have reduced
  FEVT for each interval

41
SPIROMETRY

• Forced Expiratory Volume Ratio (FEVT)
• A decrease FEV1/FVC ratio is the hallmark of
  obstructive disease
• FEV1/FVC lt75

42
SPIROMETRY

• Forced Expiratory Volume Ratio (FEVT)
• Patients with restrictive disease often have
  normal or increased FEVT values
• FEV1 and FVC are usually reduced in equal
  proportions
• The presence of a restrictive disorder may by
  suggested by a reduced FVC and a normal or
  increased FEV1/FVC ration

43
SPIROMETRY

• Forced Expiratory Flow 25 - 75
• (maximum mid-expiratory flow)
• FEF 25-75 is measured from a segment of the FVC
  that includes flow from medium and small airways
• Normal values 4 5 L/sec

44
SPIROMETRY

• Forced Expiratory Flow 25 - 75
• In the presence of a borderline value for
  FEV1/FVC, a low FEF 25-75 may help confirm
  airway obstruction

45
SPIROMETRY

• Flow Volume Curve
• AKA FlowVolume Loop (FVL)
• The maximum expiratory flow-volume (MEFV) curve
  shows flow as the patient exhales from maximal
  inspiration (TLC) to maximal expiration (RV)
• FVC followed by FIVC

46
SPIROMETRY

• FVL
• X axis Volume
• Y axis Flow
• PEF (Peak Expiratory Flow)
• PIF (Peak Inspiratory Flow)
• .
• Vmax 75 or FEF 25
• FVC Remaining or Percentage FVC exhaled
• .
• Vmax 50 or FEF 50
• .
• Vmax 25 or FEF 75

FEF 25 or Vmax 75
FEF 75 or Vmax 25
47
SPIROMETRY

• FVL
• FEVT and FEF can be read from the timing marks
  (ticks) on the FVL

48
SPIROMETRY

• FVL
• Significant decreases in flow or volume are
  easily detected from a single graphic display

49
SPIROMETRY

• FVL Severe Obstruction

50
SPIROMETRY

• FVL Bronchodilation

51
SPIROMETRY

• Peak Expiratory Flow (PEF)
• The maximum flow obtained during a FVC maneuver
• Measured from a FVL
• In laboratory, must perform a minimum of 3 PEF
  maneuvers
• Largest 2 of 3 must be within 0.67 L/S (40 L/min)
• Primarily measures large airway function
• Many portable devices available

52
SPIROMETRY

• Peak Expiratory Flow (PEF)
• When used to monitor asthmatics
• Establish best PEF over a 2-3 week period
• Should be measured twice daily (morning and
  evening)
• Daily measurements are compared to personal best

53
SPIROMETRY

• Peak Expiratory Flow (PEF)
• The National Asthma Education Program suggests a
  zone system
• Green 80-100 of personal best
• Routine treatment can be continued consider
  reducing medications
• Yellow 50-80 of personal best
• Acute exacerbation may be present
• Temporary increase in medication may be needed
• Maintenance therapy may need increases
• Red Less than 50 of personal best
• Bronchodilators should be taken immediately
  begin oral steroids clinician should be notified
  if PEF fails to return to yellow or green within
  2 4 hours

54
SPIROMETRY

• Peak Expiratory Flow (PEF)
• PEF is a recognized means of
• monitoring asthma
• Provides serial measurements
• of PEF as a guide to treatment
• ATS Recommended Ranges
• 60-400 L/min (children)
• 100-850 L/min (adults)

55
SPIROMETRY

• Maximum Voluntary Ventilation (MVV)
• The volume of air exhaled in a specific interval
  during rapid, forced breathing

56
SPIROMETRY

• MVV
• Rapid, deep breathing
• VT 50 of VC
• For 12-15 seconds

57
SPIROMETRY

• MVV
• Tests overall function of respiratory system
• Airway resistance
• Respiratory muscles
• Compliance of lungs/chest wall
• Ventilatory control mechanisms

58
SPIROMETRY

• MVV
• At least 2 acceptable maneuvers should be
  performed
• Two largest should be within 10 of each other
• Volumes extrapolated out to 60 seconds and
  corrected to BTPS
• MVV is approximately equal to 35 time the FEV1

59
SPIROMETRY

• MVV
• Selection Criteria
• The highest MVV (L/min, BTPS) and MVV rate
  (breaths / min) should be reported

60
SPIROMETRY

• MVV
• Decreased in
• Patients with moderate to severe obstructive lung
  disease
• Patients who are weak or have decreased endurance
  
• Patients with neurological deficits

61
SPIROMETRY

• MVV
• Decreased in
• Patients with paralysis or nerve damage
• A markedly reduced MVV correlates with
  postoperative risk for patients having abdominal
  or thoracic surgery

62
SPIROMETRY

• Before/After Bronchodilator
• Spirometry is performed before and after
  bronchodilator administration to determine the
  reversibility of airway obstruction

63
SPIROMETRY

• Before/After Bronchodilator
• An FEV1 less than predicted is a good indication
  for bronchodilator study
• In most patients, an FEV1 less than 70
  indicates obstruction

64
SPIROMETRY

• Before/After Bronchodilator
• Any pulmonary function parameter may be measured
  before and after bronchodilator therapy
• FEV1 and specific airway conductance (SGaw) are
  usually evaluated

65
SPIROMETRY

• Before/After Bronchodilator
• Lung volumes should be recorded before
  bronchodilator administration
• Lung volumes and DLco may also respond to
  bronchodilator therapy

66
SPIROMETRY

• Before/After Bronchodilator
• Routine bronchodilator therapy should be withheld
  prior to spirometry
• Ruppel 9th edition, pg. 66 Table 2-2
• Short-acting ß-agonists 4 hours
• Short-acting anticholinergic 4 hours
• Long-acting ß-agonists 12 hours
• Long-acting anticholinergic 24 hours
• Methylxanthines (theophyllines) 12 hours
• Slow release methylxanthines 24 hours
• Cromolyn sodium 8-12 hours
• Leukotriene modifiers 24 hours
• Inhaled steroids Maintain dosage

67
SPIROMETRY

• Before/After Bronchodilator
• Minimum of 10 minutes, up to 15 minutes, between
  administration and repeat testing is recommended
  (30 minutes for short-acting anticholinergic
  agents)
• FEV1, FVC, FEF25-75, PEF, SGaw are commonly
  made before and after bronchodilator
  administration

68
SPIROMETRY

• Before/After Bronchodilator
• Percentage of change is calculated
• Change Postdrug Predrug X 100
• Predrug

69
SPIROMETRY

• Before/After Bronchodilator
• FEV1 is the most commonly used test for
  quantifying bronchodilator response
• FEV1 should not be used to judge bronchodilation
  response
• SGaw may show a marked increase after
  bronchodilator therapy

70
SPIROMETRY

• Before/After Bronchodilator
• Significance and Pathophysiology
• Considered significant if
• FEV1 or FVC increase 12 and 200 ml
• SGaw increases 30 - 40

71
SPIROMETRY

• Before/After Bronchodilator
• Significance and Pathophysiology
• Diseases involving the bronchial (and
  bronchiolar) smooth muscle usually improve most
  from before to after
• Increase gt50 in FEV1 may occur in patients with
  asthma

72
SPIROMETRY

• Before/After Bronchodilator
• Significance and Pathophysiology
• Patients with chronic obstructive diseases may
  show little improvement in flows
• Inadequate drug deposition (poor inspiratory
  effort)
• Patient may respond to different drug
• Paradoxical response lt8 or 150 ml not
  significant

73
SPIROMETRY

• Maximal Inspiratory Pressure (MIP)
• The lowest pressure developed during a forceful
  inspiration against an occluded airway
• Primarily measures inspiratory muscle strength

74
SPIROMETRY

• MIP
• Usually measured at maximal expiration (residual
  volume)
• Can be measured at FRC
• Recorded as a negative number in
• cm H20 or mm Hg, e.g. (-60 cm H2O)

75
SPIROMETRY

• MIP

76
SPIROMETRY

• MIP
• Significance and Pathophysiology
• Healthy adults gt -60 cm H2O
• Decreased in patients with
• Neuromuscular disease
• Diseases involving the diaphragm, intercostal, or
  accessory muscles
• Hyperinflation (emphysema)

77
SPIROMETRY

• MIP
• Significance and Pathophysiology
• Sometimes used to measure response to respiratory
  muscle training
• Often used in the assessment of respiratory
  muscle function in patients who need ventilatory
  support

78
SPIROMETRY

• Maximal Expiratory Pressure (MEP)
• The highest pressure developed during a forceful
  exhalation against an occluded airway
• Dependent upon function of the abdominal muscles,
  accessory muscles of expiration, and elastic
  recoil of lung and thorax

79
SPIROMETRY

• MEP
• Usually measured at maximal inspiration (total
  lung capacity)
• Can be measured at FRC
• Recorded as a positive number in cm H20 or mm Hg

80
SPIROMETRY

• MIP and MEP

81
SPIROMETRY

• MEP
• Significance and Pathophysiology
• Healthy adults gt80 to 100 cm H2O
• Decreased in
• Neuromuscular disorders
• High cervical spine fractures
• Damage to nerves controlling abdominal and
  accessory muscles of inspiration

82
SPIROMETRY

• MEP
• Significance and Pathophysiology
• A low MEP is associated with inability to cough
• May complicate chronic bronchitis, cystic
  fibrosis, and other diseases that result in
  excessive mucus production

83
SPIROMETRY

• Airway Resistance (Raw)
• The drive pressure required to create a flow of
  air through a subjects airway
• Recorded in cm H2O/L/sec
• When related to lung volume at the time of
  measurement it is known as specific airway
  resistance (SRaw)

84
SPIROMETRY

• Raw
• Measured in a plethysmograph as the patient
  breathes through a pneumo-tachometer

85
SPIROMETRY

• Raw
• Criteria of Acceptability
• Mean of three or more acceptable efforts should
  be reported individual values should be within
  10 of mean

86
SPIROMETRY

• Airway Resistance (Raw)
• Normal Adult Values
• Raw 0.6 2.4 cm H2O/L/sec
• SRaw 0.190 0.667 cm H2O/L/sec/L

87
SPIROMETRY

• Airway Resistance (Raw)
• May be increased in
• Bronchospasm
• Inflammation
• Mucus secretion
• Airway collapse
• Lesions obstructing the larger airways
• Tumors, traumatic injuries, foreign bodies

88
SPIROMETRY

• Raw
• Significance and Pathology
• Increased in acute asthmatic episodes
• Increased in advanced emphysema because of airway
  narrowing and collapse
• Other obstructive disease, e.g., bronchitis may
  cause increase in Raw proportionate to the degree
  of obstruction in medium and small airways

89
SPIROMETRY

• Airway Conductance (Gaw)
• A measure of flow that is generated from the
  available drive pressure
• Recorded in L/sec/cm H2O
• Gaw is the inverse of Raw
• When related to lung volume at the time of
  measurement it is known as specific airway
  conductance (SGaw)

90
SPIROMETRY

• Gaw
• Measured in a plethysmograph as the patient
  breathes through a pneumo-tachometer

91
SPIROMETRY

• Gaw
• Criteria of Acceptability
• Mean of three or more acceptable efforts should
  be reported individual values should be within
  10 of mean

92
SPIROMETRY

• Airway Conductance (Gaw)
• Normal Adult Values
• Gaw 0.42 1.67 L/sec/cmH2O
• SGaw 0.15 0.20 L/sec/cm H2O/L

93
SPIROMETRY

• Airway Conductance (Gaw)
• Significance and Pathology
• SGaw Values lt0.15 0.20 L/sec/cm H2O/L are
  consistent with airway obstruction

94
Quiz Practice

• Most clinical laboratories consider two standard
  deviations from the mean as the normal range when
  determining predicted values since it includes
  95 of the normal population.
• False
• Only for those individuals with lung disease
• This applies only to cigarette smokers
• True

95
Quiz Practice

• Vital capacity is defined as which of the
  following?
• The volume of gas measured from a slow, complete
  exhalation after a maximal inspiration, without a
  forced effort
• The volume of gas measured from a rapid, complete
  exhalation after a rapid maximal inspiration
• The volume of gas measured after 3 seconds of a
  slow, complete exhalation
• The total volume of gas within the lungs after a
  maximal inhalation

96
Quiz Practice

• Which of the following statements are true
  regarding the acceptability criteria for vital
  capacity measurement?
• End-expiratory volume varies by less than 100 ml
  for three preceding breaths
• Volume plateau observed at maximal inspiration
  and expiration
• Three acceptable vital capacity maneuvers should
  be obtained volume within 150 ml
• Vital capacity should be within 150 ml of forced
  vital capacity in healthy individuals
• I, II, and IV
• II, III, and IV
• III and IV
• I, II, III, IV

97
Quiz Practice

• Which of the following best describes the Forced
  Vital Capacity (FVC) maneuver?
• The volume of gas measured from a slow, complete
  exhalation after a maximal inspiration, without a
  forced effort
• The volume of gas measured from a slow, complete
  exhalation after a rapid maximal inspiration
• The volume of gas measured after 3 seconds of a
  rapid, complete exhalation
• The maximum volume of gas that can be expired
  when the patient exhales as forcefully and
  rapidly as possible after maximal inspiration

98
Quiz Practice

• All of the following are true regarding the
  acceptability criteria of an FVC maneuver EXCEPT?
• Maximal effort, no cough or glottic closure
  during the first second no leaks of obstruction
  of the mouthpiece
• Good start of test back extrapolated volume less
  than 5 of the FVC or 150 ml
• Tracing shows a minimum of 3 seconds of
  exhalation
• Three acceptable spirograms obtained two largest
  FVC values within 150 ml two largest FEV1 values
  within 150 ml

99
Quiz Practice

• The FEV1 is the expired volume of the first
  second of the FVC maneuver.
• True
• False
• Only when done slowly
• Only when divided by the FVC

100
Quiz Practice

• Which of following statements is true regarding
  FEV1?
• FEV1 may be larger than the FVC
• FEV1 is always 75 of FVC
• May be reduced in obstructive and restrictive
  lung disease
• Is only reduced in restrictive disease

101
Quiz Practice

• The FEV1 is useful in distinguishing between
  obstructive and restrictive causes of reduced
  FEV1 values
• True
• False
• Only helps to distinguish obstructive lung
  disease
• Only helps to distinguish restrictive lung disease

102
Quiz Practice

• Which statements are true regarding the FEV 1,
  also known as the FEV1/FVC?
• A decreased FEV1/FVC is the hallmark of
  obstructive disease
• Patients with restrictive lung disease often have
  normal or increased FEV1/FVC ratios
• The presence of a restrictive disorder may be
  suggested by a reduced FVC and a normal or
  increased FEV1/FVC ratio
• A normal FEV1/FVC ratio is between 75 - 85
• I and II
• I, II and III
• II, III and IV
• I, II, III and IV

103
Quiz Practice

• What test is represented by the graph to the
  right?
• Forced Vital Capacity
• Flow-Volume Loop
• Slow Vital Capacity
• Total Lung Capacity Maneuver

104
Quiz Practice

• What type of pulmonary disorder is represented
  by the graph below?
• Obstructive lung disease
• Restrictive lung disease
• Upper airway obstruction
• Normal lung function
• (The dotted lines represent the predicted values)

105
Quiz Practice

• Which is true regarding Peak Expiratory Flow
  (PEF)?
• Primarily measures large airway function
• Is a recognized means of monitoring asthma
• Serial measurements of PEF are used a guide to
  treat asthma
• When less than 50 of personal best, it is an
  indication that immediate treatment is required
• I only
• II and III
• II, III, and IV
• I, II, III, and IV

106
Quiz Practice

• MVV is decreased in patients with which of the
  following disorders?
• Moderate to severe obstructive lung disease
• Weak or with decrease endurance
• Neurological defects
• Paralysis or nerve damage
• I and IV
• II and III
• III and IV
• I, II, III, and IV

107
Quiz Practice

• Spirometry before and after bronchodilator
  therapy is used to determine which of the
  following?
• Reversibility of airway obstruction
• The severity of restrictive disorders
• The rate at which CO diffuses through the lung
  into the blood
• If the patient has exercised induced asthma

108
Quiz Practice

• What is the minimum amount of time between
  administration of bronchodilator therapy and
  repeat pulmonary function testing?
• 5 minutes
• 10 minutes
• 30 minutes
• 60 minute

109
Quiz Practice

• Bronchodilation is considered significant when
  which of the following occurs?
• FEV1/FVC increases by 12
• SGaw increases by 12
• FVC and/or FEV1 increases by 12 and 150 ml
• DLco increases by 12

110
Quiz Practice

• Which of the following is true regarding Maximal
  Inspiratory Pressure (MIP)?
• Primarily measures inspiratory muscle strength
• Measures airway resistance during inspiration
• Is decreased in patients with neurological
  disease
• Often used in the assessment of respiratory
  muscle function in patients who need ventilatory
  support
• I, II, and III
• I, III, and IV
• II and III
• II, III, and IV

111
Quiz Practice

• Airway resistance (Raw) is the drive pressure
  required to create a flow of air through a
  subjects airway.
• True
• False
• Only in patients with COPD
• Only in patients with restrictive disorders

112
Quiz Practice

• Airway resistance may be increased in which of
  the following patients?
• Purely restrictive lung disorders
• Acute asthmatic episodes
• Mucus secretion
• Lung compliance changes
• I only
• I and IV
• II and III
• I, II, III, and IV

113
Quiz Practice

• Airway Conductance (Gaw) is a measure of flow
  that is generated from the available drive
  pressure.
• True
• False
• Only in patients with COPD
• Only in patients with restrictive disorders

114
Quiz Practice

• A patients pulmonary function tests reveal the
  following
• Actual Predicted Predicted
• FVC 4.01 L 4.97 L 81
• FEV1 2.58 L 3.67 L 56
• FEV1 51 gt75 _
• Select the correct interpretation
• Restrictive pattern
• Obstructive pattern
• Inconclusive
• Normal

115
Quiz Practice

• A patients pulmonary function tests reveal the
  following
• Actual Predicted Predicted
• FVC 3.75 L 4.97 L 75
• FEV1 2.80 L 3.67 L 76
• FEV1 75 gt/75 _
• Select the correct interpretation
• Restrictive pattern
• Obstructive pattern
• Inconclusive
• Normal