Pulmonary Function Testing

CRT 7? = 5%

RRT 4?

Which of the following are purposes of assessing pulmonary function?

I. Screen for pulmonary diseaseII. Evaluate patients for surgical riskIII. Assess the progression of diseaseIV.Assist in determining pulmonary disabilityV. Modify the therapeutic approach to patient

care

A. I, III, and IV B. III, IV, and V C. I, II, III, IV, and V D. II, IV, and V

Which of the following techniques are used to measure RV?

I. Helium dilutionII. Body plethysmographyIII. Nitrogen washoutIV.Flow-volume loops

A. II and IV B. I, II, and III C. I, II, III, and IV D. I, III, and IV

600 ml10% He

Helium Dilution Closed Method A known % of He is

diluted by the patient’s FRC. The change in the He% is used to determine FRC

Nitrogen Washout, Open Method The FRC is washed out of the lung by having the

patient inspire 100% O2 to replace the N2 from the FRC. The amount of N2 removed is used to calculate FRC

Boyle’s Law to TGV Patient pants at FRC

while pressures and volumes are obtained

Raw can be determined by measuring changes in pressure vs. flow 0.6 – 2.4 cmH2O/L/sec

Compliance can be determined by measuring the volume change per unit pressure change 60 – 100 mL/cmH2O

Plethysmography Body Box

During a helium dilution test for FRC, you notice that it takes 19 minutes for equilibration between the gas concentrations in the spirometer and the patient's lungs. Based on this information, what can you conclude?

A.The patient has restrictive lung disease. B.The spirometer is leaking helium. C.The patient has obstructive lung disease. D.Insufficient oxygen was added to the system.

What is the gas normally employed to measure the diffusing capacity of the lung?

A.O2 B.CO C.CO2 D.He

Gas Diffusion (DLCO)Carbon monoxide diffusion capacity Evaluates diffusion across the A-C membrane Patient inhales a VC breath of gas containing

a known amount of CO. Breath hold for 10 sec. Exhaled gas is analyzed. Normal 25 mLCO/min/mmHg emphysema, pulmonary fibrosis,

sarcoidosis, edema, O2 toxicity

On a patient undergoing testing in the pulmonary function laboratory, you observe a "box–shaped" flow–volume loop with equal reductions in inspiratory and expiratory flows. What does this most likely indicate?

A.Fixed upper airway obstruction B.Variable extrathoracic airway obstruction C.Variable intrathoracic airway obstruction D.Chronic obstructive pulmonary disease

Flow volume loop from a healthy subject

Obstructive airway disease

Severe obstructive disease

Restrictive lung disease

Fixed major airway obstruction

Fixed upper-airway obstruction (intrathoracic or extrathoracic).

Variable extrathoracic obstruction.

Variable intrathoracic obstruction.

What time period is generally used to measure MVV?

A.6 to 8 seconds B.12 to 15 seconds C.30 to 40 seconds D.40 to 60 seconds

Maximum Voluntary Ventilation: tests the ability of the patients chest muscles to expand and contract

Pt breaths in and out as fast as possible Normal 170 L/min Decreased in

Obstructive dz Increased Raw Muscle weakness Decreased

compliance poor patient effort

The best way to check the accuracy of a water-seal spirometer is to use a

A.3-L syringe.

B.pneumotachometer.

C.vortex sensor.

D.Wright respirometer.

Calibration

Volume: 3 L syringe Flow: rotometer Timing devices: stopwatch Plethysmograph

Rotometer for flow Barometer for pressure

After a resting expiration, air still remains in the lungs. What is this volume called?

A.FRC B.VC C.RV D.ERV

Know your lung volumes and capacities!

3500 ml3000 ml

1000 ml

2500 ml

1500 ml

4500 ml

Memorize numbers from Persing.

Egan fig. 17-1

During each cycle of normal quiet breathing, a volume of gas is moved into and out of the lungs. What is this cyclical volume called?

A.IRV B.Tidal volume (VT) C.ERV D.Vital capacity (VC)

Which of the following volumes or capacities cannot be measured by simple spirometry?

I. Functional residual capacity ( FRC)II. Expiratory reserve volume ( ERV)III. Residual volume (RV)IV.Inspiratory reserve volume ( IRV)

A. I, III, and IV B. I, II, III, and IV C. I and III D. I and IV

Egan fig. 17-1

Which of the following is equal to total lung capacity (TLC)?

A.VT + ERV + IRV + RV B.IC + VT + ERV C.VC + ERV D.FRC + IRV

Egan fig. 17-1

A patient has a VC of 4200 ml, an FRC of 3,300 mL and an ERV of 1500 ml. What is the RV?

A.5700 ml B.2700 ml C.1800 ml D.7500 ml

Egan fig. 17-1

Which of the following is a true statement? A.VC = FRC + VT B.VC = IRV + VT + ERV C.VC = VT + IRV + RV D.FRC = VT + ERV

Egan fig. 17-1

What is the amount of gas that can be inhaled over and above that which is normally inhaled during quiet breathing?

A.FRC B.ERV C.IRV D.VC

Egan fig. 17-1

After the most strenuous expiratory effort, air still remains in the lungs and cannot be removed voluntarily. What is this volume called?

A.IRV B.RV C.ER D.FRC

Egan fig. 17-1

What is the amount of gas that can be exhaled below the resting expiratory level?

A.ERV B.RV C.FRC D.VC

Egan fig. 17-1

Which of the following is the maximum amount of air that can be exhaled from the maximum inspiratory level?

A.vital capacityB.residual volumeC.functional residual capacityD.expiratory reserve volume

Egan fig. 17-1

How can you ensure reliability when measuring the ERV?

A.Have the patient perform the maneuver twice, assure consistency, then take best value.

B.Have the patient perform the maneuver 3 times, then take the last value.

C.Have the patient perform the maneuver twice, assure consistency, then take mean value.

D.Have the patient perform the maneuver until they become fatigued, then take the last value.

A patient has an expired minute ventilation of 14.2 L and a ventilatory rate of 25/min. What is the average VT?

A.568 ml B.635 ml C.725 ml D.410 ml

The respiratory therapist instructed a patient to take a deep breath and then exhale as quickly as possible. The therapist observed a recording of the fastest air movement. Which of the following was measured?

A. peak flow

B. vital capacity

C. FEV 1

D. FEF 25-75%

A patient has a prebronchodilator peak expiratory flow rate (PEFR) of 4.5 L/sec. The postbronchodilator value is 5.0 L/sec. What is the percent change?

A.11 B.22 C.33 D.50

Peak Flow

Normal 400 – 600 L/min 6.5 – 10 L/sec

Percent Change Post – Pre x 100

Pre Percent Predicted

Actual x 100

Predicted

Which of the following is being measured if a respiratory care practitioner instructs a patient to take a maximum deep breath and then exhale as much and as fast as possible?

A.RV B.VC C.TLC D.FVC

Egan fig. 17-5

FVC = volume Restrictive Obstructive

FVC with Normal SVC

FEVtime = flow Restrictive Obstructive So look at FEV1/FVC%

FEV1/FVC % Normal in Restrictive Obstructive

60%

75%

94%

97%

A patient has a predicted FEV1 of 4.2 L and a measure FEV1 of 3.5 L. What is the predicted FEV1 in percent?

A.76 B.83 C.92 D.120

A patient with chronic obstructive pulmonary disease (COPD) has a normal slow vital capacity (SVC) of 3400 ml and an FVC of 2300 ml. Which of the following mechanisms best explains this difference?

A.Airway trapping during forced expiration B.Muscle fatigue during forced expiration C.Decreased compliance during forced

expiration D.Poor instruction by the pulmonary technologist

Compared to predicted normals, a patient has an increased RV and a decreased percent FEV1/FVC. Test results are repeatable. Which of the following is most likely the underlying problem?

A.Generalized obstruction with air trapping B.Poor patient effort during the test C.Restrictive disorder of the lungs D.Combined restrictive and obstructive disease

Compared to predicted normals, a patient has a reduced TLC and a decreased percent FEV1/FVC. Test results are repeatable. Which of the following is most likely the underlying problem?

A.Poor patient effort during the test procedure B.Restrictive disorder of the lungs or chest wall C.Combined restrictive and obstructive disease D.Peripheral (small) airway obstruction

What is the term for the standard measure of the average expiratory flow during the middle portion of an FVC maneuver?

A.FEV1 B.FEF200-1200 C.PEFR D.FEF25%-75%

Egan fig. 17-8

FEF 25% - 75% Decreased in

early obstructive disease

Associated with small (peripheral) airway obstruction

Typically 5 L/sec

Compared to predicted normals, a patient has a normal percent FEV1/FVC, but a reduced FEF25%-75%. Test results are repeatable. Which of the following is most likely the underlying problem?

A.Combined restrictive and obstructive disease B.A restrictive disorder of the chest wall C.Severe central (large) airway obstruction D.Peripheral (small) airway obstruction

Compared to predicted normals, a patient has a normal percent FEV1/FVC, normal FEF25%-75%, but a markedly reduced FVC. Test results are repeatable. Which of the following is most likely the underlying problem?

A.Poor patient effort during the test procedure B.Combined restrictive and obstructive disease C.A restrictive disorder of the lungs or chest wall D.Severe central (large) airway obstruction

What is the term for the standard measure of the average expiratory flow during the first 1000 mL after 200 mL is expired?

A.FEV1 B.FEF200-1200 C.PEFR D.FEF25%-75%

Egan fig. 17-7

FEF 200-1200 Decreased in large

airway obstruction Typically = 8 L/sec

For you to characterize a patient as having a mild impairment on a measured pulmonary function parameter, it should fall within what range of the predicted value?

A.80% to 120% B.80% to 100%C.60% to 79%D.40% to 59%

What conclusions can you draw from the following data, obtained on a 32-year-old 53 kg woman admitted for elective surgery?

ACTUALPRED %PRED | ACTUALPRED %PREDTLC 4.93 5.27 94% |FVC 3.67 3.86 95%FRC 2.41 2.43 99% |FEV1% 84% 75%RV 1.29 1.35 96% |FEF200–1200 5.66 5.74 99%VC 3.64 3.86 94% |FEF 25%–75% 3.53 3.49 101%

A.Results indicate a mild restrictive lung disorder. B.Results indicate normal pulmonary function. C.Results indicate a combined disease process. D.Results indicate generalized airway

obstruction.

What conclusions can you draw from the following data, obtained on a 67-year-old 76 kg man admitted for pulmonary complications arising from silicosis?

A. Results indicate generalized airway obstruction. B. Results indicate normal pulmonary function. C. Results indicate a combined disease process. D. Results indicate a restrictive lung disorder.

Actual Predicted % Predicted

TLC 4.34 7.73 56%

FRC 1.73 4.36 40%

RV 1.45 2.63 55%

VC 2.89 4.74 61%

FVC 2.86 4.74 60%

FEV1 96% 75%

FEF 200-1200 6.89 6.71 103%

FEF 25%-75% 2.78 2.88 96%

What conclusions can you draw from the following data, obtained from a 41-year-old man who admits to "occasional smoking" but otherwise reveals no past history of pulmonary problems?

A. Results indicate small airway obstruction. B. Results indicate generalized airway obstruction. C. Results indicate a restrictive lung disorder. D. Results indicate a combined disease process.

Actual Predicted % Predicted

TLC 4.75 4.90 97&

FRC 2.31 2.21 105%

RV 1.28 1.20 106%

VC 3.48 3.63 96%

FVC 2.96 3.63 82%

FEV1 80% 75%

FEF 200-1200 4.33 5.45 82%

FEF 25%-75% 1.95 3.37 58%

The following pulmonary function results are obtained for patient:                      

Predicted   Observed  % Predicted

Which of the following is the most likely conclusion?

A.severe obstructive pattern

B.severe restrictive pattern

C.mild obstructive pattern

D.mild restrictive pattern

The information below was obtained from the pulmonary function report for a40-year-old male who weighs 73 kg (161 lb) and is 177 cm (5 ft 9 in) tall:There is no significant response to the bronchodilator. These data most strongly suggest

A.interstitial fibrosis.

B.emphysema.

C.chronic bronchitis.

D.cystic fibrosis.

Spirometry testing reveals results below: With which of the following are these values the most consistent?

A. acute asthma

B. normal lung function

C. small airway obstruction

D. pulmonary fibrosis

A patient has the pulmonary function results shown below: Which of the following is the most appropriate interpretation of these results?

A.bronchitis

B.restrictive disease only

C.obstructive disease only

D.mixed restrictive and obstructive disease

The End

Three liters of air are injected into a water-seal spirometer from a certified-volume standard syringe. The observed tracing shows 2.6 L. Which of the following should the respiratory therapist conclude about the disparity? A. The plunger was pushed too slowly. B. The difference is within the acceptable error range. C. The time scale was incorrectly calibrated. D. There was a leak in the system. EXPLANATIONS: (u) A. The flow of gas into the spirometer should not affect the accuracy of its volume. (u) B. This is outside the 10% acceptable error range. (u) C. The volume deflection is unaffected by the time scale. (c) D. A leak is the likely cause for the difference of 400 mL and is one of the reasons for checking spirometers with a calibrated syringe.