Pulmonary Function Testing CRT 7? = 5% RRT 4?

Which of the following are purposes of assessing pulmonary function? Screen for pulmonary disease Evaluate patients for surgical risk Assess the progression of disease Assist in determining pulmonary disability Modify the therapeutic approach to patient care I, III, and IV III, IV, and V I, II, III, IV, and V II, IV, and V

Which of the following techniques are used to measure RV? Helium dilution Body plethysmography Nitrogen washout Flow-volume loops II and IV I, II, and III I, II, III, and IV I, III, and IV

Helium Dilution Closed Method 600 ml 10% 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

Patient pants at FRC while pressures and volumes are obtained 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? The patient has restrictive lung disease. The spirometer is leaking helium. The patient has obstructive lung disease. Insufficient oxygen was added to the system.

What is the gas normally employed to measure the diffusing capacity of the lung? CO CO2 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? Fixed upper airway obstruction Variable extrathoracic airway obstruction Variable intrathoracic airway obstruction Chronic obstructive pulmonary disease

Severe obstructive disease Flow volume loop from a healthy subject Obstructive airway disease Fixed major airway obstruction Restrictive lung disease

Fixed upper-airway obstruction (intrathoracic or extrathoracic). Variable extrathoracic obstruction. Variable intrathoracic obstruction.

What time period is generally used to measure MVV? 6 to 8 seconds 12 to 15 seconds 30 to 40 seconds 40 to 60 seconds

Pt breaths in and out as fast as possible 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. EXPLANATIONS: (c) A. A 3-L syringe is the only piece of equipment that provides accurate volumes for calibration. (u) B. A pneumotachometer measures flow and does not directly measure volume. (u) C. A vortex sensor spirometer measures flow integrated with time and is not sufficiently accurate for calibration. (u) D. A Wright respirometer is not sufficiently accurate to be used as a volume standard.

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

Know your lung volumes and capacities! 3000 ml 3500 ml 4500 ml 1000 ml 2500 ml 1500 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? IRV Tidal volume (VT) ERV Vital capacity (VC)

Which of the following volumes or capacities cannot be measured by simple spirometry? Functional residual capacity ( FRC) Expiratory reserve volume ( ERV) Residual volume (RV) Inspiratory reserve volume ( IRV) I, III, and IV I, II, III, and IV I and III I and IV

Egan fig. 17-1

Which of the following is equal to total lung capacity (TLC)? VT + ERV + IRV + RV IC + VT + ERV VC + ERV 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?

Egan fig. 17-1

Which of the following is a true statement? VC = FRC + VT VC = IRV + VT + ERV VC = VT + IRV + RV 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? FRC ERV IRV 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? IRV RV ER FRC

Egan fig. 17-1

What is the amount of gas that can be exhaled below the resting expiratory level? ERV RV FRC VC

Egan fig. 17-1

C.functional residual capacity D.expiratory reserve volume Which of the following is the maximum amount of air that can be exhaled from the maximum inspiratory level? A.vital capacity B.residual volume C.functional residual capacity D.expiratory reserve volume EXPLANATIONS: (c) A. Vital capacity is the maximum volume exhaled after a maximum inhalation. (u) B. Residual volume is the volume remaining in the lungs and airways after maximum exhalation. (u) C. Functional residual capacity is the volume of gas remaining in the lungs and airways at the end of a resting tidal exhalation. (u) D. Expiratory reserve volume is the maximum volume of air that can be exhaled from the end tidal volume.

Egan fig. 17-1

How can you ensure reliability when measuring the ERV? Have the patient perform the maneuver twice, assure consistency, then take best value. Have the patient perform the maneuver 3 times, then take the last value. Have the patient perform the maneuver twice, assure consistency, then take mean value. Have the patient perform the maneuver until they become fatigued, then take the last value.

A patient has an expired minute ventilation of 14 A patient has an expired minute ventilation of 14.2 L and a ventilatory rate of 25/min. What is the average VT? 568 ml 635 ml 725 ml 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% EXPLANATIONS: (c) A. Peak flow is the maximum flow during a forced expiratory maneuver. (u) B. Vital capacity is the volume exhaled during this maneuver. (u) C. FEV 1 is the volume exhaled in the first second of this breath. (u) D. FEF 25-75% is the average flow through the mid 50% of this breath, not a peak flow.

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? 11 22 33 50

Peak Flow Normal Percent Change Percent Predicted 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? RV VC TLC FVC

Egan fig. 17-5 FVC = volume FEVtime = flow FEV1/FVC % 97% 75% 60% 94%  Restrictive Obstructive  FVC with Normal SVC FEVtime = flow  Obstructive So look at FEV1/FVC% FEV1/FVC % Normal in Restrictive 97% 75% 60% 94% Egan fig. 17-5

A patient has a predicted FEV1 of 4. 2 L and a measure FEV1 of 3. 5 L 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? 76 83 92 120

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? Airway trapping during forced expiration Muscle fatigue during forced expiration Decreased compliance during forced expiration 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? Generalized obstruction with air trapping Poor patient effort during the test Restrictive disorder of the lungs 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? Poor patient effort during the test procedure Restrictive disorder of the lungs or chest wall Combined restrictive and obstructive disease 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? FEV1 FEF200-1200 PEFR FEF25%-75%

Egan fig. 17-8 FEF 25% - 75% Decreased in early obstructive disease Associated with small (peripheral) airway obstruction Typically 5 L/sec Egan fig. 17-8

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? Combined restrictive and obstructive disease A restrictive disorder of the chest wall Severe central (large) airway obstruction 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? Poor patient effort during the test procedure Combined restrictive and obstructive disease A restrictive disorder of the lungs or chest wall 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? FEV1 FEF200-1200 PEFR FEF25%-75%

Egan fig. 17-7 FEF 200-1200 Decreased in large airway obstruction Typically = 8 L/sec Egan fig. 17-7

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? 80% to 120% 80% to 100% 60% to 79% 40% to 59%

Results indicate a mild restrictive lung disorder. What conclusions can you draw from the following data, obtained on a 32-year-old 53 kg woman admitted for elective surgery? ACTUAL PRED %PRED | ACTUAL PRED %PRED TLC 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% Results indicate a mild restrictive lung disorder. Results indicate normal pulmonary function. Results indicate a combined disease process. Results indicate generalized airway obstruction.

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? Results indicate generalized airway obstruction. Results indicate normal pulmonary function. Results indicate a combined disease process. 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 60% FEV1 96% 75% FEF 200-1200 6.89 6.71 103% FEF 25%-75% 2.78 2.88

Results indicate small airway obstruction. 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? Results indicate small airway obstruction. Results indicate generalized airway obstruction. Results indicate a restrictive lung disorder. 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 82% FEV1 80% 75% FEF 200-1200 4.33 5.45 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 EXPLANATIONS: (c) A. The significantly decreased FEV1, FEV1/FVC%, and FEF25-75% indicate severe obstruction. (u) B. Although the FVC is reduced, the TLC is actually 1.1 L larger than expected. (u) C. Mild obstruction is characterized by smaller decreased flows and an FEV1/FVC ratio in the range of 60-70%. (u) D. Although the FVC is markedly reduced, the TLC is increased by 1.1 L.

A.interstitial fibrosis. B.emphysema. C.chronic bronchitis. The information below was obtained from the pulmonary function report for a 40-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. EXPLANATIONS: (c) A. Reduced vital capacity suggests restrictive defect. Reduced diffusing capacity and lack of obstruction make this the most likely diagnosis. (u) B. The FEV1/FVC of 90% does not indicate an obstructive component, which may rule out emphysema, even though FVC and DLCO may be reduced with emphysema. (u) C. Individuals with chronic bronchitis usually have an obstructive defect characterized by a reduced FEV1/FVC and a response to bronchodilator therapy. Chronic bronchitis does not cause a reduction in diffusing capacity. (u) D. Although individuals with cystic fibrosis may have a reduced vital capacity and DLCO, the FEV1/FVC ratio of 90% is inconsistent with this diagnosis.

C. small airway obstruction D. pulmonary 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 EXPLANATIONS: (u) A. During an acute asthma episode, pulmonary function results are consistent with an obstructive defect. (c) B. These results are within normal limits. (u) C. In small airway obstruction, the FEF 25-75% is typically less than 70% of predicted. (u) D. With a diagnosis of pulmonary fibrosis, pulmonary function results are consistent with a restrictive defect.

B.restrictive disease only C.obstructive disease only 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 EXPLANATIONS: (u) A. Bronchitis is usually associated with an obstructive pulmonary function pattern and does not cause a decrease in total lung capacity. (c) B. These values are consistent with a restrictive pattern only. Lung volumes are reduced. Peak flow and MVV are normal or better. FEV1/FVC is normal. (u) C. The decreased VC and TLC indicate restrictive disease. FEV1/FVC is normal, not reduced as in obstructive disease. (u) D. The flow values are not consistent with an obstructive disease component.

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.