PFT-SAS-3 Pulmonary Function Testing PDF

RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Sc...

RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Lesson title: Materials: FORCED VITAL CAPACITY MANUEVER, LOW DENSITY GAS SPIROMETRY, Pen, paper, index card, book, PEAK EXPIRATORY FLOW MONITORING References: Learning Targets: Pulmonary Function Testing and Cardiopulmonary At the end of the module, students will be able to: Testing (Second Edition), Vincent Madama, M.Ed, 1. Describe the measurement and assessment of a forced vital RRT capacity maneuver and its component, 2. Describe the measurement and assessment of a low density gas spirometry. 3. Describe the measurement and assessment of a peak expiratory flow monitoring A. LESSON PREVIEW/REVIEW Introduction Hello, PHINMA Ed students! Welcome to RET 01: Pulmonary Function Testing. In today’s session, you are tasked to set expectations as you get oriented with what the subject is all about and to determine the nature of flexible learning. Before we begin with the formal course orientation, let’s pause and reflect by briefly answering the questions below: B.MAIN LESSON FORCED VITAL CAPACITY MANUEVER The forced vital capacity maneuver is the most frequently used method for assessing dynamic pulmonary function. Table 2- 1provides the definition for an FVC maneuver. It is evaluated on the basis of both volume and flow rates measured from the maneuver. A PFM or PVM spirometer may either be used. TEST ADMINISTRATION The usefulness of a dynamic measurement such as FVC depends primarily on the subject’s understanding, cooperation, and effort. Instructions should be given before starting the procedure. An active demonstration of the breathing maneuver by the technologist is recommended. During the procedure, appropriate and directive coaching is needed. The subject must be strongly encouraged to perform a maximal inspiration and to continue inspiratory effort at full total lung capacity This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ (TLC) level for one or two seconds. A maximally forceful and complete expiration to the residual volume (RV) level should then be performed. According to the ATS recommendations, the subject’s forced expiration should be continued for a minimum of six seconds unless there is an obvious volume plateau demonstrated on the volume/time curve. After the forced expiratory maneuver is performed, some measuring systems require that the subject perform a maximally forceful inspiration back to TLC level. This last inspiration provides a full flow/volume loop graph for analysis. This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ CRITERIA FOR FVC TEST ACCEPTABILITY Relating to the start of expiratory effort – o No excessive subject hesitation or false start by the subject. o Not a back-extrapolated volume exceeding 5% of the FVC volume or 0.15 litre, whichever is greater. Relating to end of the expiratory effort – o No expiratory maneuver performed for less than six seconds unless a volume plateau is present on the volume/time curve display. Relating to the presence of artifacts during the maneuver – o No cough during the first second of the maneuver (affecting FEV1) or that, in the technologists opinion, interferes the accuracy of the test results. o No valsalva maneuver performed before or during the forced expiration. o No variable effort demonstrated by the subject during the maneuver. o No volume loss because of leak in the system. o No obstruction of the spirometer mouthpiece. o No premature termination of forced expiration This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ CRITERIA FOR FVC TEST REPRODUCIBILITY After the first three acceptable tests have been recorded, tests are reproducible and testing may be ended if both of the following are true: o The two largest FVC values are within 0.2 liter of each other. o The two largest FEV1 values are within 0.2 liter of each other. If both of these criteria are not met, testing must continue until o Both criteria are met with the performance of additional acceptable test maneuvers. o A total of eight tests have been performed. o The patient cannot or should not continue. At the minimum, the best three maneuvers should be saved. Pulmonary function studies should be evaluated in conjunction with data from the subject’s history, physical examination, and other types of clinical assessment. Interpretation of the test results from a FVC maneuver is based on analysis of a number of factors. Included is evaluation of the volume and the flow-rate components. VOLUME/TIME CURVE (Picture A) Interpretive Significance of FVC and its Components This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Parameter General Significance FVC Relates directly to changes in VC from volume spirometry. PEFR Relates to flow rates and disorders in the large, upper airways. Also used to monitor asthma and bronchodilator therapy. FEV 0.5, FEV1, Relate to flow rates and disorders FEF 200-1000 in the large, upper airways. May be relatively effort-dependent. FEF2, FEF25%- Relate to flow rates and disorders 75% in smaller bronchi and larger bronchioles. FEV3, FEF Relate to flow rates and disorders 75%-85% in smaller bronchioles, FEVt% Relates to both flow rates and lung volumes. Generally, opposite results are demonstrated between restrictive and obstructive disorders. This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ The volume/time curve resulting from an FVC maneuver is traced or plotted with volume indicated FEFx% Relates most significantly to flow on the vertical axis and time on the horizontal axis. rates and disorders in the large Steeper or more vertical lines produce a larger value upper airways. for slope and indicate faster rates of Forced Expiratory Flow (FEF) and Forced Inspiratory Flow (FIF). The Peak Expiratory Flow Rate (PEFR) can be determined from a volume/time tracing. It is based on a line drawn tangent to the steepest part of the curve. PEFR is an extremely effort-dependent parameter, and low or inconsistent values may be due to insufficient subject effort. In other words, PEFR values can indicate the quality and/or reproducibility of subject effor FLOW/VOLUME LOOP (Picture B) The flow/volume loop is plotted with flow indicated on the vertical axis and volume on the horizontal axis. It is possible to plot both a maximum expiratory flow/volume (MEFV) curve and a maximum inspiratory flow/volume (MIFV) curve. Most spirometer systems allow for plotting of both and produce a complete flow/volume loop. Flow/volume loops are beneficial for a number of reasons. They allow for inspiratory and expiratory peak flow rates to be read directly from the graph. This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Restrictive Disorders Obstructive Disorders PULMONARY LARGE AIRWAY OBSTRUCTION Interstitial Fibrosis Tracheal Stenosis Vascular Congestion Large Substernal Goiter Pneumoconioses Tracheal Carcinoma Sarcoidosis Laryngeal Carcinoma EXTRAPULMONARY SMALL AIRWAY OBSTRUCTION Kyphoscoliosis Bronchial Rheumatoid Asthma Spondylitis Emphysema Ascites Chronic Peritonitis Bronchitis Bronchiectasis Severe Obesity This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Poliomyelitis Cystic Fibrosis Myasthenia Gravis ANALYSIS OF FLOW/VOLUME LOOP The flow/volume loop has proved a valuable tool in demonstrating pulmonary disorders. It provides a simple graphic representation of the parameters measured with forced expiratory and inspiratory VC maneuvers. More significantly, it also demonstrates a very characteristic shape in certain disorders This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ With a restrictive disorder, the primary change is a decrease in volume. The entire loop is displaced downward to a lower lung volume. In small airway obstruction, the latter portion of the expiratory loop begins to take on a concave appearance the entire loop is displaced to a higher lung volume. Fixed large airway obstruction causes relatively equal decreases in both inspiratory and expiratory flow rates. Intrathoracic variable large airway obstruction causes a flattening of the expiratory portion of the flow/volume loop caused by the limitation of the expiratory flows. Extrathoracic variable large airway obstruction causes a flow limitation on inspiration, with a characteristic of flattening of the flow/volume loop’s inspiratory portion. LOW DENSITY GAS SPIROMETRY Low-density spirometry involves measuring an FVC maneuver after the subject has breathed a helium/oxygen (80% He/20% O2) mixture. Analysis is based on a flow/volume curve derived from the maneuver. This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ This curve is then compared to a curve derived from a standard FVC maneuver. The comparison can serve as a sensitive method for detecting the early stages of small airway disease. It may also help to differentiate the site of an obstruction between larger versus smaller airways. The standard and He/O2 loops selected for comparison must demonstrate FVC volumes within 2.5%-5% of being the same. The loops may be superimposed at either RV or TLC. PEAK EXPiRATORY FLOW MONITORING Generally consists of using a portable, hand-held peak flow meter to evaluate periodically a subject’s peak flow capabilities. Often used in monitoring asthma patients and their management with bronchodilators. Done by having the subject perform a maximal inspiration followed by a short, maximally forceful expiration through the PEFR monitoring device. Pediatric PEFR meter measurements typically range from 60 l/min to 100 l/min. Adult PEFR meter measurements typically range from 100 l/min to 850 l/min. Adult subjects can generally produce peak expiratory flow rates of 400-600 l/min. young adults may generate PEFRs greater than 600 l/min. Clinically, decreased PEFR values are most specifically related to obstruction of the large upper airways. However the reduction in PEFR is not specific as to where the site of obstruction may be. This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Check for Understanding 1. Which of the following is not a criteria for FVC test acceptability? a. No valsalva maneuver performed before or during the forced expiration. b. No premature termination of forced expiration. c. No volume loss because of leak in the system. d. Not a back-extrapolated volume exceeding 15% or 0.5 L of the FVC volume. 2. What component of FVC relates to flow rates and disorders in smaller bronchi and larger bronchioles? a. FEF 75%-85% b. FEF 25%-75% c. FEF 200-1200 d. FEF 15%-25% 3. What happens to the total lung capacity (TLC) of a patient with restrictive disorder? a. Increases b. Decreases c. Stays normal d. Both A or C 4. What type of pulmonary disorder shows flattening of the flow/volume loop’s inspiratory portion? a. Small airway obstruction b. Restrictive disorder c. Intrathoracic variable large airway obstruction d. Extrathoracic variable large airway obstruction 5. In a He/O2 mixture that is used for low density gas spirometry, how many percent of O2 is in the mixture? a. 80% b. 20% c. 21% d. 60% 6. Which of the following disorders causes the latter portion of expiratory portion of the flow/volume loop to take a concave appearance? a. Kyphoscoliosis b. Tracheostenosis c. Sarcoidosis d. Chronic Bronchitis 7. Which component of FVC relates to flow rates and disorders in the large upper airways? a. FVC b. FEF c. MIP d. PEFR 8. Can a forced vital capacity maneuver diagnose restrictive lung disorders? a. Yes b. No c. Maybe This document is the property of PHINMA EDUCATION  RET 01: Pulmonary Function Testing Module #3 Student Activity Sheet Name: _________________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ d. Both yes and no 9. What happens to the total lung capacity (TLC) of a patient with emphysema? a. Decrease b. Normal or decreases c. Normal or increases d. Both A and B 10. When doing a peak expiratory flow monitoring, what value should be reported? a. The first value recorded b. The largest value recorded c. Any of the values recorded d. The average value recorded C. LESSON WRAP-UP FORCED VITAL CAPACITY MANUEVER The forced vital capacity maneuver is the most frequently used method for assessing dynamic pulmonary function. Table 2- 1provides the definition for an FVC maneuver. It is evaluated on the basis of both volume and flow rates measured from the maneuver. A PFM or PVM spirometer may either be used. TEST ADMINISTRATION The usefulness of a dynamic measurement such as FVC depends primarily on the subject’s understanding, cooperation, and effort. Instructions should be given before starting the procedure. An active demonstration of the breathing maneuver by the technologist is recommended. During the procedure, appropriate and directive coaching is needed. The subject must be strongly encouraged to perform a maximal inspiration and to continue inspiratory effort at full total lung capacity This document is the property of PHINMA EDUCATION