You Take My Breath Away. Student Information Page 5C Part 1

Transcription

1 You Take My Breath Away Student Information Page 5C Part 1 Students with asthma or other respiratory problems should not participate in this activity because it involves repeated maximal inhalations and exhalations which could leave the students short of breath or, possibly, trigger an asthmatic episode. Activity Background: In the previous activity, You Really Are Full of Hot Air!, you learned just how much hot, humid air your lungs can normally hold and explored some variables that might affect lung volumes such as age, height, and gender. Lung volumes are also affected by the presence or absence of lung diseases. Some of these diseases, such as asthma, are seen in both young people and adults while others are primarily seen in older individuals with a history of smoking or jobs that expose them to harmful fumes and dust particles. Whatever the circumstances people with lung disorders are all too familiar with the phrase, You Take My Breath Away, because their condition robs them of the breath most of us take for granted. Activity Background: Through this activity you explore some lung conditions from the perspective of both the doctor and the patient by first simulating diseases and then interpreting the test results to formulate a preliminary diagnosis. Before beginning this activity you should first review the vocabulary introduced in You Really Are Full of Hot Air! then become familiar with the new lung function terms outlined below: Forced Vital Capacity (FVC) the largest volume of air that can be expired when exhaling forcefully after a maximal inhalation Forced Expiratory Volume in One Second (FEV 1 ) the volume of air expired in the first second of a forced exhalation after a maximal inhalation FEV 1 /FVC(%) the ratio, or percent, of FVC represented by FEV 1 (FEV 1 /FVC X 100) Predicted Normal Values A set of values describing normal lung function measurements by age and height (in cm). These values are created using data collected from thousands of people, children and adults, with normal, healthy lung function %Predicted the ratio, or percent, of the predicted value represented by the measured value (measured value/predicted value X 100) 2006 The University of Texas Health Science Center at San Antonio 18

2 Activity Background: All materials listed require one per group unless otherwise noted. Lung Volume Bag or spirometer Disposable mouthpieces one for each group member #3 or 4 rubber stopper; one hole Ace bandage Calculator Thermometer (for measuring room temperature) Stopwatch (for measuring FEV1) BTPS conversion table Predicted Normal Values tables You Take My Breath Away Lung Disease Decision Tree Lab procedures and record sheet one per student Nose clip one for each group member (Some nose clips can be cleaned in the dishwasher and re-used if one is available at the school, so be sure to check the package information insert) Activity Instructions: 1. For this activity you will work in groups of three. Assign each group member a letter designation of Student A, Student B, or Student C. 2. Record each person s age in the appropriate column on Data Table 1 Age and Height Measurements in Part 1 of the Student Data Page. 3. Using the Height Station provided by the teacher, measure the height (in cm) of each group member. Record in Data Table 1 on your Student Data Page. Standing height is the most important predictor of lung function so be sure to make this measurement as accurately as possible following the instructions posted at the station The University of Texas Health Science Center at San Antonio 19

3 4. Using the thermometer find the room temperature in o C and record this temperature on Data Table 1 on your Student Data Page. Look up the conversion factor for this temperature on the BTPS Conversion Chart below and record on Data Table 1 in Part 1 of the Student Data Page. This is the conversion factor you will use to find the corrected lung volumes for all measurements. BTPS Conversion Chart Room Temperature o C BTPS Factor Assumes a barometric pressure of 760mmHg Chart adapted from Pocket Guide to Spirometry by David P. Johns and Rob Pierce; McGraw-Hill, San Francisco; The University of Texas Health Science Center at San Antonio 20

4 5. Using the Predicted Normal Values tables provided by your teacher, determine the predicted values for FVC, FEV 1 and FEV 1 /FVC(%) for each group member and record in the appropriate column on Data Tables 2, 3, and 4 on your Student Data Page, Part Review the procedures for making the lung measurements then gather the materials required. 7. Remember accurate lung volume measurements require that procedures be followed carefully and consistently so be sure to thoroughly familiarize yourself with the techniques described. 8. Please note that these measurements are similar to those you learned in You Really Are Full of Hot Air! but they all require maximal inhalation followed by forced exhalation, meaning that you should breathe in as much air as possible and then exhale into the lung volume bag as forcefully as you can. 9. Distribute a disposable mouthpiece and nose clip to each group member. Mark your mouthpiece with your designation (Student A, B or C). Give the one-holed rubber stopper to Student A and the Ace bandage to Student B. Student C will use only the disposable mouthpiece. 10. Begin the lung function tests with Student A. Place the rubber stopper in one end of the disposable mouthpiece and then place the mouthpiece in the plastic extension tube on the lung volume bag. Student A will make all lung function measurements with this rubber stopper in place. 11. Once the lung volume bag is set up properly (See Figure 1), Student A should place the nose clip on his or her nose. Instruct Student A to take three normal breaths breathing through the mouth. On the fourth breath inhale as a large a breath as possible and then forcefully and quickly exhale into the lung volume bag until he or she simply cannot exhale any further The University of Texas Health Science Center at San Antonio 21

5 12. As described in the previous activity You Really Are Full of Hot Air!, grab the lung volume bag with your free hand and wrap the bag around the palm of your hand to push the collected air to the bottom of the bag. Using the liter markings on the side of the lung volume bag read the amount of air collected. Use the BTPS Conversion Factor to convert the FVC measurement and then record this figure in the correct column on Data Table 2 Measurement of FVC. Remember from You Really Are Full of Hot Air!, the formula for converting volumes to BTPS is BTPS factor X Measured Volume. Figure Repeat steps 10 and 11 two more times for a total of three trials. Using the calculator if needed find the average of the three FVC readings and record on Data Table 2 on your Student Data Page, Part Remove the disposable mouthpiece and have Student B insert his or hers. Before Student B makes the lung function measurements, the Ace bandage must first be in place. Have a group member of the same gender (or teacher) assist Student B in wrapping the Ace bandage tightly around his or her abdomen just below the rib cage. The bandage should be tight enough to limit movement of the abdomen while breathing but not so tight as to be painful. 15. Once the Ace bandage is in place Student B should repeat steps to obtain and record his or her FVC measurements. Be sure to record measurements converted to BTPS. 16. Remove the disposable mouthpiece of Student B and replace it with Student C s mouthpiece. Remember that Student C uses only the disposable mouthpiece and no extra equipment The University of Texas Health Science Center at San Antonio 22

6 17. Repeat steps to obtain and record the FVC measurements for Student C. Be sure to record measurements converted to BTPS. 18. Once all FVC measurements are recorded return the lung volume bag to Student A. Insert Student A s mouthpiece (including the rubber stopper) to make the FEV 1 measurement. Another group member should be ready with the stopwatch to time the measurement for one second. 19. As in the previous activity, You Really Are Full of Hot Air!, take three normal breaths breathing through the mouth. On the fourth breath inhale maximally and then exhale forcefully into the bag. Start the stopwatch as soon as Student A places his or her mouth on the mouthpiece and instruct him or her to stop at the 1 second mark on the stopwatch. 20. Using the technique described earlier measure the amount of air in the lung volume bag and convert this amount to BTPS. Record this figure in the appropriate column on Data Table 3 Measurement of FEV Repeat steps 19 and 20 two more times for a total of three trials and then find the average FEV 1 measurement and record it on Data Table 3 in Part 1 of Student Data Page. 22. Repeat steps to obtain FEV 1 measurements for Students B and C. 23. Remove the rubber stopper from the mouthpiece of Student A and the Ace bandage from Student B. Return these items to the equipment container. Dispose of all used mouthpieces and nose clips as instructed. 24. Using the calculator find the FEV1/FVC ratio and record in the appropriate column on Data Table 4 Measurement of FEV 1 /FVC(%). 25. Calculate and record the %Predicted for all measurements on all tables and then transfer the average measurements to the appropriate columns on Data Table 5 Summary of %Predicted and Preliminary Diagnosis. 26. Examine the summary data table carefully then, using the You Take My Breath Away Lung Disease Decision Tree, work together to determine whether each student can be categorized as Healthy or suffering from Obstructive or Restrictive Lung Disease. Record your preliminary diagnoses on Data Table 5 and then answer the Processing Out Questions on your Student Data Page The University of Texas Health Science Center at San Antonio 23

7 You Take My Breath Away Student Data Page Activity 5C Part 1 Data Table 1 Age and Height Measurements Room Temp o C: BTPS Conversion Factor: Trial Age (yr) Height (cm) AVERAGE Trial 1 Data Table 2 Measurement of FVC Predicted (L) Measured (L) %Predicted (L) 2 3 AVERAGE 2006 The University of Texas Health Science Center at San Antonio 24

8 Trial 1 Data Table 3 Measurement of FEV 1 Predicted (L) Measured (L) %Predicted (L) 2 3 AVERAGE Trial 1 Data Table 4 Measurement of FEV 1 /FVC(%) Predicted (L) Measured (L) %Predicted (L) 2 3 AVERAGE Student Data Table 5 Average % Predicted and Preliminary Diagnosis FVC FEV 1 FEV 1 /FVC(%) Diagnosis A B C 2006 The University of Texas Health Science Center at San Antonio 25

9 Processing Out Questions: Answer the following questions and be prepared to discuss them with the class. 1. Describe the %Predicted measurements and preliminary diagnoses for each student: 2. Based on the measurements you made and the information provided in the Lung Disease Decision Tree, write an explanation of how the measurements are used to distinguish between obstructive and restrictive lung diseases. 3. Using the knowledge you gained in this activity write a definition in your own words of each type of lung disease. OBSTRUCTIVE RESTRICTIVE 2006 The University of Texas Health Science Center at San Antonio 26