| Question |
Answer |
| After performing a multi-breath Nitrogen washout on a patient you observe the following tracing. What is the result of the tracing? |
Leak |
| When should you suspect poor effort by the patient when comparing the SVC and FVC? |
When the FVC is larger than the SVC |
| In the normal patient, how should the FVC and SVC compare |
They should be the same |
| When performing measurements with the body-box and Helium dilution tests you notice that the results are higher on the results from the body-box. What would account for this difference? |
Body-box measures the traped gases. Helium dilution does not. |
| List 4 measurements commonly made with the body-box |
FRC TLC TGV RV RV/TLC% Raw |
| Once the FRC has been determined how are the RV and TLC calculated? |
FRC - ERV = RV RV + VC = TLC |
| When should the patient be 'switched in' to start the nitrogen washout test? |
at FRC |
| Why does the nitrogen washout test not require a CO2 absorber? |
open circuit, no rebreathing |
| How long should it take the normal patient to washout during the nitrogen washout test? |
3 minutes |
| Briefly describe how to perform the nitrogen washout procedure. |
1. Have the patient breath 100% O2 and measure the %N2 exhaled. 2. Switch-in occurs at FRC 3. Test ends when %N2 is < 1% or 7 minutes |
| What 3 measurements are determined during the nitrogen washout procedure? |
1. FRC 2. RV 3. TLC |
| What would explain why a Helium dilution test never equilibrates and the [He] falls to zero? |
leak |
| Briefly describe how to perfom the Helium dilution test on a typical patient |
1. Switch-in occurs at FRC. 2. O2 must be added because of consumption 3. Test ends when [He] change < 0.2% in 30 second interval or after 7 minutes 4. Rebreathing requires CO2 and H2O absorbers (closed circuit) |
| What three (3) volumes/capacities can be measured/calculated with the Helium dilution test? |
FRC RV TLC |
| ______________ is the only capacity/flowrate used to identify restriction |
Vital Capacity |
| What are the 3 volumes measured during the SVC test? and what are there typical values? |
1. Vt 0.5 L 2. IRV 3.1 L 3. ERV 1.2 L |
| Given: ERV = 1400 mlTLC = 6200 mlVt = 600 mlIC = 3700 mlCalculate; IRV & VC |
IRV = 3700 - 600 = 3100 VC = TLC - RV = 6200 - 1100 = 5100 |
| Given: ERV = 1400 mlTLC = 6200 mlVt = 600 mlIC = 3700 mlCalculate; FRC & RV |
FRC = 6200 - 3700 = 2500 RV= 2500 - 1400 = 1100 |
| Briefly describe the principle of the multi-breath, open circuit, nitrogen washout test |
washes out the nitrogen in the lungs by having the patient breath 100% oxygen for several minutes |
| _________ Volume of air remaining in the lungs at tidal volume end-expirtaory level |
FRC |
| _________ Maximum amount of air the can be exhaled after maximun inhaltion |
VC |
| _________ Volume of air in the lungs after maximum inhalation |
TLC |
| _________ Maximum amount of air that can be inhaled from tidal volume end-expiratory level |
IC |
| _________ Volume of air remaining in the lungs after maximum exhalation |
RV |
| ___________ Maximum amount of air that can be exhaled below the tidal volume end expiratory level. |
ERV |
| The results of a Helium dilution test show an equilibrium time of 7 minutes with an increase in FRC value, this is most likely due to; |
the patient has obstructive lung disease |
| You notice that you have entered information on a female instead of a male. What results of % predicted would change which you switch the computer over to a male? |
FVC |
| Which of the following is best for meauring Raw? |
plethysmography |
| Which of the following parameters are NOT used to calculate the predicted normals for an individual? |
weight |
| A FVC that is reduced and a SVC that is normal would indicate |
obstructive disorder |
| A patient with a FEV-1/FVC of greater than 35% would be consistent with; |
obstructive disorder |
| Which of the following would be consistent with a pure restrictive lung disorder? |
decreased VC, increased FEV-1 |
| Which of the following is measured by the Plethysmograph? |
TGV |
| In a healthy subjects who have no lung disease, a graph of N2 washout curve appear ______ when displayed on a semilogrhythmic graph |
straight line |
| The FEF(25%-75%) is depends on which of the following? |
FVC |
| Which of the following are characteristics of obstructive lung disease when measured values are compared to predicted normals? |
The FRC is increased The RV is increased The RV/TLC is increased |
| A patient has the following results from a pulmonary function test:SVC---4.35FRC---3.40ERV---1.20IRV---2.65Vt ---0.50The residual volume would be: |
Choose the answer2.2 L 0.25 L 2.90 3.15 |
| A patient has the following results from a pulmonary function test:SVC---4.35FRC---3.40ERV---1.20IRV---2.65Vt ---0.50The total lung capacity would be: |
Choose the answer7.75 L 6.05 L 6.55 L 7.25 L |
| A patient has the following lung volumes:-------Measured-------%PredictedSVC------2.95-------------71%FRC------1.85-------------67%RV-------1.03-------------75%TLC------3.98-------------67%The intrepretation would most likely state: |
(Choose the answer)normal lung volumes hyperinflation restrictive pattern or process mixed obstructive and restrictive pattern or process |
| Which of the following correctly describes the measurement of FRC by the nitrogen washout method? |
The test is continued until alveolar N2 is 1%. Some N2 is released from the blood/tissue |
Biology Lab Midterm
