Diagnostic Testing Pt 1 Flashcards
Principles of Pulm Med Chapter 3, Appendix A, and Appendix B 1. List and discuss the indications for and limitations of pulmonary function tests, bronchoscopy, and computed tomography. 2. Define the values for lung volumes and spirometry: -Tv -IC -IRV -ERV -FVC -SVC -RV -FRC -TLC -FEV1 -PEFR -FEF 3. Discuss and explain the normal range of values and interpretation of pulmonary function tests. 4. When given a clinical scenario and pulmonary function test results, determine of a
What is a PFT?
Pulmonary Function Test
What are PFTs used for?
- Evaluation of Symptoms
- Determination of Disability
- Classification of Dz
- Follow up of Dz progression or response to therapy
- Evaluation of drugs and treatments
- Screening for surgical risk
- Epidemiologic
- Screening for those exposed to Pulmonary toxins
What do we get from PFTs?
- Flow/Volume Loops
- Spirometry with or without bronchodilators
- Lung volumes
- Diffusing Capacity
When doing PFTs, values are “predicted” as to what should be “normal” for the patient. What factors are taking into account for a “predicted” value?
- Age
- Sex
- Height
- Race Corrections for Blacks and Asians
- ** Little Data for “normal” older adults >80
- ** Common references: NHANES III, Crapo
What types of Disease Patterns can be detected using PFTs?
- Obstructive Ventilatory Dysfunction
2. Restrictive Ventilation Dysfunction
What are common Obstructive Resp. Diseases?
- Asthma
- COPD
- Bronchiectasis
What are common Restrictive Resp. Diseases?
Intrinsic Lung Diseases (Scarring of Lung Tissues)
Diaphragm/Chest Wall Dysfunction
Neuromuscular Disorders
What is the biggest symptom/sign that would indicate spirometry?
Dyspnea
Spirometry can be used in an outpatient clinic in order to:
Monitor diseases severity or effect of current therapy.
What values do you receive from spirometry?
FEV1 and FVC
Is this test objective?
No, it is based on the coaching of the Tech and the Patient’s effort
What would poor effort on a patient’s part cause to the curves/values coming out of the spirometry test?
The results can mimic certain disease processes, leading to a false assumption and clinic and potentially unnecessary testing.
Difference between spirometry and PFTs?
Spirometry is one test of PFTs
What are all the components of PFTs?
- Spirometry
- Post-Bronchodilator Spirometry
- Bronchoprovocation Testing (Methacholine) –asthma
- Lung Volumes
- Diffusing Capacity for Carbon Monoxide
- Maximal Respiratory Pressures
- Maximal Voluntary Ventilation
What is an important rule of thumb for Spirometry testing?
Must be completed for 10 second to be a valid test.
When looking at a spirometry test, what would you see in a “normal” curve?
Very steep slope for the first second and then tapers off
When looking at a spirometry test, what would you see in an “obstructive” curve?
Very gradual slope up over time
When looking at a spirometry test, what would you see in a “restrictive” curve?
Sharp slope up, like normal, but tapers off at a smaller volume.
What is PEFR (Peak Expiratory Flow Rate) most commonly used for?
Monitoring Asthmatic Patients
When looking at a spirometry flow chat, what does the curve above the axis represent?
Expiration
When looking at a spirometry flow chat, what does the curve below the axis represent?
Inspiration
If the spirometry flow curve is narrowed in on the X-axis, what are we looking at?
Restrictive Pulmonary Disease
If you see significant flattening “hockey shaped” Expiratory flow on a spirometry graph, you would assume that the patient has
Obstructive Pulmonary Disease
What factor on the PFT could indicate to the reader that the PFT was completed properly?
FEV1/FVC Ratio
If all the numbers in the Lung Volumes section of the PFT are reduced, what would that indicate?
Restrictive Disease
When you see a fluttering during inspiration (ups and downs), what does this indicate? What is most commonly the answer?
Indicative of something underlying occurring.
Sleep Apnea or Parkinson’s
You get a PFT back and all the numbers for Spirometry and Diffusion Capacity look normal, but then you look at the flow curve and notice a flattening on the inspiratory part of the flow. What would this indicate to you?
Mass on the Vocal Cords
After starting a patient on a bronchodilator, what is the intended effect in relation to PFT results?
- Increase in FEV1 and FVC by greater than or equal to 12%
- Absolute increase of about 200 cc
**Note a lack of an acute response does not mean the bronchodilator treatment is of no benefit.
What is a normal FEV1?
> 80% predicted
What is a normal FVC?
> 80% predicted
What is a normal FEV1/FVC?
> 90% predicted
>0.7