DSA Interpreting Pulmonary Function Test

Question 1

difference between the Obstructive disease and Restrictive disease

Answer 1

Obstructive disease: Air has a hard time moving due to problems in the airways. In some cases, COPD, emphysema, compliance is high (lungs are stretchable)

Restrictive disease: The compliance is low and lungs resist inhalation

Question 2

what are the 6 indications for pulmonary function testing?

Answer 2

• To evaluate symptoms and signs of lung disease (cough, dyspnea, cyanosis, wheezing, hyperinflation, hypoxemia, hypercapnia)
• To asses the progression of lung disease
• TO monitor the effectiveness of therapy
• To evaluate preoperative patients in selected sitations
• To screen people at risk of pulmonary disease such as smokers or people with occupational exposure to toxic substances in occupational surveys
• To monitor for the potentially toxic effects of certain drugs or chemicals

Question 3

What are the three most important measures of the Lung volume and capacities graph

Answer 3

FVC = forced vital capacity

FEV1 = Forced expiratory volume in one second

FEV1/FVC ratio
-used to determine if the pattern is obstructive, restrictive, or normal

Question 4

when is the diffusion of the lungs most efficient

Answer 4

when the surface area for gas transfer is high and the blood is readily able to accept the gas being transferred

Question 5

what is the first step in interpreting pulmonary function tests

Answer 5

confirm the patients demographic data

Question 6

when is diffusion decreased?

Answer 6

• conditions that minimize the abillity of the blood to accept and bind the gas that is diffusing (anemia)
• COnditions that decrease the surface area of the alveolar-capillary membrane (emphysemia, pulmonary embolism)
• Conditions that alter the membranes permeabillity or increase its thickness (pulmonary fibrosis)

Question 7

when can pulmonary functions become confusing

Answer 7

paitent may appear to have a pulmonary disease based on interpretation of the PFTs when the problem is really caused by what the heart is doing to the lungs (heart failure)

Question 8

obstructive vs restrictive patterns for FVC, FEV1, FEV1/FVC and TLC

Answer 8

Obstructive:
Forced vital capacity: Decreased or normal
FEV1: Decreased
FEV1/FVC ratio: Decreased
TLC: normal or increased

Restrictive: 
FVC: Decreased
FEV1: Decreased or normal
FEV1/FVC: normal or high
TLC: Decreased

Question 9

what are some extra paraenchymal causes of restriction patterns

Answer 9

Obesity
Neuromuscular disease
Chest wall deformities
large pleural effusions

anything outside the lung to impair inflation of the lung

Question 10

what are some Pulmonary parenchymal causes of restriction

Answer 10

inside the lung parenchyma would be lung fibrosis