Pulmonary Function Tests and Clinical Approaches Flashcards
What lung test is used to determine if there is obstruction?
Spirometry
What lung test is used to determine if there is restriction?
Helium dilution
Body plethysmography
What lung test is used to determine if there is a diffusion defect?
CO diffusion test
What do pre and post mean on a PFT?
Pre = before bronchodilator administration
Post = after bronchodilator administration
What is the primary value for determining obstruction?
FEV1/FVC ratio
If less than 0.70, there is evidence of obstruction
What is the appearance of the flow volume loop when there is small airway obstruction?
Scooping of the expiratory portion of the loop
How could you test for reversible obstruction? What are the criteria for reversibility?
Administer a bronchodilator, then measure another flow volume loop
Need 200ccs and 12% improvement in FEV1 to classify as reversible
If the PFT is normal initially, how could you induce obstruction and indicate hyperreactivity?
Methacholine challenge test
What are the common obstructive diseases (lower airway)?
Asthma
Emphysema
Chronic Bronchitis
Bronchiectasis
Describe the basic pathology behind small airway diseases. How is the airflow affected over the course of expiration?
The obstruction worsens as lung volume decreases
There is gradually decreasing airflow as the lung volume gets smaller due to less tethering of the bronchioles
Describe the flow volume loop appearance of Upper Airway Obstruction
May be fixed or variable
Fixed - both the expiratory and inspiratory loops have a flattened appearance
Variable - either the expiratory or inspiratory loop is flattened, but not both
Which loop is flattened in an extrathoracic upper airway obstruction?
Inspiratory loop is flattened
Which loop is flattened in an intrathoracic upper airway obstruction?
Expiratory loop is flattened
What intrinsic lung property determines the total lung capacity?
The lung elastic recoil
At what lung volume are the lung’s and chest wall’s elastic recoils balanced?
FRC
What is the primary problem in restrictive lung disease?
TLC is low
What are the 3 main categories of restrictive lung diseases?
Interstitial lung disease
Chest wall disease
Neuromuscular disease
List the potential causes of Interstitial Lung Disease
Sarcoid Hypersensitivity pneumonitis IPF Tuberculosis Fungal Aspiration/Asbestosis Connective Tissue Disorder/Cancer Eosinophilic granuloma Drugs (amiodarone, bleomycin)
What is a normal DLco? What is the equation to calculate it (uncorrected)?
DLco is normally 25mL/min/mmHg
DLco = [CO]inhaled = [CO]exhaled
What is the DLco equation corrected for hemoglobin?
DLco corrected = DLco x (15/Hbg)
What conditions may cause a reduced DLco?
Loss of alveoli (emphysema and ILD)
Loss of capillaries (Pulm HTN)
Anemia
When DLco is low but spirometry and lung volumes are normal, you should suspect…
Pulmonary HTN
The volume of the lungs may appear very different on CXR in certain diseases. When would the lungs appear big? Small?
Obstructive diseases have large lungs and flat diaphragms
Restrictive diseases have small lungs and domed diaphragms
What is the primary pathological problem in asthma?
Smooth muscle hypertrophy due to inflammation
It is reversible and intermittent obstruction
What does “persistent” mean in asthma classification?
The patient needs persistent treatment for their asthma
What are the two kinds of treatments used for asthma?
"Relievers" Emergency bronchodilators (albuterol, B2 agonist)
“Controllers”
Regularly used anti-inflammatories
What is the first line asthma controller? What might you add if that is inadequate?
Inhaled corticosteroid
May add a long acting beta agonist if needed
What is a common side effect on inhaled corticosteroids for asthma? How can this be avoided?
Thrush (oral-pharyngeal deposition of the medicine)
Use a spacer to prevent thrush
What 4 symptoms may people with asthma present with (in any combination)?
SOB
Wheezing
Chest tightness
Cough
What is cough variant asthma?
Asthma presenting only with a cough
What is exercise induced asthma? How does it occur?
Asthma presenting after exercise.
Increased ventilation during exercise leads to lots of beta agonist flowing in your blood, dilating the airways. However, the person may feel worse after stopping exercise due to dry mucus membranes and mast cell degranulation
What is RADS?
Reactive Airways Dysfunction Syndrome
Asthma that occurs after a single large exposure to an irritating agent
What is Samter’s Triad?
Asthma
Aspirin sensitivity
Nasal polyps
People who take NSAIDs (aspirin) may develop asthma
What is ABPA?
Allergic Bronchopulmonary Aspergillosis
Hyperinflammatory response leading to reaction in the airways, causing asthma
What are the two diseases considered COPD?
Emphysema
Chronic Bronchitis
Describe Pink Puffers and the disease associated with it
Emphysema
Patient is pink and skinny. Normal pO2 and pCO2. They have increased work of breathing so they are thin (cachectic)
Describe Blue Bloaters and the disease associated with it
Chronic Bronchitis
Patient is edematous and cyanotic. Accepts a low pO2 (hypoxia), leading to hypoxic pulmonary vasoconstriction. Less tachypnea. Lots of mucus production
What are the treatments of COPD?
Smoking cessation
Medications - short and long acting bronchodilators (B agonists or anti-cholinergics)
Long Term O2 therapy
Cardiopulmonary Rehab (Exercise)
Transplant
Exogenous Alpha-1-Antitrypsin
What is the number one indication for a lung transplant?
Emphysema
What is bronchiectasis?
Permanent abnormal dilatation of the bronchi
Tons of mucus is trapped in the airways and you get permanent abnormal dilatation with bacterial colonization and inflammation
What is the sign of bronchiectasis that may be seen on CT?
Signet ring appearance
Airway is bigger in diameter than the corresponding blood vessel
What is pneumoconiosis?
Buildup of dust particles in the lung and the tissue’s response
Causes restrictive lung disease
What are some physical exam findings of interstitial lung disease?
Crackles
Small lungs
Clubbing of fingernails
What is sarcoidosis?
Nonspecific tissue reaction with noncaseating granulomas in the lungs and other areas of body.
See lymphadenopathy (hilar) and interstitial lung disease
Where in the lung does sarcoidosis have its primary effect?
Upper lobes
Where in the lung does idiopathic pulmonary fibrosis have its primary effects?
Lower lobes and periphery
See an extra whiteness around the base of the lungs on CT (fibrosis)
What is the end stage appearance of IPF?
Honeycomb lung
