Pulmonary Flashcards
What is tested in lung volume testing?
Plethysmography measures the following components: Functional Residual Capacity, Expiratory Reserve Volume, and Slow Vital Capacity.
Total Lung Capacity and Residual Volume are then calculated from those measures.
What is the total lung capacity?
The amount of air in the lungs after maximal inhalation
What is the residual volume?
The volume of air in the lungs after a maximal exhalation
What is functional residual capacity?
Air in the lungs after a normal expiration
What is slow vital capacity?
The volume of air maximally exhaled during expiration
What can total lung capacity differentiate in restrictive lung patterns?
Is restriction due to primary parenchymal process or chest cage restriction from factors such as obesity, muscle weakness, or scoliosis?
In obstructive lung disease, what can total lung capacity and RV differentiate?
increased TLS is suggestive of hyperinflation and high compliance, and an increased RV is suggestive of air trapping.
What is DLCO a measure of?
capacity for gas transfer through alveolar-capillary membrane
What does DLCO stand for?
Diffusing capacity for carbon monoxide
What elevates DLCO?
clinical disorders that recruit blood to the alveoli (cardiac shunt, asthma, erythrocytosis, alveolar hemorrhage)
What decreases DLCO?
conditions that decrease the surface area available for diffusion, decrease permeability across the alveolar-capillary membrane, or otherwise interfere with gas transfer. e.g. reduced DLCO in patient with low TLC or restriction on spirometry is suggestive of parenchymal or interstitial process. DLCO may also be diminished in COPD (from parenchymal destruction) or in conditions that affect the pulmonary vasculature such as pulmonary hypertension or chronic pulmonary thromboembolic disease
Indications for low dose CT scan screening
Ages 55-80 with 30 pack year smoking and currently smoke or quit in last 15 years
Diagnosis of CF
Biochemical: Sweat chloride testing, nasal potential difference
Genetic: CFTR analysis
