Restrictive Lung Disease Flashcards
What is the pulmonary interstitium
network of tissue that extends throughout both lungs that provides support to the alveoli and capillary beds for gas exchange
PFTs
non invasive tests that measure how well the lings are expanding and contractions and how efficient gas exchange is
Tidal volume
volume of air moved in and out during each breath
Vital capacity
maximum volume of air that can be exhaled after a maximal inspiration
Residual volume
volume of air remaining in the lungs after maximal inspiration
Total lung capacity
volume of air in the lungs after maximal inspiration
What does spirometry measure
the volume of air exhaled at specific time points during a forceful and complete exhalation
What are the three values spirometry generate
FVC, FEV1 and the FEV1/FVC ratio
What does spirometry help differentiate between
obstructive and restrictive lung disease
What is FVC
maximum amount of air exhaled after a maximal inhalation
What is FEV1
amount of air exhaled in the first second
What is normal FEV1
about 70% or above
What does the FEV1/FVC ratio show
air flow obstruction (<70%)
When would you do flow volume loops
when patient has stridor or unexplained dyspnea
Obstructive flow volume loop
concave appearance
Restrictive flow pattern loop
smaller loop
FEV1, FVC and FEV1/FVC ratio in obstructive lung disease
FEV1- normal (mild disease) or decreased (mod/severe disease)
FVC- normal (mild/mod disease) or decreased (severe disease)
FEV1/FVC ratio- <70%
FEV1, FVC and FEV1/FVC ratio in restrictive lung disease
FEV1- normal or decreased
FVC- decreased
FEV1/FVC ratio- normal or increased (greater than or equal to 70)
What is the benefit of DLCO
differentiate the etiology of restrictive lung disease
Low DLCO
interstitial lung disease
What does DLCO measure
the overall function of the alveolar capillary membrane
Normal DLCO
extrathoracic cause or restriction (obesity, chest wall disorder, neuromuscular disorder)
What is restrictive disease associated with
decreased total lung capacity
Intrinsic restrictive pulmonary disease
diseases of the lung parenchyma, inflammation or scarring of the lung tissue
(idiopathic fibrotic disease, pneumoconioses, sarcoidosis)
Extrinsic restrictive pulmonary disease
extra-pulmonary diseases involving the chest wall, pleura and respiratory muscles
(obesity, myasthenia gravis, ALS, kyphoscoliosis)
What medications induce interstitial lung disease
amiodarone, methotrexate, nitrofuranotoin
Risk factors for idiopathic fibrosing interstitial pneumonia
- smoking
- occupational exposure (stone, metal, wood, organic dust)
- GERD (micro-aspiration)
Symptoms of idiopathic fibrosing interstitial pneumonia
- insidious dry cough
- exertional dyspnea
- fatigue
- tachypnea
Exam characteristics for idiopathic fibrosing interstiital pneumonia
- clubbing
- inspiratory rales
PFTs in idiopathic fibrosing interstitial pneumonia
- FVC, FEV1/FVC ratio
- DLCO
- reduced FVC
- normal or elevated FEV1/FVC ration
- Reduced DCLO
- impaired 6 minute walk
Idiopathic firbosing interstitial pneumonia on CXR?
CT?
CXR- increase in reticular markings
CT- diffuse patchy fibrosis with pleural based honeycombing
Definitive diagnosis of idiopathic fibrosing interstitial pneumonia
lung biopsy, can also help rule out other causes
Treatment options for idiopathic fibrosing interstitial pneumonia
- supportive care (supplemental o2, vaccinations, pulm rehab)
- medications
- surgery (lung transplant)
What medications are used for idiopathic fibrosing interstitial pneumonia
Nintedanib (tyrosine kinase inhibitor)
Pirfenidone (anti-fibrotic drug)
Qualifications for lung transplant
- age <65
- free of stubstance abuse
- acceptable BMI range of 20 to 29
Pneumoconioses
interstitial lung disease caused by the inhalation and deposition of inorganic particles and mineral dust with subsequent reaction of the lung
Clinically important pneumoconioses
- coal workers pneumoconiosis
- silicosis
- asbestosis
What is the milder form of coal worker’s pneumoconioses
anthracosis
When do symptoms of coal worker’s pneumoconioses begin to develop? What are they?
10-15 years after exposure
chronic cough, fever, DOE
What shows up on radiography with coal worker’s pneumoconoises
smaller, rounded, nodular opacities with a preference with the upper lobe
Clinical stages of silicosis
acute, chronic, accelerated
Clinical presentation of silicosis
- cough
- dyspnea
- possible fever or pleuritic chest pain
PFTs with silicosis
- decreased FEV1 and DCLO
- normal FEV1/FVC ratio
Findings on CXR/CT with silicosis
acute- bilateral, diffuse, groundglass opacities
chronic- small, innumerable rounded densities
What are the 3 key elements diagnosis of silicosis is based on
- history of silica exposure
- chest imaging consistant with silicosis
- absence of any other diagnosis
Treatment of silicosis
- no proven specific therapy
- avoid further exposures
- supportive care
- steroid therapy
- lung transplant
Associated complications with silicosis
- mycobacterial infection
- asergillosis
- lung cancer
- chronic kidney disease
Clinical presentation of asbestosis
- asymptomatic for 20-30 years after exposure
- dyspnea on exertion
- cough
- weight loss
PFTs in asbestosis
- reduced vital capacity and total lung capacity
- low DCLO
Complication in asbestosis
malignant mesothelioma
Sarcoidosis
multisystem granulomatous disorder of unknown etiology
What is sarcoidodsis characterized by
presence of non-caseating granuloma
Clinical presentation of sarcoidosis
- dry, hacking cough
- progressive worsening dyspnea
- atypical chest discomfort
- fever/night sweats
- weight loss
Radiographic imaging for sarcoidosis?
CXR?
CT?
CXR- bilateral hilar adenopathy
CT- right paratracheal lymphadenopathy along with bilateral diffuse reticular infiltrates
How to diagnose sarcoidosis
- endobronchial US guided biopsy
- cervical mediastinoscopy
- VATS lung biopsy
Treatment of sarcoidosis
- observation is asymptomatic
- tapering course of abx over 4 to 6 weeks
