Pleural Effusions
What is a normal (physiologic) volume of pleural fluid, and what role does it serve?
5-10 mL; Reduces friction between the pleural membranes.
In interstitial lung diseases such as pneumoconiosis, fibrosis increases what mechanical property of the lungs?
Elastic recoil
What is the latency period from first exposure to mesothelioma diagnosis?
~ 20-50 years
Explain what the FEV₁/FVC ratio is and how it changes in Pneumoconiosis.
The FEV₁/FVC ratio is the proportion of the forced vital capacity exhaled in the first second, and in pneumoconiosis, it's either normal or increased.
A patient comes in with dyspnea, dry cough, and fatigue. Suspecting some lung disease, you get an X-ray. What are the potential differentials if you find:
1. Upper Lobe Fibrosis
2. Lower Lobe Fibrosis
3. Pleural Fibrosis
4. Lymphadenopathy
1. Coal workers' pneumoconiosis/Silicosis
2. IPF/Asbestosis
3. Asbsestosis/Autoimmune
4. CWP/Silicosis/Berylliosis/Sarcoidosis
What are the classical lung sounds associated with pleural effusions?
Decreased breath sounds and tactile fremitus
Which immune cell is primarily responsible for releasing cytokines that stimulate pulmonary fibrosis?
Alveolar macrophages
What is the more common complication of asbestos exposure? Bronchogenic carcinoma vs. Mesothelioma?
Bronchogenic carcinoma
Increased elastic recoil, decreased compliance, and reduced lung volumes.
After getting our CXR back, we notice irregularities. What tests can we order to differentiate between obstructive and restrictive lung disease?
FEV1/FVC ratio and total lung capacity (TLC).
What is primarily responsible for the transport of serous fluid within the pleural space?
Intercostal microvessels
Which pneumoconiosis presents similarly to sarcoidosis?
Berylliosis
In mesothelioma, pleural effusions are typically classified as this type using Light’s criteria.
Exudative
In pulmonary fibrosis how does the rate of oxygen diffusion change?
Decreased DLCO
The patient's PFTs come back, suggesting some form of restrictive lung disease. What questions/info can we ask or gather to narrow down the DDX?
Exposures (environmental or drug), autoimmune conditions, risk factors (gender, race, etc.)
What is a chylothroax, and what causes it?
Lymphatic fluid within the pleural space; Thoracic duct puncture
Because lung compliance is reduced, patients often adopt what breathing pattern to minimize the work of breathing?
Rapid, shallow breaths
What physical exam finding(s) are common in mesothelioma?
Pleuritic chest pain
A patient comes in with pulmonary fibrosis. What does the lung pressure-volume curve look like?
Moves to the right (lower volume side)
The patient is a black female farmer who ONLY has pulmonary symptoms. We also lost their imaging results. What test can we use to support a diagnosis of sarcoidosis?
Bronchoalveolar lavage. (CD4/CD8 count)
What is the MCC of pleural effusions?
CHF
What is Caplan syndrome?
Pneumoconiosis superimposed on rheumatoid arthritis.
What is the most sensitive and specific tumor marker for mesothelioma?
Calretinin
What rib levels do the lungs and pleura extend along the anterior, lateral, and posterior chest wall?
6,8,10; 8,10,12
Your clinic finds the missing results, and the med student gives a summary. A 32-year-old African American woman who works as a farmer presents with a chronic dry cough and dyspnea. Chest X-ray shows diffuse reticulonodular opacities with mild lymphadenopathy. PFTs demonstrate restrictive lung disease, lung biopsy reveals non-caseating granulomas, and bronchoalveolar lavage shows a decreased CD4/CD8 ratio. What is the most likely diagnosis?
Hypersensitivity Pneumonitis