Restrictive Disorders Flashcards
What is Idiopathic Pulmonary Fibrosis?
It is a type of interstitial lung disease for which the cause is unknown. It is a progressive, chronic, and fatal condition characterized by excessive fibrotic tissue in the interstitial tissues of the lungs.
What are some other names for Idiopathic Pulmonary Fibrosis?
Usual Interstitial Pneumonia, cryptogenic fibrosing alveolitis, interstitial fibrosis.
What are some factors that may increase the risk of developing idiopathic pulmonary fibrosis?
Genetics, environmental exposures to dusts and tobacco, iatrogenic causes- medication or radiation, comorbidities such as GERD, obesity, emphysema.
What role does inflammation play in idiopathic pulmonary fibrosis?
It doesn’t. It may be present but it is not the primary driving factor.
What is the primary driving factor of idiopathic pulmonary fibrosis?
Aberrant response of the epithelial cells to micro-injuries. Fibro-genetic cytokines are released in response to injury which results in fibroblast proliferation. Also decreased responsiveness to apoptosis so normal pruning of tissue is limited and scar tissue develops uninhibited.
What is TGF-B?
Transforming growth factor B1 is a secrete protein that performs many cellular functions, including control of cell growth, proliferation, differentiation, and apoptosis. It enhances the remodeling of lung interstitium in idiopathic pulmonary fibrosis.
What happens to Type I and Type II pneumocytes in idiopathic pulmonary fibrosis?
The integrity of the basement membrane as well as the Type I pneumocytes is lost, and rapid growth of Type II pneumocytes occurs to re-establish the barrier as there is a signal failure to stop proliferation.
Describe the disease process of idiopathic pulmonary fibrosis.
- Some initial injury damages alveolar surface and basement membrane, we have formation of a wound clot and initiation of platelets and fibrin
- We re-establish the extracellular matrix, new vessels form, alveolar type II cells re-establish barrier
- There is a lack of pruning of the new extracellular matrix and lack of conversion of AECII cells to AECI cells
- The tension provided by the extracellular matrix on the airways is what produces the honeycomb pattern on HRCT which eventually causes traction bronchiectasis
What are the signs and symptoms of idiopathic pulmonary fibrosis?
Dry and non-productive cough, new onset exertional dyspnea, finger clubbing, fine late inspiratory crackles
What is an important thing to ask about in the patient’s history when you suspect idiopathic pulmonary fibrosis?
A detailed occupational history and any potential exposures to causative agents (organic/inorganic dust, tobacco smoke, etc.)
What might you expect to see on inspection and on an ABG of someone with idiopathic pulmonary fibrosis?
High RR and shallow Vt; Unless the patient is very end-stage they often have respiratory alkalosis
What receptors are stimulated and cause shallow breathing in idiopathic pulmonary fibrosis patients?
Pulmonary irritant receptors (increased traction due to restriction) and Juxtacapillary receptors (fibrotic changes to A/C membrane or interstitium.
Is the rapid shallow breathing in idiopathic pulmonary fibrosis due to chemical or non-chemical factors?
Non-chemical
What disease may pulmonary fibrosis lead to if left untreated?
Pulmonary hypertension; could see JVD and peripheral edema
What findings may you observe on CXR of someone who has pulmonary fibrosis?
Bilateral lower lobe opacities and possible decrease in lung volumes
What lab findings may be found in a patient with pulmonary fibrosis?
Results of blood tests are generally normal and there is no associated systemic disease because it is isolated to the lungs.
How do we diagnose idiopathic pulmonary fibrosis?
It requires exclusion of known causes like environmental exposure, medications, and systemic diseases
What diagnostic tools would we use to diagnose idiopathic pulmonary fibrosis?
CT, lung biopsy, PFT indicating restrictive disease, BAL to rule out other inflammatory causes.
What are the goals of therapy for a patient with idiopathic pulmonary fibrosis?
To slow progression, improve function, comfort, and avoid complications (we cannot cure or reverse the disease)
What is Pirfenidone?
Used to treat IPF. Anti-inflammatory, antioxidant, antifibrotic; used to slow progression
What is Nintedanib?
Use to treat IPF. Inhibits fibroblast, vascular, and platelet derived growth factors and slows decline in lung function.
What drug may be used to treat IPF but is still under investigation?
Thalidomide. It is anti-inflammatory, anti-angiogenic, and immunomodulatory; suppressed fibrotic response in animal models.
When IPF has progressed enough to cause pulmonary HTN, what is a treatment we may use?
Sildenafil: a phosphodiesterase 5 inhibitor that dilates well ventilated vessels.
What are some alternative therapies for pulmonary fibrosis?
Lung transplantation, pulmonary rehab, prevention of exacerbation
Why should we avoid invasive ventilation in pulmonary fibrosis patients?
High RR can lead to poor synchrony and there is a high mortality (87%) once intubated.
What is pleural effusion?
An accumulation of an abnormal amount of fluid in the pleural cavity.
What are the two types of effusion?
Transudative and exudative.
What is transudative effusion?
Fluid accumulating as a result of disturbance of the balance between transcapillary pressure and plasma oncotic pressure. Fluid moves from pulmonary capillaries into the pleural space. It is thin, watery, and has low protein and blood cell counts.
What is exudative effusion?
Fluid formation due to increased capillary permeability. It has a higher protein and cell count. Generally caused by inflammation, infection, or malignancy.
What is neoplasm?
A disturbance of the normal reabsorption of fluid secondary to the obstruction of the mediastinal lymph nodes draining the parietal pleura
What fluids can get into the pleural space (other than transudate and exudate)?
Pus (empyema), blood (hemothorax), chyle (chylothorax).
What are the signs and symptoms of a pleural effusion?
Chest pain, dyspnea, increased RR, decreased fremitus, mediastinal shift to opposite sides in severe cases, dry, non-productive cough, JVD
What is the key diagnostic tool for diagnosis of pleural effusions?
CXR showing density over the affected area; entire side of lung will be obscure and might have meniscus sign.
What does the pH value of a thoracentesis tell us about a pleural effusion?
<7.2- empyema
7.2-7.3 - take in clinical context; watch and wait
>7.4- CHF/malignancy
7.6 is normal
What is the safe triangle?
The safe place to put a chest tube. Usually in the 4th or 5th intercostal space in the axillary zone. We want to put it as high as possible so it does not damage the diaphragm
What is the best treatment for a pleural effusion?
To treat whatever else that is going on to cause it. (ex. heart failure, lung infection, etc.)
What is pleurodesis?
Injecting a substance such as tetracycline (antibiotic) directly into the pleural cavity to cause the surface of the lung to adhere directly to the chest wall, reducing recurrent effusions.
What is PleurX?
An indwelling pleural catheter used to treat recurring pleural effusions.
What is a pneumothorax?
Air within the pleural space
What are the three types of pneumothorax?
Closed, open, and tension
What is a closed pneumothorax?
Air enters the pleural space from the lung through a tear in the visceral pleura
What is an open pneumothorax?
A puncture through the chest wall that allows air in from the outside.
What is pendelluft?
A phenomenon created by an open pneumothorax where air from the collapsed lung is pushed into the unaffected lung and the mediastinum swings towards unaffected side, compressing it. On exhalation, air escapes through the wound and the mediastinum swings back towards collapsed lung. Because of this swinging, air is being re-breathed between the two lungs.
What is a tension pneumothorax?
A pneumothorax where air can enter the pleural space but cannot leave, so the chest is continuously filling with air. It compresses lungs and compromises cardiopulmonary function, so it is life-threatening.
What is the biggest sign of a tension pneumothorax?
Tracheal deviation and hyperinflation of chest.
Why do we place chest tubes above the ribs?
To avoid the nerve bundles and blood vessels that run in the grooves on the underside of the ribs.