RESPIRATORY: 606 - 607 Flashcards
What are pneumoconioses?
Chronic occupational exposure to small fibrogenic particles that leads to interstitial fibrosis
Give 4 examples of pneumoconioses.
- Asbestosis
- Coal workers’ pneumoconiosis
- Silicosis
- Berylliosis
What does pneumoconiosis increase the risk of?
- Cor pulmonale
2. Caplan syndrome (rheumatoid arthritis and pneumoconioses with intrapulmonary nodules)
What professions are associated with asbestosis?
Shipbuilding, roofing, plumbing
Describe the plaques found in asbestosis.
Ivory white, calcified pleural plaques
Asbestosis is associated with increased risk of what 2 cancers.
Bronchogenic carcinoma»_space; mesothelioma
Does asbestosis tend to affect the upper or lower lobes?
Lower
What do asbestos (ferruginous) bodies look like?
Golden-brown fusiform rods resembling dumbbells; has iron deposits
What accumulates in macrophages in coal workers’ pneumoconiosis?
Carbon
Are the lung in coal workers’ pneumoconiosis shrunken or swollen?
Shrunken (from inflammation and fibrosis)
What is another name for coal workers’ pneumoconiosis?
Black lung disease
Does coal workers’ pneumoconiosis tend to affect the upper or lower lobes?
Upper
What is anthracosis?
Asymptomatic condition found in many urban dwellers exposed to sooty air –> collection of carbon laden macrophages in the lung from mild exposure
What is silicosis associated with?
Foundries, sandblasting, mines
Describe the pathophysiology of silicosis.
Macrophages respond to silica and release fibrogenic factors leading to fibrosis
Why is silicosis thought to relate to increased risk of TB?
Silica may disrupt phagolysosomes and impair macrophages increasing susceptibility to TB infection
What is the only pneumoconiosis associated with an increased risk of TB?
Silicosis
Does silicosis tend to affect the upper or lower lobes?
Upper
Describe the hilar lymph nodes in silicosis.
“Eggshell” calcification
What two occupations are at increased risk of berylliosis?
- Beryllium miners
2. Workers in aerospace industry
In what ways is berylliosis similar to sarcoidosis?
Both present with noncaseating granulomas in the lung, hilar lymph nodes, and systemic organs
Berylliosis increase the risk of what?
Lung cancer
Describe the pathophysiology in neonatal respiratory distress syndrome.
Surfactant deficiency –> increased surface tension –> alveolar collapse
What is predictive of neonatal respiratory distress syndrome as a lab test?
Lecithin:sphingomyelin ratio < 1.5 in amniotic fluid
Why is there a risk of patent ductus arteriosus in neonatal respiratory distress syndrome?
Persistently low O2 tension
Therapeutic supplemental O2 for NRDS can result in what sort of damage?
Free radical damage:
- Retinopathy of prematuriy
- Bronchopulmonary dysplasia
How can we treat neonatal respiratory distress syndrome?
- Maternal steroids before birth
2. Artificial surfactant for infant
What are 3 risk factors for NRDS?
- Prematurity
- Maternal diabetes
- C-section delivery
Why is maternal diabetes a risk factor for NRDS?
Increased sugars –> increased fetal insulin –> insulin inhibits surfactant production
Why is C-section delivery a risk factor for NRDS?
Decreased release of glucocorticoids
With a normal delivery, there is release of glucocorticoids (stress hormone) which increases production of surfactant and causes already made surfactant to be released by type II pneumocytes into the lung
What are some of the clinical features of NRDS?
- Increased respiratory effort after birth
- Tachypnea with use of accessory muscles
- Grunting
- Hypoxemia with cyanosis
- Diffuse granularity of lung on X ray
What are some of the causes of acute respiratory distress syndrome?
- Trauma
- Sepsis
- Shock
- Gastric aspiration
- Uremia
- Acute pancreatitis
- Amniotic fluid embolism
Describe the pathophysiology in acute respiratory distress syndrome.
Diffuse alveolar damage –> increase alveolar capillary permeability –> protein-rich leakage into alveoli and noncardiogenic pulmonary edema –> eventual formation of intra-alveolar hyaline membrane
What are 2 problems resulting from the formation of hyaline membrane?
- Thickened diffusion membrane leads to hypoxemia and cyanosis
- Membranes are sticky and increase the surface tension of the air sacs leading to diffuse collapse
What is the initial damage of ARDS due to?
Activation of neutrophils induces protease mediated and free radical damage to type I and type II pneumocytes
Also activates coagulation cascade
Compare FEV1/FVC in normal vs. obstructive vs. restrictive lung disease.
Normal = 80%
Obstructive < 80%
Restrictive > 80%
