Pulmonary vascular disease Flashcards
Under normal conditions, interstitial spaces of the lung is kept dry by
Pulmonary lymphatics located within the axial and peripheral interstitium of the lung
Because there are no lymphatic structures immediately within the alveolar walls (parenchymal interstitium), filtered interstitial fluid is drawn to lymphatics by a
Pressure gradient from alveolar interstitium to the axial and peripheral interstitium
When the rate of fluid accumulation in the interstitium exceeds the lymphatic drainage capabilities of the lung, fluid accumulates first within the
Interstitial spaces
Most common mechanism of pulmonary edema
Change in the normal starling forces that govern fluid movement in the lung
Imbalance of starling forces in pulmonary edema is most commonly the result of
Increase capillary hydrostatic pressure, and less commonly diminished plasma oncotic or interstitial hydrostatic pressure
Other mechanisms in pulmonary edema aside from imbalance in starling forces
- obstruction or absence of the normal pulmonary lymphatics, which leads to the excess accumulation of interstitial fluid.
- disorders can injure the epithelium of the capillaries and alveoli, causing an increase in capillary permeability that allows protein-rich fluid to escape from the capillaries into the pulmonary interstitium
Thickening of axial interstitium results in what imaging findings
Loss of definition of intrapulmonary shadows and thickening of peribronchovascular interstitium causing peribronchial cuffing and tram tracking
Involvement of peripheral and subpleural interstitial structures in pulmonary edema produces
Kerley lines and subpleural edema
Represents thickening of central connective tissue septa and peripheral interlobular septa, respectively
Kerley A and B lines
Kerley C lines represent a network of thickened interlobular septa
It is the accumulation of fluid within the innermost (interstitial) layer of the visceral pleura
subpleural edema
subpleural edema are is best seen in ____ and appears as smooth thickening of the interlobular fissures
lateral radiographs
Develops when fluid in the interstitial spaces extends into the alveoli
Airspace pulmonary edema
Most common form of pulmonary edema
Hydrostatic pulmonary edema
Hydrostatic pulmonary edema is usually caused by
elevation in pulmonary venous pressure (pulmonary venous hypertension)
Causes of pulmonary venous hypertension may be divided into four major categories
- obstruction to left ventricular inflow,
- left ventricular systolic dysfunction (LV failure),
- mitral valve regurgitation and
- systemic or pulmonary volume overload
classic cause of obstruction to left ventricular inflow is
mitral stenosis
more common causes of LV inflow obstruction
poor left ventricular compliance (diastolic dysfunction), such as caused by hypertrophy or chronic ischemic subendocardial fibrosis
3 Common causes of LV failure include
- ischemic heart disease,
- aortic valve stenosis and regurgitation, and
- nonischemic cardiomyopathy
Normal pcwp
8-12 mmHg
Pcwp level that leads to findings of interstitial pulmonary edema such as loss of vascular definition, peribronchial cuffing and Kerley lines
19-25 mmHg
- Mild elevation of PCWP (12 to 18 mm Hg) produces constriction of lower lobe vessels and enlargement of upper lobe vessels.
- Progressive elevation of PCWP (19 to 25 mm Hg) leads to the findings of interstitial pulmonary edema:
• loss of vascular definition,
• peribronchial cuffing, and
• Kerley lines.
Pcwp level that produces alveolar filling with radiographic findings of bilateral airspace opacities in the perihilar and lower lung zones
More than 25 mmHg
classic radiographic findings of Pulmonary Venous Hypertension
enlargement of pulmonary veins and redistribution of pulmonary blood flow to the nondependent lung zones
True or false: with PVH in the upright patient with normal lung parenchyma, the upper zone vessels are frequently as large as or larger in diameter than the lower zone vessels
true
alveolar pulmonary edema localized to the right upper lung may be seen in patients with
severe mitral regurgitation
When respiratory failure develops as a result of this condition, and is associated with increased lung stiffness (noncompliance) it is termed
acute lung injury or when severe, ARDS
6 most common causes of increased permeability edema
shock, severe trauma, burns, sepsis, narcotic overdose and pancreatitis
key factors in the development of capillary endothelial damage
recruitment and activation of neutrophils in the lung, with release of enzymes and oxygen radicals
Stage of ARDS: happens within 12-24 hours following initial insult, damage to capillary endothelium produces engorged capillaries and proteinaceous interstitial edema
Stage 1: exudative
Stage of ARDS: within the first week, injury to type 1 pneumocytes leads to flooding of alveoli with edema fluid and proteinaceous and cellular debris, which form hyaline membranes lining the distal airways and alveoli
Stage 2: proliferative
Stage of ARDS: occurring 10 to 14 days following the initial insult, type 2 pneumocytes proliferate in an attempt to reline the denuded alveolar surfaces and fibroblastic tissue proliferates within the interspaces
Stage 3: fibrotic
Radiographic pattern of ARDS
patchy peripheral airspace opacities by 12-24 hours, with minimal or absent interlobular septal thickening, coalesce over the next days to produce confluent bilateral airspace opacities with air bronchograms, after a week becomes coarse reticulonodular, if unchanged, honeycombing
in pulmonary edema associated with chronic cardiac failure, the vascular pedicle, which represents the mediastinal width at the level of SVC and left subclavian artery measures
> 53 mm on PA radiograph
90% of all primary tracheal tumors in adults are malignant or benign?
Malignant
Most common histologic type of primary tracheal malignancy
Squamous cell carcinoma
Majority of tracheal malignancy arise in what area
Distal trachea, within 3-4 cm of tracheal carina
Second next common site in tracheal neoplasms
Cervical trachea
Malignant neoplasm that arises from the tracheal salivary glands and accounts for 40% of primary tracheal malignancies. Tends to involve the posterolateral wall of the distal 2/3 of trachea or main or lobar bronchi
Adenoid cystic carcinoma
Arises from tracheal cartilage and is identified by the presence of calcified chondroid matrix within the tumor
Chondrosarcoma
Most common type of thyroid malignancy to invade the trachea
Papillary and follicular
Extrathoracic primary tumors that are most often associated with hematogeneous endotracheal metastases are carcinomas of
Breast, kidney and colon and melanoma
capillary permeability edema can sometimes be distinguished from hydrostatic edema by the following:
a non-dependent or peripheral distribution of edema, absence of other signs of hydrostatic edema such as interlobular septal thickening and subpleural edema, and a lack of short term change
true or false: in neurogenic pulmonary edema, both hydrostatic and increased permeability mechanisms are involved
true
high altitude pulmonary edema happens in individuals who had rapid ascent of altitudes above
3500 m
Pathophysiology of high altitude pulmonary edema
edema typically develops within 48-72 hours of ascent and appears to reflect a varied individual response to hypoxemia, in which scattered areas of pulmonary arterial spasm result in transient pulmonary arterial hypertension—> causes damage to capillary endothelium and increase permeability edema, typically with a patchy distribution
more susceptible to reexpansion pulmonary edema
rapid evacuation of large pneumothorax or PE present for more than 48 hours and young age
Pulmonary edema may also happen after immediate treatment of acute upper airway obstruction due to
creation of markedly negative intrathoracic pressure by attempts to inspire against an extrathoracic airway obstruction, producing decreased interstitial hydrostatic pressure, thereby promoting transudation of fluid into lungs
severe and often fatal form of pulmonary edema tha may develop in a pregnant woman when amniotic fluid gains access to the systemic circulation during labor
amniotic fluid embolism
fetal distress and demise may happen in amniotic fluid embolism because of ___ which play a key role in the pathogenesis of this disorder
mucin within fetal meconium
contributes to vascular collapse leasding to sudden PAH, cor pulmonale with decreased CO and pulmonary edema in amniotic fluid embolism
anaphylactoid reaction and DIC
There may be enlargement of central pulmonary arteries and right heart as manifestation of
cor pulmonale
common complication occurring 24 to 72 hours after the fracture of a long bone such as the femur
fat embolism
mechanism of pulmonary edema in fat embolism
fat is hydrolyzed to its component fatty acids causing increased pulmonary capillary permeability and hemorrhagic pulmonary edema
systemic findings of fat embolism
petechial rash, CNS depression and pulmonary changes
6 Autoimmune diseases associated with pulmonary hemorrhage
Goodpasture syndrome, idiopathic pulmonary hemorrhage, granulomatosis with polyangiitis, sytemic lupus erythematosus, RA and polyarteritis nodosa
autoimmune disease characterized by damage to the alveolar and renal glomerular basement membranes by a cytotoxic antibody. the antibody is directed primarily against renal glomerular basement membrane and cross reacts with alveolar basement membrane to produce renal injury and pulmonary hemorrhage characteristics of this disorder
Goodpasture syndrome
diagnosis of Goodpasture disease
immunofluoresent studies of renal or lung tissue
development of pulmonary hemorrhage in vasculitides such as granulomatosis with polyangitis, SLE, RA and polyarteritis nodosa are due to
small vessel pulmonary arteritis and capillaritis which results in spontaneous hemorrhage
main laboratory test in patients with suspected pulmonary embolism
plasma D-dimer level
It is a degradation product of fibrin and is a very sensitive indicator of the presence of venous thrombosis
D-dimer
First examination obtained in all patients with suspected PE
chest radiograph
most common radiographic findings in pulmonary embolism without infarction are
peripheral airspace opacities and linear atelectasis
Known as the westermark sign which is extremely rare finding in pulmo embolism
localized peripheral oligemia with or without distended proximal vessels
known as Hampton hump in infarction related to pulmo embolism
presence of pleural effusion and the development of a pleura-based wedge-shaped opacity which lacks air bronchogram
Hampton hump in pulmo embolism is usually seen in what area
posterior or lateral costophrenic sulcus of the lung
in embolism without infarction, airspace opacities should resolve completely within how many days
7-10 days
first imaging study to be done in pregnant women with a normal chest radiograph in the diagnosis of pulmo embolism
Ventilation/perfusion lung scintigraphy using IV macroaggregated albumin radiolabeled with technetium (Tc-99m)
Recommended study for detection of pulmonary embolism
CT angiography of pulmonary arteries
CT pulmo angiography is better done in what phase of respiration
expiratory
chronic emboli should be suggested when
filling defect is adherent to the vessel wall rather that in the center of lumen or when a web is present
technique selectively used whena definitive diagnosis of pulmo embolism or DVT cannot be achieved by less invasive means. It requires right heart and pulmonary artery catheterization
digital subtraction angiography
3 secondary signs of pulmo embolism in pulmonary angiography include
prolonged arterial phase,
diminished peripheral perfusion and
delay in the venous phase
causes of nonthrombotic pulmonary embolism
air embolism, fat embolism, methylmethacrylate embolization complicating vertebroplasty, radioactive seed implant embolization from prostate brachytherapy
pulmonary tumor emboli usually comes from what 4 malignancies
renal cell carcinoma,
breast cancer,
HCC and
GI malignancy
pulmonary arterial hypertension is defined as a systolic pressure in the pulmonary artery exceeding ___ mmHg either measured directly by right heart catheterization or as estimated by echocardiography
30
typical radiographic findings of PAH
enlarged main and hilar pulmonary arteries that taper rapidly toward the lung periphery
useful measurement for enlargement of central pulmonary artery, usually indicating PAH in the absence of a left-to-right shunt is a transverse diameter of proximal interlobar artery on PA radgiograph that exceeds
16 mm
in patients younger than 50 years, in the diagnosis of PAH, a ratio of diameter of the MPA( measured at the level of the main Right PA) to the transverse diameter of ascending aorta at the same level greater than 1 strongly correlated with a mean PA pressure greater than
20 mmHg
In patients older than 50 years, a maximum transverse measurement of MRA greater than ___ mm correlates better with PAH
30
Flattening or bowing of the interventricular septum toward the LV indicates
RV hypertension
Signs of long standing PAH
RV hypertrophy, RV dilatation, and right heart failure (cor pulmonale)
disease among young women in whom medial hypertrophy and intimal fibrosis obliterate the muscular arteries
plexogenic pulmonary arteriopathy
a condition related to PVOD which is characterized by the proliferation of capillaries throughout the pulmonary interstitium, resulting in venular obstruction
pulmonary capillary hemangiomatosis
combination of pulmonary edema with a normal sized heart, absent findings for PVH, normal PCWP and insiduous onset of dyspnea should suggest this diagnosis rather than left heart failure, mitral valve disease or large vessel pulmonary venous occlusion
pulmonary capillary hemangiomatosis/PVOD
radiographic findings in PCH/PVOD
interlobular septal thickening, centrilobular nodular ground-glass opacities, and pleural effusions
