Notes by dr. Claudio Italiano
see also: fibrosi polmonare
We are talking about restrictive pneumopathies as pathological conditions that
involve the reduction of pulmonary air volumes, caused by:
-Alterations of the pulmonary parenchyma (intrinsic).
- Diseases of the pleura, the chest wall or the neuromuscular apparatus (extrinsic).
They are inflammatory and / or fibrotic diseases of the pulmonary interstitium;
they are characterized by the occupation of air spaces by exudates and / or
cellular debris; also alveolar pneumonias are restrictive pneumopathies are
considered in this group.
-Interstitial pneumons
-ARDS (Adult Respiratory Distress Syndrome)
-NRDS (Neonatal Respiratory Distress Syndrome)
- Chronic interstitial diseases
From the pathophysiological point of view it can be stated that:
restrictive parenchymal diseases cause air space reduction due to localized or
widespread interstitial increase. When we talk about interstitium we refer to
the connective that surrounds the veins and the bronchovascular tree and to the
wall of the alveolar septa. Under these conditions the respiratory flows are
reduced proportionally to the lung volumes. Hypoxemia and hyperventilation at
rest results.
In order to determine an intrinsic interstitiopathy, that is, of the most
intimate structures of the lung, injuries must be performed. They start from
lesions of the alveolar capillaries with production of hemorrhage, protein
exudation and accumulation of inflammatory elements in the alveolar spaces; or
you may have edema and inflammatory interstitial infiltration; in the final
analysis we will have interstitial fibrosis as a frequent consequence of the
previous conditions.
From an etiopathogenetic point of view the causes are represented by:
From influenza virus: for ex. bilateral thickening of the broncho-vascular plot
and reduction of transparency
Ethiological agents: viruses, bacteria (mycoplasma pneumoniae), fungi
Favorable evolution in most viral forms
Unfavorable evolution in fibrosis
It is an acute restrictive disease due to widespread alveolar damage due to the
systemic release of cytokines.
Multi-factorial etymology (cranial trauma, embolism of amniotic fluid, CID,
massive transfusions, extensive burns, acute pancreatitis, etc.
It is characterized by insufficiency of surfactant (immaturity, maternal
diabetes, aspiration of amniotic fluid)
Pulmonary collapse and endoalveolar exudation of fibrin (hyaline membranes)
Fatal in 50% of newborns <1000 g.
Complications: cerebral hemorrhage, necrotizing enterocolitis, bronchopulmonary
dysplasia
These are non-muscular pathologies of the chest wall and pleura which are
responsible for poor respiratory mechanics; there are conditions of
kyphoscoliosis, rind and pleural plaques, effusions and tumors. In other
conditions such as neuromuscular disorders, the altered respiratory mechanics
depends on degenerative diseases of the motor neurons, and myopathies.
Exudative: necrosis of alveolar lining, fibrin exudation, hyaline membranes,
capillary thrombosis, activation of lithic neutrophils enzymes, endoalveolar
hemorrhages
Organizational: carnation and pulmonary fibrosis
They are divided into:
Idiopathic pulmonary fibrosis
Extrinsic allergic pneumonia
Atypical pneumonitis
Pulmonary fibrosis during systemic connectivopatie
Pneumoconiosis
Average age of presentation 50 years
Progressive and fatal progression
Pathology: alveolitis with neutrophil infiltrates
Pathogenesis: deposition of immunocomplexes with activation of macrophages,
neutrophil infiltration and release of lysosomal enzymes, chronic inflammation
and deposition of fibers (interstitial fibrosis)
pathology
Lymphoplasmacellular interstitial infiltrates and histiocytes, tendency to dense
fibrosis
Alveolar spaces occupied by lymphocytes, plasma cells, macrophages and
neutrophil granulocytes
BAL: 10-20% of neutrophil granulocytes
Histopathological pictures
UIP (usual interstitial pneumonitis): interstitial infiltrate, increase in
thickness of alveolar septa with fibrosis (advanced form?)
DIP (desquamative interstitial pneumonitis): alveolar spaces whipped with
macrophages, slightly thickened septa, modest fibrosis (early form?)
Proliferation of fibroblasts in alveolar septa with collagen production
Organization of the intra-alveolar exudate with fusion of the septa
It can be the final stage of different pathological processes
Pathology: fibrosis of the septa which delimit large air spaces
They are determined by inhalation of biological material in the form of
powders or aerosols (spores, animal proteins, etc.)
We distinguish acute and chronic forms
Possible evolution in pulmonary fibrosis
Multiple parenchymal nodules
Infectious histiocytes and eosinophil granulocytes
Proliferation of Langerhans cells
Storage and retention of inorganic powders at the pulmonary level, and consequent tissue reaction.
Amount of dust retained in the lungs
- Concentration of the substance in the air
- Exposition time
- Efficiency of disposal mechanisms
Shape and size of particles
Chemical composition of particles
- for example, silica is very fibrogenic
- coal is not very fibrogenic
pneumology index