Pulmonology- through fibrotic dz Flashcards
What are the two types of pneumocytes, their functions
Type I- epithelium
Type II- make surfactant, lung stem cells
What are the functions of Macrophages in the lugns
Digest Antigens and clear surfactant
What cells make surfactant?
How is it released?
What happens to extra surfactant?
Surfactant is made by type II pneumocytes, stored in lamellar bodies which look like onions on EM.
The tubular myelin flattens out and gets absorbed onto the surface.
Excess surfactant is either reabsorbed and recycled by the type II pneumocytes or cleared by macrophages
How is pulmonary vasculature different than systemic vasculature
Pulmonary vasculature vasoconstricts in response to decreased oxygen to shunt blood to better oxygenated BV. Systemic BV do the opposite.
What are the 4 congenital anomalies
Pulmonary hypoplasia
Bronchogenic Cyst
Tracheo-esophogeal fistula
Bronchopulmonary sequestration
Pulmonary Hypoplasia- Si/Sx of presentation
Etiology
Presentation- neonate with respiratory distress
2 etiologies - Potters sequence and Diaphragmatic hernia
Potters Sequence
Renal Agenesis or lower urinary tract blockage –> dec amniotic fluid vol –> many issues but causes BILATERAL pulmonary Hypoplasia
Diaphragmatic Hernia
If diaphragm doesnt form correctly a loop of bowel may be in the thorax and inhibit the ability of the lungs to form.
Occurs more commonly on the left because the liver is on the right.
UNILATERAL
Would see bowel on a chest xray
Bronchogenic Cyst
Cystic space lined by bronchial epithelium so it fills with muccus.
Space occupying lesion leading to respiratory insufficiency
can potentially become infected
Tracheo-esophogeal fistula
Most common type
Presentation
dx
Anomalous connection between trachea and esophagus
most commonly it is atresia of the esophagus with proximal and distal connections to the trachea
Presents during the first feeding with coughing/ spitting and predisposes the pt to lipoid pneumonia
dx w/ barium x ray
Bronchopulmonary sequestration
segment of lung that is not connected to the main bronchus.
Has a different airway connection and different vasculature connection (comes off of thoracic aorta)
This is a space occupying lesion that is fatal if hemorrhages and is predisposed to infection
Atelectasis- definition
Collapse of alveoli
Atelectasis- complications
hypoxemia due to the poor ventilation
Risk of infection
4 types of atelectasis
Resorptive
Compression
Contraction
Neonatal
Resoprtive Atelactasis causes
bronchial obstruction or tumor that isolates part of the lung leading to all of the air in those alveoli to be absorbed
Tumor or muccus
Compression atelectasis- casues
External pressure on lungs that cause the lung to collapse ie tumor, pneumothorax, pleural effusion
Contraction type atelactasis- scar
scarring of lung from
Neonatal atelactasis- 2 causes
Premature babies can have atelectasis because surfactant production doesn’t start till 28 weeks and isn’t sufficient till 34 weeks. If a baby is going to be born prematurely can give the baby gluccocorticoids to stimulate surfactant production
Maternal Diabetes- insulin inhibits surfactant production.
Pulmonary edema- MCC
Left heart failure but can also be caused by infection, toxin, drowning
Pulmonary edema- pathogenesis
hemodynamic causes ie dec hydrostatic pressure ie LHF or dec oncotic pressure
Microvaacular injury- vessels become leaky ie drugs, toxins, infections
Pulmonary edema progression
Interstitial edema- lugns become stiff and pt has SOB
Alveolar edema- fluid enters alveolar airspace causes blocked ventilation and hypoxemia. As a side note this is a good medium for pneumonia- pneumonia secondary to edema
Chronic congestion- small hemorrhages allow blood to leak into the alv leading to the eventual formation of Heart Failure cells
What is a Heart failure cell
Hemosiderin laden macrophage from digesting RBCs
Pulmonary edema- Gross and microscopic appearance
Gross- frothy fluid
Microscopic- lungs are full of fluid but there are no PMNs thats how you know its not pneumonia
Pulmonary Edema- Si/ Sx
Symptoms- paroxysmal noctural dyspnea, orthopnea, SOC on exertion
Signs- Rales/ Ronchi, evidence of HF- JVD, hepatomegaly, pedal edema
Pulmonary edema- appearance on CXR
kerley B lines and blunted costophrenic angles
Adult respiratory Distress Syndrome- (ARDS or DAD) MCC
Has a huge variety of causes- Sepsis is most common
also- shock, trauma, oxygen toxicity, drugs, gas, drowning, aspiration, trauma, pneumonia, chemo
ARDS- pathogenesis
Any of the causes can damage either the type I pneumocytes or the capillary endothelium. Damage to one quickly progresses to damage to the other
ARDS- first phase
Acute/ exudative phase has 3 charecteristics
leaky endothelium –> pulmonary edema
necrosis of type I pneumocytes –> hyaline membrane formation which serves as a barrier to gas diffusion
damage to type II pnemocytes –> atelactasis
ARDS- second phase
repair/ organization
Type II pneumocytes flatten out and become type I pneumocytes.
ARDS- long term sequellae
Pts may end up with permanent and progressive fibrosis or may end up healed
ARDS- presentation
Acute onset of SOB + hx of inciting event - LHF
Hypoxemia will be unresponsive to supplemental oxygen
ARDS CXR
bilateral opacities
Pulmonary embolus- Etiology
Form in legs or pelvis normally in the femoral vein and make their way to the lung.
Normally a thrombus but can also be air, bone marrow, or fat
Pulmonary embolus- risk factors
Virchow’s triad- statis, hypergoagulable state, endothelial damage
Pulmonary embolism- pathology
Do not form an infarction but cause hemorrhagic necrosis due to the dual blood supply
Pulmonary embolism- presentation
may be asymptomatic but can cause coughing, SOG, dyspnea, pleuritic chest pain
What happens if you have several asymptomatic pulmonary emboli
Pulmonary HTN
What is the main complication of a saddle embolus
sudden death
Pulmonary HTN- etiology
Anything that increases the vascular pulmonary resistance
Pulmonary HTN- Causes
normally secondary to another cause.
Heart: Mitral stenosis, LHF, L –> R shunt
COPD can cause chronic hypoxia induced vasoconstriction
Recurrent pulmonary emboli
Idiopathic
Genetic- BMPR2 mutation
immune disease
pulmonary fibrosis
Primary is very rare can be from familial from BMPR2 mutation
Pulmonary HTN- pathology
This is the only time there will be atheroslcerosis in the pulmonary pulmonary arteries. So it is pathonemonic
Onion skinning of the pulmonary arteries
Plexiform lesions of the arteriolar wall means that the HTN was severe
What do plexiform lesions resemble
Glomeruli
Pulmonary HTN- presentation
start as asymptomatic but later pts have fatigue, SOB, dry cough, peripheral edema
what is a major complication of Pulmonary HTN
Cor Pulmonale
Spirometry measures for obstructive vs Restrictive
FEV1 FEV1: FVC peak expiratory flow RV TLC VC
Spirometry in restrictive dz
FEV1 dec or no change FEV1: FVC inc or no change peak expiratory flow: no change RV variable RLC dec VC dec
Spirometry in obstructive dz
FEV1 dec FEV1: FVC dec Peak expiratory flow dec RV inc TLC inc VC dec
Restrictive lung dz- main categories
Chest wall disorders ie Kyphosis, phrenic nerve impairment, diaphragmatic paralysis, kyphosis, pleural dz
Interstitial dz which are split into ARDS and chronic interstitial lung dz
3 categories of chronic interstitial lung dz
Fibrotic
Granulomatous
Eosinophillic
Restrictive fibrotic lung dz
Cryptogenic organizing pneumonia Idiopathic pulmonary fibrosis Phenoconioses CT disorders radiation pneumonitis drugs
Granulomatous lung dz
Sarcoidosis
Hypersensitivity pneumonitis
Eosinophillic lung dz
Primary Eosinophilia
Characteristics of Restrictive lung dz: Etiology Pathogenesis Hx lung description
Disease is due to common and repeated insults
These insults trigger T cells and B cells to activate macrophages which in genetically predisposed individuals activate fibroblasts for collagen deposition for repair
Hx is very important- occupations, hobbies, travel, allergies, smoking
lungs will be stiff with dec compliance and inc elasticity
Pneumoconiosis
description
examples
medium sized air particles in the air get trapped in by macrophages in the lung which cannot break them down and so they stimulate fibrosis
mostly seen in upper lungs except for asbestosis
examples- coal workers pneumoconiosis, silicosis, asbestosis, silicatosis
Coal Workers Pneumoconiosis hx etiology pathology versions
hx- coal workers or miners
coal dust is fileld with coal, organics, and silica
coal- nbd, but turns lung black
organics and silica cause damage
coal macule- build up of coal dust in the lung, its dark, and leads to centrilobular emphysema
Progressive massive fibrosis- immune response to coal can lead to scar tissue formation and is bad
Silicosis- Hx pathology chest x ray microscopy
normally occurs in sandblasters or stone grinders requiring massive amounts of long term exposure
the silica is ingested by macrophages which cant break it down –> cytokine release –> fibrogenic factor release leading to a fibrogenic response. once the silica is there there dz progresses even once exposure stops
CXR- egg shell calcification of the hilar LN
microscopic- dense ball of collagen with visible flecks of silica visible under polarized light. Will be able to see these on many specimens, not always pathologic
Acute silicosis
One massive exposure leads to fibrosis
this is very rare
Asbestosis- class of disease
pneumoconiosis
Asbestosis- normal population mecahnism causes what dz risk factors for what dz pathology
seen in- fire profing, insulation, roofing, building demolition
mechanism- long thin fibers go to the lower lobes and may penetrate –> irritation
causes- pulmonary and/ or pleural fibrosis
Risk factor for- lung cancer, more so than malignant mesothelioma
Pathology- ferrunginous bodies
Ferrunginous bodies-
what dz
what are they
Asbestosis
asbestos fibers encrusted with Fe and protein
Silcatosis- etiologic agent
Organic material + divalent cation
Caplan Syndrome
Rheumatoid pneumoconiosis
severe immune response to pneumoconiosis + rhematoid nodules
Often seen in pts with RA and coal workers lung
Usual interstitial penumonitis- idiopathic pulmonary fibrosis
repeated bouts of alveolitis triggered by an unknown agent
UIP- describe the fibrosis
patchy interstitial fibrosis- heterogenous age and severity
worse in subpleural spaces and near fissures
may result in honeycombing
UIP- pathophysiology
Unknown agent activates TGF beta 1 with 3 outcomes
activates fibro and myofibroblasts
inhibits calveolin in fibroblasts (normally calveolin is inhibitory)
reduces telomerase activity causing early senescence and apoptosis
UIP- prognosis
poor response to anti-inflammatory tx
Poor prognosis
Crytogenic Organizing pneumonia or bronchiolitis obliterans organizing pneumonia)
nodules of organizing fibrous tissue in the small airways- bronchioles, alveolar ducts and alveolia
COP/BOOP- etiology
unknown
COP/BOOP- pathology
homogeneous lesions
COP/BOOP- prognosis
good response to steroids
Hypersensitivity pneumonitis- types
farmer’s lung (moldy hay), Pidgeon breeder’s lung (pidgeon stool), Humidifier lung
Hypersensitivity pneumonitis- mechanism
immune response to a known inhaled allergen
Hypersensitivity pneumonitis- are there eosinophils or IgE Abs
NO EOSINOPHILS OR IGE ABS IN HYPERSENSITIVITY PNEUMONITIS
Hypersensitivity pneumonitis- location of the lesion
Bronchiolar centered inflammation- granulomas and interstitial lymphoid infiltration
Hypersensitivity pneumonitis- tx
avoid further exposure
Sarcoidosis- definition
what rxn takes place
multisystem granulomatous dz
CD4 Th cells react to an unknown Ag
Sarcoidosis- what organs are normally affected
lungs and hilar LN skin eye liver spleen
What immune cells are involved in sarcoidosis
CH4 Th
what is the Ag is involved in sarcoidosis
unknown Ag
What is typical population for Sarcoidosis
AA female
symptoms of sarcoidosis
if they are symptomatic- cough, dyspnea, chest pain, fever, weight loss
appearance of sarcoidosis on x ray
well circumcised lesion
Pathology of sarcoidosis
non caseating perhilar granulomas- follow the lymphatics
ie non caseating granulomas that are next to the lymphatics
What is associated with sarcoidosis
elevated ACE
elevated Vit D
inc Serum Ca
Pulmonary Eosinophilia- definition
inc eosinophils in blood, sputum or lavage
pulmonary infiltrates
(results in fibrotic lung dz?)
Pulmonary Eosinophilia- types
Acute- rapidly progressive
Simple- transient or treatable
Chronic
Pulmonary Eosinophilia- associated with what dz
Asthma Aspergillus parasites Churg- Strauss Collagen- Vascular Idiopathic
Alveolar Proteionosis
Autoimmune dz of inc surfactant production
Alveolar proteonosis- pathology
Anti GM- CSF Ab –> dec clearance of surfactant by macrophages.
Alveolar proteinosis- microscopy
accumulation of surfactant in alveolar spaces
PAS +
Desquamative interstitial pneumonia- causes
related to smoking
Desquamative interstitial pneumonia- pathology
accumulation of macrophages in alveolar spaces leading to mild inflammation
Desquamative interstitial pneumonia- prognosis and tx
good porpoises
responds to steroids
What causes pulmonary fibrosis
long standing inflammatory damage by PMNs leads to pulmonary fiborsis
What dzs cause pulmonary fibrosis
Autoimmune dz- RA, scleroderma, pneumoconiosis, drugs, radiation, hypersensitivity penumonitis, sarcoidosis
Primary dz may be- usual interstitial pneumonitis
Pulmonary fibrosis- mechanisms
Restrictive- lungs are stiff due to fibrosis leading to dec complacence –>
Hypoxemic b/c fibrosis is barrier to gas exchange –>
Hypertensive- b/c of inc in vascular resistance
Pulmonary fibrosis- lung findings
honeycomb lung- alternating aerated and fibrotic areas
microscopic- inflammation, fibrosis, hyperplasia of pneumocytes
