Exam3 Pulmonary Flashcards
What is the epithelium of bronchus?
Pseudostraified ciliated columnar epithelium
Bronchus layer?
Goblet cell, smooth muscle, submucosal seromuscious glands, cartilage
Feature of Bronchioles?
lack of cartilage and submucosal glands
layer of respiratory bronchiole and alveoli
Simple cuboidal epithelium of respiratory bronchiole,
Function of type II penumocytes?
release surfactant
What is FEV1?
Forced expiratory volume in 1 sec
What is FVC?
forced virtal capaity like volume of air exhaled with force following maximal inhalation.
What is DLCO?
Measurement to assess the lung’s ability to transfer gas from inspired air to the bloodstream
Carbon monoxide is used bc of its high affinity for hemoglobin.
When is DLCO reduced?
increased thickness of diffusion barrier(fiborsis, fluids)
- loss of surface area(emphysema)
What is pulmonary edema?
Accumulation of excessive interstitial fluid in the alveoli
What is etiology of pulmonary edema?
- Increased hydrostatic pressure ex CHF. mitral stenosis
- Increased capillary permeability ex alveolar wall injury as seen in ARDS
What is clinical features of pulmonary edema?
- shortness of breath
- cough with pink frothy sputum
- crackles on auscultation
Investigation of pulmonary edema?
Chest X ray: bilateral lung infiltrates
ABG: Hypoxemia
DLCO: reduced
What is Acute lung injury?
- Characterized by Abrupt onset of dyspnea Hypoxemia Bilateral pulmonary edema In the absence of cardiac failure -manifestation of severe acute lung injury
What is etiopathogenesis of ARDS:
Direct : Pneumonia, aspiration, inhalation injury, drowning, oxygen toxicity
Indirect: Sepsis (most common cause of ARDS) , trauma with shock, acute pancreatitis, severe burn .
What is pathogenesis of ARDS?
Endothelial cells are activated secondarily to pneumocyte injury or by circulating inflammatory factors.
- Neutrophils adhere to the activated endothelium and migrate into the interstitium and alveoli, where they dregranulate and release inflammatory mediators.
- Alveolar inflammation and injury- loss of diffusion and surfactant deficiency (type II cell damage). protein rich like fibroblast, procollagen, ) + cellular debris organizae into hylaine membrane.
What is resolution of injury?
If the inflammatory stimulus lessens: macrophages remove intra-alveolar debris
- release fibrogenic cytokine such as transforming growth factor B (TGF beta)
- stimulation of fibroblast growth and collagen deposition - fibrosis of alveolar wall
- residual type II penumocytes profliferate to replace type I pneumocytes, reconstituting the alveolar lining
- endothelial restoration occurs
what is morphology of ARDS?
- Acute (day 1-7)
: Heavy and firm lungs - Congestion of alveolar capillaries
Interstitial and intra-alveolar edema/hemorrhage - necrosis and sloughing of alveolar epithelial cells
Hyaline membranes - Organizing phase(Day 7-21)
: Proliferation of type II cells
Granulation tissue forms in the alveolar walls and spaces
In most cases, granulation tissue resolves
But in some, fibrotic thickening (scarring) of alveolar septa occurs
Fibrotic phase - beyond three weeks
What are the signs/ symptoms of ARDS?
- rapid onset of dyspnea
- Cyanosis
- respiratory failure
Investigation of ARDS
Chest Xray: Diffuse bilateral infiltrates
ABG: Hypoxemia (refractory to oxygen therapy)
High resolution of CT scan
What are poor prognostic indicators?
- Advanced age
- Bacteremia/ sepsis
- progression to multisystem organ failure
Difference of pulmonary edema?
Cardiogenic: increased hydrostatic pressure
cause: CHF, mitral stenosis
Microscopy : transudate, hemosiderin- laden macrophages(heart failure cells)
Chest X ray: Bilateral bibasilare infiltrates(dependent edema: Dependent edema is a term that doctors use to describe gravity-related swelling in the lower body.)
*Non- cardiogenic: Increased vascular permeability Cause: ARDS Microscopy: Exudate, hyaline membrane Chest Xray: Bilateral infiltrates- uniform distribution
what is hemosiderin -laden macrophages?
When blood leaves a ruptured blood vessel, the red blood cell dies, and the hemoglobin of the cell is released into the extracellular space. Phagocytic cells (of the mononuclear phagocyte system) called macrophages engulf (phagocytose) the hemoglobin to degrade
Difference between Obstructive vs Restrictive diseases
- Obstructive lung disease
Site: Airway disorder
PAtho: Increased resistance to air flow (expiration lung problem )
Spirometry: Decreased FEV1: FVC ratio
Examples: EMphysema, chronic bronchitis, asthma, Bronchiectasis - Restrictive lung disease
Site: Chest wall/ Parenchmal Disorder
PAtho: Decreased expansion with reduced lung volumes : inhalation problem
Spirometry: Normal to increased FEV1: FVC ratio
Examples: Acute restrictive disease- ARDS
Chronic restrictive diseases: Interstitial fibrosis
Pneumoconiosis
Granulomatous
Chest wall deformities: KYphoscoliosis
Neuromuscular disorders affecting the chest wall muscles.
What is COPD:
Chronic obstructive pulmonary disease - Includes emphysema.chronic bronchitis - both related to smoking - similar clinical features similar management
What is emphysema?
Irreversible enlargement of airspaces distal to the terminal bronchioles (respiratory acinus) accompanied by destruction of the alveolar wall
What are the patterns of emphysema?
- Centriacinar
- Panacinar
- distal acinar(para-septal)
- Irregular
what is centriaciar?
- respiratory bronchiole is affected and distal alveoli are spared
- smoking related
- upper lung zone
- most common type
What is panacinar?
- REspiratory bronchiole to terminal alveoli are affected
- Alpha-1 antitrypsin deficiency
- lower lung zones
What is para-septal(distal acinar)?
- Next to atelectasis, along septa, subpleural rare more common in upper lobes may form bullae(large air space) Can lead to pneumothorax
What is irregular(paracicatricial)?
Surrounding scar
Asymptomatic- incidental finding
what is pathogenesis of emphysema?
-Loss of elastin leading to destruction of alveolar septa
Smoking plus air pollutant and genetic predisposition
- oxidative stress, increased apoptosis and senescence( cell age)
- inflammatory cells, release of inflammtory of mediators
- Protease-antiprotease imbalance( congenital alpha 1- antitrypsin)
leading to alveolar wall destruction
Net result: Overdistention of alveoli which can’t collapse during expiration
What are protease and antiproteases and function of them?
Protease: normally derived from the leukocytes (mainly neutrophils)
Proteases like elastase destroy lung tissue
Antiproteases: Inhibit proteases, thereby play a protective role
what does protease- antiprotease imbalance lead to ?
destruction of the alveolar parenchyma
When protease and antiprotease imbalance occurs?
- Increase in neutrophils in the lung tissue (smoking)
2. Decreased antiprotease activity(alpha-1 antitrypsin deficiency)
What is Alpha-1 antitrypsin deficiency?
- Point mutation in the Pi gene on chromosome 14
- PIMM= normal, PiZZ- most abnormal
- defect in the synthesis of alpha-1 antitrypsin by the liver, misdoing the protein and failing to release it into the circulation
- it accumulates in the liver and can eventually lead too chronic liver disease
- characterized by panacinar emphysema, seen at younger age and is more severe if patients smokes
What is polymorphisms in TGF- B gene?
- reduced TGF- B signaling causes inadequate repair elastin injury
How is pathological features of emphysema?
- Gross: Hyperinflated lungs with/without bulla formation.
Parenchyma has moth- eaten appearance
Microscopy: Destruction of alveolar septa
- free floating alveolar septa in air spaces
- overdistended alveolar spaces
- but without fibrosis of alveoli
How does loss of elastin lead to expiratory dyspnea?
- loss of elastin recoil- use of accessory muscles- forced expiratory
- REduced radial traction on respiratory bronchioles- collapse of bronchioles during expiration (air can’t go out)- functional airway obstruction like air trapping leading to expiratory dyspnea
`
How does loss of septa lead to pulmonary hypertension?
- reduced surface area- reduced gas exchange- hypoxemia- pulmonary vasoconstriction - pulmonary hypertension
- Loss of capilaries- increased resistance in remaining capilaries- pulmonary hypertension
What are the clinical features of emphysema?
- expiratory dyspnea which is insidious in onset and progressive
- barrel- chest(increased antero-posterior diameter of the chest)
- Sitting in a forward hunched position trying to squeeze air out of the lungs
- prolonged expiration through pursed lips
- weight loss: due to hyperventilation and use of accessory muscles for respiration
Investigation of emphysema?
- Spirometry: Obstructive pattern: reduced FEV1:FVC
- DLCO: Reduced(due to loss of surface area)
- Chest Xray= hyperinflated lungs, flat domes of diaphragm
- ABG: Normal until late (no cyanosis initially) later hypoxemia, hypercapnia, and respiratory acidosis
Complications of emphysema?
Pulmonary hypertension &Cor pulmonale
- Absence of cyanosis+breathing through pursed lips = Pink Puffers
What is Chronic bronchitis?
Definition: persistent cough with mucoid sputum
For at least 3 months
In the past 2 consecutive years
In the absence of any other identifiable cause
What are the etiopathogenesis of chronic bronchitis?
Common among smokers and urban dwellers, inhaled irritant
- Submucosal gland hypertrophy- hypersecretion of mucus : distinct feature
- goblet cell metaplasia in bronchioles
- Smooth muscle hyperplasia and peribronchiolar fibrosis- small airway obstruction distally
- Inflammation: infiltrate of CD8 Tcell , macrophages, and neutrophils eventually fibrosis === No eosinophils in constrast to asthma
- Small airway obstruction due to fibrosis and mucus plugging.
What are the pathological features of chronic bronchitis?
Gross: hyperemia and edema of mucous membranes
Excessive mucinous or mucopurulent secretion
Microscopy: Thickening of the mucus gland layer
Goblet cell hyperplasia &metaplasia
chronic inflammation &fibrosis
Squamous metaplasia
Clinical features of chronic bronchitis?
Early disease- persistent cough productive of mucoid sputum
over time progreses to dyspnea on exertion
Cyanosis
Investigation of chronic bronchitis?
Spirometry: Obstructive pattern Reduced FEV1: FVC
Chest X ray: Dilated heart, prominent vessel
ABG: hypoxemia, hypercapnia
Complication of chronic bronchitis?
Secondary Infection
Over time- pulmonary hypertension and cor pulmonale
Chronic bronchitis (pulmonary hypersion and cor pulmonale happened early)
Peripheral edema +cyanosis : blue bloaters
What is bronchiectasis?
Bronchi and bronchioles and ectasia meaning dilation
- destruction of smooth muscles and elastic tissue by inflammation.
- stemming from persistent or severe infection
- leads to permanent dilation of bronchi and bronchioles
What are the etiology of bronchiectasis?
- Bronchial obstuction : tumor, foreign body, and impaction of mucus.
- Necrotizing suppurative penumonia: Virulent organisms
- Congenital / herediatry conditions that predispose to chronic infections:
cystic fibrosis– mucous thickening
immunodeficiency states
primary cillary dyskinesia
Kartagener syndrome
Pathogenesis of bronchiectasis?
Impaired clearance of airways- accumulation of mucuous secretion- secondary infection - damaged/weakend wall- bronchiectasis
What are the pathological features of bronchiectasis?
Gross: usually affects the lower lobes bilaterally, particularly those air passages that are most vertical
- cut surface of lung shows markedly dilated bronchi that extend to subpleural regions, some filled with mucopurulent material
Microscopy: Squamous metaplasia of bronchial epithelium
- Intense acute and chronic inflammatory exudate in bronchial walls, necrotizing ulceration
- Fibrosis of bronchiolar walls leading to bronchiolitis obliterans / bronchiolitis meaning chronic inflammation of bronchioles and obliterans producing obstruction due to fibrosis)
- Lung abscess meaning pus may be present.
What are the clinical features of bronchiectasis?
severe persistent cough, fever
Expectorationn of foul smelling, sometimes bloody sputum
Dysonea and orthopnea in severe cases
Symptoms often episodic
- paroxysms of cough particularly frequent when the patient rises in the morning change in position cause collection of pus and secretion to drain into bronchi
- Obstructive respiratory insufficiency can lead to marked dyspnea and cyanosis
- clubbing of the fingers
What are the complication of bronchiectasis?
- sepsis and brain abscess
- pulmonary hypertension and cor pulmonale
- systemic amlyoidosis
What is primary ciliary dyskinesia?
Inheritance autosomal recessive disease
What are the pathogenesis of primary cillary dyskinesia?
Mutation in cilia gene- defective ciliary motor protein- defective ciliary function - imparied mucociliary clearance- accumulation of secretion - recurrent infection - bronchiectasis
What is kartagener syndrome?
Subset of primary of ciliary edsyskinesia
- characterized by triad: 1. bronchiectasis
2. Dextrocardia- defective movement of the organ during embryogenesis
3. sinusitis( impaired mucocilliary clearance- recurrent sinus infection )
Males - infertility ( due to sperm dysmitlity)
