First Aid: Obstructive and restrictive lung disease Flashcards
What happens to the following lung volumes in obstructive and restrictive lung disease?
a) RV
b) FRC
c) TLC
d) FEV1
e) FVC
f) FEV1/FVC
Obstructive:
Increased: RV, FRC and TLC
Decreased: FEV1 (very decreased), FVC and FEV1/FVC
Restrictive:
Decreased: RV, FRC, TLC, FEV1, FVC
Increased or normal: FEV1/FVC as the FEV 1 has decreased proportionately with the FVC
How is the flow-volume loop changed in obstructive and restrictive lung disease?
Obstructive: shifts left
Restrictive: Shifts right (R-R)
What two diseases comprise COPD?
Chronic bronchitis and emphysema
What is the pathology of obstructive lung disease?
Obstructed airflow leads to increased trapping of air in the lungs. Airways close prematurely at high lung volumes, leading to further trapping
What can chronic hypoxic pulmonary vasoconstriction lead to?
Cor pulmonale
How does chronic bronchitis commonly present?
Blue Bloater: WCPCDC
Wheezing, cyanosis, can cause secondary polycythemia, CO2 retention, dyspnea, crackles
How does chronic bronchitis cause secondary polycythemia?
As it leads to chronic hypoxemia which triggers increased EPO from the kidneys
What is the pathology of chronic bronchitis?
Hyperplasia and hypertrophy of the mucus-secreting glands
What is the Reid index and what would it indicate in chronic bronchitis?
Pathological measurement of the ratio between the thickness of submucosal mucus-secreting glands and the thickness between the cartilage and epithelia that line the bronchi, in chronic bronchitis this would be >50%
What is the diagnostic criteria for chronic bronchitis?
Productive cough for >3 months in a year, for two consecutive years
How does emphysema commonly present?
Barrel chest and pursed lips on expiration (to increase airway pressure and prevent airway collapse)
Describe the two pathological patterns of emphysema, what they’re associated with and the lobes involved
Centriacinar: affects the upper lobes, respiratory bronchioles and proximal alveoli (with sparing of the distal alveoli). Associated with smokers
Panacinar: affects the whole lung but more commonly the lung base, (including respiratory bronchioles -> distal alveoli), associated with alpha1 antitrypsin deficiency
Why is there an increase in lung compliance in emphysema?
An imbalance of proteases and antiproteases leads to increased elastase, this decreases the elastic recoil fibres and increases lung compliance
What happens as a result of the enlargement of air spaces in emphysema?
Decreased: recoil, DLCO (from the destruction of alveolar walls) and blood volume in the pulmonary capillaries
Increased: compliance
What is found on a CXR in emphysema?
- Increased AP diameter
- Increased lung field lucency
- flattened diaphragm
What are the clinical findings of asthma?
DWCTHIMP: dyspnea, wheeze, cough, tachypnea, hypoxemia, decreased inspiratory/expiratory ratio, mucus plugging, pulsus paradoxus
What are the triggers for asthma?
Viral URIs, allergens and stress
What is pulsus paradoxus and what causes it?
A significant drop in BP during inspiration (>10 mmHg)
RILE: increased bloodflow to R heart on inspiration and increased bloodflow to L heart on expiration. When the patient inspires the increase in blood in the R heart pushes on the septum, decreasing the space for blood to fill the L heart -> resulting in a decreased CO and BP
Describe the pathology of asthma (including the two microscopic findings)
- Hyper responsive bronchi leading to reversible bronchoconstriction
- Hyperplasia and hypertrophy of the smooth muscle cells
Microscopic findings:
- Curschmann spirals: mucus spiral plugs from subepithelial mucus gland ducts of bronchi
- Charcot-Leyden crystals: hexagonal, double-pointed eosinophilic crystals formed via eosinophilic degradation in the sputum
What type of hypersensitivity reaction occurs in asthma?
Type 1
What supports the diagnosis of asthma?
Spirometry and the methacholine challenge
What makes up NSAID exacerbated respiratory disease?
COX inhibitors (inhibit cyclooxygenase (COX) which helps produce prostaglandins from arachidonic acid, with this inhibited arachidonic acid forms leukotrienes (which are released from mast cells during an asthma attack) and cause bronchoconstriction
Chronic sinusitis w nasal polyps (a result of chronic inflammation)
Asthma symptoms
What are the clinical findings in bronchiectasis?
PPHD: purulent sputum, recurrent infections (most commonly P. aeruginosa), hemoptysis and digital clubbing
What happens pathologically in bronchiectasis and why?
Permanently dilated airways due to chronic necrotizing infection of the bronchi or obstruction
What is bronchiectasis associated with?
ABCC
1. Allergic bronchopulmonary aspergillosis
- Bronchial obstruction
- CF
- Impairment of mucociliary escalator: i.e due to smoking or kartagener syndrome (rare autosomal recessive ciliary disorder)
What are some associated conditions when there is poor breathing mechanics in restrictive lung disease?
Is it extrapulmonary or pulmonary, and how does it affect the DLCO and A-a gradient?
- Poor muscular effort: polio, MS, Guillain barre
- Poor structural apparatus: scoliosis, morbid obesity
Extrapulmonary, normal DLCO and A-a gradient
What are some associated conditions when there is ‘interstitial disease’ in restrictive lung disease?
Is it extrapulmonary or pulmonary, and how does it affect the DLCO and A-a gradient?
GLISPHD
- Granulomatosis with polyangiitis (Wegener’s granulomatosis)
- Pulmonary Langerhans cell histiocytosis (eosinophilic granuloma)
- Idiopathic pulmonary fibrosis
- Sarcoidosis
- Pneumoconioses (i.e coal workers pneumoconiosis, silicosis, asbestosis)
- Hypersensitivity pneumonitis
- Drug toxicity (i.e methotrexate, bleomycin, busulfan, amiodarone)
Pulmonary, decreased DLCO and increased A-a gradient
What happens in idiopathic pulmonary fibrosis? How does the lung appear?
When there are repeated cycles of lung injury and wound healing with increased collagen deposition, the lung has a “honeycomb” appearance
What is hypersensitivity pneumonitis? What symptoms can it cause, and where is it commonly seen? Is it reversible?
A mixed type 3/4 hypersensitivity reaction to an environmental antigen, can cause: dyspnea, cough, chest tightness, fever and headache
Commonly seen in farmers and those exposed to birds and is reversible in early stages if the stimulus is avoided
What is sarcoidosis characterized by? Describe what you would find in the serum levels, bronchoalveolar lavage fluid, on a CXR and a CT scan
Characterized by immune-mediated widespread noncaseating granulomas
Serum: elevated ACE and Ca2+ (hypercalcemia is due to the increase in 1alpha hydroxylase-mediated vitamin D activation in macrophages)
Bronchoalveolar lavage fluid: elevated CD4/CD8 ratio
CXR: bilateral adenopathy and coarse reticular opacities
CT: better demonstrates the extensive hilar and mediastinal adenopathy
What population is most commonly affected by sarcoidosis? Is it symptomatic?
African American females, often asymptomatic other than enlarged lymph nodes
What conditions are associated with sarcoidosis?
A facial droop is UGLIER (neurosarcoidosis can cause sudden facial weakness)
U: Uveitis
G: granulomas (noncaseating epithelioid, containing microscopic Schaumann and asteroid bodies)
L: Lupus pernio (skin lesions on face resembling lupus; hard and purplish)
I: Interstitial fibrosis
E: erythema nodosum
R: rheumatoid arthritis-like arthropathy
How is sarcoidosis treated?
With steroids, if it’s symptomatic
What causes inhalation injury and sequelae and what does it result in?
Inhalation of noxious stimuli (i.e smoke), caused by heat, particulates or irritants (i.e NH3) which leads to chemical tracheobronchitis, edema, pneumonia and ARDS
How do many patients present with inhalation injury and sequelae? What might be observed on examination?
Secondary burns, CO inhalation, cyanide poisoning or arsenic poisoning.
Singed nasal hairs or soot in the oropharynx are common on examination
What might be noted on a bronchoscopy in inhalation injury and sequelae?
Severe edema, congestion of the bronchus and soot deposition
What parts of the lungs do asbestos and silica affect?
Asbestos: base/lower lobes
“Is from the roof but affects the base”
Silica: Upper lobes
“Is from the base (earth) but affects the roof”
What increases your risk of getting asbestosis?
shipbuilding, roofing, plumbing
What is pathognomonic of asbestosis?
“Ivory white” calcified supradiaphragmatic and pleural plaques
What does asbestosis increase your risk of?
- bronchogenic carcinoma (> mesothelioma)
- Caplan syndrome (rheumatoid pneumoconiosis)
- Pleural effusions
How do asbestos particles appear histologically? Where and how can they be visualized and obtained?
Golden-brown fusiform rods, visualized in alveolar sputum using Prussian blue stain - and are often obtained via bronchoalveolar lavage
What increases your risk of getting berylliosis? How does it appear histologically and how can it be treated?
Exposure to beryllium in aerospace and manufacturing industries. Noncaseating granulomas on histology and so is occasionally responsive to steroids
Which part of the lung is affected by berylliosis and what can it increase your risk of?
The upper lobes, increased risk of cancer and cor pulmonale
Describe the pathology of coal worker’s pneumoconiosis, what can it increase your risk of?
Prolonged coal dust exposure -> leads to macrophages laden with carbon -> inflammation and fibrosis
Increased risk of Caplan syndrome
Which part of the lung is affected by coal worker’s pneumoconiosis? How does it appear on imaging
Upper lobes, small rounded nodular opacities are seen on imaging
What term is used to describe the asymptomatic nature of pneumoconiosis found in many urban dwellers exposed to sooty air
Arthracosis
What increases your risk of getting silicosis? How does it appear on a CXR?
The Silly Egg sandwich I found is mine!
Increased risk of getting it when: SANDblasting, FOUNDries, MINEs
CXR: “EGGshell” calcifications of hilar lymph nodes
How do macrophages respond to silica and what happens as a result of this?
They release fibrogenic factors leading to fibrosis
What does silicosis increase your risk of?
Silica may also disrupt phagolysosomes and impair macrophages - increasing susceptibility to TB
3 Cs: Cancer, cor pulmonale, Caplan’s syndrome
