Resp Week 7

Question 1

Provide a brief comparison between restrictive and and obstructive lung disease

Answer 1

RLD = reduction in volume due to pathology in lungs/pleura/structures of thoracic cage

W/a

OLD = airway obstruction resulting in lung volume being normal or high due to overinflation

Question 2

What are 5 broad causes of restrictive lung disease

Answer 2

Pleural pathologies

Alveolar pathologies

Interstitial pathologies

Neuromuscular pathologies

Thoracic cage abnormality pathologies

Question 3

Outline interstitial lung disease

Answer 3

Arises from conditions affecting the lung parenchyma such as pulmonary fibrosis which causes scarring and stiffening of lung tissue

Question 4

Outline extrapulmonary restrictive lung disease

Answer 4

Occurs due to factors outside the lungs that limit lung expansion, such as obesity, neuromuscular disorders or chest wall deformities

Question 5

What are 3 types of intrinsic restrictive lung disease

Answer 5

Interstitial lung disease

Alveolar conditions

Diffuse cellular infiltrates

Question 6

What are 3 types of extrinsic restrictive lung disease

Answer 6

Low respiratory muscle tone

Chest wall deformities

Space occupying

Question 7

What are 4 symptoms of RLD and provide a brief outline of their pathophysiology

Answer 7

Dyspnea - reduced lung compliance > increased work of breathing > SOB

Cough - increased interstitial lung tissue stiffness triggers cough reflex

Malaise - chronic hypoxia + decreased lung function > systemic fatigue and general discomfort

Muscle weakness - prolonged hypoxia + respiratory muscle overuse > decrease muscle strength

Question 8

What are 5 findings in a physical exam for RLD and provide a brief outline of the pathophysiology of them

Answer 8

Reduced chest expansion - stiffened lung parenchyma restricts thoracic mvmt

Tachypnea - increased RR compensates for reduced lung volume

Decreased breath sounds - reduced lung volumes reduce airflow > quieter breaths

Inspiratory crackles - alveolar + interstitial fibrosis > popping sounds during inspiration due to sudden opening of collapsed airways

Cyanosis - inadequate oxygenation of skin and mucous membranes

Question 9

Explain the effect RLD on ventilation and perfusion

Answer 9

RLD leads to impaired ventilation which results in reduced lung capacity and TV, limiting the amount of air that can be inhaled per breath

The thickening of alveolar capillary membrane in RLD hinders efficient gas exchange, which causes hypoxaemia

Despite these ventilation issues, perfusion in the lungs may remain relatively unaffected or even increase as pulmonary blood flow continues

Question 10

Outline ventilation-perfusion mismatch in RLD

Answer 10

Lead to areas of lung receiving less O2 than they should, resulting in hypoxaemia

Alveolar hypoxia may cause vasoconstriction in pulmonary arterioles, diverting blood away from poorly ventilated areas

Over time chronic hypoxaemia can lead to pulmonary HTN and RH strain due to increased resistance in pulmonary circulation

Question 11

What are 5 classifications of interstitial lung disease

Answer 11

Inorganic exposure - caused by exposure to non-organic substances e.g asbestos

Organic exposure - exposure to organic materials e.g mould

Smoking - inhalation of toxins from tobacco smoke

Rare forms of ILD - uncommon types from unique causes

Idiopathic - unknown cause

Question 12

What are 3 types of occupational lung diseases

Answer 12

Asbestosis - caused by inhalation of asbestos fibres resulting in lung scarring and impaired respiratory fn

Mesothelioma - rare + aggressive cancer that primarily affects the lining the lungs, abdomen, or heart (strongly associated with asbestos exposure)

Pleural disease - conditions affect pleura e.g pleuritis, pleural effusions, pleural plaques

Question 13

Outline results of pulmonary function tests in RLD

Answer 13

Low FVC

Reduced TLC

FEV1/FVC ratio will be increased or normal

Diffusing capacity is also reduced

ABG - hypoxia

Question 14

What are 3 investigations that can be undertaken for RLD

Answer 14

CXR

Spirometry

ABG

Question 15

What are 5 Rx options for RLD

Answer 15

Minimise exposure if known aetiology

Steroids

Lung transplant

Pulmonary rehab

Education

Question 16

What are 5 layers of defence in the respiratory system against infection

Answer 16

Mucous layer - traps pathogens

Epithelium - has goblet cells

Lamina propria - has immune cells

Type 1 pneumocytes - physical barrier b.w lung + airway

Type 2 pnemocytes - secrete surfactant

Question 17

What are 3 harmful substances to the lung and provide a brief description of each

Answer 17

Microbes - bacteria, parasites etc

DAMPs - released from damaged cells > stress

Foreign bodies - trigger hypersensitivity reactions

Question 18

What are 3 causes of compromised immunity and provide a brief description of each

Answer 18

Defective mucous - inability for lung to trap pathogens

Dysfunctional cilia - e.g caused by smoking

Immune cell defects - e.g impaired action of T lymphocytes

Question 19

What are 7 causes of lung inflammation and provide an example of each

Answer 19

Infection e.g pneumonia caused by strep agents

Pollutants e.g smog

Allergens e.g pollen

Foreign bodies e.g aspiration of small objects

Autoimmune e.g ILD associated w rheumatoid arthritis

Occupational e.g chronic bronchitis from long term exposure to coal dust

Lifestyle e.g lung diseases caused by chronic smoking

Question 20

Describe the process of acute pulmonary inflammation

Answer 20

Step 1 - immune cells detect pathogens through PRRs and TLRs and NLRs

Step 2 - macrophages, ILCs and dendritic cells recognise PAMPs and DAMPs through their PRRs > triggers activation of these cells > release cytokines e.g IL-6 and TNF and IL-10 and TGF- beta > vasodilation

Step 3 - dendritic cells and B cells present pathogen fragments to T cells > activate them > CD8+ cells directly kill infected cells and CD4+ cells act as helper cells for B cells releasing IgG antibodies

Step 4 - macrophages remove intra-alveolar debris / lymphatic system resorbs extravascular fluid / macrophages release TGF-beta which stimulates fibroblast proliferation and collagen deposition leading to fibrosis of alveolar walls > fibrotic tissues helps stabilise damaged area but can also affect normal lung function / type 2 pneumocytes proliferate to replace damaged type 1 pneumocytes and facilitate restoration of alveolar lining

Question 21

Describe the process of chronic pulmonary inflammation

Answer 21

TLRs on immune cells detect patterns shared by pathogens which leads to activation of inflammatory cells

Then, this activation triggers NF-kappa B signalling pathway which drives the production of growth factors, chemokines and proinflammatory cytokines

Then, these mediators recruit and sustain inflammatory cells in the affected tissue, increasing the inflammatory response

Then, over time chronic inflammation can lead to ongoing tissue damage and remodelling, where the tissue undergoes structural changes due to continuous inflammation and repair processes =

Then, the resolution phase aims to restore tissue homestasis

Question 22

What is a granuloma

Answer 22

Organised collection of macrophages that have transformed into epithelioid cells forming a compact cluster

These epithelioid cells are surrounded by a rim of lymphocytes and occasionally multinucleated giant cells, which are formed by the fusion of macrophages

The core centre of the granuloma may exhibit caseous necrosis which is basically a cheese like appearance due to cell death and tissue destruction

They are typically found in chronic inflammatory conditions e.g TB

Question 23

What are 4 key structures in the respiratory system that undergo inflammation

Answer 23

Alveoli

Bronchi

Interstitium

Parenchyma

Question 24

Outline the link between alveoli inflammation and associated symptoms

Answer 24

Inflammation impairs gas exchange, causing symptoms like shortness of breath and hypoxaemia

Question 25

Outline the link between bronchi inflammation and associated symptoms

Answer 25

Inflammation leads to swelling and mucus production, resulting in cough, wheezing, and difficulty breathing

Question 26

Outline the link between interstitium inflammation and associated symptoms

Answer 26

Inflammation reduces lung compliance and gas exchange, causing chronic dry cough and progressive dyspnoea

Question 27

Outline the link between parenchyma inflammation and associated symptoms

Answer 27

Inflammation affects overall lung function, leading to decreased lung volumes and symptoms such as fatigue and exercise intolerance

Question 28

Describe pharyngitis

Answer 28

Condition characterised by the inflammation of the pharynx

Presents alongside symptoms of the common cold

Predominantly caused by viruses but can also be due to bacterial infections

Question 29

What are 2 infective causes of pharyngitis and describe how it may usually present

Answer 29

Epstein-Barr virus (EBV) - glandular fever or infectious mononucleosis / tonsillar exudate / tender cervical lymphadenopathy / malaise / fever / splenomegaly

Bacterial e.g strep A - more localised symptoms that can be confirmed through specific blood tests or throat cultures

Question 30

What are 5 complications of pharyngitis

Answer 30

Peritonsillar abscess

Deep neck space infection

Rheumatic fever

Glomerulonephritis

Scarlet fever

Question 31

Briefly describe peritonsillar abscess

Answer 31

Collection of pus near the tonsils causing severe throat pain and difficulty swallowing

Question 32

Briefly describe deep neck space infection

Answer 32

Serious infection spreading to deep tissues in the neck, potentially affecting breathing and swallowing

Question 33

Briefly describe glomerulonephritis

Answer 33

Kidney inflammation that can develop after a strep infection, leading to symptoms such as blood in the urine and high BP

Question 34

Briefly describe scarlet fever

Answer 34

Condition characterised by a red, sandpaper-like rash and a high fever, typically only follows from streptococcal pharyngitis

Question 35

What are 3 major steps in the management of pharyngitis

Answer 35

Assess for life-threatening features - check for airway obstruction, deep neck space infection, sepsis

Antibiotics - if suspected bacterial cause; administered in all high risk rheumatic fever cases; also use in severe symptoms not improving after 3-7 days or immunosuppressed

Tonsillectomy - consider for recurrent significant pharyngitis; refer if more than 7 episodes per year, more than 5 episodes per year for two years, or more than 3 episodes per year for three years

Question 36

Describe laryngitis and its general management

Answer 36

Inflammation of the larynx presenting with a hoarse voice and sometimes accompanied by other symptoms

Almost always caused by respiratory viruses if infections, but can also result from vocal strain, excessive coughing or exposure to irritants such as smoke

Antibiotics not indicated, instead use symptomatic Rx such as analgesia

If no significant improvement within a month, referral to ENT specialist is recommended