Week 7: Respiratory Flashcards
Restrictive Lung disease
-Reduction in lung volume due to a pathology in the lungs, pleura, or surrounding strcutures
Causes of Restrictive Lung disease
** PAINT**
P Pleural Pathologies
A Alveolar Pathologies
I Interstitial Pathologies
N Neuromuscular Patholgies
T Thoracic cage abnormalities
Intrinsic vs extrinsic causes of Restricitve lung disease
Intrinsic: Intersitial, alveolar, diffuse cellular infiltrates
Extrinsic: Low Resp muscle tone, chest wall defomities, space occupying
Symptoms of Restrictive Lung disease
Dyspnoea: reduced lung compliance = increased work of breathing
Cough: Increased interstitial lung tissues stiffness triggers reflex
Malaise: Chronic hypoxia
Muscle weakness: Prolonged hypoxia and Resp muscle overuse
Sings of RLD
Reduced chest expansion
Tachypnoea
Decreased breath sounds upon auscultation
Inspiratory crackles (due to fibrosis)
Cyanosis
RLD Ventilation and perfusion
Impaired Ventilation: Stiff, less compliant lung tissue restricts lung expansion, decreasing total lung capacity and tidal volume.
Gas Exchange Issues: Thickened alveolar-capillary membrane slows oxygen diffusion, causing hypoxemia, especially during physical exertion.
Perfusion: Lung perfusion may remain normal or increase, but uneven ventilation worsens hypoxemia.
Dyspnea: Patients experience increased shortness of breath, particularly during activities that raise oxygen demands.
RLD: V/Q mismatch
Mismatch Impact: Areas of the lung receive inadequate oxygen, leading to hypoxemia.
Hypoxic Vasoconstriction: Alveolar hypoxia causes pulmonary arteriolar constriction, diverting blood flow from poorly ventilated areas.
Long-term Effects: Chronic hypoxemia can lead to pulmonary hypertension and right heart strain.
RLD Feature: V/Q mismatch is a hallmark of restrictive lung diseases, affecting gas exchange and oxygen delivery.
hypoxaemia
Low oxygen in blood
Interstitial Lung disease (ILD)
- Effects the tissues between the capilary endothelium and alveolar endothelium
- can progress to pulmonary fibrosis
Classifications of ILD
- Inorganic exposure: non organic substances eg asbestos or silica dust
- Organic exposure:
- Smoking
- Rare forms of ILD: eg LAM or vasculitis
- Idiopathic: unknown cause
How does asbestos cause ILD
inhalation of asbestos fibres, resulting in lung scarring and impaired respiratory function.
Mesothelioma
A rare and aggressive cancer that primarily affects the lining of the lungs, abdomen, or heart, and is strongly associated with asbestos exposure.
Diagnosing RLD
Chest X-Ray: reduced lung volume, flattened diaphragm, other abnormailites
Spirometry: decreased TLC, VC, FVC
aterial blood gas: reduced PaO2, normal or low PaCO2
Management of RLD
- Minimise exposure
- Steroids: to reduce inflammation
- Lung transplantation
- Pulmonary rehab, eduction + Resp muscle conditioning
Management of RLD
- Minimise exposure
- Steroids: to reduce inflammation
- Lung transplantation
- Pulmonary rehab, eduction + Resp muscle conditioning
Management of RLD
- Minimise exposure
- Steroids: to reduce inflammation
- Lung transplantation
- Pulmonary rehab, eduction + Resp muscle conditioning
Mucous Layer as a Immune Defence
Traps pathogens and/or foreign particles; expels them via the muco-ciliary escalator
Epithelium as a resp immune defence
Contains goblet cells that secrete mucous; creates a physical barrier