--- module: 015-01 language: en chapter: 15 title: "Obstructive, Restrictive, Vascular, Infectious, and Neoplastic Lung Disease" module_title: "Foundations" source_sha256: fa2dc14c00b8296cf2610e54e3b65a6d5041e2ef9867baf0126eb5c413c5ff41 --- # Obstructive, restrictive, vascular, infectious, and neoplastic lung disease ## Orientation ### Airways, alveoli, interstitium, vessels, pleura ### Respiratory muscles and breathing control ### Similar symptoms from different compartments ### Exposure, tempo, physiology, imaging, pathology ### Remove cause, treat disease, prevent, rehabilitate ## Asthma ### Variable obstruction with hyperresponsiveness and inflammation ### Triggers: allergen, virus, exercise, cold, smoke ### Mast cells, eosinophils, mucus, oedema, constriction ### Normal interval tests do not exclude asthma #### Bronchodilator response and peak-flow variability #### Challenge testing or anti-inflammatory response ### Inhaled corticosteroid treats inflammation, reduces exacerbations ### Long-acting beta agonist always with corticosteroid ### Severe attack: effort, tachypnoea, silent chest #### Normal or rising carbon dioxide suggests fatigue ## Chronic obstructive pulmonary disease ### Persistent limitation with remodelling, mucus, emphysema ### Tobacco, biomass, occupation, alpha one antitrypsin ### Chronic bronchitis is a mucus-hypersecretion phenotype ### Emphysema destroys distal to terminal bronchioles ### Recoil loss, expiratory collapse, mucus trap air ### Ventilation-perfusion mismatch causes hypoxaemia #### Later hypercapnia, pulmonary hypertension, right-heart failure ### Diagnosis needs post-bronchodilator obstruction ### Long-term oxygen for severe resting hypoxaemia ## Bronchiectasis and cystic fibrosis ### Irreversible dilation from a self-sustaining cycle #### Impaired clearance, infection, inflammation, wall damage ### Productive cough, recurrent infection, haemoptysis, crackles ### Clearance, sampling, targeted antibiotics, cause treatment ### Cystic fibrosis: chloride transport, dehydrated secretions #### Modulator therapy for eligible variants ## Pneumonia and tuberculosis ### Infection of the lung parenchyma ### Pathogens vary with exposure, immunity, age, geography ### Subtle signs in older or immunocompromised patients ### Complications: sepsis, abscess, necrosis, effusion #### Empyema needs drainage as well as antibiotics ### Tuberculosis: airborne spread, latent or active #### Immune tests show infection, not active disease ## Consolidation and its limits ### Inflammatory cells and fluid replace alveolar gas ### A structural pattern, not a pathogen name ### Tissue and fluid attenuate X-rays more than air ### Absent crackles do not exclude the process ### Opacity alone does not establish infection #### Oedema, haemorrhage, collapse also raise density ### Ask compartment, process, and severity separately ## Interstitial and occupational disease ### Inflammation, fibrosis, or both in alveolar walls ### Exertional dyspnoea, dry cough, fine crackles ### Low volumes, impaired diffusion, exertional desaturation ### High-resolution computed tomography narrows the differential ### Ask about birds, mould, dust, silica, asbestos ### Remove exposure, antifibrotic in progressive fibrosis ## Pulmonary vascular disease ### Embolism raises dead space and right-ventricular afterload ### Silent clot to pleuritic pain, syncope, shock ### Clinical probability guides D-dimer and imaging ### Anticoagulation, reperfusion for haemodynamic compromise ### Echocardiography estimates, catheterisation defines haemodynamics ### Vasodilators helping one group may harm another ## Pleura, pneumothorax, and lung cancer ### Effusion from pressure, inflammation, infection, malignancy ### Thoracentesis separates transudate from exudate ### Pneumothorax: spontaneous, traumatic, or iatrogenic ### Tension decompressed on instability, not imaging ### Small-cell and non-small-cell, with molecular subtypes ### Radon, occupation, pollution beyond tobacco ### Imaging, tissue, histology, molecular testing, staging ## Acute lung injury, aspiration, immune compromise ### Permeability injury, bilateral opacities, low compliance ### Hypoxaemia not fully explained by cardiac failure ### Lung-protective ventilation, prone position when severe ### Aspiration: chemical pneumonitis to bacterial pneumonia #### Antibiotics only for established or suspected infection ### Pneumocystis causes diffuse hypoxaemic pneumonia