Respiratory Pathology Flashcards
What is the definition of an infection of the upper airway?
Acute inflammatory process the affects the mucous membranes of the respiratory tract
Examples of upper airway infections
rhinitis (runny nose), laryngitis, tonsillitis, sinusitis
What is the definition of an infection of the lower airway?
Inflammation of the lung parenchyma (pneumonia)
What are the causes of pneumonia?
Infectious agents, inhalation of chemicals, chest wall trauma
What are the categories of pneumonia?
Community acquired, hospital acquired, aspiration pneumonia, chronic, necrotising and lung abscess, pneumonia in the immunocompromised host
What are the symptoms of pneumonia?
fever, rigour, SOB, pleuritic chest pain, purulent sputum, cough, increased WBC, chest x-ray changes
Describe community acquired pneumonia
V. common in elderly.
Strep. pneumoniae most common organisms.
Haemophilus influenzae.
S. aureus - complicates viral infection and in IV drug use
What is bronchopneumonia?
Characterised by pus in alveoli and air passages scattered in one or more lobe in one or both lungs
What is lobar pneumonia?
Acute inflammation of the entire lobe or lung
Describe hospital acquired pneumonia (nosocomial pneumonia)
any pneumonia acquired within 48-72 hrs post admission.
Usually bacterial - gram negative and s.aureus.
Severe and can be fatal - most common cause of death in ITU
Describe aspiration pneumonia
Develops after inhalation of foreign material.
Elderly, strokes, dementia, anaesthetic.
Usually occurs in right middle and right lower lobe
What is obstructive disease?
Characterised by partial or complete obstruction at any level from the trachea to respiratory bronchioles
What is restrictive disease?
Characterised by reduced expansion with decreased total lung capacity
What is emphysema?
Irreversible enlargement of the airspaces distal to the terminal bronchial - destruction of their walls without obvious fibrosis
What does COPD stand for?
Chronic Obstructive Pulmonary Disease
What are the different types of emphysema?
centriacinar, paracinar, paraseptal, irregular
What is the pathogenesis of emphysema?
mild chronic inflammation throughout the airways, positive imbalance of oxidants and antioxidants, role of smoking and genetics
What are the symptoms of emphysema?
dyspnoea, cough, wheezing, weight loss, expiratory airflow limitation, pink puffers, congestive heart failure, pneumothorax
What is chronic bronchitis?
Persistent cough with sputum production for at least 3 months in at least 2 consecutive years without any other identifiable cause
What causes chronic bronchitis?
Long-standing irritation by inhaled substances, hypertrophy of submucosal glands in trachea and bronchi, increase in goblet cells, mucus hypersectretion and alterations in the small airways (chronic airway obstruction)
What is the morphology of emphysema?
voluminous lungs, large alveoli, large apical bullae or blebs
What is the morphology of chronic bronchitis?
Mucus membrane hyperaemia/ swelling/ oedema, excessive mucous secretions, bronchiole narrowing causing mucous plugging/ inflammation. fibrosis, may cause obliteration
What are the symptoms of chronic bronchitis?
persistant cough (sputum), dyspnea on exertion, hypercapnia/hypoxia/mild cyanosis (blue bloaters), can cause cardiac failure
What is asthma?
Chronic inflammatory disorders of the airway with recurrent episodes of wheezing, breathlessness, chest tightness and cough, particularly at night and/or in the morning.
Bronchoconstriction and airflow limitation (at least partly reversible)
What are the different types of asthma?
extrinsic - response to inhaled antigen
intrinsic - cold, exercise, aspirin
What are the early phase responses of asthma?
bronchoconstriction, increased mucus production, vasodilation and increased vascular permeability
What are the late phase responses of asthma?
inflammation, epithelial damage, more bronchoconstriction
What is the morphology of asthma?
lung overinflation, thick mucus plugs in bronchi and bronchioles, airway remodelling
What are the symptoms of asthma?
chest tightness, wheezing, cough (sputum), increase in airflow obstruction, difficulty with exhalation
What is bronchiectasis?
permanent destruction and dilation of the airways associated with severe infections or obstructions
What causes bronchiectasis?
CF, kartageners, post infectious (TB, measles, bronchial obstruction)
What is the morphology of bronchiectasis?
dilated, inflamed airways
What are the symptoms of bronchiectasis?
persistent cough, sputum +++
What are the symptoms of restrictive lung disease?
dyspnea, tachypnea, end-inspiratory crackles, eventual cyanosis without wheezing, reductions in gas diffusion capacity/lung volume/compliance.
May lead to secondary pulmonary hypertension and right sided heart failure
What is a pulmonary embolism?
blockage of a main or branch pulmonary artery by an embolism
DVT in 95% of cases
What is the morphology of PE?
central/peripheral emboli, pulmonary haemorrhage, pulmonary infarction
What is the clinical course of PE?
abrupt onset pleuritic chest pain, SOB, hypoxia, increased pulmonary vascular resistance - right ventricular failure
What is pulmonary oedema?
Accumulation of fluid in the air spaces and parenchyma of the lungs
What is haemodynamic oedema?
Increased venous pressure (e.g. left ventricular failure), decreased oncotic pressure (e.g. nephrotic syndrome), liver failure
What are the types of pulmonary oedema?
Haemodynamic oedema, oedema of undetermined origin, oedema due to alveolar injury
What is the morphology of pulmonary oedema?
initial fluid accumulation in basal regions (dependant oedema), engorged alveolar capillaries, intra-alveolar granular pink precipitate, alveolar micro haemorrhages, hemosiderin-laden macrophages, heavy/wet lungs
What are the symptoms of pulmonary oedema?
SOB, pink frothy sputum, characteristic CXR findings
