MBBS Block 2: Pneumonia Classification and Pathogenesis

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Questions and Answers

What is a characteristic of early red hepatization?

Fibrin nets have formed

Fibroblasts are absent

Congested septal capillaries and numerous intra-alveolar neutrophils (correct)

The exudates have been converted to fibromyxoid masses

What type of bacteria may lead to tissue damage and fibrosis or abscess formation?

Pseudomonas aeruginosa

Streptococcus pneumoniae

Escherichia coli

Staphylococcus aureus (correct)

During which stage of pneumonia are fibrin nets formed?

Early organization of intra-alveolar exudate (correct)

Early red hepatization

Advanced organizing pneumonia

Acute pneumonia

What is the primary result of pneumonia in the lungs?

Solidification of lung part(s) Signup and view all the answers

Which of the following is an example of aetiological agent of pneumonia?

Staphylococcus aureus Signup and view all the answers

What is formed in advanced organizing pneumonia?

Fibromyxoid masses Signup and view all the answers

What is the main difference between lobar pneumonia and bronchopneumonia?

Anatomical pattern Signup and view all the answers

What is characteristic of early organization of intra-alveolar exudate?

The exudate is seen streaming through the pores of Kohn Signup and view all the answers

What type of cell is present in fibromyxoid masses?

All of the above Signup and view all the answers

Which type of pneumonia is more likely to occur in an otherwise healthy person?

Primary pneumonia Signup and view all the answers

What is the term for the collection of inflammatory exudate in lung parenchyma?

Pneumonia Signup and view all the answers

What is a complication of pneumonia caused by some virulent bacteria?

Both A and B Signup and view all the answers

What is the name of the stage of pneumonia characterized by congested septal capillaries and numerous intra-alveolar neutrophils?

Early red hepatization Signup and view all the answers

Which of the following is an example of viral pneumonia?

Influenza Signup and view all the answers

What is the classification of pneumonia based on the anatomical pattern of involvement?

Lobar and bronchopneumonia Signup and view all the answers

What is the name of the bacterium that is an example of a bacterium that may lead to tissue damage and fibrosis or abscess formation?

Staphylococcus aureus Signup and view all the answers

Which of the following is NOT a type of pneumonia?

Meningitis Signup and view all the answers

What is the term for the solidification of lung tissue?

Consolidation Signup and view all the answers

What is the primary symptom of lobar pneumonia?

Fever Signup and view all the answers

What is the characteristic of the sputum in lobar pneumonia?

It is purulent and may contain flecks of blood Signup and view all the answers

What is the cause of acute pleuritic chest pain in lobar pneumonia?

Inflammation of the pleura Signup and view all the answers

What is the duration of the congestion stage in lobar pneumonia?

About 24 hours Signup and view all the answers

What is the characteristic of the lung during the red hepatisation stage?

It is red and airless Signup and view all the answers

What occurs during the grey hepatisation stage?

Destruction of white cells and red cells Signup and view all the answers

What is the characteristic of the lung during the resolution stage?

It is normal and functional Signup and view all the answers

What is the duration of the resolution stage in untreated cases?

About 8-10 days Signup and view all the answers

What is the chest sign that reflects inflammation of the pleura?

Pleural friction rub Signup and view all the answers

What is the term for the patches of consolidation shown in the image?

Patches of consolidation Signup and view all the answers

Which of the following is a complication of pneumonia?

Empyema Signup and view all the answers

What is the term for the formation of solid fibrous tissue in the lung?

Fibrosis Signup and view all the answers

Which type of bacterial infection is more likely to result in abscess formation?

Klebsiella Signup and view all the answers

What is the term for the dissemination of bacteria to other organs, leading to the formation of metastatic abscesses?

Bacterial dissemination Signup and view all the answers

Which of the following is a feature of bronchopneumonia on a chest X-ray?

Patchy bronchovascular thickening Signup and view all the answers

What is the term for the inflammation of the pleural cavity?

Empyema Signup and view all the answers

Which of the following is a complication of pneumonia that can lead to the formation of abscesses in various organs?

Bacterial dissemination Signup and view all the answers

Which of the following is a feature of bronchopneumonia?

Patches of consolidation Signup and view all the answers

What is the definition of atypical pneumonia?

An acute febrile respiratory disease that manifests with patchy inflammatory changes confined to alveolar space and pulmonary interstitium Signup and view all the answers

Which of the following viruses is a causative organism of atypical pneumonia?

Influenza virus type A and B Signup and view all the answers

What is the causative organism of lipid pneumonia that occurs due to aspiration of material containing a high concentration of lipid?

Exogenous lipid Signup and view all the answers

What is aspiration pneumonia caused by?

Aspirating fluid or food into the lung Signup and view all the answers

Which of the following is an example of non-infective pneumonia?

Aspiration pneumonia Signup and view all the answers

What is the location of the inflammatory changes in atypical pneumonia?

Alveolar space and pulmonary interstitium Signup and view all the answers

Which of the following is a causative organism of atypical pneumonia?

Mycoplasma pneumoniae Signup and view all the answers

What is the characteristic feature of lipid pneumonia that occurs due to airway obstruction?

Distal collections of foamy macrophages and giant cells Signup and view all the answers

Which of the following is an example of a non-infective pneumonia?

Cryptogenic organising pneumonia Signup and view all the answers

What is the characteristic distribution of bronchopneumonia?

Patchy distribution, centred on inflamed bronchioles and bronchi Signup and view all the answers

Which type of pneumonia is more likely to occur in patients with debilitating diseases?

Bronchopneumonia Signup and view all the answers

What is the typical radiographic appearance of lobar pneumonia?

Dense consolidation of one lobe Signup and view all the answers

What is the most common age group affected by bronchopneumonia?

Old age Signup and view all the answers

Which type of bacteria may cause bronchopneumonia?

All of the above Signup and view all the answers

What is the typical distribution of lobar pneumonia?

Uniform consolidation of one lobe Signup and view all the answers

Which type of pneumonia is characterized by a uniform consolidation of one lobe?

Lobar pneumonia Signup and view all the answers

What is the primary difference between bronchopneumonia and lobar pneumonia?

Distribution of lesions Signup and view all the answers

Which type of pneumonia is more likely to affect previously healthy individuals?

Lobar pneumonia Signup and view all the answers

What is the typical distribution of lesions in bronchopneumonia?

Basal area, due to secretions gravitating into lower lobe Signup and view all the answers

Which bacterium is commonly associated with lobar pneumonia?

Pneumococci Signup and view all the answers

What is the characteristic of bronchopneumonia?

Focal inflammation centred on the airways Signup and view all the answers

What is the characteristic of the sputum in bronchopneumonia?

Purulent, non-haemorrhagic Signup and view all the answers

What is the most common cause of acute pneumonia?

S.pneumoniae (the pneumococcus) Signup and view all the answers

Which type of pneumonia is more severe?

Lobar pneumonia Signup and view all the answers

What is the typical immune status of individuals affected by bronchopneumonia?

Immunosuppressed Signup and view all the answers

What is the characteristic of bacterial pneumonia?

Predominantly intra-alveolar neutrophilic inflammation Signup and view all the answers

What is the characteristic of lobar pneumonia?

Diffuse inflammation affecting the entire lobe Signup and view all the answers

What is the characteristic of viral pneumonia?

Interstitial lymphocytic inflammation Signup and view all the answers

Which of the following viruses is a causative organism of pneumonia?

Influenza virus Signup and view all the answers

What is the definition of pneumonia?

Collection of inflammatory exudate in lung parenchyma distal to terminal bronchioles Signup and view all the answers

What is a complication of pneumonia that results from tissue destruction?

Abscess formation Signup and view all the answers

What is seen on a chest X-ray in bronchopneumonia?

Patchy bronchovascular thickening Signup and view all the answers

What is the term for the formation of solid fibrous tissue in the lung?

Fibrosis Signup and view all the answers

What is the term for the dissemination of bacteria to other organs, leading to the formation of metastatic abscesses?

Bacterial dissemination Signup and view all the answers

What is the term for the inflammation of the pleural cavity?

Empyema Signup and view all the answers

What type of pneumonia is characterized by patchy consolidation on a chest X-ray?

Bronchopneumonia Signup and view all the answers

What is a complication of pneumonia that can lead to the formation of abscesses in various organs?

Bacterial dissemination Signup and view all the answers

What is the characteristic feature of atypical pneumonia?

Patchy inflammatory changes confined to the alveolar space and pulmonary interstitium Signup and view all the answers

Which of the following is a causative organism of atypical pneumonia?

Mycoplasma pneumoniae Signup and view all the answers

What is the definition of lipid pneumonia?

Pneumonia caused by aspiration of material containing a high concentration of lipid Signup and view all the answers

Which of the following is an example of non-infective pneumonia?

Cryptogenic organising pneumonia Signup and view all the answers

What is the location of the inflammatory changes in atypical pneumonia?

Alveolar space and pulmonary interstitium Signup and view all the answers

Which of the following viruses is a causative organism of atypical pneumonia?

Influenza virus type B Signup and view all the answers

What is aspiration pneumonia caused by?

Aspiration of food or fluid Signup and view all the answers

What percentage of lobar pneumonia cases are caused by Streptococcus pneumoniae?

90% Signup and view all the answers

Which type of pneumonia is more likely to occur in an otherwise healthy person?

Lobar pneumonia Signup and view all the answers

What is a common factor that can compromise pulmonary defense mechanisms?

All of the above Signup and view all the answers

Which type of pneumonia is more likely to occur in patients with debilitating diseases?

Bronchopneumonia Signup and view all the answers

What is the characteristic distribution of bronchopneumonia?

Patchy, diffuse, and scattered Signup and view all the answers

What is the typical age group affected by lobar pneumonia?

20-50 years Signup and view all the answers

Which type of pneumonia is more likely to occur in an elderly person?

Klebsiella pneumonia Signup and view all the answers

What is the common factor that can impair the host's immunity?

All of the above Signup and view all the answers

What is the characteristic of lobar pneumonia in terms of affected segments?

Affects anatomically delineated segments or the entirety of a lobe Signup and view all the answers

Which type of pneumonia is caused by the aspiration of material containing a high concentration of lipid?

Lipid pneumonia Signup and view all the answers

Study Notes

Definition and Classification of Pneumonia

Pneumonia is defined as a collection of inflammatory exudate in lung parenchyma distal to terminal bronchioles, resulting in consolidation (solidification) of lung part(s).
Classification of pneumonia can be based on anatomical pattern, clinical circumstances, and aetiological agents.
Anatomical pattern classification includes bronchopneumonia and lobar pneumonia.
Clinical circumstance classification includes primary and secondary pneumonia.
Aetiological agent classification includes bacterial, viral, and fungal pneumonia.

Clinical Features of Pneumonia

Symptoms include cough, fever, production of sputum, and occasional hemoptysis.
Fever can be very high (over 40°C), with rigors (shaking chills).
Acute pleuritic chest pain on deep inspiration reflects inflammation of the pleura (pleurisy).
Signs include dullness to percussion, bronchial breathing, and pleural friction rub.

Morphological Changes in Lobar Pneumonia

Congestion: the first stage, lasting about 24 hours, with protein-rich exudate and venous congestion.
Red hepatisation: the second stage, lasting a few days, with massive accumulation of polymorphs, lymphocytes, and macrophages in alveolar spaces.
Grey hepatisation: the third stage, lasting a few days, with further accumulation of fibrin, destruction of white cells and red cells.
Resolution: the fourth stage, occurring at about 8–10 days in untreated cases, with resorption of exudate and enzymatic digestion of inflammatory debris.

Bronchopneumonia

Characterized by patches of consolidation.
Chest X-ray shows patchy bronchovascular thickening.

Complications of Pneumonia

Abscess formation: results from tissue destruction, more common in Klebsiella or type III Pneumococcal infections.
Empyema: virulent bacterial strains induce suppuration in the pleural cavity.
Fibrosis: organization of intra-alveolar exudate may convert affected lung into solid fibrous tissue.
Bacterial dissemination: dissemination of bacteria may lead to endocarditis, pericarditis, meningitis, suppurative arthritis, and formation of metastatic abscesses in various organs.

Atypical Pneumonia

Defined as an acute febrile respiratory disease with patchy inflammatory changes confined to alveolar space and pulmonary interstitium.
Causative organisms include Mycoplasma pneumoniae, influenza virus, respiratory syncytial viruses, adenovirus, rhinovirus, rubeola, varicella virus, Chlamydia, and Coxiella burnetii.

Non-Infective Pneumonias

Cryptogenic organising pneumonia.
Aspiration pneumonia: when fluid or food is aspirated into the lung.
Lipid pneumonia: endogenous (associated with airway obstruction) and exogenous (due to aspiration of material containing a high concentration of lipid).

Lobar Pneumonia

Affects anatomically delineated segment(s) or the entirety of a lobe or lung
Relatively uncommon in infancy and old age
Affects males more than females
90% due to Streptococcus pneumoniae (pneumococcus)
Pneumococcal pneumonia typically affects otherwise healthy adults between 20 and 50 years of age
Lobar pneumonia caused by Klebsiella typically affects the elderly, diabetics, or alcoholics

Bronchopneumonia

Patchy consolidation of multiple lobes (bilateral)
Often several lobes or bilateral
Characterized by focal inflammation centered on the airways
Typically occurs in old age, infancy, and patients with debilitating diseases
Common causes include staphylococci, streptococci, and Haemophilus influenzae
Pleural exudate is common

Pathogenesis of Pneumonia

Occurs when defense mechanisms of the respiratory system are impaired or host immunity is low
Pulmonary defense mechanisms may be compromised by factors such as:
- Loss or suppression of the cough reflex
- Dysfunction of the mucociliary apparatus
- Accumulation of secretions in conditions such as cystic fibrosis and bronchial obstruction
- Interference with the phagocytic and bactericidal activities of alveolar macrophages
- Pulmonary congestion and edema

Complications of Pneumonia

Abscess formation
Empyema
Fibrosis
Bacterial dissemination leading to endocarditis, pericarditis, meningitis, suppurative arthritis, and formation of metastatic abscesses in various organs

Atypical Pneumonia

Defined as an acute febrile respiratory disease with patchy inflammatory changes confined to the alveolar space and pulmonary interstitium
Caused by organisms such as Mycoplasma pneumoniae, influenza virus, respiratory syncytial viruses, adenovirus, rhinovirus, rubeola, and varicella virus, Chlamydia, and Coxiella burnetii

Non-Infective Pneumonias

Cryptogenic organising pneumonia
Aspiration pneumonia
Lipid pneumonia
Pneumocystis jiroveci, Mycoplasma, Aspiration, lipid, eosinophilic

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Description

Identify and describe the different types of pneumonia, including lobar pneumonia and bronchopneumonia, and their clinicopathological features. Learn about the pathogenesis and morphology of pneumonia.