5. Pneumonia Flashcards
Define Pneumonia.
It is the proliferation of microbial pathogens at the alveolar level in a host and the host’s response to those pathogens.
What is the main characteristic of a patient with Pneumonia?
Consolidation of Lobes of the Lung (Alveoli are filled with inflammatory exudate, WBCs and bacteria)
Classify Pneumonia.
It can be classified according to these criterias :
- Anatomical Pattern (Lobar and Bronchopneumonia)
- Clinical Circumstances
- Host’s Reaction
- Etiological Agents
- Sources of Infection
State the different clinical circumstances that may lead to Pneumonia.
- Primary (Healthy person)
2. Secondary (Local/Systemic defects in host’s defence)
State the different host’s reaction that may occur in Pneumonia.
It could be fibrinous or suppurative, depending on the dominant component of the exudate.
State the etiological agents that may lead to Pneumonia.
- Bacterial
- Viral
- Fungal
- Others
Name the bacterial aetiological agents that may lead to Pneumonia.
- Streptococcal pneumonia
- TB pneumonia
- Staphylococcus aureus
Name the viral aetiological agents that may lead to Pneumonia.
- Measles
- Influenza
- RSV
- Adenovirus
- Coronavirus
Name the fungal aetiological agents that may lead to Pneumonia.
- Cryptococcus neoformans
- Candida sp.
- Aspergillus
Name the other aetiological agents that may lead to Pneumonia.
- Mycoplasma pneumoniae
2. Pneumocystis jiroveci
State the different sources of infections that may lead to Pneumonia.
- Community-acquired pneumonia (CAP)
- Hospital-acquired pneumonia (HAP)
- Ventilator-acquired pneumonia (VAP)
How does an infection occur in the lungs and give examples.
- Aspiration of content from the Oropharynx (Ex; Saliva)
- Hematogenous Spread (Ex; Pathogens from Tricuspid Endocarditis)
- Contiguous extension (Ex; Infected Pleural/Mediastinal Space)
State the risk factors that may lead to Pneumonia.
- Age
- Co-morbidity (Diabetes, Asthma, COPD, Bronchiectasis)
- Immunosuppresion
- Neoplasia
- Neurological disorders
- Alcohol/Tobacco consumption
- Other various lifestyle factors
Define Community-acquired Pneumonia.
It is pneumonia which develops in a healthy person outside the hospital or in a person who has been in the hospital for less than 48 hours.
State the bacterial aetiological agents causing CAP.
- Typical Bacterial Pathogens :
- Strep. pneumoniae
- Haemophilus influenzae
- Staphyloccoccus aureus
- Gram negative bacili (Klebsiella pneumoniae, Pseudomonas aeruginosa)
- Atypical Bacterial Pathogens :
- Mycoplasma pneumoniae
- Chlamydophilia pneumoniae
- Legionella pneumoniae
- Chlamydia psittaci (commonly found in birds)
- Coxiella burnetti (commonly found in cattle/cats)
What are the symptoms seen in a patient with CAP?
- High fever with chills
- Cough
- Rusty/Mucopurulent sputum
- Dyspnoea
- Pleuritic Chest Pain
What the signs elicited in a patient with CAP?
- Fever
- Tachycardia
- Tachypneoea
- Cyanosis
- Hypotension
What is observed in the respiratory examination of a patient with CAP?
- Decreased respiratory (chest) movements, exclusively in the affected lobe.
- Impaired note on percussion (woody dull note)
- Tubular bronchial breath sounds
- Increased vocal resonance
- Aegophony
- Crepitations
- Pleural effusion/rub
What is observed in the respiratory examination of a patient with CAP?
Elevated WBC count
State the complications that might occur in a patient with CAP.
- Lung abscess
- Para-pneumonic effusions
- Empyema
- Sepsis
- Metastatic infections (Meningitis, Endocarditis, Arthritis)
- ARDS
- Respiratory Failure
- Circulatory Failure
- Renal Failure
- Multiorgan Failure
How would you handle a suspected case of Pneumonia?
- Obtain relevant details from the history
- Check for signs and symptoms
- Conduct blood investigations
- Conduct a Chest X-Ray
- Send a sputum sample to the lab for Culture and Gram Staining
- Other tests : Chest CT, Blood culture, Antigen test, Serology, Bronchoscopy, Bronchoalveolar lavage, PCR.