8.2 Pathophysiology of Pneumonia Flashcards
Provide a simple definition of pneumonia
Acute infection of the pulmonary parenchyma
How many hospital admissions for pneumonia per year in Australia?
77,000
Pneumonia was the ___th leading cause of death in Australia in 2019
9th
List some risk factors for pneumonia
- Age > 65
- Chronic lung disease (e.g. COPD, cystic fibrosis)
- Immunocompromised conditions (e.g. HIV)
- Lifestyle factors (smoking, alcohol, toxic inhalation of substances)
Additional important questions to ask during history of suspected TB patient
- Living environment
- Current/previous employment
- Travel and emigration
- Sick contacts
- Toxic exposures
- Vaccinations
Symptoms of pneumonia
- Productive cough
- Dyspnoea
- Pleuritic chest pain
- Lethargy
Signs of pneumonia
- Tachypnoea
- Fever
- Tachycardia
- Hypoxia
- Dullness to percussion
- Decreased breath sounds
- Bronchial breathing
- Coarse crackles
Describe the SMART COP mnemonic for pneumonia severity
- Systolic BP <90mmHg
- Multilobar CXR involvement
- Albumin < 3.5 g/dL
- Resp Rate >30
- Tachycardia >125bpm
- Confusion
- O2 sats <90%
- pH <7.35
Explain the CURB-65 severity scoring
- Confusion
- Urea >7 mmol/L
- Respi rate >30
- Blood pressure (sys <90 or dia <60)
- Age: >65
List some acute complications of pneumonia
- Sepsis
- Parapneumonic effusion
- Empyema
- Respiratory failure
What is parapneumonic effusion?
Accumulation of fluid in pleura due to inflammatory response to pneumonia
What is empyema?
Direct infection/pus buildup in pleural space
How is community acquired pneumonia transmitted (mechanism of transport)?
Droplets/aerosols
Describe the pathophysiology of community acquired pneumonia (starting with transmission)
- Droplets/aerosols
- Colonise nasopharynx
- Microaspiration -> parenchyma
- If macrophage cannot contain, it releases cytokines
- Systemic and local inflammatory response
Aetiological classifications of pneumonia
- Bacterial
- Viral
- Aspiration
- Atypical
- Opportunistic
Acquisition-based classifications of pneumonia
- Community acquired
- Healthcare associated
- Ventilator associated
In order, list some common bacterial causes of community acquired pneumonia
- Streptococcus pneumoniae
- Mycoplasma pneumoniae
- Haemophilus influenzaae
In order, list some common viral causes of community acquired pneumonia
- Influenza A/B
- Picronaviruses
- Adenovirus
In order, list some common causative organisms of healthcare associated pneumonia
- Streptococcus pneumoniae
- Escherichia coli
- Klebsiella pneumoniae
- MRSA
Lobar vs bronchopneumonia
Lobar: one or more lobes
Bronchopneumonia: patches all throughout lungs
Why is an EUC important in suspected cases of pneumonia
- Measures renal function
- Important before giving antibiotics
What would be expected in an FBC of a pneumonia patient?
Raised white blood cells
Would inflammatory markers be expected to be raised or lowered in pneumonia
Raised
What is the purpose of sputum microscopy and culturing in suspected pneumonia patients?
To see if any bacteria or fungi are present
What could be seen on a CXR of a pneumonia patient?
- Consolidation
- Effusions (parapneumonic effusion vs empyema)
What organisms would make you suspicious of opportunistic pneumonia?
- Cryptococcus
- Pneumocystis
When is bronchoscopy used in suspected cases of pneumonia?
- Immunosuppressed patient with high rsk of fungal pneumonia
- Severe pneumonia, no identified organism, not responding to normal therapy
- Concern for endobronchial obstruction casuing pneumonia
- Concern of non-infective pneumonia
What are the three main aspects of pneumonia management?
- Antiobiotic therapy
- Supportive therapy
- Assess reversibility of risk factors
Describe some non-antibiotic therapies for pneumonia patients
- Oxygen as required (usually above 92%; CO2 retainers: 88-92%)
- Allied health—mukltidisciplinary approach
- Rehab
- DVT prophylaxis
- Adequate nutrition
Class 1 pneumonia treatment
- Amoxicillin
- Doxycycline
- Can probably go home
Class 2 Pneumonia treatment
- IV amoxicillin
- Azithromycin
- Gentamicin (if high risk)
Class 3 pneumonia treatment
- Amoxicillin
- Azithromycin
- Gentamicin
- May or may not need other support
If there is dense consolidation of CT, patient may need repeat CT in 3 months. Why?
- Ensure resolution
- Ensure no underlying lesion
Effect of pneumonia on vocal resonance?
Increase+