Resp17 - Lower Respiratory Tract Infections & Pneumonia

Question 1

3 general features of pneumonia

What is it?
Anatomical Classifications
Complications x3

Answer 1

1. ) What is it? - inflammation of the lung parenchyma due to infection often w/ cellular exudate in alveolar spaces
   - inflammation due to non-infective causes (physical or chemical is called pneumonitis)
2. ) Anatomical Classifications
   - lobar pneumonia: localised to a particular lobe(s)
   - bronchopneumonia: more diffuse and patchier

3.) Complications - pleural effusion, emphysema, lung abscess formation

Question 2

Types of Pneumonia (+organisms)

Community Acquired (CAP)
Hospital-Acquired (Nosocomial)
Aspiration Pneumonia
Immunocompromised

Answer 2

1. ) Community-Acquired Pneumonia
   - S.pneumoniae (90%), H. influenzae, Moraxella catarrhalis, Klebsiella pneumoniae, S.aureus
   - rapid onset w/ fatal outcome in a short period of time
   - atypical (can last several weeks): Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophilia
2. ) Nosocomial Pneumonia - LRTI in hospitalised patients >48hrs after admission w/o incubated before
   - organisms: g-ves (E. coli, Klebsiella), S. aureus
3. ) Aspiration Pneumonia - aspiration of food, drink, saliva or vomit leading to an infection. Occurs due to:
   - altered consciousness: anaesthesia, alcohol, drug OD
   - swallowing problems: neuromuscular problems or oesophageal disease
   - causative organisms: oral flora and anaerobes
4. ) Pneumonia in the Immunocompromised
   - pneumocystis jiroveci, aspergillus, cytomegalovirus

Question 3

Diagnosis of Pneumonia

Clinical Features
CURB-65
Investigations

Answer 3

1. ) Clinical Features
   - fever, SOB, productive cough (green sputum)
   - pleuritic chest pain
   - dull on percussion, ↑vocal resonance
2. ) CURB-65 - assessment to aid management ,
   - Confusion (new), Urea (>7 mmol/L), RR (>30), BP (systolic <90 or diastolic <60), Age >65
   - 0 or 1 managed as outpatient, 2 inpatient, 3+ consider ICU admission
3. ) Investigations
   - bloods: ↑WCC, ↑CRP, U+Es, sputum culture, ABG,
   - blood cultures and atypical pneumonia screen (serology and urine legionella test)
   - chest X-ray: consolidation

Question 4

Management of Pneumonia

General Measures
Antibiotics for Community Acquired Pneumonia
Antibiotics for Atypical Organisms
Antibiotics for Noscocmial Pneumonia
Follow Up

Answer 4

1. ) General Management
   - A-E assessment, analgesia, stay hydrated
   - IV fluids and oxygen in more severe illness
2. ) Antibiotics for Community Acquired Pneumonia
   - mild (0/1): PO amoxicillin 500mg TDS for 5 days, OR PO doxycycline 200mg TDS for 5 days (pen allergy)
   - moderate (2): PO amoxicillin 1g TDS + PO doxycycline 200mg TDS for 5 days, doxycycline only if pen allergic
   - severe (3+): IV co-amoxiclav 1.2g TDS + PO doxycycline 200mg TDS for 5 days OR IV meropenem 1g TDS + PO doxycycline 200mg TDS for 5 days
3. ) Antibiotics for Atypical Organisms - don’t have cell wall so you target protein synthesis
   - macrolides (erythromycin or clarithromycin) or tetracycline (doxycycline)

4.) Antibiotics for Noscocmial Pneumonia - g-ve organisms are most common so IV Co-Amoxiclav given

5. ) Follow Up
   - HIV test, flu and pneumococcal vaccine
   - immuniglobulins: pneumococcal, H influenzae IgG
   - follow up in CXR with a repeat CXR