Pneumonia

Question 1

Describe the typical presentation of a patient with a community aquired pneumonia (CAP)

(symptoms and signs)

Answer 1

Symptoms:

• Acute systemic illness
  
  • Fever
  • Rigors
  • Vomiting
• Cough
  
  • Initally short, dry and painful progressing to a productive with mucopurulent sputum
• Dyspnoea
• Pleuritic chest pain - may be referred to shoulder or anterior abdominal wall

Signs:

• Tachypnoea
• Decreased chest expansion on the affected side
• Dullness to percussion over the affected area
• Coarse crackles and a pleural rub over the affected area, with bronchial breathing
• Increased vocal resonance
  
  • ‘Blue balloons’ can be heard better: seen in consolidation, can’t hear as well in effusions, pneumothorax or collapse
• Upper abdominal tenderness: in lower lobe pneumonia

Question 2

How is the severity of pneumonia assessed?

Answer 2

CURB-65

• Confusion: mini mental test score <8
• Urea >7mmol/l
• Respiratory rate >30 per minute
• Blood pressure: hypotensive <90/60
• 65 years or older

One point for each finding

0/1 = non-severe CAP

2 = moderately severe CAP
\>2 = severe CAP

Question 3

How is hospital acquired pneumonia defined?

Answer 3

• Pneumonia that develops at least 48 hours after admission to hospital, with no signs of incubation on adission or develops in somebody in hospital in the past 10 days

Question 4

List the common pathogens causing community acquired pneumonia

Answer 4

• Conventional bacteria (60-80%)
  
  • Streptococcus pneunomia (most common)
  • Haemophilus influenzae
• Atypical bacteria (10-20%)
  
  • mycoplasma pneumonia
  • Chylamdia pneumonia
  • Legionella pneumonia
• Viruses (10-20%)
  
  • Influenza/parainfluenza

Question 5

List the common pathogens causing hospital acquired pneumonia

Answer 5

• Gram –ve bacteria (E Coli, Pseudomonas, Klebsiella)
• Staph Aureus

Question 6

Who is more suspectable to pneumonia?

Answer 6

Patients at most risk are those following viral infection, hospitalized and ill, smokers, alcoholics, bronchiectasis, bronchial obstruction, immunosuppressed, IVDU, GORD.

Question 7

How can pneumonia be classified with regard to the main site of the inflammatory response?

Answer 7

• Pneumonia can be classified into lobar pneumonia or bronchopneumonia based on the main site of inflammatory response within lung parenchyma (s the portion of the lung involved in gas transfer - the alveoli, alveolar ducts and respiratory bronchioles)
• Inflammatory exudate within the alveolar air spaces is what renders the infected areas of the lung macroscopically solid in ‘consolidation’

Question 8

Describe the pathology of bronchopneumonia

Who is it most common in? Why?

Where is the lobe does it mot commonly affect?

Answer 8

• Primary infection centres around the bronchi, spreading to involve adjacent alveoli which become consolidated
• The initial consolidation is patchy (involves lobules), but if untreated can become confluent (involves whole lobes)
• Most common in infancy and old age due to immobility and retention of secretions thus bronchopneumonia moster most commonly affects lower lobes due to effect of gravity

Question 9

Describe the pathology of lobar pneumonia

Answer 9

• Organims gain entry to distal air spaces rather than colonising bronchi, thus there is rapid spread of infection through alveolar air spaces
• Macroscopically, the whole of the lobe becomes consolidated and airless
• These patients are normally adults, and become severely ill with associated bacteraemia

Question 10

What investigations would you do for a patient presenting with community-acquired pneumonia

Answer 10

• Observations & oxygenation assessment
• Bloods: FBC, CRP, U&Es, LFTs
• Blood cultures
• CXR
• Sputum sample for culture
  
  • Plus mycoplasma PCR if suspected
• Urine for legionella/pneumococcal antigen if moderate/severe (empiral treatment wont cover legionella)
• Serum mycoplasma IgM if suspected
• Throat swab in viral transport medium if sever pneumonia or suspected viral pneumonia

Question 11

What antibiotic treatment woud you give for a patient with community acquired pneumonia?

Answer 11

• CURB 65 0/1: Non-severe CAP
  
  • Oral amoxicillin
  • Managed as outpatietn
• CURB 65 2: moderately severe CAP
  
  • Oral amoxicillin and clarithromycin
  • Usually admitting patient
• CURB 65 >2: severe CAO
  
  • IV clarithromycin plus co-amoxiclav
  • Admit to high-dependency unit

Antibiotic treatment should be guided to sputum sensitivity results, microbiology advice, trust guidelines and patient’s allergy status.

Question 12

Other than antibiotic how else should a patient with CAP be treated?

Answer 12

• Patients should stop smoking
• have physiotherapy to clear mucous and ensure no decline with regards to ADL once infection is resolved
• should be kept well oxygenated
• should have fluid balance maintained
• should be kept out of pain with pharmacological consideration of co-morbidities

Question 13

What complications of pneumonia can occur?

Answer 13

• Parapneumonic effusion/Empyema (presence of pus in the pleural cavity)
• Post-infective bronchiectasis
• Lung abscess: clubbing
• Sepsis

Question 14

Elicit the classical features of consolidation

Answer 14

Dullness, increased vocal fremitus and bronchial breathing are all a result of consolidation.

Question 15

Recognise the radiological features of consolidation on CXR

Answer 15

Greyness - patchy in broncho, homogenous in lobar.

Middle lobe = heart border obscured

Lower lobe = diaphragm obscured