Pneumonia

Question 1

What is the pathological classification of pneumonia?

Answer 1

lobar vs bronchopneumonia

• BRONCHOPNEUMONIA
  
  • widespread patchy inflammation centred on airways
  • often bilateral
  • patchy areas of consolidation
  • bronchi containing acute inflammatory exudate
  • also upper lobe emphysema
• LOBAR PNEUMONIA
  
  • diffuse inflammation affecting an entire lobe/lobes
  • photo - entire lobe, paler than other
  • consolidation due to accum of acute inflammatory exudate within alveoli
  • abrupt demarcation at interlobar fissure

This classification largely was based on macroscopic exam of lungs at autopsy in pts w/ florid pneumonias in a pre-antibiotic era. Problem - difficult to apply in most cases as patterns overlap + classical picture is extremely blurred by modern day abx therapy.

Question 2

What does consolidation refer to?

Answer 2

• on CXR - refers to replacement of air in alveoli by fluid or other material, with preservation of underlying alveolar architecture
• in case of pneumonia, air is replaced by acute inflammatory exudate
• there is no destruction of underlying architecture

Question 3

What are the typical organisms that cause community-acquired pneumonia?

Answer 3

1. streptococcus pneumonia (pneumococcus) - most common bacterial cause, affects all ages particularly elderly. Also presents w/ herpes labialis + rusty sputum. Most common (60-75%). Lobar consolidation on CXR.
2. haemophilus infulenzae - common cause of pneumonia in pre-existing lung disease: COPD. Can be diffuse or confined to one lobe.

Question 4

The remainder of organisms causing CAP are a mixed bag termed ‘atypicals’ (an unhelpful term).

What are the ‘atypical’ organisms that cause CAP?

Answer 4

Question 5

What organisms are responsible for hospital-acquired pneumonia (HAP)?

Answer 5

• E.coli (gram-negative)
• staphlococcus aureus
• pseudomonas
• klebsiella
• bacteroides
• clostridia

Question 6

What organisms are responsible for pneumonia in the immunocompromised patient?

Answer 6

• bacteria: strep pneumoniae, staph aureus, pseudomonas
• fungi: pneumocystitis, candida albicans, aspergillus
• virus: influenza A virus, adenovirus, CMV, HSV, SARS, varicella

Question 7

What are risk factors for pneumonia?

Answer 7

• underlying lung disease (COPD, bronchiectasis, obstruction)
• age (v young + v old)
• smoking
• alcohol xs
• winter months
• hospitalisation
• immunocompression
• IV drug use
• inhalation from oeseophageal obstruction

Question 8

What are the symptoms of pneumonia?

Answer 8

• fever + rigors
• malaise
• anorexia
• dyspnoea
• cough + purulent sputum
• haemoptysis
• pleuritic chest pain

Question 9

What are the signs of pneumonia?

Answer 9

• tachypnoea
• reduced chest expansion over affected area
• inc vocal resonance/tactile fremitus
• dull percussion note
• bronchial breathing
• coarse inspiratory crackles
• confusion
• cyanosis
• tachycardia
• hypotension

Question 10

The severity of CAP is assessed based on the CURB-65 criteria.

What is the criteria?

Answer 10

• Confusion of new onset (AMT ≤8)
• Urea >7mmol/L
• Resp rate ≥30
• BP <90 systolic or ≤60 diastolic
• 65 years or

0-1 = home tx, 2 = hosp therapy, >3 = severe pneumonia (ITU)

Question 11

What are clinical features that suggest an atypical organism is responsible?

Answer 11

• headache + flu-like symptoms
• dry cough
• extra-thoracic, systemic symptoms:
  
  • abdo pain + diarrhoea (legionella)
  • night sweats + weight loss (pneumocystitis or tb)
• discordance between chest signs and illness of pt
• NO leukocytosis
• sometimes no consolidation

Question 12

What are the investigations for pneumonia?

Answer 12

• Bloods - FBC, U+E, LFT, CRP, cultures
• Urine (-> strep pneumoniae + legionella ag)
• Sputum
• CXR
• Oxygen saturation
• ABG
• Pleural fluid
• Bronchoscopy + bronchoalveolar lavage

Question 13

What might a CXR show for pneumonia?

Answer 13

• lobar or multilobar consolidation
• cavitation
• pleural effusion

Question 14

What is the management of CAP?

Answer 14

• NON-SEVERE (CURB65 0-1)
  
  • oral amoxicillin or clarithromycin or doxycycline
• SEVERE (CURB65 2-5)
  
  • benzylpenicillin IV
  • clarithromycin IV

Oral switch to doxycycline or amoxicillin (+/- carithromycin PO)

Question 15

What antibiotic should be used for legionella?

Answer 15

fluoroquinolone combined w/ clarithromycin or rifampicin

Question 16

What antibiotic is used for pneumocystitis jirovecii?

Answer 16

co-trimoxazole

Question 17

What is the management of HAP?

Answer 17

• mobile pt, reduce sedation, pain control
• physiotherapy
• oral co-amoxiclav
• IV penicillin and gentamycin

Question 18

What is the management of aspiration pneumonia?

Answer 18

• cephalosporin IV + metronidazole IV

Question 19

Who is the pneumococcal vaccine indicated for?

Answer 19

• over 65s
• chronic heart, liver, renal or lung conditions
• diabetes mellitus
• immunosuppression (decreased spleen fxn, aids, chemo, steroids)

Re-vaccination is necessary after 6yrs

Question 20

Who is the influenza vaccine indicated for?

Answer 20

• over 65yrs old
• chronic heart, liver, renal, lung conditions
• diabetes mellitus
• COPD, asthma
• immunosuppression
• pregnancy, lactation
• children from 6months - 2yrs
• healthcare workers
• ppl living in large institutions

vaccination recommended once a year

Question 21

Who is the BCG vaccine indicated for?

Answer 21

• infants under 1yr living in areas of UK w/ high rate of TB
• infants under 1yr whose parents have lived in high-risk areas
• children (under 16yrs) who have migrated from high-risk areas
• adults under 35yrs who have come from high-risk areas
• health-workers, prison staff, those intending to stay in areas with high rate of TB + those w/ contact to people with active TB

Lifetime immunity is acquired through vaccination

Question 22

What are potential complications of pneumonia?

Answer 22

• para-pneumonic pleural effusion
• epyema
• lung abscess
• resp failure
• septicaemia
• pericarditis
• myocarditis