Pneumonia

Question 1

What are the types of pneumonia

Answer 1

Community acquired (CAP): typical or atypical
Hospital acquired = A pneumonia onset >48 hours in hospital
Aspiration pneumonia

Question 1

Aetiology of community acquired pneumonia

Answer 1

Typical:
Strep. pneumoniae (70%)
H. influenzae (COPD, unvaccinated)
Staph. aureus (after influenza)
Moraxella catarrhalis (COPD)

Atypical:
Mycoplasma pneumoniae: dry cough, erythema multiforme, arthralgia → reticulo-nodular shadowing in the R region
Legionella: found in water and soil (plumber, cruise ship, airplane rides, hotels) → hyponatraemia, lymphopenia, abnormal LFTs
Chlamydia psittaci: pet birds/parrots → splenomegayly, rash, haemolytic anaemia
Coxiella burnetii: farm animals → hepatitis
Pneumocystis jirovecii (PCP): HIV/immunosuppression → desaturation on exercise

Question 2

Aetiology of hospital acquired pneumonia

Answer 2

Enterobacteriaceae
- E. coli
- Klebsiella pneumoniae: alcoholics, DM, elderly → cavitating lesion
Staph aureus: cavitating lesions
Pseudomonas aeruginosa

Early-onset (48 hours to 4 days): streptococcus pneumoniae
Late onset (>4 days): Enterobacteria (E. coli, K. pneumoniae) > S. aureus (MRSA) > Pseudomonas

Question 3

Aetiology of aspiration pneumonia

Answer 3

Anaerobes (from gut flora)
Klebsiella pneumoniae

Question 4

Aetiology of viral pneumonia

Answer 4

Influenza virus (adults)
RSV
Parainfluenza virus

Question 5

Risk factors for pneumonia

Answer 5

Abnormal ciliary function: Smoking, Kartagener’s, viral infections
Abnormal mucous: cystic fibrosis
Immunocompromised
Age >65
Residence in a healthcare setting
COPD
Travel
Poor oral hygiene
Poor swallow: CVA, muscle weakness, Alcohol abuse

Question 6

Symptoms of pneumonia

Answer 6

Typical
- Productive cough (green sputum)
- Dyspnoea
- Pleuritic chest pain
- Fever and/or rigors
- Confusion

Atypical
- Dry cough
- Headache
- Diarrhoea
- Myalgia
- Hepatitis
- abdominal pain

Klebsiella: red current jelly
PCP: desaturation on exercise

Question 7

Signs of pneumonia on examination

Answer 7

General
- Resp. distress
- Accessory muscle use
- Cyanosed
Obs: tachycardia, tachypnoea, fever

Resp
- Palpation: reduced chest expansion
- Percussion: dull
- Auscultation: basal crepitations, bronchial breathing, increased vocal resonance/tactile vocal fremitus

Question 8

Investigations for pneumonia

Answer 8

Sputum MC&s
Urinalysis for urinary antigens: for legionella and strep. pneumoniae

FBC: raised WCC, legionella → lymphopenia
CRP: raised
U&Es: legionella → hyponatraemia
LFTs: legionella → deranged
ABG: ?T1RF
Blood cultures
Serology for atypical antigens
Blood film: mycoplasma → RBC agglutination by cold agglutinins
Antibody testing; paired serum samples for chlamydia, legionella

CXR: lobar/patchy shadowing
- Legionella → usually upper lobes
- Staph aureus → cavitating lesion
Bronchoscopy and BAL
Pleural fluid MC&S

Question 9

Management for uncomplicated community acquired pneumonia

Answer 9

Calculate CURB-65 score

Confusion
Urea >7
Resp rate >30
BP <90/60
Age >65

0/1 → amoxicillin oral 500mg 5-7 days (3% mortality risk)
2 → hospital based care (3-15% mortality)
4 → intensive care (15% mortality)

Question 10

Management for moderate-severe community acquired pneumonia

Answer 10

1. A-E and calculate CURB score → admit
2. Supportive:
   - Oxygen, sit up
   - IV fluids
   - Analgesia
3. Abx
   - Moderate: amoxicillin PO + clarithromycin 500mg PO
   - Severe: Cefuroxime 1.5g IV + Clarithromycin 500mg IV
   - Atypical → clarithromycin or doxycyline

Consider:
NIV: CPAP, BiPAP
ITU
Surgical drainage for empyema.abscess
Offering vaccination

Question 11

Management for hospital acquired pneumonia

Answer 11

1. A-E and calculate CURB score → admit
2. Supportive:
   - Oxygen, sit up
   - IV fluids
   - Analgesia
3. Abx
   Empirically: Co-amox/Ciprofloxacin ± vancomycin
   - Staph → Flucloxacillin
   - MRSA → Vancomycin
   - Pseudomonas → piptazobactam
   - Klebsiella → ceftriaxone
   - Severe → piptazobactam

5 day course then review

Question 12

Management for aspiration pneumonia

Answer 12

Metronidazole or co-amoxiclav

Question 13

Discharge management after pneumonia

Answer 13

Switch to PO Abx: co-amoxiclav + clarithromycin
All cases of pneumonia should have a repeat chest X-ray at 6 weeks after clinical resolution to ensure that the consolidation has resolved and there is no underlying secondary abnormalities (e.g. a lung tumour).

Advise on time course:
1 week: fever resolves
4 weeks: chest pain + sputum reduced
6 weeks: cough + SOB reduced
3 months: fatigue only
6 months: completely normal

Question 14

Complications of pnuemonia

Answer 14

Pleural effusion
Lung abscess (often S. aureus) -> swinging fevers, persistent pneumonia, foul smelling sputum)
Empyema (persistent fever)
Pneumothorax
ARDS
Septic shock
Acute renal failure
Cardio: heart failure, acute coronary syndrome, arrhythmias

Question 15

What should be considered if there is failure to improve after treatment for pneumonia

Answer 15

Empyema/abscess
Proximal obstruction (tumour)
Resistant organisms (travel hx)
Not receiving/absorbing antibiotics
Immunosuppression
Other diagnosis (lung cancer, cryptogenic organising pneumonia

Question 16

Prognosis for pneumonia

Answer 16

For patients admitted to hospital, mortality rate ranges from 5% to 15%, but increases to 20% to 50% in patients requiring admission to the intensive care unit (ICU)
Patients treated in the community generally have a good prognosis
The all-cause mortality for HAP is 30% to 70%, while the attributable mortality is approximately 10%. Many people with HAP die of their underlying cause