Pneumonia

Question 1

What is the epidemiology of pneumonia?

Answer 1

350 per 100,000 per year
>£400million/year
20-50% hospitalised, 5-10% require ITU
6-8 days stay

Mortality:
1% community
10% hospital
30% ITU

Risk factors:
Infants and elderly 
COPD 
Immunocompromised
Nursing home residents
Impaired swallow (neurological conditions)
Diabetics 
Congestive heart disease 
Alcoholics and IV drug users

Question 2

What is are the types of pneumonia and the most common agents causing it?

Answer 2

Community acquired pneumonia (CAP):
- Bugs picked up OOH
- Most common bacteria = Streptococcus pneumoniae (pneumococcus), a G+diplococci
- Also:
Viral spp; H.influenzae, Klebsiella pneumoniae, S.aureus; mycoplasma, legionella
- ALWAYS CHECK LOCAL PATTERNS

Hospital Acquired Pneumonia (HAP)

• Bugs picked up in hospital, occurs >48hrs after admission and not thought to be incubating prior to
• Early onset <4d = often the same bugs as CAP; better prognosis
• Late onset >5d = G-ve bacilli e.g. Pseudomonas aeruginosa, Klebsiella spp., also MRSA; poorer prognosis

Aspiration pneumonia:
- Aspiration of gastric contents up oesophagus and down into trachea can lead to a sterile, chemical pneumonitis; or the translocation of oropharyngeal bacteria leading to a bacterial pneumonia

Severe disease if excessive inflammation, lung injury, failure to resolve without damage

Question 3

How does pneumonia present?

Answer 3

Symptoms:

• Fever, sweats
• Rigour
• Cough + sputum (sometimes rusty brown)
• SOB
• Pleuritic chest pain
• Weakness and malaise
• Confusion

Signs:

• Tachycardia
• Tachypenia
• Hypotension
• Dehydration
• Lung consolidation on percussion and auscultation = dullness, decreased air entry, bronchial breath sounds, crepitations and wheeze

Progression to sepsis

Question 4

How do you investigate pneumonia?

Answer 4

Bloods:

• FBC - WCC raised
• U+E - urea (increased) and electrolyte imbalances
• CRP - raised
• Blood cultures - if CURB >2 and PCR
• ABG - variable pictures

CXR:

• Focal areas of consolidation
• White spots due to puss - snowy texture
• Abscess w or w/o fluid
• Air bronchogram - to look for consolidation

Sputum:
- MC+S - if CURB >3 OR >2 and not already had Abx

Additional:
Urine - pneumococcal and legionella antigens
Respiratory virus PCRs
HIV test

Question 5

How do you assess pneumonia for severity and subsequent management?

Answer 5

CURB65 score: (one point for each heading)

1. Confusion
2. Urea >7mmol/L
3. Respiratory rate > 30/min
4. BP - Low systolic <90mm/HG or diastolic <60mm/HG
5. Age >65

Scores:
0-1 = Mild – only admit in special circumstances e.g. previous co morbidities ie asthma, response to other treatments
2 = Moderate – admit to hospital
3-5 = Severe – admit and monitor closely
4-5 = Consider admittance to critical care

In community setting, no urea sampling so 3-4 severe

Question 6

How do you manage pneumonia?

Answer 6

Abx:

• Depends on known local trends as well as other patient factors (e.g. mycoplasma more common in immunocompromised)
• Start ASAP after diagnosis of CAP - ideally <4hrs, or <1hr if sepsis suspected

CURB 0-2:
- Amoxicillin PO 500mg TDS 5/7
- AND/OR clarithromycin PO 500mg BD
5/7 (if allergy or atypical suspected)

CURB 3+ (severe):
- Co-amoxiclav (PO) IV 1.2g TDS 5/7 (depending on severity)
AND clarithromycin (PO) IV 500mg BD 5/7

Review Abx, change according to cultures, allergy and pregnancy status, discussion with micro etc.
- R/V at 48hrs and if improving consider oral switch

Oxygen
- Aim for sats >96%, titrate oxygen appropriately

Fluids + monitoring
- Keep an eye on renal function, fluid balance etc

Analgesia

VTE prophylaxis

If no improvement by day 3:
- Repeat CRP and CXR (look for pleural effusion/empyema)

Question 7

How do you prevent pneumonia?

Answer 7

Polysaccharide pneumococcal vaccine:
- 23 serotype protection
For elderly or Immunocompromised

Pneumococcal conjugate vaccine:

• 13 serotypes
• Mostly used in children

Smoking cessation and management of other modifiable risk factors

Question 8

What else is important to tell a patient with pneumonia?

Answer 8

Possible side effects of antibiotics

How long symptoms might last

• week 1: fever should resolve
• week 4: chest pain and sputum should have significantly reduced
• week 6: cough and shortness of breath should have significantly reduced
• month 3: most symptoms should have resolved, except for tiredness
• month 6: should be returned to normal

What to do in the community if symptoms do not improve or deteriorate or they become systemically unwell

Repeat CXR as O/P 6/52 post recovery is required if pt had CXR on admission
- To check for complete resolution and to exclude sinister pathology that may have been hidden by signs of infection

Question 9

What are some common bugs causing pneumonia and their discriminating features?

Answer 9

S. pneumoniae:

• G+ve diplococci
• 80% of all CAP

S. aureus:

• G+ve cocci (cluster); coagulase +ve, catalase +ve
• Most common after viral influenza

H. influenza:

• G-ve coccobacillus coccobacillus
• Common in COPD

K. pneumonia:

• G-ve rod
• Common in alcoholics and diabetics
• Red-currant jelly sputum

Legionella pneumophila:

• G-ve coccobacillus
• Infected air conditioning units; recent travel (Spain)
• Hyponatraemia and lymphopaenia

Pseudomonas aeruginosa:

• G-ve rod
• Common infection in cystic fibrosis