Bacterial Pneumonia

Question 1

CAP and requirements of diagnosis

Answer 1

Community Acquired Pneumonia

Evidence of lower respiratory tract infection (LRTI), e.g.

• Cough
• Sputum
• Breathlessness
• Chest pain

AND

CXR evidence of pneumonia

Question 2

What is the likely diagnosis of this patient

Answer 2

Pneumonia

Question 3

Risk factors of CAP

Answer 3

Males
Elderly
Alcoholics
Chronic Disease

Question 4

Aetiology of CAP

Answer 4

Conventional bacteria [most common]
‘Atypical’ bacteria
Viruses

Question 5

Conventional vs Non-conventional bacteria

Answer 5

Conventional bacteria have cell walls and thus can be treated with antibacterials that target cell walls; non-conventional bacteria do not have cell walls

Question 6

Examples of bacteria that cause pneumonia

Answer 6

Streptococcus pneumococcus
H. influenzae
Mycoplasma pneumoniae (atypical bacteria)

Question 7

Streptococcus pneumococcus

Answer 7

Most common cause of CAP in those without COPD
Capsular polysaccharide is the major virulence factor

Relative resistence to penicillin is becoming common

Question 8

Haemophilus influenzae

Answer 8

The capsulated bacteria is primary cause of CAP in children who have not received Haemophilus vaccination

Non-capsulated H. influenza is an important cause of disease in COPD

Question 9

Mycoplasma pneumoniae

Answer 9

Second most cause of CAP

Causes >30% of CAP in 17-44 year olds; seasonal

Can cause occasional epidemics

Has characteristic extra-pulmonary features (e.g. skin)

Question 10

Legionella pneumophila

Answer 10

Cause of both sporadic and outbreak CAP

Can cause severe disease, especially in immunocompromised patients and smokers

Requires specific high dose fluoroquinolone or macrolide antibiotic treatment

Question 11

Which serogroup of Legionella pneumophila causes almost all human infection with the disease

Answer 11

Serogroup 1

Question 12

Investigation of CAP (Clue, 4 steps)

Answer 12

Confirm diagnosis (CXR)

Assess severity of disease
Define aetiological agent (respiratory sample, blood sample)

Identify complications

Question 13

Microbiological Investigations of pneumonia

Answer 13

Sputum analysis and culture
Immunofluorescence on sputum samples
Blood Cultures
Urinary pneumococcal and legionella antigen

Question 14

Antimicrobial Chemotherapy

Answer 14

Based on:
Assessment of likely pathogen
Severity of illness
Likelihood of drug resistance (local and national); tell the lab about how infection was acquired

Question 15

CURB65 Score

Answer 15

Score for pneumonia severity

Confusion (MMT score 8 or less)
Urea (new elevation >7 mmol/L)
Respiratory rate > 30bpm
BP (Systolic <90, DS <60)
65 or more years old

Question 16

Low severity CAP

Answer 16

CURB 65 0 or 1

Oral antibiotics amoxicillin 500mgs qds for 5 days
OR
Doxycycline 200mgs loading then 100mg od

Only IV if unable to take oral therapy

If severe allergy to penicillin, ciproflaxacin (quinolone) 400mgs bd + (glycopeptide) vancomycin

These patients should be manageable in community unless frail

JESUS CHRIST DO NOT MEMORISE THIS!!! JUST BE VAGUELY AWARE

Question 17

Where is the pneumonia in this patient

Answer 17

Right upper lobe

Question 18

Moderate severity CAP

Answer 18

CURB 65 2

Amoxicillin 500mgs qds 7 days + clarithromycin 500mgs bd for 7 days
OR
Doxycycline 200mgs loading then 100mg od

IV only if unable to take oral treatement

Normally managed in a hospital environment

JESUS CHRIST DO NOT MEMORISE THIS!!! JUST BE VAGUELY AWARE

Question 19

Severe CAP

Answer 19

CURB 65 3

Co-amoxiclav 1.2g tds + amoxacillin 1g tds + clarithromycin 500mgs bd iv for 10 days

If severe allergy to penicillins or MRSA
Levofloxacin 500mgs bd + vancomycin 1g bd

Question 20

Severe CAP (Score >3)

Answer 20

Continue treatment of score = 3,

Add levofloxacin 500mgs bd for 14 days

Ensure legionella antigen in urine requested and culture sputum if possible (alert lab)