Pneumonia & other lower respiratory tract infections

Question 1

What scoring system is used for people with pneumonia to determine severity?

Answer 1

CURB-65 = Confusion, Urea, Respiratory rate, Blood pressure
Urea > 7mmol/l
Respiratory rate>30
BP systolic<90mmHg or diastolic<60mmHg
Age>65
Each feature scores 1 if present

Question 2

What are general tests to order for pneumonia cases?

Answer 2

FBC
CRP
Blood cultures
Sputum MCS
CXR
HIV
Urine

Question 3

What is consolidation in an xray?

Answer 3

Fluid in the lung e.g. pus, blood, water instead of air

Question 4

What are signs and symptoms of pneumonia?

Answer 4

Malaise/confusion
Fever/chills
Rigor
Tachycardia
Tachypnoea/dyspnoea
Cough (productive)
Vomiting
Diarrhoea

Question 5

What are risk factors of pneumonia?

Answer 5

Older than 65
Smoker
Malnourished
Underlying lung disease
Immunocompromised
Certain medications
Recent resp infection

Question 6

What are some pulmonary defences?

Answer 6

Cough reflex
Mucus secretion
Alveolar macrophages
IgA antibody
Microflora
Nose hairs

Question 7

What are some causative bacterial organisms?

Answer 7

Strep. pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
Staphylococcus aureus
Legionella spp
Mycoplasma pneumoniae
Mycobacterium tuberculosis

Question 8

What are some causative viral organisms?

Answer 8

Influenza
Parainfluenza
Respiratory syncytial virus
Human metapneumovirus
Rhinovirus
Coronaviruses

Question 9

What are some causative fungi organisms?

Answer 9

Pneumocystis jirovecii
Asperillus sp
Histoplasma sp
Cryptococcus sp

Question 10

How can pneumonia be classified?

Answer 10

Community acquired
Hospital acquired
Ventilator associated
Aspiration

Question 11

Describe community acquired pneumonia

Answer 11

No hospitalisation within month prior to presentation
Strep pneumoniae, viruses, H.influenzae, Mycoplasma

Question 12

Describe hospital acquired pneumoniae

Answer 12

Acquired after at least 2 days of hospitalisation
E.coli, Klebsiella, Enterobacter, viruses

Question 13

Describe ventilatory associated pneumonia?

Answer 13

Occurring more than 48h after intubation
Staph aureus, pseudomonas, stenotrophomonas, acinetobacter

Question 14

Describe aspiration pneumonia

Answer 14

Occurring as a result of inhalation of stomach contents
Chemical pneumonitis, oral anaerobes, alpha-haem strep

Question 15

What antibiotics should be given to someone with pneumonia with a CURB score of 0-1?

Answer 15

Doxycycline
Erythromycin
Amoxicillin 3-5 days

Question 16

What antibiotics should be given to someone with pneumonia with a CURB score of 2-5?

Answer 16

IV benzylpenicillin and doxycycline/erythromycin
Oral amoxicillin +/- doxycycline/erythromycin OR levofloxacin

Question 17

What is legionellosis?

Answer 17

Outbreaks associated with water systems, cooling towers, water features, showers
Caused by Legionella sp

Question 18

Describe Legionella sp

Answer 18

Environmental
Survive in protozoa
Aerobic gram negative flagellated bacteria
Fastidious (difficult to culture)
Can be detected by urine antigen test

Question 19

What are the 2 species of Legionella sp?

Answer 19

L.pneumophilia (water)
L.longbeachae (soil, compost)

Question 20

What is the pathophysiology of Legionella?

Answer 20

Inhalation of micro-aerosis
Survives and replicates in macrophages - toxin, enzyme production
Pontiac fever 4-6h

Question 21

What are antibiotics used to treat legionellosis?

Answer 21

1st line = levofloxacin 750mg IV/oral
2nd line = doxycycline 200mg oral, 7-10 days

Question 22

Why are organisms that cause VAP different to CAP?

Answer 22

Microaspiration of oropharyngeal/GI colonisers
Contaminated ventilation devices
Immune suppression
Inhalation of infectious aerosols
Hospital acquired MDR organisms

Question 23

What antibiotics are given to treat HAP?

Answer 23

co-amoxiclav IV/ oral 5-7 dayd OR levofloxacin

Question 24

What antibiotics are given to treat VAP?

Answer 24

piperacillin-tazobactam IV and amikacin (or meropenem) + vancomycin and rifampicin if MRSA

Question 25

What are risk factors of aspiration pneumonia?

Answer 25

Reduced consciousness
Neurological deficit (dysphagia)
UGIT disorder (GORD)
Mechanical disruption (scope/intubation)
Vomiting
Poor dental hygiene

Question 26

Describe aspiration pneumonia

Answer 26

Chemical pneumonitis - acidic stomach contents
Oedema
Peribroncheal haemorrhage
Damage to bronchial epithelial cells

Question 27

What can occur, but very rarely, as a result of aspiration pneumonia?

Answer 27

Bacterial super-infection (13-26%) by S.aureus, pseudomonsa, aerobic falcultative gram-negative bacilli
Anaerobes - peptostreprococcus, fusobacterium, prevotella, bacteroides

Question 28

What are fungi that cause pneumonia in immunosuppressed individuals?

Answer 28

Pneumocystis jirovecii
Aspergillus sp.
Cryptococcus
Histoplasma

Question 29

Mycobacteria that cause pneumonia in immunosuppressed?

Answer 29

M. Tb
NTM - non-tuberculosis mycobacteria

Question 30

Viruses that cause pneumonia in immunosuppressed?

Answer 30

CMV
VZV
SARS-CoV2

Question 31

How can the causative organism be identified?

Answer 31

Nose/throat swab - PCR, lateral flow
Sputum/BAL - microscopy, culture, PCR
Blood - culture, PCR, biomarkers, serology
Urine - antigen agglutination tests

Question 32

What agar is used for strep pneumoniae?

Answer 32

Horse blood agar
Draft shape colonies

Question 33

What agar is used for H. influenzae?

Answer 33

Chocolate agar

Question 34

What agar is used for aspergillus?

Answer 34

Sabaroud dextrose agar

Question 35

What agar is used for pseudomonas?

Answer 35

CLED - cysteine lactose electrolyte deficient

Question 36

What are the gram positive bacteria causing pneumonia?

Answer 36

Staph aureus
Strep pneumoniae

Question 37

What are the gram negative bacteria that cause pneumonia?

Answer 37

E.coli
Klebsiella
Pseudomonas
Haemophilus
Moraxella

Question 38

What bacteria are urine antigen tests used for?

Answer 38

Strep pneumoniae
Legionella pneumophila