Pneumonia

Question 1

Definition

Answer 1

Infection of lung parenchyma distal to terminal bronchioles

Question 2

Common Agents

Answer 2

Virus, bacteria and Mycobacteria

Question 3

Routes of infection

Answer 3

Endogenous: Patient’s own upper resp tract microbiome (normal flora)

Exogenous: Pathogens transmitted (droplet or airborne) from other people, the environment or animals (zoonoses)

Question 4

Flora of URT: normal flora

Answer 4

Strep. viridans (IE)

Anaerobes (aspiration pneumonia, lung abscess, empyema)

Question 5

Flora of URT: Pathogens that are carried asymptomatically

Answer 5

-Streptococcuspneumoniae
– Haemophilusinfluenzae
– Moraxellacatarrhalis
– Neisseria meningitidis (meningitis/ sepsis)
– Streptococcus pyogenes (rheumatic fever)
– Corynebacterium diphtheriae (diptheria)

Question 6

Flora of URT: Colonization due to antimicrobial therapy

Answer 6

All cause hosptial-acquired infections
– Klebsiellaspp.
-- E. coli
– Pseudomonasspp.
– Acinetobacterbaumanii
– Candidaalbicans

Question 7

Pathogenesis: Breach of local defence mechanism

Answer 7

Cold air
Viral infection 
Smoke
Allergies 
Aspiration Intubation
Mech. ventilation

Question 8

Pathogenesis: Response

Answer 8

Swelling of mucosa
+
Paralysis of cilia

Question 9

Pathogenesis: Obstruction of drainage

Answer 9

Accumulation of nutrient rich fluid
+
Overgrowth of normal flora

Question 10

Clinical Syndromes

Answer 10

CAP!!!
HAP (>48 hours after admission or within 1 month after admission)
Aspiration 
Pneumonia in I/C patient 
Acute exacerbation of COPD 
Lung Abscess

Question 11

Organisms causing CAP: Bacteria

Answer 11

– Streptococcus pneumoniae +++
– Staphylococcus pneumoniae++
– Haemophilus influenzae+
– Klebsiella pneumoniae+

Question 12

Organisms causing TYPICAL CAP: Mycobacteria

Answer 12

M. TB

Question 13

Organisms causing CAP: Viruses

Answer 13

Influenza A

RSV

Question 14

Treatment of bacterial pneumonia

Answer 14

Penicillin or Co-amoxiclav or Ceftriaxone or

Moxi- or levofloxacin

Question 15

Organisms causing ATYPICAL CAP: Bacteria

Answer 15

– Mycoplasma pneumonia +++ – Chlamydophila pneumonia ++

– Legionella pneumophila +

Question 16

Treatment of ATYPICAL BACTERIAL CAP

Answer 16

Macrolides (Clarithromycin/ Azithromycin)

Question 17

Organisms causing ATYPICAL CAP: Zoonoses (uncommon)

Answer 17

– Chlamydia psittaci
– Coxiella burnetti (Q fever)
– SARS, MERS- & 2019 nCoV

Question 18

Organisms causing ATYPICAL CAP: Viruses (uncommon)

Answer 18

– RSV
– Measles
– Varicella

Question 19

HAP: Causes (1)

Answer 19

Aerobic Gram - bacilli (+++)
– Klebsiella pneumoniae
– Pseudomonas spp
– E. coli

Rx: Piptaz + Amikacin or
Carbapenem antibiotics
• Ertapenem/Imipenem/Meropenem

Question 20

HAP: Causes (2)

Answer 20

Staph aureus (++)

Rx: Vancomycin

Question 21

Aspiration Pneumonia: Causative organisms

Answer 21

– Peptostreptococci
–Bacteroides
– Fusobacterium

Rx: Co-amoxiclav or
Ceftriaxone + Metronidazole

Question 22

Acute exacerbation of COPD: Causative organisms

Answer 22

Viral (most common)
Rx: Oseltamivir if influenza considered

Bacteria:
– Strep pneumoaniae
– Haemophilus influenzae
– Moraxella catharalis

Rx: Co-amoxiclav or Ceftriaxone or Doxycycline

Question 23

Pneumonia in I/C patients: Splenectomy/ IG defect

Answer 23

Encapsulated bacteria
• Streptococcus pneumoniae
• Haemophilus influenzae

Question 24

Pneumonia in I/C patients: Neutropenic patients

Answer 24

– Non-encapsulatedbacteria
• Pseudomonas aeruginosa
• Klebsiella pneumoniae
• Staphylococcus aureus

– Fungus
• Aspergillus fumigatus
• Candida spp.

Question 25

Pneumonia in I/C patients: Chronic steroid therapy/ DM

Answer 25

– Mycobacterium tuberculosis | – Nocardia spp.

Question 26

Pneumonia in I/C patients: HIV

Answer 26

– Streptococcus pneumoniae –Mycobacterium tuberculosis – Pneumocystis jerovecii** – Klebsiella pneumoniae

Question 27

Lung abscess: Causes

Answer 27

– Mixed gram negatives and anaerobes – Streptococcus anginosus (a viridans species) – Staphylococcus aureus Rx: Co-amoxiclav or Ceftriaxone + Metronidazole

Question 28

CAP Risk Factors

Answer 28

``` • Age ≥ 65yrs • Viral infections (influenza) • Smoking • Chronic alcohol use • Co-morbidities – Immunosuppression: HIV, DM, etc. – Chronic cardiac & respiratory disease ``` • CCF, asthma/COPD/bronchi-ectasis – Chronic liver disease – Chronic renal failure • Aspiration – Epilepsy, stroke, ↓ Level of consciousness • Animal exposure • Drugs – IV drug abuse – Chronic steroid use

Question 29

TYPICAL CAP Symptoms

Answer 29

``` – Acute onset- Fever, malaise – Cough +/- sputum • rusty colouredpurulent – Dyspnoea ++ – Pleuritic chest pain – May have • Confusion (elderly) • Mild haemoptysis ```

Question 30

ATYPICAL CAP Symptoms

Answer 30

– Sub acute onset - Fever, malaise – Cough (mucoidpurulent) >>> dyspnoea / chest pain – Extra-pulmonary symptoms may initially predominate • Headache • Arthralgia / Myalgia • Diarrhoea • Skin rash

Question 31

CAP Signs

Answer 31

* Fever (>38oC) * Tachypnoea! & tachycardia • Consolidation – Classic findings --Consolidation +/- focal crackles – Often focal/diffuse crackles • May have evidence of complications: – Cyanosis / respiratory failure – Pleural effusion

Question 32

Signs of consolidation

Answer 32

* ↓/N Expansion * ↑ Vocal fremitus * Dullness on percussion (not stony dull) * Bronchial breathing (not amphoric) * Vocal resonance * Whispering pectoriloquy

Question 33

CAP CXR Findings

Answer 33

1. Consolidation (opacity + air bronchograms)

Question 34

CAP: Seek aetiological agent

Answer 34

1. Blood culture 2. Sputum 3. Pleural tap if + pleural effusion

Question 35

Severity of CAP (CURB-65)

Answer 35

``` Confusion Urea >7 mmol/L Respiratory rate >30 BP low (SP <90; DP <60) Age =/>65 ```

Question 36

CAP local complications

Answer 36

1. Pleural effusion 2. Empyema 3. Abscess 4. Respiratory Failure 5. ARDS 6. Non-resolving pneumonia

Question 37

CAP systemic complications

Answer 37

1. Septiceaemia 2. Metastatic abscess 3. Multi-organ dysfunction

Question 38

Outpatient Rx

Answer 38

Young +healthy: High dose amoxicillin >65 and/or comorbidities: Oral co-amoxiclav

Question 39

Inpatient Rx

Answer 39

Young&healthy: • IV Pen G or Ampicillin ± macrolide >65 &/or co-morbidities: • IV Co-amoxiclav or 3rd generation cephalosporin + macrolide – Critically ill(shocked)/ICU: • IV Co-amoxiclav or 3rd generation cephalosporin + macrolide

Question 40

CAP Follow-up CXR

Answer 40

4-6 weeks after discharge: 50% resolved at 2 weeks 75% resolved at 6 weeks

Question 41

CAP avoidable risk factors

Answer 41

``` Smoking Alcohol Type 2 DM CVD HIV Drug use ```

Question 42

CAP Vaccination

Answer 42

Annual influenza vaccine H. influenzae vaccine Pneumococcal vaccine