Lung Infections

Question 0

Causes of community acquired pneumonia

Answer 0

Most common: Strep pneumoniae
Next: H. influenzae (old), M. pneumoniae (young)
Other: S. aureus (post viral), legionella, Moraxella catarrhalis, Chlamydia
Rare: gram negatives, Coxiella burnetii, anaerobes
Viruses: 15%

Question 1

Causes of hospital acquired pneumonia

Answer 1

Most common: gram negative enterobacteria, S. aureus

Also : pseudomonas, klebsiella, bacteroides, clostridia

Question 2

Those at risk of aspiration pneumonia

Answer 2

CNS: stroke, MG, bulbar palsy
Reduced consciousness (eg drunk, post ictal)
Oesophageal disease
Poor dental hygiene

Question 3

Pneumonia in the immunocompromised

Answer 3

S. pneumoniae
H. influenzae
S. aureus
M. catarrhalis
M. pneumoniae
Gram negatives 
Pneumocystis jiroveci
CMV/HSV
TB

Question 4

Tests for patient with pneumonia

Answer 4

CXR, ABG if O2 <92%, FBC, U&E, LFT, CRP, blood cultures, sputum cultures, ? Fluid aspiration or bronchoscopy if severe

Question 5

Treatment of mild CAP (S.pneumoniae, H.influenzae)

Answer 5

Amoxicillin 500mg-1g/8h PO
Or
Clarithromycin 500mg/12h PO
Or
Doxycline 200mg loading then 100mg/day

Question 6

CURB65 score

Answer 6

Confusion (amts 7), RR > 30,

BP (systolic <92%

Question 7

Treatment of moderate CAP (S.pneumoniae, H.influenzae, M.pneumoniae)

Answer 7

Amoxicillin 500mg-1g/8h PO PLUS clarithromycin 500mg/12h PO (both can be IV at same dose)
OR
doxycycline 200mg loading then 100mg/12h PO

Question 8

Treatment of severe pneumonia

Answer 8

Co-amoxiclav 1.2g/8h IV
OR
Cefuroxime 1.5g/8h IV
Either PLUS
Clarithromycin 500mg/12h IV
ADD
flucloxicillin +/- rifampicin for staph
OR vancomycin for MRSA

Question 9

Treatment of severe PVL Staph aureus

Answer 9

Seek urgent help. Treat as for severe plus IV linezolid, clindamycin and/or rifampicin

Question 10

Treatment of Legionella pneumophilia

Answer 10

Fluoroquinine with clarithromycin or rifampicin for 2-3 weeks

Question 11

Treatment of Chlamydia pneumonia

Answer 11

Doxycline or clarithromycin

Question 12

Treatment of Pneumocystis jiroveci

Answer 12

High dose co-trimoxazole with prednisolone

Stabilise CD4 count

Question 13

Treatment of hospital acquired pneumonia (gram negatives, pseudomonas, anaerobes) or neutropenic patients

Answer 13

Aminoglycoside IV (eg gentamicin 5mg/kg/day) plus antipseudomonal penicillin IV (eg ticarcillin) or 3rd gen cephalosporin IV (eg cefotaxime 1-2g /6-12h). 
Consider antifungals after 48h

Question 14

Treatment of aspiration pneumonia (Step pneumoniae, anaerobes)

Answer 14

Cephalosporin IV
PLUS
Metronidazole IV

Question 15

Findings and treatment of staphylococcal pneumonia

Answer 15

Bilateral cavitating bronchopneumonia.

Treatment flucloxicillin +/- rifampicin

Question 16

Findings and treatment of pneumococcus

Answer 16

Lobar consolidation - rust coloured sputum and poss haemoptosis
Treat with amoxicillin, benzylpenicillin or cephalosporin

Question 17

Findings and treatment of Klebsiella pneumonia

Answer 17

Cavitating pneumonia in upper lobes.
Treat with cefotaxime or imipenem.
Often drug resistant

Question 18

Findings and treatment of mycoplasma pneumoniae

Answer 18

Reticular nodular shadowing or patchy consolidation of lower lobe.
Treat with clarithromycin (500mg/12h) or doxycycline (200mg loading then 100mg OD) or fluroquinolone.
Beware meningitis, Stevens Johnson or Guillain Barré

Question 19

5 ways aspergillus affects the lungs

Answer 19

1. Asthma
2. Allergic bronchopulmonary aspergillosis
3. Aspergilloma
4. Invasive aspergillosis
5. Extrinsic allergic alveolitis

Question 20

Asthma caused by aspergillus

Answer 20

Type 1 hypersensitivity to spores

Question 21

Allergic bronchopulmonary aspergillosis hypersensitivity reaction

Answer 21

Type 1 and 3.
Affects 1% asthmatics and 2-25% CF.
Causes mucus plugs of fungal hyphae and bronchiectasis.
Treat with prednisolone

Question 22

Cause of aspergilloma

Answer 22

Pre existing cavity from TB or sarcoidosis in which a fungus ball can lie.
Can cause massive haemoptysis

Question 23

Risk factors for invasive aspergillosis

Answer 23

Immunocompromised, AI disease, after broad spec Abx

Question 25

Treatment and prognosis of invasive aspergillosis

Answer 25

Voriconazole IV. Also miconazole or ketoconazole. | 30% mortality

Question 26

URTIs

Answer 26

Common, usually short term and due to viruses - generally Coryza, acute pharyngitis or tracheobronchitis

Question 27

Coryza

Answer 27

The common cold due to rhinovirus infection leading to sore throat, malaise, sneezing, cough, rhinohorrea & hoarseness. If complicated by tracheitis/bronchitis wheeze and chest tightness can occur.

Question 28

Whooping Cough

Answer 28

A very contagious cause of URTI which causes corzya and, rarely, severe bouts of 'whooping coughs' Diagnose by PCR of a NP swab and treat with macrolides.

Question 29

Rhinosinusitis

Answer 29

A combination of nasal congestion, blockage and discharge which can be followed by facial pain, pressure and anosmia. Exclude polyps and dental infection. Treat with decongestants, nasal douching. Often bacterial but abx only necessary if symptoms persist for >5days.

Question 30

Definition of Pneumonia

Answer 30

An acute respiratory infection associated with recent radiographic changes. Can be 'lobar' - homogenous consolidation of one or more lobes, or 'bronchopneumonia' - patchy consolidation with bronchial inflammation and bilateral lower lobe involvement.

Question 31

Epidemiology of CAP

Answer 31

5-10/1000 adults/yr and accounts for 5-12% of LRTIs | Most common at extremes of age

Question 32

Viral causes of CAP

Answer 32

Influenza and parainfluenza Measles HSV and CMV Adenovirus or Coronavirus

Question 33

Features of CAP

Answer 33

``` Systemic = fever, rigors, malaise, anorexia, poss headache Pulmonary = cough (dry then productive - muco/mucopurulent), pleuritic chest pain (can refer to shoulder or upper abdo wall) ```

Question 34

Signs in patients with CAP

Answer 34

Systemic = low BP, high HR and RR, poss pyrexia, cyanosis/ desataturation Chest = bronchial breathing, dullness to percussion, crackles, increased vocal resonance

Question 35

General management of CAP

Answer 35

Humidified oxygen up to CPAP IV fluids for elderly or hypotensive patients Analgesia for pleuritic pain

Question 36

Complications of Pneumonia

Answer 36

Para-pneumonia effusion or empyema DVT or PE Pneumothorax or abscess formation - staph aureus Retention of sputum causing lobar collapse.

Question 37

Factors leading to HAP

Answer 37

Reduced host defences - reduced immunity or reduced cough reflex Aspiration - reduced consciousness, vomiting, dysphagia or reflux Introduction of bacteria into the LRT - Intubation, bronchoscopes, dental infectio Bacteraemia - abdominal sepsis, Cannula infection, infected emboli

Question 38

Definition of HAP

Answer 38

Pneumonia developed at least 2 days after admission - early HAP is usually due to the same organisms as CAP, but later gram negatives or anerobes are more to blame

Question 39

Suppurative, aspiration and abscess forming pneumonia

Answer 39

Conditions characterized by destruction of lung parenchyma - these are most often due to inhalation of septic material. More commonly in the apical segment of the lower lobe.

Question 40

Features of suppurative pneumonias

Answer 40

Cough with large amounts of sputum, can be fetid or blood-stained pleural pain common sudden expectoration of copious amounts of foul sputum if abscess ruptures into a bronchus

Question 41

Signs of suppurative pneumonias

Answer 41

``` High remittent fever with profound systemic upset Digital clubbing may develop over 1-2wks Evidence of consolidation Pleural rub is commmon Rapid weight loss can occur ```