Lower Respiratory Tract Infections

Question 1

Examples of LRTIs

Answer 1

Acute bronchitis
Exacerbation of COPD
Pneumonia
Empyema
Lung Abscess
Bronchiectasis

Question 2

Pneumonia Symptoms

Answer 2

Malaise
Fever
Pleuritic chest pain
Cough
Purulent sputum (rusty)
SOB

Question 3

Pneumonia Signs

Answer 3

Pyrexia
Tachypnoea
Central cyanosis
Dullness on percussion of affected lobes
Bronchial breathing sounds
Inspiratory crepitations
Increased vocal resonance

Question 4

What investigations might you do if you suspect pneumonia?

Answer 4

Serum biochem and FBC
CXR
Blood cultures
Throat swab (for atypical pathogens)
Urinary legionella antigen
Sputum microscopy/culture

Question 5

What organisms are usually responsible for pneumonia?

Answer 5

Strep pneumoniae (36%)
H. flu (10%)
Mycoplasma pneumoniae (1.3%)
Chlamydia psiticca (1.3%)
Staph Aureus (0.8%)
Legionella (0.4%)

Viral (13%)

Question 6

How is pneumonia scored?

Answer 6

CURB65

Confusion?
Urea in blood >7?
Respiratory rate >30?
BP diastolic <60?
65+ years old?

0 = low risk, community treated
1-2 = hospital treatment
3+ = high risk of death, ITU

Question 7

How is pneumonia treated?

How does it vary with it’s staging?

Answer 7

CURB 0-1:
Amoxicillin or clarithromycin/doxycycline

CURB 2:
Amoxicillin and clarithromycin or levofloxacin

CURB 3+:
Co-amoxiclav and clarithromycin or levofloxacin (if penicillin allergy)

O2
IV Fluids
CPAP
Intubation/Ventilation

Question 8

What are some complications of pneumonia?

Answer 8

Septicaemia
Acute kidney damage
Empyema
Lung abscess
Haemolytic anaemia (mycoplasma)
ARDS

Question 9

Differential diagnoses for pneumonia?

Answer 9

TB
Lung cancer
Pulmonary embolism
Cardiac failure
Pulmonary vasculitis (Wegner's granulomatosis)

Question 10

What are some causes of Bronchiectasis?

Answer 10

Idiopathic
Immotile cilia syndrome
CF
Childhood infections such as measles
Hypogammaglobulinaemia
Allergic bronchopulmonary aspergillosis (ABPA)

Question 11

Bronchiectasis symptoms?

Answer 11

Chronic cough
Daily sputum production (copius)
Sometimes:
- wheeze
- SOB
- tiredness
- flitting chest pains
- haemoptysis

Question 12

Bronchiectasis signs?

Answer 12

Finger clubbng

Coarse inspiratory crepitations on auscultation

Question 13

What investigations might you do in suspected bronchiectasis?

Answer 13

High resolution CT thorax
Sputum culture
- often H flu, Staph Aureus, pseudomonas aeruginosa
Serum Ig
Total IgE and aspergillus precipitins
CF genotyping

Question 14

What are some treatments for bronchiectasis?

Answer 14

Chest physio
Prompt treatment of infections with appropriate antibiotics
May require inhaled therapy including beta2 agonist and ICS

Question 15

What is the most common pathogen in empyema?

Answer 15

Streptococcus (52%)
Staph Aureus (11%)
Anaerobes (20%)

Question 16

Empyema symptoms?

Answer 16

Chest pain prominent
Absence of cough
High swinging fever

Question 17

Investigations in suspected empyema?

Answer 17

CXR and pleural ultrasound

Diagnosed by diagnostic pleural aspiration (pH<7.2)

Question 18

Empyema treatment?

Answer 18

Chest drain and IV antibiotics

Ab treatment may be prolonged (6 weeks)

Intraplueral t-PA/DNase
(tissue plasminogen activator/dornase alpha)

Surgery in those not improving from above

Question 19

What organisms are more likely to result in cavitating pneumonia (lung abscess)?

Answer 19

Staph Aureus
Pseudomonas
Anaerobes

Question 20

What are symptoms of a lung abscess?

Answer 20

Lethargy
Weight loss
High swinging fever

Question 21

Investigations in lung abscess?

Answer 21

CT thorax
Sputum culture
(including TB microscopy and culture)

Question 22

Lung abscess treatments?

Answer 22

Prolonged antibiotics

Drainage via bronchial tree, but occasionally percutaneous drainage may be necessary