PNEUMONIA - Community Acquired Pneumonia

Question 1

what is pneumonia?

Answer 1

= inflammation of the substance of the lungs

Question 2

what typically causes pneumonia?

Answer 2

• bacteria most commonly

- but also viruses and fungi

Question 3

what is the hallmark of pneumonia both clinically and on the chest X-ray?

Answer 3

CONSOLIDATION.

= region of lung tissue that has filled with something other than air, e.g. liquid, pus, blood.

Question 4

how is pneumonia classified?

Answer 4

it is classified by the setting in which the person contracted the infection.

1) Community acquired
2) hospital acquired
3) Pneumonia in immunocompromised hosts.
- through either a genetic defect, immunosuppressive mediation, acquired immunodeficiency e.g. HIV.

Question 5

what organism is the commonest cause of community acquired pneumonia?

Answer 5

streptococcus pneumonias 70%

• however, in 30-50% of cases no organism is identifiable
• in 20% of cases more than one organism is present
• haemophilus influenza 5%
• staphylococcus aureus 4%

Question 6

Where are the 2 sites of community acquired pneumonia?

Answer 6

1) lobar pneumonia
= infection is localised, affecting whole of one or more lobes

2) bronchopneumonia
= widespread small patches of consolidation in both lungs, mainly the lobules of the lungs are affected
- caused by infection centred in the bronchi or bronchioles

Question 7

how is pneumonia spread?

Answer 7

it is spread by respiratory droplets

Question 8

what are the clinical features of pneumonia?

Answer 8

1) cough
- dry or productive
- haemoptysis

2) breathlessness
- alveoli become filled with pus & debris impairing gas exchange
- coarse crackles are heard of auscultation, due to consolidation of lung parenchyma

3) fever
- presence of fevers often indicates empyema

4) extra-pulmonary features;
- myalgia, arthralgia & malaise
= common in infections caused by Legionella & mycoplasma

• myocarditis & pericarditis
  = most common in mycoplasma pneumonia
• headache
  = common in legionella pneumonia
• abdominal pain, diarrhoea & vomiting
• labial herpes simplex
  = common in pneumoccal pneumonia
• skin rashes

5) other features
- in elderly, confusion or current falls

Question 9

in pneumococcal pneumonia what colour is the sputum?

Answer 9

characteristically a rust colour.

Question 10

What does the CURB-65 score stand for?

Answer 10

C = confusion 
U = urea level > 7 
R = respiratory rate > 30 
B = systolic blood pressure < 90mmHg; diastolic < 60mmHg 
65 = age > 65 

1 point for each of the above

Score 0-1 = outpatient
Score 2 = admit to hospital
Score 3 = ICU

Question 11

if symptoms have been present for several weeks of have failed to respond to antibiotics, what diagnosis could be ruled out?

Answer 11

Tuberculosis

Question 12

what would you find on examination of the patient?

Answer 12

• reduced expansion
• dullness to percussion
• coarse crepitations
• bronchial breathing (occasionally)
• pleural rub

Question 13

what investigations should be done?

Answer 13

1) chest X-ray

2) blood tests
- full blood counts
- electrolytes
- urea
- biochemistry
- C reactive proteins a

3) sputum culture & gram sain
4) blood culture
5) pulse oximetry & arterial blood gas analysis
6) HIV test

Question 14

what would the typical white cell count of strep pneumonia be?

Answer 14

• white cell count would be >15 x 10^9

Question 15

what would the typical white cell count be for mycoplasma?

Answer 15

white cell count would be normal

Question 16

what would the blood tests show for legionella?

Answer 16

• lymphopenia without marked leucocytosis, hyponatraemia, hypoalbuminaemia & high serum levels of liver aminotransferases

Question 17

describe the gram stain for strep pnneumoniae, staph aureus, H influenza and M catarrhallis?

Answer 17

Strep pneumonia;

• Gram positive
• diplococci

Staph aureus

• gram positive
• clusters (like bunch of grapes)

Diagnostic infections caused by Staph Aureus, H. influenzae, M catarrhalis and gram negative organisms.

Question 18

what oxygen saturation warrants pulse oximetry and arterial blood gas analysis to be done?

Answer 18

if the oxygen saturation is < 94%.

Question 19

why should an HIV test be done?

Answer 19

because pneumonia is a common initiation presenting illness in patients with previously undiagnosed HIV infection.

Question 20

how would you manage somebody with community acquired pneumonia?

Answer 20

1) oxygen
2) intravenous fluids
3) antibiotics
4) thrombo-prophylaxis
5) physiotherapy
6) nutritional supplementation
7) analgesia

Question 21

when supplemental oxygen is given, what % are you trying to keep saturation between?

Answer 21

• between 94-98% (provided the patient is not at risk of CO2 retention)
• in patients with known COPD, oxygen sats should be maintained between 88% & 92%

Question 22

how many hours of presentation of symptoms should you given in a hospital before administering antibiotics?

Answer 22

4 hours.

Question 23

what link is there with some antibiotics, such as cephalosporins, to illness?

Answer 23

these antibiotics can cause an increase incidence of clostridium difficile associated diarrhoea (CDAD).

Question 24

give examples of what analgesias could be used?

how analgesias help?

Answer 24

examples;

• paracetamol
• NSAIDS
• they help treat pleuritic pain thereby reducing the risk of further complications due to restricted breathing due to pain

Question 25

what are 3 complications of community acquired pneumonia?

Answer 25

1) lung abscess
2) para-pneumonic effusion
3) empyema

Question 26

what can pleural effusions develop into?

Answer 26

may develop into an empyema

Question 27

what are early indications of an empyema?

Answer 27

• fever

- rising or persistently elevated inflammatory markers

Question 28

what does the pH of an exudative effusion with pleural fluid need to be to suggest an empyema?

Answer 28

pH < 7.2

Question 29

what is a lung abscess?

Answer 29

severe localised suppuration within the lung associated with cavity formation.

Question 30

name some causes of a lung abscess?

Answer 30

1) aspiration pneumonia
2) TB
3) pneumonia caused by certain species
4) septic emboli containing staphylococci
5) inadequately treated CAP
6) spread from amoebic liver abscess
7) bronchial obstruction by an endolumial cancer
8) foreign body inhalation

Question 31

what are the clinical features of a lung abscess?

Answer 31

• persisting or worsening pneumonia
• production of large amounts of sputum
• foul smelling sputum
• fever
• weight loss
• malaise