Pneumonia basics

Question 1

what is pneumonia

Answer 1

an acute infection causing inflammation in the lungs

Question 2

which organisms cause CAP?

Answer 2

• mainly caused by strep pneumonia (70%)
• haemophilus influenzae (5%)
• staph. aureus (4%)
• Influenza A

Question 3

what patients may present with a staph aureus infection?

Answer 3

IV drug users with boggy swelling near groin

Question 4

what are the atypical causes of CAP?

Answer 4

• mycoplasma
• legionella
• chlamydophila pneumoniae/psittaci
• coxiella brunetti

Question 5

what are the risk factors for CAP?

Answer 5

age : below 16 or over 65

co-morbidities: HIV infection, diabetes mellitus, chronic kidney disease, malnutrition, recent viral respiratory infection

Other respiratory conditions

lifestyle: cigarette smoking, excess alcohol, IV drug use

Iatrogenic: immunosuppressant therapy

Question 6

which respiratory conditions are a risk factor for CAP?

Answer 6

CF, bronchiectasis, COPD, obstructing lesion (endoluminal cancer, inhaled foreign body)

Question 7

which organisms cause HAP?

Answer 7

• 60% gram negative : e.coli, klebsiella spp., pseudomonas spp
• CAP organisms
• staph aureus
• anaerobes

Question 8

which organisms are involved in immunocompromised pneumonia ?

Answer 8

pneumocystis jirovecii pneumonia (PCP)

this is one of the most frequent and severe opportunistic infection in people with weakened immune systems (like AIDs)

Question 9

how is PCP acquired ?

Answer 9

inhalation of fungus

Question 10

what are the symptoms of pneumonia ?

Answer 10

• malaise
• chest pain
• fever
• rigors
• myalgia
• arthralgia
• headache
• confusion
• cough
• pleurisy
• haemoptysis
• dyspnoea
• preceding URTi
• sputum
• abdo pain
• anorexia
• diarrhoea

Question 11

what causes chest pain in pneumonia?

Answer 11

it is pleuritic in nature and results from inflammation of the pleura

a pleural rub may be heard early on in the illness

Question 12

what does a swinging fever indicate?

Answer 12

an empyema

Question 13

what organisms commonly causes a headache and coldsores?

Answer 13

legionella

Question 14

why do people get dyspnoea?

Answer 14

the alveoli become filled with pus and debris, impairing gas exchange

Question 15

what are the signs of pneumonia

Answer 15

• fever
• cyanosis
• confusion
• herpes labialis
• tachypnoea
• crackles
• rub
• hypotension
• reduces chest expansion - if very bad
• dull percussion note
• increased resonance
• skin rash

Question 16

why are coarse crackles heard?

Answer 16

due to consolidation of the parenchyma

Question 17

what may be heard over areas of consolidated lung?

Answer 17

coarse crackles and bronchial breath

increased vocal fremitus and dull percussion

Question 18

which organism may cause rust coloured sputum?

Answer 18

strep pneumoniae

Question 19

what causes a rub?

Answer 19

inflammation of the pleura

Question 20

what causes cold sores?

Answer 20

when the immune system is shocked - you can get a recurrence of the herpes virus

this is not uncommon in people who have penumococcal pneumonia

Question 21

which skin rashes are found in mycoplasma penumonia

Answer 21

erythema nodosum,

erythema multiforme

Question 22

what are signs of severe pneumonia

Answer 22

CXR: more than one lobe involved 
PaO2  20 x10 ^9/L ) 
blood culture - positive 
other co-morbidities 
absence of fever in the elderly