Pneumonia Flashcards
Definition of pneumonia.
Inflammation of the substance of the lung.
Classifications of pneumonia.
CAP
HAP
Aspiration pneumonia
Pneumonia in the immunocompromised host
Ventilator-acquired pneumonia
Risk factors of CAP.
<16 yo and >65 yo
Co-morbidities such as HIV, DM, CKD, Malnutrition and recent viral resp infection
CF, Bronchiectasis, COPD, obstructing lesion
Smoking, alcohol, IV drug use
Immunosuppressant therapy
What is lobar pneumonia?
When the whole of one or more lobes is affected.
What is diffuse pneumonia?
When the lobules of the lung are mainly affected
What is bronchopneumonia?
When the infection is centred on the bronchi and bronchioles.
Clinical features of CAP.
Dry or productive cough, sometimes haemoptysis
Dyspnoea
Fever
Chest pain (usually pleuritic)
Extrapulmonary features
Non-specific such as recurrent falls.
CXR features of pneumonia.
Airspace opacification
Filling of the alveoli with infectious material and pus
Initially patchy
Becomes confluent as infection develops
Examination findings of pneumonia.
Dullness on percussion
Decreased breath sounds
Bronchial breath sounds
Rhonchi
Crackles, Rales
Increased vocal fremitus
Causative organisms of CAP.
S. pneumoniae
H. influenzae
Moraxella catarrhalis
Atypicals such as…
Mycoplasma pneumoniae
S. aureus
Legionella pneumophila
Chlamydophila psittaci
What are extrapulmonary features of CAP?
Myalgia, arthralgia and malaise
Myocarditis and pericarditis
Headache
Abdo pain, diarrhoea and vomiting
Hepatitis
Labial herpes simplex reactivation
Erythema multiforme
Erythema nodosum
Stevens-Johnson syndrome
In which particular causative organisms are extrapulmonary features more common?
Legionella pneumophila
Mycoplasma pneumoniae
What causative organisms is associated with the following;
Myalgia, arthralgia and malaise
Myocarditis and pericarditis
Erythema nodosum and multiforme.
Mycoplasma pneumoniae
What causative organisms is associated with the following;
Myalgia, arthralgia and malaise
Headache
Meningoencephalitis
Hepatitis
Legionella pneumophila
Which organism is associated with labial herpes simplex reactivation?
Pneumococcal pneumonia
What is the initial assessment of CAP?
Assessing the severity of the pneumonia.
Chest examination
How is the severity of pneumonia assessed?
CURB-65
Explain CURB-65
Confusion (< 8/10 score)
Urea level (> 7 mmol/l)
Resp rate (> 30 b/min)
Blood pressure (systolic < 90 mmHg, diastolic < 60 mmHg)
Age > 65
What is a mild pneumonia infection?
CURB-65 of 0-1
How should a mild pneumonia be treated?
Send back home
No need for microbiological diagnostic tests or further investigations.
Give oral amoxicillin 500mg TD
or
ora clarithromycin 500mg BD
or doxycycline 100 mg OD
for 5 days
When should a patient with pneumonia be referred to hospital?
If scoring above 1.
At the score of 1 it can still be a clinical judgment, especially if urea levels are normal.
Usually urea levels are only measured if referral to hospital.
This means that a CURB65 score of 1 might be 2.
What other markers can assess the severity of pneumonia?
CXR (more than one lobe involved)
PaO2 ( < 8kPa)
Low albumin ( < 35 g/L)
WCC ( < 4 x 10^9/L or > 20 x 10^9/L)
Positive blood culture
Co-morbidities
Absence of fever in elderly
What investigations should be done on patients requiring hospital admission?
CXR
Blood tests
Microbiological tests.
A CXR might come back normal, why should it be repeated after 2-3 days?
Because the radiological abnormalities might lag behind the clinical signs.
Should the CXR be repeated again after this?
Why/Why not?
After 6 weeks it should be repeated to rule out underlying bronchial malignancy.
What blood tests should be done in CAP?
FBC
Serum creatinine
Electrolytes
Biochemistry
CRP
Abnormal bloods in S. pneumoniae.
WCC > 15 x 5^9/L
Inflammatory markers significantly elevated;
ESR > 100 mm/h
CRP > 100mg/L
Abnormal bloods in mycoplasma.
WCC usually normal
If there is anaemia haemolysis needs to be ruled out via Coombs test and measurement of cold agglutinins.
Blood tests of Legionella.
Lymphopenia without marked leucocytosis.
Hyponatraemia
Hypoalbuminaemia
High serum levels of liver aminotransferases (hepatitis)
What other tests might be done in CAP?
Sputum culture and blood cultures
ABGs if sats less than 94%
HIV test