Pneumonia Flashcards
Define pneumonia
acute infection of lung parenchyma
Pneumonia risk factors
smoking
chronic lung disease (eg. asthma, COPD)
chronic heart disease
alcohol excess
immunosuppression
4 broad classifications of pneumonia
community acquired pneumonia (CAP)
hospital acquired pneumonia (HAP)
aspiration pneumonia
pneumonia in immunocompromised patients
Clinical features of pneumonia
shortness of breath (SOB)
cough
sputum production
pleuritic chest pain
fever
confusion (especially in elderly)
Examination features of pneumonia
pyrexia
tachycardia
tachypnoea
reduced lung expansion
signs of consolidation found
coarse crackles may be heard as infection resolves
Patients at risk of CAP
primary (healthy adults)
secondary (underlying lung disease):
- COPD
- Interstitial lung disease
- Bronchial cancer
Common organisms that cause CAP
Streptococcus pneumoniae
Haemophilus influenzae
Mycoplasma pneumoniae
Patients at risk of HAP
elderly
immobile
pain (causes basal atelectasis)
immunosuppression
immunocompromise
Common organisms that cause HAP
Staphylococcus aureus
Gram-negative enterobacteria
Pseudomonas
Klebsiella
Patients at risk of aspiration pneumonia
alcohol excess
impaired consciousness
swallowing problems (eg. stroke)
Common organisms that cause aspiration pneumonia
anaerobes
Gram-negative enterobacteria
Staphylococcus aureus
Patients at risk of pneumonia in immunocompromised patients
HIV
transplant patients
chemotherapy
leukaemia/lymphoma
Common organisms that cause pneumonia in immunocompromised patients
CAP organisms (Streptococcus pneumonia, Haemophilus influenzae, Mycoplasma pneumoniae)
HAP organisms (Staphylococcus aureus, Gram-negative enterobacteria, Pseudomonas, Klebsiella)
Viruses (CMV, VZV)
Fungi (Aspergillus)
Mycobacteria
What investigations can be used to diagnose pneumonia?
sputum culture - identify causative organism
FBC - raised WBC, neutrophilia, raised inflammatory markers
U+E - dehydration common (raised urea and creatinine)
LFT - can be deranged in atypical pneumonia (eg. Legionella)
Cultures (only if pyrexial) - identify organism
ABG - identify respiratory failure
CXR - consolidation or effusion
Electrocardiograph - AF common in pneumonia, rule out cardiac causes of chest pain
When would you do an atypical pneumonia screen?
atypical presentation
severe pneumonia
pneumonia that is not responding to antibiotics
What is in an atypical pneumonia screen?
Urinary legionella antigen
Cold agglutinins (present in mycoplasma)
Mycoplasma, chlamydia serology
Pneumococcal antigen
What is the CURB-65 score?
objective assessment of pneumonia severity
C (confusion) - abbreviated mental test score <8
U (urea) - urea >7mmol/L
R (respiratory rate) - >30 breaths/min
B (BP) - systolic BP <90 mmHg
65 (age) - >65 years
Describe interpretation of CURB-65 score
0-1 = mild = consider treatment at home with oral antibiotics
2 = moderate = treatment in hospital
3+ = severe = consider HDU, high mortality rate
Pneumonia general management
Oxygen (maintain sats >94%)
IV fluids to correct dehydration (cautious with heart failure patients)
Antibiotics (oral or IV depending on severity)
Complications of pneumonia
respiratory failure
parapneumonic effusions (pleural effusion that forms in the pleural space adjacent to a pneumonia)
empyema
lung abscess
atrial fibrillation
Pathophysiology of pneumonia
Infection to lung
Inflammatory response initiated alveolar oedema + exudate formation
Alveolar and respiratory bronchioles fill with serous exudate, blood cells, fibrin, bacteria
Consolidation of lung tissues
When does HAP typically present?
3 days after admission
3 types of pneumonia (pathogenesis wise)
Bronchopneumonia
Lobar pneumonia
Interstitial pneumonia
Streptococcus pneumonia sputum colour
Rust-coloured
Pseudomonas aeruginosa sputum colour
Green
Klebsiella sputum colour
Redcurrant jelly sputum
Sputum with anaerobes
Bad-smelling or bad-tasting
What can lobular pneumonia progress to if treated insufficiently?
Empyema of pleural effusions
CAP moderate and severe treatment
Penicillin and macrolide (eg. Amoxicillin/tazobactam + clarithromycin)
CAP prevention
Smoking cessation
Vaccines
4 types of HAP
Ventilator associated pneumonia
Aspiration pneumonia
Environmental source (Legionella pneumophila)
Hospital transmission
TB symptoms
Productive cough
Fever
Night sweats
Weight loss
TB CXR findings
Upper love consolidation
Nodular
TB treatment
Isoniazid
Rifampicin
Pyrazinamid
Ethambutol
Which 2 organisms can be detected on urinary antigen dipstick?
Legionella
Pneumococcus
Primary infection prevention
Prevent or reduce exposure
Immunisation (pneumococcus, influenza)
Secondary infection prevention (TB)
Chemoprophylaxis
Contact tracing
Tertiary infection prevention
Minimise disability arising from infection
Effective treatment
Physiotherapist
