Respiratory Flashcards
(48 cards)
What is a pleural effusion?
Fluid in the pleural space. Effusions can be divided by their protein concentration into transudates (less than 25g/L) and exudates (more than 35 g/L)
What causes transudates? (4)
- Increased venous pressure (cardiac failure, constrictive pericarditis, fluid overload)
- Hypoproteinaemia (cirrhosis, nephrotic syndrome, malabsorption)
- Hypothyroidism
- Meigs’ syndrome (right pleural effusion and ovarian fibroma)
What causes exudates?
Mostly due to increased leakiness of pleural capillaries secondary to infection, inflammation or malignancy
Causes: pneumonia, TB, pulmonary infarction, rheumatoid arthritis, SLE, bronchogenic carcinoma, malignant metastases, lymphoma, mesothelioma, lymphangitis carcinomatosis
What signs can be seen in a pleural effusion? (3)
- Decreased expansion, stony dullness on percussion and diminished breath sounds on affected side
- Decreased tactile vocal fremitus and vocal resonance (inconsistent and unreliable)
- There may be tracheal deviation AWAY from effusion if large
What investigations can be done in pleural effusions? (4)
- CXR: blunting of costophrenic angles
- US - identifies presence of pleural field and used in diagnostic/therapeutic aspiration
- Diagnostic aspiration
- Pleural biopsy
How are pleural effusions managed? (3)
- Treat underlying cause!
- Drainage if effusion is symptomatic (aspiration or intercostal drain)
- Pleurodesis with tetracycline, bleomycin or talc for recurrent effusions
Define chronic bronchitis
Chronic sputum production every day for at least 3 months per year for 2 consecutive years
What are the lung function test features of a ‘pink puffer’?
PaO2 - normal to slightly diminished
PaCO2 - normal to slightly diminished
TLC - increased
DLCO - diminished
What are the lung function test features of a ‘blue boater’?
PaO2 - low
PaCO2 - elevated
Normal TLC and DLCO
What pathologic changes occur with smoking?
Upper lobe centrilobular emphysema
What is the pathologic change that occurs with alpha-1 antitrypsin disease?
Panacinar emphysema that favours the lower lobes
Which bacterial pathogens can cause community-acquired pneumonia in adults? (5)
Strep pneumonia - most common
Mycoplasma pneumoniae
Chlamydophila pneumoniae
Legionella
HiB - less than 5%
How is pneumonia investigated?
CXR - usually establishes diagnosis
O2 saturation - (+/- ABG if severely ill)
Sputum Gram stain and culture appropriate if deep cough + collect specimen before commencing treatment
How is mild community-acquired pneumonia treated?
Outpatient
Amox 1g 8 hourly for 5 to 7 days
OR if mycoplasma, chlamydia or legionella suspected
Doxy 200mg for first dose then 100mg daily for further 3 days
What is the CORB tool?
Assesses severity of pneumonia based on most abnormal results obtained during initial 24 hours of inpatient stay
C = acute confusion O = oxygen saturation 90% or less R = resp rate 30 breaths or more per minute B = SBP less than 90 or DBP 60 or less
Severe = the presence of at least 2 of these features
How do you treat moderate community-acquired pneumonia (nontropical regions)?
Nontropical regions - benpen IV + either oral doxy OR oral clarithro
How do you treat moderate community-acquired pneumonia (tropical regions with risk factors)?
Risk factors - diabetes, heavy alcohol consumption, chronic renal failure and chronic lung disease
ceftriaxone IV + gentamicin
How do you treat severe community acquired pneumonia? (non tropical)
IV
azithromycin + ceftriaxone or benpen + gent or cefatoxime
How do you treat mild hospital-acquired pneumonia (in low risk of MDR organisms scenario)?
amox + clavulanate
OR if nil orally ben pen + gentamicin
How do you treat moderate/severe hospital-acquired pneumonia (in low risk of MDR organisms scenario)?
ceftriaxone
What Gram stain findings are associated with pneumococcal pneumonia?
Gram positive oval shaped diplococci
What Gram stain findings are associaed with S. aureus?
Gram-positive cocci in clusters, chains and pairs
What Gram stain findings are associated with N. meningitidis
Gram-negative cocci
What Gram stain findings are associated with H. influenzae pneumoniae?
Gram-negative coccobacilli and many PMNs