Flashcards in Respiratory Deck (48):
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)
1. Increased venous pressure (cardiac failure, constrictive pericarditis, fluid overload)
2. Hypoproteinaemia (cirrhosis, nephrotic syndrome, malabsorption)
4. 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)
1. Decreased expansion, stony dullness on percussion and diminished breath sounds on affected side
2. Decreased tactile vocal fremitus and vocal resonance (inconsistent and unreliable)
3. There may be tracheal deviation AWAY from effusion if large
What investigations can be done in pleural effusions? (4)
1. CXR: blunting of costophrenic angles
2. US - identifies presence of pleural field and used in diagnostic/therapeutic aspiration
3. Diagnostic aspiration
How are pleural effusions managed? (3)
1. Treat underlying cause!
2. Drainage if effusion is symptomatic (aspiration or intercostal drain)
3. 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
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?
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)
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)?
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
What Gram stain findings are associated with H. influenzae pneumoniae?
Gram-negative coccobacilli and many PMNs
What are the most common causes of typical pneumonia?
What are the most common causes of atypical pneumonia?
Viruses - influenza, parainfluenza and adenovirus
What is the daily regimen for drug-susceptible tuberculosis?
Rifampicin - 6 months
Isoniazid - 6 months
Pyrazinamide - 2 months
Ethambutol - 2 months
What are the typical symptoms of active TB?
Night sweats, fever, weight loss and cough, developing over 2-3 weeks or more
How is suspected active TB investigated? (3)
2. Sputum cultures x3
3. Acid-fast microscopy using Ziehl-Neelsen stain
What is the Mantoux test?
Aka tuberculin skin test
Assesses inflammation in dermis following intradermal injection of tuberculin protein. Test needs to be read 48-72 hours after administration.
When can false positive Mantoux tests occur?
Previous BCG vaccination and exposure to environmental Mycobacterium spp.
Obstructive lung disease - spirometry results
FEV reduced more than FVC therefore, FEV/FVC ratio is decreased
Restrictive lung disease - spirometry results
FEV/FVC ratio is normal or increased
In which type of COPD patient should supplemental oxygen be given with care?
Blue bloaters - respiratory centres are insensitive to CO2, rely on hypoxic drive to maintain respiratory effort
What is Type 1 respiratory failure?
Hypoxia with normal or low PaCO2. Caused by V/Q mismatch - pneumonia, pulmonary oedema, PE, asthma
What is type 2 respiratory failure?
Hypoxia with hypercapnia (PaCO2 > 6 kPa). Caused by alveolar hypoventilation, with or without V/Q mismatch - reduced respiratory drive, neuromuscular disease (diaphragmatic paralysis, poliomyelitis), thoracic wall disease (flail chest, kyphoscoliosis), pulmonary disease (asthman, COPD, pneumonia, OSA)
How is respiratory failure managed?
Type 1 - treat underlying cause, give oxygen
Type 2 - treat underlying cause, be more careful about giving oxygen
What is the most common cause of interstitial lung disease?
Idiopathic pulmonary fibrosis
Which condition(s) are early inspiratory crackles suggestive of?
COPD/bronchiectasis - often cleared by cough
Which condition(s) are late inspiratory crackles suggestive of?
What constitutes mild, moderate and severe COPD?
FEV/FVC for all 0.7 (post-bronchodilator)
Mild - FEV = 60-80% predicted
Moderate - FEV = 40-59% predicted
Severe - FEV less than 40% predicted
What non-pharmacological interventions should be considered in COPD management? (5)
1. Risk reduction: smoking cessation, influenza and pneumococcal immunisation handbook
2. Optimise function: encourage physical activity, review nutrition, provide education
3. Consider co-morbidities: osteoporosis, coronary disease, anxiety and depression
4. Refer to pulmonary rehab (once moderate severity)
5. Once severe: Consider oxygen therapy, surgery, palliative care and advanced care directive
What pharmacological interventions should be considered in the management of COPD? (3)
1. Short-acting reliever medication: e.g. ventolin
2. In moderate severity: Symptom relief e.g. long-acting muscarinic antagonist or long-acting beta agonist
3. Exacerbation prevention: when FEV below 50% predicted AND patient has had 2 or more exacerbations in the previous 12 months - ICS/LABA ccombination therapy e.g. seretide (fluticasone and salmeterol) or symbicort (budesonide and eformeterol)
What is Seretide?
Combination therapy - ICS/LABA
Fluticasone and salmeterol
What is symbicort?
Combination - ICS/LABA
Budesonide and eformeterol
How does one interpret and increase vs a decrease in tactile fremitus?
Increase = there is a direct solid communication from the bronchus through the lung out to the chest wall e.g. consolidation
Decrease = a process is preventing communication e.g. bronchial obstruction or lung is displaced from chest wall by air or fluid in the pleural space
What are the classical ECG changes for PE?
1. S wave in lead 1
2. Q wave and T wave inversion in lead III
3. T wave inversion in leads V1 to V4