Respiratory Flashcards
(119 cards)
Pathophysiology of Asbestos-related Lung Disease
Asbestos activates macrophages and neutrophils which causes the release of reactive oxygen species and nitrogen species which causes DNA damage, thus increasing the risk of cancer
What 2 pleural features are seen in asbestos-related lung disease?
Pleural plaques- which are BENIGN and usually detected on CXR incidentally and this is the most common form of asbestos-related lung disease
Pleural thickening- there is diffuse pleural thickening, similar to haemothorax or empyema
Is asbestosis restrictive or obstructive? and are the lower or upper zones predominantly affected?
restrictive disease and the lower zones are predominantly affected in asbestosis
What is mesothelioma?
it is a form of asbestos-related lung disease. it is a malignant disease of the pleura
Where does the malignancy in mesothelioma commonly metastasise to?
the contralateral lung and the peritoneum and usually affects the right lung more than the left
Asbestosis requires long term exposure to asbestos, what about mesothelioma?
occurs with SHORT-TERM exposure as well
What type of T cell drives asthma?
Th2
What are the three risk factors for an exacerbation of asthma?
a known diagnosis of asthma
viral infection
pollutants
What determines the severity of the asthma exacerbation? (The checklist for near fatal (1 requirement), life-threatening (4 requirements) and severe (2 requirements))
Near fatal- pCO2>6
Life-threatening- SpO2<92%/ pO2<8/ Cyanosis/ Hypotension
Severe- Respiratory rate>25/ HR>110
What are 4 investigations to be conducted in the event of an asthma exacerbation?
Peak flow expiratory volume-
- it is severe if <50% of the baseline and life-threatening if <33% of the baseline
ABG- assess the pO2 and pCO2
- a normal or severe pCO2 is very concerning
Inflammatory markers- there will be raised WCC and CRP if the cause is an infective trigger such as a virus
CXR- there will be HYPEREXPANSION
What is the immediate (3) and subsequent (2) management for an exacerbation of asthma?
and when can they be discharged?
Immediate-
1) Oxygen (aim for an SpO2 of 94-98%)
2) Nebulised Bronchodilators (SALBUTAMOL first and then IPRATROPIUM BROMIDE)
3) Corticosteroids (Prednisolone or IV hydrocortisone)
Subsequent-
1) IV Bronchodilator (Magnesium sulphate works)
2) Admission to ICU (for further bronchodilator treatment- SALBUTAMOL and AMINOPHYLLINE)
Discharge when PEFR>75%
What are the signs of asthma? (not an exacerbation but a general diagnosis)- there are 4 listed here
symptoms are worse at night and early morning
a DRY cough
wheeze and chest-tightness
dyspnoea and an expiratory wheeze
What are the 2 investigations which support a diagnosis of asthma?
FEV1/FVC <0.7
Fractional exhaled nitric oxide >40
What is the seven step management approach to stable asthma?
1) SABA
If SABA is not working or symptoms involve patients waking up at night OR occur more than 2 times a week-
2) SABA + low dose ICS
3) SABA + low dose ICS + LTRA
4) SABA + low dose ICS + LABA (+/- LTRA)
5) SABA + MART (which is basically just low dose ICS and LABA) (+/- LTRA)
6) SABA + MART (with higher ICS dose) (+/- LTRA)
or SABA + moderate dose ICS + LABA (+/- LTRA)
7) SABA + high dose ICS (+/- LTRA)
or SABA + theophylline or LAMA (+/- LTRA)
What are the four side effects of salbutamol?
Tachycardia
Palpitations
Headache
Tremor
What are some examples of ICS? (4)
Budesonide
Mometasone
Beclomethasone dipropionate
Fluticasone propionate
What are the four side effects of ICS (as asthma therapy)?
Sore throat
Cough
Oral candidiasis (thrush)
Stunted growth in children
What are two examples of LABA?
Salmeterol
Folmeterol
What are three examples of LTRA?
Montelukast
Zafirlukast
Pranlukast
What are the three side effects of LTRA?
Irritability
Akasthisia
Insomnia
What are the two sub-conditions that make up COPD?
Emphysema- loss of alveolar integrity due to an imbalance between proteases and protease-inhibitors (Alpha 1 antitrypsin)- this is triggered by chronic inflammation such as smoking
Bronchitis- mucus secretion which occurs secondary to ciliary dysfunction and increased size and number of goblet cells this leads to the destruction of the lung parenchyma and impairs gas exchange
What are the three risk factor for COPD?
Smoking Occupational exposure (dust, coal, cotton etc) Alpha-1-antitrypsin deficiency
What are the 9 signs of COPD?
Plus 3 signs of exacerbation
Dyspnoea
Productive cough (may not always be)
Wheeze
BARREL CHEST
HYPER RESONANCE
Quiet breath sounds
TAR STAINING of fingers
PERIPHERAL CYANOSIS
POTENTIALLY SIGNS of COR PULMONALE- right heart failure due to a peripheral oedema caused by COPD
EXACERBATION-
- SIGNIFICANT dyspnoea/ wheeze/ cough
- Coarse crepitation
- Pyrexia
What are the 7 investigations to be conducted on a COPD patient?
1) FEV1/FVC <0.7
2) CXR
- Flattened diaphragm
- Hyperinflation and bullae
- Check for lung cancer
3) FBC
- it can show CHRONIC HYPOXIA which can result in POLYCYTHAEMIA
4) BMI
5) A reduced TLCO
6) Serum alpha-antitrypsin levels
7) ECG to check for signs of right heart failure- RIGHT AXIS DEVIATION and RIGHT BUNDLE BRANCH BLOCK