Respiratory Flashcards
- A raised NT-proBNP blood test result indicates right ventricular failure
- Echo can be used to estimate pulmonary artery pressure
What organisms cause hospital acquired pneumonia?
Pseudomonas aeruginosa
Staphylococcal aureus
Enterobacteria
Risk factors for aspiration pneumonia?
This occurs in patients with an unsafe swallow. Risk factors include stroke, myasthenia gravis, bulbar palsy, alcoholism, and achalasia.
Features of STAPHylococcal pneumonia
A bilateral cavitating bronchopneumonia.
Found in: IV drug users, elderly patients, or patients who already have an influenza infection.
Features of a klebsiella pneumonia?
Primarily affects the upper lobes resulting in a cavitating pneumonia, presenting with “red-currant” sputum.
Furthermore, there is an increased risk of developing complications including empyema, lung abscesses and pleural adhesions.
Patients at risk of Klebsiella pneumonia are those with weakened immune systems such as elderly, alcoholics, and diabetics.
Additional at-risk groups include patients with malignancy, chronic obstructive pulmonary disease, long term steroid use and renal failure.
Features of legionella pneumonia:
Fever, myalgia and malaise followed by a dyspnoea and a dry cough. It is associated with Legionnaire’s disease, usually in patients who have been exposed to poor hotel air conditioning.
Investigations for legionella pneumonia:
Look for hyponatraemia and deranged LFTs on blood tests. Legionella antigen may be present in the urine.
Summary of pneumocystis jiroveci.
This is associated with patients who are immunosuppressed (malignancy or chemotherapy) or HIV positive.
The causative organism is known as pneumocystis jiroveci and is a fungus. In patients who are HIV-positive the risk of PCP increases when the CD4+ <200 cells/uL.
Symptoms include exertional dyspnoea, dry cough, and fever.
What is curb 65?
Used to classify the severity of pneumonia:
C – confusion: An abbreviated mental test of ≤8
U – urea: >7mmol/L
R - Respiratory rate: ≥30/ min
B - blood pressure <90 systolic and/ or <60mmHg diastolic
65 - age: >65year old
What is curb 65?
Used to classify the severity of pneumonia:
C – confusion: An abbreviated mental test of ≤8
U – urea: >7mmol/L
R - Respiratory rate: ≥30/ min
B - blood pressure <90 systolic and/ or <60mmHg diastolic
65 - age: >65year old
Signs of pleural effusion on examination:
The trachea is central or deviated away from the affected side (if large).
Chest expansion is reduced on the affected side.
The percussion note is stony dull on the affected side.
On auscultation there are reduced/absent breath sounds over the effusion. There may be bronchial breathing at the upper border of the pleural effusion.
Vocal resonance/tactile vocal fremitus is reduced over the effusion.
How are the causes of pleural effusion subdivided?
Causes of pleural effusions are mainly divided into exudative (protein content >35 g/L) and transudative (protein content <35 g/L)
Causes of an exudative pleural effusion:
Infections such as pneumonia or TB.
Malignancy such as bronchial carcinoma, mesothelioma, or lung metastases.
Inflammatory conditions such as rheumatoid arthritis, lupus, or acute pancreatitis.
Pulmonary infarct (for example secondary to a pulmonary embolism) and trauma.
Causes of an exudative pleural effusion:
Infections such as pneumonia or TB.
Malignancy such as bronchial carcinoma, mesothelioma, or lung metastases.
Inflammatory conditions such as rheumatoid arthritis, lupus, or acute pancreatitis.
Pulmonary infarct (for example secondary to a pulmonary embolism) and trauma.
Causes of an transudative pleural effusion:
Transudative pleural effusions are caused by imbalances in the Starling forces that govern the formation of interstitial fluid.
Conditions that increase the capillary hydrostatic pressure (forcing fluid out of the pulmonary capillaries into the pleural space) include congestive cardiac failure.
Conditions that reduce the capillary oncotic pressure (impairing the reabsorption of fluid from the pleural space into the pulmonary capillaries) include cirrhosis, nephrotic syndrome/chronic kidney disease, and gastrointestinal malabsorption/malnutrition (eg. Coeliac disease).
Less common causes of transudative pleural effusions include hypothyroidism and Meig’s syndrome (described by the triad of ascites, pleural effusion, and benign ovarian tumour).
Read aloud:
Glucose: low in rheumatoid arthritis, TB, or malignancy
pH: <7.2 in empyema
Amylase: raised in pancreatitis
Immunology: rheumatoid factor is useful if rheumatoid arthritis is suspected; anti-nuclear antibody (ANA) is useful if systemic lupus erythematosus (SLE) is suspected; complement is typically low in pleural effusions caused by rheumatoid arthritis or SLE.
What is Lights criteria?
Used to determine transudative vs exudative pleural effusion:
If the protein content is equivocal (25-35 g/L), Light’s criteria can be applied:
This states that an effusion is an exudate if: the pleural fluid to serum protein ratio is >0.5, the pleural fluid to serum LDH ratio is >0.6, or the pleural fluid LDH is >2/3 the upper reference limit for serum LDH.
Non-small cell lung cancer encompassess what main cancers?
Non-small cell lung cancer makes up around 80% of lung cancer and includes:
- Adenocarcinoma (around 40%)
- Squamous cell carcinoma (around 20%)
- Large-cell carcinoma (around 10%)
- Other types (around 10%)
Describe what is characteristic about small cell lung cancer:
Small cell lung cancer cells contain neurosecretory granulesthat can releaseneuroendocrine hormones. This makes SCLC responsible for multiple paraneoplastic syndromes.
A patient with lung cancer presents with facial swelling, difficulty breathing and distended veins in the neck and upper chest and Pemberton’s sign. What is the underlying issue?
Superior vena cava obstructionis a complication of lung cancer. It is caused by direct compression of the tumour on the superior vena cava. It presents with facial swelling, difficulty breathing and distended veins in the neck and upper chest.
What is Pemberton’s sign?
“Pemberton’s sign” is where raising the hands over the head causes facial congestion and cyanosis. This is a medical emergency.
What is the triad seen in Horner’s syndrome?
Partial ptosis
Anhidrosis
Miosis
How does a recurrent laryngeal nerve palsy present in lung cancer?
Recurrent laryngeal nerve palsy presents with a hoarse voice. It is caused by cancer pressing on or affecting the recurrent laryngeal nerve as it passes through the mediastinum.
What is Limbic encephalitis?
Limbic encephalitis. This is a paraneoplastic syndrome where small cell lung cancer causes the immune system to make antibodies to tissues in the brain, specifically the limbic system, causing inflammation in these areas. This causes symptoms such as short term memory impairment, hallucinations, confusion and seizures. It is associated with anti-Hu antibodies.
What is Lambert eaton syndrome?
Lambert-Eaton myasthenic syndrome is a result of antibodies produced by the immune system against small cell lung cancer cells. These antibodies also target and damage voltage-gated calcium channels sited on the presynaptic terminals in motor neurones. This leads to weakness, particularly in the proximal muscles but can also affect intraocular muscles.
Symptoms of Lambert-Eaton syndrome:
Weakness, particularly in the proximal muscles but can also affect intraocular muscles causing:
Diplopia
Ptosis
Affect pharyngeal muscles causing slurred speech and dysphagia.
Patients may also experience dry mouth, blurred vision, impotence and dizziness due to autonomic dysfunction.
In older smokers with symptoms of Lambert-Eaton syndrome consider what?
Small cell lung cancer
Mesothelioma is strongly linked to what?
Asbestos inhalation
Treatment for mesothelioma?
The prognosis is very poor. Chemotherapy can improve survival but it is essentially palliative.
In patients with pneumonia NICE advises anyone with a score greater than what to be admitted to hospital?
1 or 2 consider admitting
3 urgent admission
Common pathogens that cause pneumonia:
- Streptococcus pneumoniae (50%)
- Haemophilus influenzae(20%)
What pathogen is commonly seen causing pneumonia in CF patients?
- Pseudomonas aeruginosa in patients with cystic fibrosis or bronchiectasis
- Staphylococcus aureus in patients with cystic fibrosis
Moraxella catarrhalis causes pneumonia in what patients?
In immunocompromised patients or those with chronic pulmonary disease
Which electrolyte needs to be monitored in Legionella pneumophila and why?
Hyponatraemia(low sodium) due to causing an SIADH.
SIADH = Syndrome of inappropriate antidiuretic hormone secretion (excess ADH).
What patients typically get legionella pneumophila?
Patients that have had cheap hotel holidays.
Which pneumonia causes erythema multiforme and neurological symptoms in young patients?
Mycoplasma pneumoniae.
This causes milder pneumonia and can cause a rash - erythema multiforme.
It can also cause neurological symptoms in young patients in exams.
Coxiella burnetii AKA “Q fever”.
This is linked to exposure to animals and their bodily fluids. Patient is a farmer with a flu like illness?
Remember the 5 causes of atypical pneumonia with the mnemonic:
“Legions of psittaci MCQs”
M – mycoplasma pneumoniae
C – chlamydydophila pneumoniae
Qs – Q fever (coxiella burnetii)
Summary of fungal pneumonia:
Read aloud if don’t know!
Pneumocystis jiroveci (PCP) pneumonia occurs in patients that are immunocompromised. It is particularly important in patients with poorly controlled or new HIV with a low CD4 count. It usually presents subtly with a dry cough without sputum, shortness of breath on exertion and night sweats.
Treatment for PCP pneumonia:
Treatment is with co-trimoxazole (trimethoprim/sulfamethoxazole) known by the brand name “Septrin”. Patients with low CD4 counts are prescribed prophylactic oral co-trimoxazole to protect against PCP.
How do LAMA’s work?
+ name one
Long-acting muscarinic antagonists (LAMA), for example tiotropium. These block the acetylcholine receptors. Acetylcholine receptors are stimulated by the parasympathetic nervous system and cause contraction of the bronchial smooth muscles. Blocking these receptors leads to bronchodilation.
Name of a commonly used ICS for chronic asthma:
Beclometasone
How does montelukast work in chronic asthma?
Leukotriene receptor antagonists, for example, montelukast. Leukotrienes are produced by the immune system and cause inflammation, bronchoconstriction and mucus secretion in the airways. Leukotriene receptor antagonists work by blocking the effects of leukotrienes.
Summary of theophylline use in asthma:
Theophylline. This works by relaxing the bronchial smooth muscle and reducing inflammation. Unfortunately, it has a narrow therapeutic window and can be toxic in excess so monitoring plasma theophylline levels in the blood is required. This is done 5 days after starting treatment and 3 days after each dose changes.
If you see a patient with a thoracotomy scar in your OSCEs, they are likely to have had one of what three procedures?
A lobectomy, pneumonectomy or lung volume reduction surgery for COPD.
What are the two different types of thoracotomy scar?
Anterolateral
Posterolateral
How to interpret the cause of a thoracotomy scar clinically:
If you see a patient with a thoracotomy scar in your OSCEs, they are likely to have had a lobectomy, pneumonectomy or lung volume reduction surgery for COPD. If they have no breath sound on that side, this indicates a pneumonectomy rather than lobectomy. If they have absent breath sound in a specific area on the affected side (e.g., the upper zone), but breath sounds are present in other areas, this indicates a lobectomy. Lobectomies and pneumonectomies are usually used to treat lung cancer. In the past, they were often used to treat tuberculosis, so keep this in mind in older patients. If it is a cardiology examination and they have a right-sided mini-thoracotomy incision, this is more likely to indicate previous minimally invasive mitral valve surgery.
When would you be likely to use Bipap as non-invasive ventilation?
The criteria for initiating Bipap: Respiratory acidosis (pH < 7.35, PaCO2 >6) despite adequate medical treatment.
You would be likely to use Bipap in type 2 respiratory failure typically due to COPD>
What is required prior to starting non-invasive ventilation and why?
Chest x-ray to rule out a pneumothorax.
Non-invasive ventilation is contraindicated for pneumothorax).
How is Bipap for a respiratory acidosis monitored?
Repeat an ABG 1 hour after every change and 4 hours after that until stable. The IPAP is increased by 2-5 cm increments until the acidosis resolves.
Indications for CPAP:
Obstructive sleep apnoea
Congestive cardiac failure
Acute pulmonary oedema
Explain how CPAP works:
CPAP stands for continuous positive airway pressure. It provides continuous air being blown into the lungs that keeps the airways expanded so that air can more easily travel in and out. It is used to maintain the patient’s airway in conditions where it is prone to collapse.
What are the two medications that slow the progression of IPF?
Pirfenidone is an antifibrotic and anti-inflammatory
Nintedanib is a monoclonal antibody targeting tyrosine kinase
How is interstitial lung disease diagnosed?
Diagnosis of interstitial lung disease requires a combination of clinical features and high resolution CT scan of the thorax. HRCT shows a “ground glass” appearance with interstitial lung disease. When diagnosis is unclear lung biopsy can be used to take samples of the lung tissue and confirm the diagnosis on histology.
What drugs can induce pulmonary fibrosis?
- Amiodarone
- Cyclophosphamide
- Methotrexate
- Nitrofurantoin
Pulmonary fibrosis can occur secondary to what conditions?
- Alpha-1 antitripsin deficiency
- Rheumatoid arthritis
- Systemic lupus erythematosus (SLE)
- Systemic sclerosis
What is hypersensitivity pneumonitis?
Hypersensitivity pneumonitis is a type III hypersensitivity reaction to an environmental allergen that causes parenchymal inflammation and destruction in people that are sensitive to that allergen.
How is hypersensitivity pneumonitis diagnosed?
Bronchoalveolar lavage involves collecting cells from the airways during bronchoscopyby washing the airways with fluid then collecting that fluid for testing. This shows raised lymphocytes and mast cells in hypersensitivity pneumonitis.
How is hypersensitivity pneumonitis managed?
Management is by removing the allergen, giving oxygen where necessary and steroids.
Example of causes of hypersensitivity pneumonitis:
Examples of specific causes:
Bird-fanciers lung is a reaction to bird droppings
Farmers lung is a reaction to mouldy spores in hay
Mushroom workers’ lung is a reaction to specific mushroom antigens
Malt workers lung is a reaction to mould on barley
Practice: Defining, presentation, diagnosis and management of cryptogenic organising pneumonia:
Read aloud summary after:
Cryptogenic organising pneumonia was previously known as bronchiolitis obliterans organising pneumonia. It involves a focal area of inflammation of the lung tissue. This can be idiopathic or triggered by infection, inflammatory disorders, medications, radiation or environmental toxins or allergens.
Presentation is very similar to infectious pneumonia with shortness of breath, cough, fever and lethargy. It also presents on similarly to pneumonia on a chest xray with a focal consolidation.
Diagnosis is often delayed due to the similarities to infective pneumonia. Lung biopsy is the definitive investigation. Treatment is with systemic corticosteroids.
What are the four main complications of asbestosis?
Lung fibrosis
Pleural thickening and pleural plaques
Adenocarcinoma
Mesothelioma
How are pleural effusions grouped?
Exudative = High protein
Transudative = Low protein
Causes of exudative pleural effusion:
Lung cancer
Pneumonia
Rheumatoid arthritis
Tuberculosis
Causes of transudative pleural effusion:
Congestive cardiac failure
Hypoalbuminaemia
Hypothroidism
Meig’s syndrome
Understanding exudative vs transudative pleural effusion:
Exudative causes are related to inflammation. The inflammation results in protein leaking out of the tissues in to the pleural space (ex- meaning moving out of). Think of the causes of inflammation.
Transudative causes relate to fluid moving across into the pleural space (trans- meaning moving across). Think of the causes of fluid shifting.
What is Meig’s syndrome?
Right sided pleural effusion with ovarian malignancy
Why is the pleural effusion commonly on the right side in Meig’s syndrome?
Pleural effusion is usually bilateral, but in patients with Meigs syndrome, it is usually unilateral with a predominance on the right side due to the larger diameter of transdiaphragmatic lymphatic channels on the right side.
Presentation of pleural effusion:
- Shortness of breath
- Dullness to percussion over the effusion
- Reduced breath sounds
- Tracheal deviation away from the effusion if it is massive.
Investigations for a patient with suspected pleural effusion:
Chest xray shows:
Blunting of the costophrenic angle
Fluid in the lung fissures
Larger effusions will have a meniscus. This is a curving upwards where it meets the chest wall and mediastinum.
Tracheal and mediastinal deviation if it is a massive effusion.
Taking a sample of the pleural fluid by aspiration or chest drain is required to analyse it for protein count, cell count, pH, glucose, LDH and microbiology testing.
Treatment for pleural effusion:
Conservative management may be appropriate as small effusions will resolve with treatment of the underlying cause. Larger effusions often need aspiration or drainage.
Pleural aspiration involves sticking a needle in and aspirating the fluid. This can temporarily relieve the pressure but the effusion may recur and repeated aspiration may be required.
Chest drain can be used to drain the effusion and prevent it recurring.
Define empyema and it’s management:
Empyema is where there is an infected pleural effusion. Suspect an empyema in a patient who has an improving pneumonia but new or ongoing fever. Pleural aspiration shows pus, acidic pH (pH < 7.2), low glucose and high LDH. Empyema is treated by chest drain to remove the pus and antibiotics.
When to aspirate a pneumothorax?
If SOB and/or there is a > 2cm rim of air on the chest x-ray then it will require aspiration and reassessment.
When to put a chest drain in for a pneumothorax:
If aspiration fails twice it will require a chest drain.
Unstable patients or bilateral or secondary pneumothoraces generally require a chest drain.
Management of a tension pneumothorax:
WORD FOR WORD
“Insert a large bore cannula into the second intercostal space in the midclavicular line.”
Where are chest drains inserted?
Chest drains are inserted into the “triangle of safety”. This triangle is formed by:
The 5th intercostal space (or the inferior nipple line)
The mid axillary line (or the lateral edge of the latissimus dorsi)
The anterior axillary line (or the lateral edge of the pectoris major)
The needle is inserted just above the rib to avoid the neurovascular bundle that runs just below the rib. Once the chest drain is inserted obtain a chest xray to check the positioning.
The triangle of safety is made up by what?
The 5th intercostal space (or the inferior nipple line)
The mid axillary line (or the lateral edge of the latissimus dorsi)
The anterior axillary line (or the lateral edge of the pectoris major)
What prophylaxis should be given for people at risk of VTE?
Low molecular weight heparin such as enoxaparin
What scoring system is used for PE’s?
Wells Score
Patients with a PE will likely show up as what on an ABG?
Patients with a pulmonary embolism often have a respiratory alkalosis when an ABG is performed. This is because the high respiratory rate causes them to “blow off” extra CO2. As a result of the low CO2, the blood becomes alkalotic. It is one of the few causes of a respiratory alkalosis, the other main cause being hyperventilation syndrome.
Initial treatment for a PE:
The initial recommended treatment is apixaban or rivaroxaban.
What is used in place of apixaban/rivaroxaban to treat a PE and why?
Low molecular weight heparin (LMWH) is an alternative where these are not suitable, or in antiphospholipid syndrome.
Long-term anticoag options post VTE:
The options for long term anticoagulation in VTE are warfarin, a NOAC or LMWH.
3 most common direct-acting oral anticoagulants
Apixaban
Dabigatran
Rivaroxaban
