Respiratory Flashcards
Lung cancer is the third most common cancer in the UK behind breast and prostate. Cigarette smoking is the biggest cause, around what % of lung cancers are thought to be preventable ?
Around 80%
What’re the three most common types of lung cancer ?
-Non-small cell lung cancer:
-Squamous cell carcinoma
-Adenocarcinoma
-Small cell lung cancer (SCLC)
How can SCLC be responsible for multiple paraneoplastic syndromes ?
They contain neurosecretory granules that can release neuroendocrine hormones.
S+S of lung cancer (7) ?
-SOB
-Cough
-Haemoptysis (coughing up blood)
-Finger clubbing
-Recurrent pneumonia
-Weight loss
-Lympadenopathy - often supraclavicular nodes are the first to be found on examination
What is the first line investigation in suspected lung cancer ? + Name four findings that could suggest cancer ?
-CXR
-Hilar enlargement
-Peripheral opacity - a visible lesion in the lung field
-Pleural effusion - usually unilateral in cancer
-Collapse
Besides a CXR what other investigations could be used to investigate for lung cancer (name three/four) ?
-Staging CT chest of chest, abdomen and pelvis
-PET-CT
-Bronchoscopy with endobronchial ultrasound (EBUS)
-Histological diagnosis
Why is CT scan of the chest, abdomen and pelvis done when investigating lung cancer?
To establish the stage and check for lymph node involvement and metastasis. This should be contrast enhanced using an injected contrast to give more detailed information about different tissues
What is a PET-CT (positron emission tomography) scan ?
IT involves injecting a radioactive tracer (usually attached to glucose molecules) and taking images using a combination of a CT scanner and a gamma ray detector to visualise how metabolically active tissues are. They are useful in identifying areas that the cancer has spread to by showing areas of increased metabolically activity.
What is a bronchoscopy with EBUS ?
It involves endoscopy with ultrasound equipment on the end of the scope. This allows detailed assessment of the tumour and ultrasound guided biopsy.
How is a histological diagnosis of lung cancer obtained ?
A biopsy is performed either by bronchoscopy or percutaneously
What is the first line treatment for non-small cell lung cancer pts that have the disease isolated to a single area ? + what else can be curative ?
SURGERY
-Lobectomy is first line
-Segmentectomy or wedge resecting is also an option
-Radiotherapy can also be curative
How can chemotherapy be used in relation to lung cancer (two ways) ?
-It can be offered in addition to surgery or radiotherapy in certain pts to improve outcomes (“adjuvant chemotherapy”)
-Or it can be used as palliative treatment to improve survival and quality of life in later stages of non-small cell lung cancer (“palliative chemotherapy”)
What is the most common treatment for small cell lung cancer ?
Usually chemotherapy and radiotherapy
Which type of lung cancer generally has the worse prognosis: NSCLC or SCLC ?
SCLC
What can be done as part of palliative treatment to relieve bronchial obstruction caused by lung cancer ?
Endobronchial treatment with stents or debulking
How does a recurrent laryngeal nerve palsy present + how can it be caused by a lung cancer ?
-It presents with a hoarse voice
-It is caused by the cancer pressing on or affecting the recurrent laryngeal nerve as it passes through the mediastinum
How can a lung cancer cause a phrenic nerve palsy + how does this present ?
-Due to nerve compression
-This causes diaphragm weakness and presents as shortness of breath.
How can a lung cancer cause superior vena cava obstruction, how does it present and what is Pemberton’s sign ?
-It is caused by direct compression of the tumour on the SVC
-It presents with facial swelling, difficulty breathing and distended veins in the neck and upper chest.
-Pemberton’s sign is where raising the hands over the head causes facial congestion and cyanosis. This is a medical emergency.
What is Horner’s syndrome and how can it be caused by a lung cancer ?
-It’s a triad of ptosis, anhidrosis and miosis
-It can be caused by a Pancoast tumour (tumour in the pulmonary apex) pressing on the sympathetic ganglion
Which type of lung cancer can cause SIADH and how does it present ?
-Caused by ectopic ADH secretion by a small cell lung cancer
-Presents with hyponatraemia (due to dilation of blood solutes)
Which type of lung cancer can cause Cushing’s syndrome/ how does it do this ?
Caused by ectopic ACTH secretion by a small cell lung cancer
Which type of lung cancer can cause hypercalcaemia and how does it do this ?
Caused by a ectopic parathyroid hormone from a squamous cell carcinoma
Which type of lung cancer can cause limbic encephalitis/ what is it, name four symptoms this could present with and what antibodies is it associated with ?
It’s a paraneoplastic syndrome where the SCLC 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 myasthenic syndrome ?
Is a result of antibodies produced by the immune system against SCLC 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 causing diplopia , levator muscles in the eyelid causing ptosis and pharyngeal muscles causing slurred speech and dysphagia. This weakness gets worse with prolonged use of the muscles.
This syndrome has similar symptoms to myasthenia gravis although the symptoms tend to be more insidious and less pronounced in Lambert-Eaton syndrome. In older smokers with symptoms of Lambert-Eaton syndrome consider a SCLC.
What is a mesothelioma, what’s is it linked to and what is the prognosis/treatment options ?
It is a lung malignancy affecting the mesothelial cells of the pleura. It is strongly linked to asbestos inhalation. There is a huge latent period between exposure to asbestos and the development of mesothelioma of up to 45 years. The prognosis is very poor. Chemotherapy can improve survival but it is essentially palliative.
What is pneumonia and how can it be seen ?
It is simply an infection of the lung tissue. It causes inflammation of the lung tissue and production of sputum that fills the airways and alveoli. Pneumonia can be seen as consolidation on a CXR.
What are the three different classifications of pneumonia ?
-Community acquired pneumonia
-Hospital acquired pneumonia (if it develops more than 48hrs after hospital admission)
-Aspiration pneumonia
Presentation of pneumonia ? (seven points)
-SOB
-Cough productive of sputum
-Fever
-Haemoptysis (coughing up blood)
-Pleuritic chest pain (sharp chest pain worse on inspiration)
-Delirium
-Sepsis
In pneumonia there may be a derangement in basic observations. These can indicate sepsis secondary to the pneumonia. Name 6 of these signs ?
-Tachypnoea
-Tachycardia
-Hypoxia
-Hypotension
-Fever
-Confusion
Characteristic chest signs when examining someone with pneumonia (three) ?
-Bronchial breath sounds - these are harsh breath sounds equally loud on inspiration and expiration. These are caused by consolidation of the lung tissue around the airway.
-Focal coarse crackles - these are caused by air passing through sputum in the airways similar to using a straw to blow air through a drink.
-Dullness to percussion - due to lung tissue collapse and/ or consolidation
NICE recommend using the scoring system CRB-65 out of hospital and CURB 65 in hospital for assessing the severity of a pneumonia. What does CURB 65 stand for ?
C-Confusion
U-Urea >7
R-Respiratory rate > or equal to 30
B -BP < 90 systolic or < or equal to 60 diastolic
65 - Age > or equal to 65
What does the CURB 65 scoring mean ?
0/1 = Consider treatment at home
2 or above = Consider hospital admission
3 or above = Consider intensive care assessment
Common causes of pneumonia (two) ?
Streptococcus pneumoniae (50%)
Haemophilus influenzae (20%)
Other causes of pneumonia and associations (three) ?
-Moraxella catarrhalis in immunocompromised pts or those with chronic pulmonary disease
-Pseudomonas aeruginosa in pts with cystic fibrosis or bronchiectasis
-Staphylococcus aureus in pts with cystic fibrosis
What is atypical pneumonia, what don’t they respond to and what can they be treated with ?
A pneumonia caused by an organism that cannot be cultured in the normal way or detected using a gram stain. They don’t respond to penicillins. They can be treated with macrolides, fluoroquines and tetracyclines.
Mnemonic for remembering 5 causes of atypical pneumonia + what does it stand for ?
Legions of psittaci MCQs
Legions - Legionella pneumophilia
Psittaci - Chlamydia psittaci
M - Mycoplasma pneumoniae
C - Chlamydophila penumoniae
Qs - Q fever (coxiella burnetii)
What is legionella pneumophila (Legionnaires’ disease) ?
An atypical pneumonia. Typically caused by infected water supplies or air conditioning units. It can cause hyponatraemia by causing an SIADH. The typical exam pt has recently had a cheap hotel holiday and presents with hyponatraemia.
What is mycoplasma pneumoniae ?
An atypical pneumoniae. This causes a milder pneumonia and can cause a rash called erythema multiforme characterised by varying sized “target lesions” formed by pink rings and pale centres. It can also cause neurological symptoms in young pts in the exams.
What is chlamydophilia pneumoniae ?
An atypical pneumonia. The presentation might be a school aged child with mild to moderate chronic pneumonia and wheeze. Be cautious though as this presentation is very common without chlamydophilia pneumoniae infection.
What is coxiella burnetii AKA “Q fever” ?
An atypical pneumonia. It is linked to exposure to animals and their bodily fluids. The MCQ pt is a farmer with a flu like illness.
What is chlamydia psittaci ?
An atypical pneumonia. This is typically contracted from contact with infected birds. The MCQ pt is a parrot owner.
What is pneumocystis jiroveci pneumonia (PCP), what pts does it occur in, how does it present and whats the treatment ?
It is a fungal pneumonia that occurs in pts that are immunocompromised. It is particularly important in pts with poorly controlled or new HIV with a low CD4 count. It usually presents subtly with a dry cough without sputum, SOB on exertion and night sweats. Treatment is with co-trimoxazole (trimethoprim/sulfamethoxazole), which is known by the brand name “Septrin”. Pts with low CD4 counts are prescribed prophylactic oral co-trimoxazole to protect against PCP.
Patients in the community with a CRB 0 or 1 pneumonia do not necessarily need investigations. NICE suggest considering a “point of care” test in primary care for CRP level to help guide management, however this is not widely available. If they arrive in hospital they will probably get a minimum of what (four) ?
-CXR
-FBC (raised white cells)
-U&Es (urea)
-CRP (raised in inflammation and infection)
Pts with moderate or severe cases of pneumonia should also have what (three) ?
-Sputum cultures
-Blood cultures
-Legionella and pneumococcal urinary antigens (send a urine sample for antigen testing)
Inflammatory markers such as WBCs and CRP are roughly raised in proportion to the severity of the pneumonia infection. This trend can be helpful in monitoring progress of pts towards recovery. For example repeating WBC and CRP after 3 days of antibiotics may show a downward trend suggesting the antibiotics are working. Which of these two tests commonly shows a delayed response ?
-CRP
-WBCs typically responds faster and gives a more “up to date picture”
What is the problem with using WBCs and CRP to look at how a pneumonia infection is progressing in an immunocompromised pt ?
Pts that are immunocompromised may not show an inflammatory response and may not have raised inflammatory markers despite severe infection.
When choosing antibiotics for pneumonia always follow your local area guidelines. These are developed by looking at the bacteria in your local area for their antibiotic resistance. Moderate or severe pneumonia or septic pts usually start with IV antibiotics. These are then changed to oral antibiotics guided by clinical improvement or improvement in their inflammatory markers. What are the typical antibiotic course lengths for mild CAP and moderate to severe CAP + what drugs might you give?
Mild CAP: 5 day course of oral antibiotics (amoxicillin or macrolide)
Moderate to severe CAP: 7-10 day course of dual antibiotics (amoxicillin and macrolide)
Name five complications of pneumonia ?
-Sepsis
-Pleural effusion
-Lung abscess
-Empyema
-Death
What are lung function tests ?
They are used to help establish a diagnosis in lung disease. They are particularly helpful in obstructive and restrictive lung disease where there will be recognisable findings on the tests.
What is spirometry ?
A test used to establish objective measures of lung function. It involves different breathing exercises into a machine that measures volumes of air and flow rates and produces a report.
What is reversibility testing ?
It involves giving a bronchodilator to someone prior to repeating a spirometry test to see the impact this has on the results
What is FEV1 ?
Forced expiratory volume in 1 second. This is the volume of air a person can exhale as fast as they can in 1 second. This is a measure of how easily air can flow out of the lungs. It will be reduced if there is any air flow OBSTRUCTION.
What is FVC ?
Forced vital capacity. This is the total amount of air a person can exhale after a full inhalation. This is a measure of the total volume of air that the person can take in to their lungs. It will be reduced if there is any RESTRICTION on the capacity of their lungs.
How can obstructive lung disease be diagnosed ?
When the FEV1 is less than 75% of the FVC (FEV1:FVC ratio < 75%). This suggests that there is some obstruction slowing the passage of air getting out of the lungs. The person may have a relatively good lung volume but air is only able to move in and out of the lungs slowly due to obstruction.
In asthma what causes the obstruction ?
A narrowed airway due to bronchoconstriction.
In COPD what causes the obstruction
Chronic airway and lung damage.
Are asthma and COPD reversible (i.e. by giving a bronchodilatory)?
Asthma is typically reversible but COPD isn’t
If FEV1 and FVC are equally reduced and the FEV1:FVC ratio > 75% what does this suggest ?
Restrictive lung disease
What is restrictive lung disease ?
Where there is a restriction in the ability of the lungs to expand and fill with air. The lungs are restricted from effectively expanding. This can be differentiated from obstructive lung disease where there is obstruction of air flow through the airways in to and out of the lungs. This restriction of lung expansion leads to inadequate ventilation of the alveoli and therefore inadequate oxygenation of the blood.
Why will restrictive lung disease cause the FEV1/FVC ratio to be normal or raised ?
As there is no obstructive pathology present that would be affecting air flow through the airways. The FVC will be reduced because there is a restriction of the overall expansion and thus maximum capacity of the lungs.
5 causes of restrictive lung disease ?
-Interstitial lung disease e.g. pulmonary fibrosis
-Sarcoidosis
-Obesity
-MND
-Scoliosis
What is peak flow, how is it measured and what disease is it useful in looking at ?
It is a measurement of the fastest point of a persons expiratory flow of air. It is a simple way of demonstrating how much obstruction to airflow is present in a pts lungs. It is measured using a peak flow meter. It is useful in obstructive lung disease, particularly asthma, to measure how well the asthma is controlled and how severe an acute exacerbation is.
Technique for peak flow ?
To stand tall, take a deep breath in, make a good seal around the device with the lips and blow as fast and hard as possible into the device. Take three attempts and record the best result.
How is peak flow recorded and why ?
It is usually recorded as a % of predicted. The predicted peak flow can be obtained based on sex, height and age using a reference chart. Peak flow varies dramatically based on the size and age of the pt.
For example an asthmatic pt with a predicted peak flow of 400 that only manages a score of 200 on their best attempt of 3 currently has a peak flow at 50% of predicted.
What is asthma ?
A chronic inflammatory condition of the airways that causes episodic exacerbations of bronchoconstriction. This narrowing of the airways causes an obstruction to airflow going in and out of the lungs. This airway obstruction is reversible and typically responds to bronchodilators such as salbutamol. The bronchoconstriction is caused by airway hypersensitivity and can be triggered by environmental factors.
Name 6 typical triggers of asthma ?
-Infection
-Night time or early morning
-Exercise
-Animals
-Cold, damp or dusty air
-Strong emotions
Presentation suggesting a diagnosis of asthma (6 bullet points)?
-Episodic symptoms
-Diurnal variability. Typically worse at night
-Dry cough with wheeze and SOB
-A history of other atopic conditions such as eczema, hayfever and food allergies.
-Family history
-Bilateral widespread “polyphonic” wheeze heard by a healthcare professional
Presentation indicating a diagnosis other than asthma (5 bullet points) ?
-Wheeze related to coughs and colds more suggestive of viral induced wheeze
-Isolated or productive cough
-Normal investigations
-No response to treatment
-Unilateral wheeze. This suggests a focal lesion or infection.
BTS/Sign guidelines (2016) on diagnosis of asthma ?
-High probability of asthma clinically: Try treatment
-Intermediate probability of asthma: Perform spirometry with reversibility testing
-Low probability of asthma: Consider referral and investigating for other causes.
NICE guidelines (2017) on diagnosis of asthma ?
NICE recommend assessment and testing at a “diagnostic hub” to establish a diagnosis. They specifically advise not to make a diagnosis clinically and require investigations.
First line investigations for asthma (two) ?
-Fractional exhaled nitric oxide
-Spirometry with bronchodilator reversibility
In asthma if there is diagnostic uncertainty after first line investigations these can be followed up with what further testing (two) ?
-Peak flow variability measured by keeping a diary of peak flow measurements several times per day for 2 to 4 weeks.
-Direct bronchial challenge test with histamine or methacholine.
How do Short acting beta 2 adrenergic receptor agonists work ?
They act cause smooth muscles of the airways the relax resulting in bronchodilation
How do long-acting beta 2 agonists (LABA) work ?
Same as SABAs but have a much longer action
Why are ICSs e.g. betclometasone effective in treating asthma ?
They reduce the inflammation and reactivity of the airways
How do long-acting muscarinic antagonists (LAMA) e.g. tiotropium work ?
They block the acetylcholine receptors. Acetylcholine receptors are stimulated by the parasympathetic nervous system and cause contraction of the bronchial smooth muscles therefore blocking these receptors leads to bronchodilation
How do leukotriene receptor antagonists e.g. montelukast work ?
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..
How does theophylline work ?
By relaxing bronchial smooth muscle and reducing inflammation. Unfortunately it has a narrow therapeutic window and can be toxic in excess so monitoring plasma theophylline levels is required. This is done 5 days after starting treatment and 3 days after each dose change
What is maintenance and reliever therapy (MART) ?
This is a combination inhaler containing a low dose inhaled corticosteroid and a fast acting LABA. This replaces all other inhalers and the pt uses this single inhaler both regularly as a “preventer” and also as a “reliever” when they have symptoms.
Principles of using asthma stepwise ladder (five) ?
-Start at the most appropriate step for the severity of the symptoms
-Review at regular intervals based on severity
-Step up and down the ladder based on symptoms
-Aim to achieve no symptoms or exacerbations on the lowest dose and number of treatments (This is often difficult in practice)
-Always check inhaler technique and adherence at review
