Week 5 formative quiz questions

Question 1

Myaesthenia gravis is associated with thyroid tumours.

Answer 1

False – myasthenia gravis is associated with thymus tumours. Anybody with a new diagnosis of MG will undergo investigation for thymus tumour, and many of these people will end up having surgery.

Question 2

Narcolepsy is associated with delayed onset of REM sleep.

Answer 2

False – it is associated with rapid onset of REM sleep, and hallucinations at the time of falling asleep and/or waking.

Question 3

Patients with pulmonary embolism in whom an underlying cause is found generally require shorter periods of anticoagulation than patients in whom no cause is found.

Answer 3

True – this is because in “provoked” PE – i.e. cases where it has resulted from trauma or a period of immobility, we can fairly confidently say that we know what caused it, so it is unlikely to happen again. In “unprovoked” PE, where no cause is found, we are less sure, and so assume that the patient remains at high risk of further PE. These patients often have longer courses of treatment, which may be lifelong.

Question 4

Vibration injuries would be classed as a Physical occupational environmental impact.

Answer 4

True - other examples include noise and radiation

Question 5

Usual interstitial pneumonitis predominantly affects the apices.

Answer 5

False – UIP classically has a basal predominance.

Question 6

People with giant bullae in their lungs should not fly in planes.

Answer 6

True – the pressure changes that occur during commercial air travel can cause the bulla to expand in size and cause tearing or air emboli, both of which could be fatal.

Question 7

CF patients are encouraged to meet other CF patients to provide mutual support.

Answer 7

False – unfortunately, due to risk of cross-infection with bacteria like Pseudomonas and Burkholderia (which carry a poor prognosis for people with CF), CF patients must be kept strictly segregated.

Question 8

A d-dimer blood test has a high negative predictive value and a low positive predictive value for pulmonary embolism.

Answer 8

True. This means that if a d-dimer blood test is negative, you are very unlikely to have a PE. However, if the test is positive, there are lots of things that may explain this, so more tests are needed. Remember, a d-dimer blood test is an indication of intravascular blood clotting.

Question 9

Downwards movement of abdominal muscles during inspiration may be seen in chronic ventilatory failure due to neuromuscular weakness.

Answer 9

True – this is called paradoxical abdominal wall motion (paradoxical because normal movement of the abdominal wall is upwards and outwards during inspiration). This indicates diaphragmatic weakness, which is the underlying cause of the ventilatory failure.

Question 10

An Epworth Sleepiness Score of 5 or more is abnormal.

Answer 10

False – a score of 11 or more is abnormal.

Question 11

Laryngomalacia carries a risk of malignant change.

Answer 11

False – there is no increased risk of malignancy associated with laryngomalacia. Congenital Pulmonary Airway Malformation can occasionally be associated with risk of malignant change.

Question 12

Cystic fibrosis is the most common autosomal dominant disorder in Caucasians.

Answer 12

False – CF is inherited in an autosomal recessive pattern. It is the most common autosomal recessive disorder in Caucasians.

Question 13

Sleep apnoea is treated by continuous positive airway pressure.

Answer 13

True – CPAP is delivered through an airtight mask that blows high pressure air into the airway as the patient sleeps, keeping it patent.

Question 14

A patient who becomes hypoxaemic on exertion may have a diffusion impairment.

Answer 14

True – diffusion impairments in lung disease (such as interstitial lung disease) mean it takes longer for the blood and air oxygen to equilibrate. If you give the blood less time in contact with the alveoli (e.g. by increasing the heart rate during exercise) then often the arterial oxygen levels will fall.

Question 15

Babies with CF can be diagnosed before birth.

Answer 15

True – although these tests can come with a slightly increased risk of miscarriage (e.g. chorionic villus sampling, amniotic fluid sampling). Diagnosis can also be carried out pre-implantation, if parents are undergoing IVF.

Question 16

Transient tachypnoea of the newborn is caused by surfactant deficiency.

Answer 16

False – TTN is due to delayed reabsorption of pulmonary fluid at birth, and is a self-limiting condition. Infant Respiratory Distress Syndrome is caused by surfactant deficiency.

Question 17

Patients with cystic fibrosis must be encouraged to adhere to a low calorie diet.

Answer 17

False – these patients have inefficient digestion and high caloric requirements, so they must eat a high calorie diet.

Question 18

Pulmonary hypertension in chronic respiratory disease occurs due to chronic hypercapnia.

Answer 18

False – it occurs due to chronic hypoxia. Hypoxia triggers a reflex constriction of pulmonary vessels, and this constriction increases the vascular resistance and therefore the pressure of the pulmonary circulation.

Question 19

Alveolar hypoventilation can cause type 2 respiratory failure.

Answer 19

True – insufficient movement of air in and out of the alveoli means that carbon dioxide is not able to diffuse out of the bloodstream along its concentration gradient. It can therefore accumulate, causing type 2 respiratory failure (type 2 respiratory failure = problem with 2 gases).

Question 20

Hypersensitivity pneumonitis tends to begin in a centriacinar pattern.

Answer 20

True – laminar airflow deposits antigens primarily in the centriacinar region of the acinus, so this area is most affected by the resulting chronic inflammation.

Question 21

Pulmonary hypertension is defined as a mean pulmonary arterial pressure of >10mmg

Answer 21

False – it is defined as a mean pulmonary arterial pressure of >25mmHg.

Question 22

Tracheo-oesophageal fistula in babies can resolve without treatment.

Answer 22

False – this condition arises as a failure of the airway to fully separate from the oesophagus during embryonic development. There are a number of variations, but they all require surgical correction.

Question 23

1 in 2000-2500 people in Northern Europe are carriers of a Cystic Fibrosis mutation.

Answer 23

False – the proportion is much larger – about 1 in 25 people in Northern Europe are carriers. 1 in 2000-2500 live births have cystic fibrosis.

Question 24

Babies are born with fully-developed lungs.

Answer 24

False – the alveolar phase of lung development continues after birth, and the lungs are not fully developed until between 2 and 3 years of age.

Question 25

Congenital diaphragmatic hernias are more common on the left side.

Answer 25

True – these occur more commonly on the left. Right-sided lesions tend to have a worse outcome.

Question 26

In most cases of Usual Interstitial Pneumonitis, no underlying cause is found.

Answer 26

True – most cases of UIP are idiopathic.

Question 27

Obstructive sleep apnoea is associated with an increased risk of road traffic accidents.

Answer 27

True – due to the lack of refreshing sleep and resulting poor concentration and daytime sleepiness, people with OSA are more likely to be involved in RTAs.

Question 28

The most common mutation seen in cystic fibrosis causes a severe form of the disease.

Answer 28

True – the most common mutation, ΔF508, causes a block in processing of the CFTR protein, which causes severe disease. Remember that Class I-III mutations cause severe disease, while Class IV-VI cause a milder version of the disease.

Question 29

Idiopathic pulmonary fibrosis is a cause of finger clubbing.

Answer 29

True – this is one of many respiratory causes of clubbing (remember there are non-respiratory causes too!)

Question 30

Diffusion impairment causes type 2 respiratory failure.

Answer 30

False – because CO2 dissolves so much faster than oxygen, arterial CO2 is unlikely to be a problem in diffusion impairment.

Question 31

In type 1 respiratory failure, PaCO2 may be low.

Answer 31

True – type 1 respiratory failure is more common than type 2, and results from a failure of oxygenation only (type 1 = problem with 1 gas, type 2 = problem with 2 gases). As hyperventilation often occurs as a compensatory mechanism, this may result in more CO2 being blown off (remember CO2 is highly soluble) and therefore the PaCO2 can be low.

Question 32

Pleural effusion can cause a restrictive pattern on spirometry.

Answer 32

True – although spirometry is not routinely done for pleural effusion, it would show a restrictive pattern, as it reduces the volume available in the thoracic cavity for the lungs.

Question 33

Regarding spirometry: In restrictive lung conditions, the FEV1 and FEV1/FVC is reduced, but the FVC is normal.

Answer 33

False – the above description is of an obstructive lung disease. In a restrictive lung disease such as interstitial fibrosis, the lungs are stiffer and do not allow as much air in (hence “restrictive”), but the gas trapping of obstructive lung disease is not present, so a normal proportion of the FVC can be exhaled in 1 second, even if the overall volumes are smaller. Purely restrictive lung disease may even have an increased FEV1/FVC, as the stiff lungs force air out more quickly.

Question 34

Most cases of sarcoid require treatment with systemic steroids.

Answer 34

False – many cases are mild and self-limiting and do not require any treatment. In many other instances, treatment with topical steroids or NSAIDs (eg ibuprofen) may be sufficient.

Question 35

Babies with a very low chloride level in their sweat are likely to have cystic fibrosis.

Answer 35

False – CF is associated with a high chloride concentration in sweat.

Question 36

Haemoptysis in patients with cystic fibrosis is usually caused by lung cancer.

Answer 36

False – although patients with CF may develop lung cancer (as can anyone else), haemoptysis is far more commonly caused by destruction of the bronchial walls through the CF disease process.

Question 37

Hypoxaemia due to low V/Q does not respond well to supplementary oxygen.

Answer 37

False – Low V/Q means that some of the alveoli are poorly ventilated due to focal disease, and is the commonest cause of hypoxaemia. It generally responds well to increased FiO2 (giving additional oxygen), as this increases the oxygenation of poorly ventilated alveoli.

Question 38

The embryonic lungs are derived from the mesoderm.

Answer 38

False – like the gut, the lungs are derived from the endoderm.

Question 39

Normal PaCO2 is 10.5-13.5 kPa

Answer 39

False – normal CO2 is 4.8-6.0 kPa. The figures above describe normal PaO2.

Question 40

In neuromuscular weakness of the diaphragm, FEV1/FVC will be <0.7.

Answer 40

False – neuromuscular weakness of the diaphragm will give a restrictive picture on spirometry, therefore FEV1/FVC will be normal or elevated. FEV1/FVC <0.7 would be seen in an obstructive lung condition such as COPD.