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Question 1
Correct
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A 40 year old truck operator who smokes one and a half packs of cigarette per day complains of a cough and fever for the last three days. He also has right-sided chest pain when he inhales. On examination he is slightly cyanosed, has a temperature of 38.1°C, a respiratory rate of 39/min, a BP of 104/71 mm/Hg and a pulse rate of 132/min. He has basal crepitations and dullness to percussion at the right lung base. What could be a probable diagnosis?
Your Answer: Bronchopneumonia
Explanation:Bronchopneumonia presents as a patchy consolidation involving one or more lobes, usually the dependent lung zones, a pattern attributable to aspiration of oropharyngeal contents.
Symptoms of bronchopneumonia may be like other types of pneumonia. This condition often begins with flu-like symptoms that can become more severe over a few days. The symptoms include:
– fever
– a cough that brings up mucus
– shortness of breath
– chest pain
– rapid breathing
– sweating
– chills
– headaches
– muscle aches
– pleurisy, or chest pain that results from inflammation due to excessive coughing
– fatigue
– confusion or delirium, especially in older peopleThere are several factors that can increase your risk of developing bronchopneumonia. These include:
– Age: People who are 65 years of age or older, and children who are 2 years or younger, have a higher risk for developing bronchopneumonia and complications from the condition.
– Environmental: People who work in, or often visit, hospital or nursing home facilities have a higher risk for developing bronchopneumonia.
– Lifestyle: Smoking, poor nutrition, and a history of heavy alcohol use can increase your risk for bronchopneumonia.
– Medical conditions: Having certain medical conditions can increase your risk for developing this type of pneumonia. These include: chronic lung disease, such as asthma or chronic obstructive pulmonary disease (COPD), HIV/AIDS, having a weakened immune system due to chemotherapy or the use of immunosuppressive drugs. -
This question is part of the following fields:
- Respiratory
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Question 2
Incorrect
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Which area in the body controls the hypoxic drive to breathe?
Your Answer: Hypothalamus
Correct Answer: Carotid body
Explanation:The carotid body consists of chemosensitive cells at the bifurcation of the common carotid artery that respond to changes in oxygen tension and, to a lesser extent, pH. In contrast to central chemoreceptors (which primarily respond to PaCO2) and the aortic bodies (which primarily have circulatory effects: bradycardia, hypertension, adrenal stimulation, and also bronchoconstriction), carotid bodies are most sensitive to PaO2. At a PaO2 of approximately 55-60 mmHg, they send their impulses via CN IX to the medulla, increasing ventilatory drive (increased respiratory rate, tidal volume, and minute ventilation). Thus, patients who rely on hypoxic respiratory drive will typically have a resting PaO2 around 60 mm Hg.
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This question is part of the following fields:
- Respiratory
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Question 3
Incorrect
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A 14 year old known asthmatic presents to the A&E department with difficulty breathing. She was seen by her regular doctor the day before with a sore throat which he diagnosed as tonsillitis and was prescribed oral Amoxicillin for 5 days. Past medical history: Ulcerative colitis diagnosed four years ago. Current medications: Inhaled salbutamol and beclomethasone Mesalazine 400 mg TDS She was observed to be alert and oriented but she had laboured breathing. Inspiratory wheeze was noted. She was pale, sweaty and cyanosed. Her temperature was 36.7ºC, pulse 121/minute and blood pressure 91/40 mmHg. The lungs were clear and the remainder of the examination was normal. She was given high-flow oxygen through a face mask but despite this her breathing became increasingly difficult. What is the most likely causative agent?
Your Answer: Streptococcus pneumoniae
Correct Answer: Haemophilus influenzae
Explanation:Acute epiglottitis is a life-threatening disorder with serious implications to the anaesthesiologist because of the potential for laryngospasm and irrevocable loss of the airway. There is inflammatory oedema of the arytenoids, aryepiglottic folds and the epiglottis; therefore, supraglottitis may be used instead or preferred to the term acute epiglottitis.
Acute epiglottitis can occur at any age. The responsible organism used to be Hemophilus influenzae type B (Hib), but infection with group A b-haemolytic Streptococci has become more frequent after the widespread use of Hemophilus influenzae vaccination.
The typical presentation in epiglottitis includes acute occurrence of high fever, severe sore throat and difficulty in swallowing with the sitting up and leaning forward position in order to enhance airflow. There is usually drooling because of difficulty and pain on swallowing. Acute epiglottitis usually leads to generalized toxaemia. The most common differential diagnosis is croup and a foreign body in the airway. A late referral to an acute care setting with its serious consequences may result from difficulty in differentiation between acute epiglottitis and less urgent causes of a sore throat, shortness of breath and dysphagia.
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This question is part of the following fields:
- Respiratory
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Question 4
Incorrect
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An 80 year-old Zimbabwean woman with known rheumatoid arthritis was admitted to hospital with a four week history of weight loss, night sweats and cough. She was given a course of Amoxicillin for the past week but her condition deteriorated and she was referred to the hospital when she developed haemoptysis. She was on maintenance prednisolone 10 mg once per day and four weeks earlier, she had received infliximab for a flare up of rheumatoid arthritis. She lived with her husband but had been admitted to hospital himself with influenza four days earlier. She was a lifelong non-smoker and worked most of her life as a missionary in Zimbabwe and South Africa. On examination she looked cachexic and was pyrexial with a temperature of 38.5°C. Her blood pressure was 181/101 mmHg, pulse 121 beats per minute and oxygen saturations of 89% on room air. Her heart sounds were normal and there were no audible murmurs. Auscultation of her lung fields revealed bronchial breath sounds in the left upper zone. Examination of her abdomen was normal. Mantoux test < 5mm (after 48 hours) A chest radiograph revealed cavitating left upper lobe consolidation. What is the most likely diagnosis?
Your Answer: Pneumocystis jirovecii pneumonia
Correct Answer: Post-primary tuberculosis
Explanation:Post-primary pulmonary tuberculosis is a chronic disease commonly caused by either endogenous reactivation of a latent infection or exogenous re-infection by Mycobacterium tuberculosis.
Post-primary pulmonary tuberculosis (also called reactivation tuberculosis) develops in 5%–20% of patients infected with M. tuberculosis.Found mainly in adults, this form of tuberculosis arises from the reactivation of bacilli that lay dormant within a fibrotic area of the lung. In adults, reinfection with a strain of mycobacterium that differs from that which caused the primary infection is also possible. Predisposing factors include immunosuppression, diabetes, malnutrition and alcoholism.
Infliximab is a monoclonal antibody against tumour necrosis factor α (TNF-α). It is FDA approved for many autoimmune conditions, including rheumatoid arthritis and Crohn’s disease. One of the many known side effects of infliximab therapy is reactivation of latent tuberculosis (TB). Because of the resemblances in clinical and radiological features, tubercular lesions in the lung may mimic malignancy. TB accounts for 27% of all infections initially presumed to be lung cancer on imaging studies.
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This question is part of the following fields:
- Respiratory
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Question 5
Incorrect
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A 40-year-old non-smoker is diagnosed as having emphysema. Further tests reveal that he has alpha-1 antitrypsin deficiency. What is the main role of alpha-1 antitrypsin in the body?
Your Answer: 5-alpha-reductase inhibitor
Correct Answer: Protease inhibitor
Explanation:Alpha-1-antitrypsin (AAT) is a member of the serine proteinase inhibitor (serpin) family of proteins with a broad spectrum of biological functions including inhibition of proteases, immune modulatory functions, and the transport of hormones.
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This question is part of the following fields:
- Respiratory
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Question 6
Incorrect
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Which of the following regarding malignant mesothelioma is correct?
Your Answer: is a pulmonary malignancy due to asbestos
Correct Answer: is treated with radiotherapy
Explanation:Malignant mesothelioma is a type of cancer that occurs in the thin layer of tissue that covers the majority of the internal organs (mesothelium).
Malignant Mesothelioma (MM) is a rare but rapidly fatal and aggressive tumour of the pleura and peritoneum. Aetiology of all forms of mesothelioma is strongly associated with industrial pollutants, of which asbestos is the principal carcinogen.Thoracoscopically guided biopsy should be performed if mesothelioma is suggested; the results are diagnostic in 98% of cases. No specific treatment has been found to be of benefit, except radiotherapy, which reduces seeding and invasion through percutaneous biopsy sites.
Median survival for patients with malignant mesothelioma is 11 months. It is almost always fatal.
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This question is part of the following fields:
- Respiratory
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Question 7
Correct
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A 35 year old factory worker presents with a history of episodic dyspnoea. The complaint worsens when he is working. He starts to feel wheezy, with a tendency to cough. Which diagnostic investigation would be the most useful in this case?
Your Answer: Serial peak flow measurements at work and at home
Explanation:Serial Peak Expiratory Flow measurement at work and home is a feasible, sensitive, and specific test for the diagnosis of occupational asthma. For a diagnosis of occupational asthma, it is important to establish a relationship objectively between the workplace exposure and asthma symptoms and signs. Physiologically, this can be achieved by monitoring airflow limitation in relation to occupational exposure(s). If there is an effect of a specific workplace exposure, airflow limitation should be more prominent on work days compared with days away from work (or days away from the causative agent). Airflow limitation can be measured by spirometry, with peak expiratory flow (PEF) and/or forced expiratory volume in 1 s(FEV1) being the most useful for observing changes in airway calibre. Other tests mentioned are less reliable and would not help in establishing a satisfactory diagnosis of occupational asthma.
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This question is part of the following fields:
- Respiratory
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Question 8
Incorrect
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A 20 year old woman presents to the hospital with sharp, left-sided chest pain and shortness of breath. On examination her pulse is 101 beats per minute and blood pressure is 124/61 mmHg. She is seen to be mildly breathless at rest but her oxygen saturation on air was 98%. CXR reveals a left pneumothorax with a 4 cm rim of air visible. Which management strategy is appropriate in this patient?
Your Answer: Admit and repeat chest x ray in 24 hours
Correct Answer: Needle aspiration
Explanation:Pneumothorax is defined as air in the pleural space and may be classified as spontaneous, traumatic or iatrogenic. Primary spontaneous pneumothorax occurs in patients without clinically apparent lung disease.
Primary pneumothorax has an incidence of 18-28 per 100,000 per year for men and 1.2-6 per 100,000 per year for women. Most patients present with ipsilateral pleuritic chest pain and acute shortness of breath. Shortness of breath is largely dependent on the size of the pneumothorax and whether there is underlying chronic lung disease.Young patients may have chest pain only. Most episodes of pneumothorax occur at rest. Symptoms may resolve within 24 hours in patients with primary spontaneous pneumothorax. The diagnosis of a pneumothorax is confirmed by finding a visceral pleural line displaced from the chest wall, without distal lung markings, on a posterior-anterior chest radiograph.
Breathless patients should not be left without intervention regardless of the size of pneumothorax. If there is a rim of air >2cm on the chest X-ray, this should be aspirated.
Aspiration is successful in approximately 70 per cent of patients; the patient may be discharged subsequently. A further attempt at aspiration is recommended if the patient remains symptomatic and a volume of less than 2.5 litres has been aspirated on the first attempt.If unsuccessful, an intercostal drain is inserted. This may be removed after 24 hours after full re-expansion or cessation of air leak without clamping and discharge may be considered.
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This question is part of the following fields:
- Respiratory
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Question 9
Incorrect
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A 23 year old female presents to the hospital with worsening shortness of breath, increased volume of purulent sputum and left-sided chest pain. She has a history of cystic fibrosis. Medical notes state that she is under consideration for the transplant list and for some years has been colonised with pseudomonas. On examination she has a temperature of 38.4°C and FEV1 falling below 75% of the previous value that was recorded. She looks unwell and is tachycardic and hypotensive with a respiratory rate of 21/min. Burkholderia cepacia is confirmed as the pathogen in this case. What would be the most appropriate antibiotic regime?
Your Answer: Colomycin
Correct Answer: Ceftazidime and aminoglycoside
Explanation:Burkholderia cepacia is an aerobic gram-negative bacillus found in various aquatic environments. B cepacia is an organism of low virulence and is a frequent colonizer of fluids used in the hospital (e.g., irrigation solutions, intravenous fluids).
B cepacia, as a non-aeruginosa pseudomonad, is usually resistant to aminoglycosides, antipseudomonal penicillin, and antipseudomonal third-generation cephalosporins and polymyxin B.
B cepacia is often susceptible to trimethoprim plus sulfamethoxazole (TMP-SMX), cefepime, meropenem, minocycline, and tigecycline and has varying susceptibility to fluoroquinolones.
Based on the options available, ceftazidime and aminoglycoside would be the best option. -
This question is part of the following fields:
- Respiratory
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Question 10
Incorrect
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A 14 year old girl with cystic fibrosis (CF) presents with abdominal pain. Which of the following is the pain most likely linked to?
Your Answer: Irritable bowel syndrome
Correct Answer: Meconium ileus equivalent syndrome
Explanation:Meconium ileus equivalent (MIE) can be defined as a clinical manifestation in cystic fibrosis (CF) patients caused by acute intestinal obstruction by putty-like faecal material in the cecum or terminal ileum. A broader definition includes a more chronic condition in CF patients with abdominal pain and a coecal mass which may eventually pass spontaneously. The condition occurs only in CF patients with exocrine pancreatic insufficiency (EPI). It has not been seen in other CF patients nor in non-CF patients with EPI. The frequency of these symptoms has been reported as 2.4%-25%.
The treatment should primarily be non-operative. Specific treatment with N-acetylcysteine, administrated orally and/or as an enema is recommended. Enemas with the water soluble contrast medium, meglucamine diatrizoate (Gastrografin), provide an alternative form for treatment and can also serve diagnostic purposes. It is important that the physician is familiar with this disease entity and the appropriate treatment with the above mentioned drugs. Non-operative treatment is often effective, and dangerous complications following surgery can thus be avoided.
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This question is part of the following fields:
- Respiratory
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Question 11
Incorrect
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A 66 year old man visits the clinic because he has been experiencing increasing breathlessness for the past five months while doing daily tasks. His exercise tolerance is now limited to 75 metres while on a flat surface and walking up the stairs makes him breathless. He sleeps on four pillows and has swollen ankles in the morning. He occasionally coughs up phlegm. Past Medical history of importance: 36 pack year smoking history Hypertension Ischaemic heart disease Coronary artery stenting done 10 months ago Pulmonary function testing revealed: FEV1 0.90 L (1.80 – 3.02 predicted) FVC 1.87 L (2.16 – 3.58 predicted) Diffusion capacity 3.0 mmol/min/kPa (5.91 – 9.65 predicted) Total lung capacity 4.50 L (4.25 – 6.22 predicted) Residual volume 2.70 L (1.46 – 2.48 predicted) Which condition does he have?
Your Answer: Sarcoidosis
Correct Answer: Chronic obstructive pulmonary disease
Explanation:Whilst asthma and COPD are different diseases they cause similar symptoms, which can present a challenge in identifying which of the two diseases a patient is suffering from. COPD causes chronic symptoms and narrowed airways which do not respond to treatment to open them up. In the case of asthma the constriction of the airways through inflammation tends to come and go and treatment to reduce inflammation and to open up the airways usually works well.
COPD is more likely than asthma to cause a chronic cough with phlegm and is rare before the age of 35 whilst asthma is common in under-35s. Disturbed sleep caused by breathlessness and wheeze is more likely in cases of asthma, as is a history of allergies, eczema and hay fever. Differentiating between COPD and asthma requires a history of both symptoms and spirometry. The spirometry history should include post bronchodilator measurements, the degree of reversibility and, ideally, home monitoring which gives a history of diurnal variation.
Airflow Obstruction: Both asthma and COPD are characterised by airflow obstruction. Airflow obstruction is defined as a reduced FEV1 and a reduced FEV1/FVC ratio, such that FEV1 is less than 80% of that predicted, and FEV1/FVC is less than 0.7.
These episodes are usually associated with widespread, but variable, airflow obstruction within the lung that is often reversible either spontaneously or with treatment.
COPD: COPD is a chronic, slowly progressive disorder characterised by airflow obstruction (reduced FEV1 and FEV1/VC ratio) that does not change markedly over several months. The airflow obstruction is not fully reversible.
Spirometry COPD Asthma
VC Reduced Nearly normal
FEV1 Reduced Reduced in attack
FVC (or FEV6) Reduced Nearly normal
FEV1 Ratio
(of VC/FVC/FEV6) Reduced in attackThis man has a low FEV1 and FVC. His diffusions capacity is also low despite having a normal total lung capacity. These values confirm a diagnosis of COPD.
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This question is part of the following fields:
- Respiratory
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Question 12
Incorrect
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A 50 year old woman with a 30 pack year history of smoking presents with a persistent cough and occasional haemoptysis. A chest x-ray which is done shows no abnormality. What percentage of recent chest x-rays were reported as normal in patients who are subsequently diagnosed with lung cancer?
Your Answer: 35%
Correct Answer: 10%
Explanation:A retrospective cohort study of the primary care records of 247 lung cancer patients diagnosed between 1998–2002 showed that 10% of the X-rays were reported as normal.
Other tests may include:
– Imaging tests: A CT scan can reveal small lesions in your lungs that might not be detected on an X-ray.
– Sputum cytology: sputum may reveal the presence of lung cancer cells.
– Tissue sample (biopsy): A sample of abnormal cells may be removed for histological analysis. A biopsy may be performed in a number of ways, including bronchoscopy, mediastinoscopy and needle biopsy. A biopsy sample may also be taken from adjacent lymph nodes. -
This question is part of the following fields:
- Respiratory
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Question 13
Correct
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An elderly woman is referred with worsening chronic pulmonary disease (COPD). She smokes seven cigarettes per day. Her exercise tolerance is only a few yards around the house now. Her FEV1 is 37% of predicted. What is the most appropriate intervention for this patient?
Your Answer: Give regular high-dose inhaled fluticasone and inhaled long-acting β-agonist
Explanation:The Stages of COPD:
Mild COPD or Stage 1—Mild COPD with a FEV1 about 80 percent or more of normal.
Moderate COPD or Stage 2—Moderate COPD with a FEV1 between 50 and 80 percent of normal.
Severe COPD or Stage 3—Severe emphysema with a FEV1 between 30 and 50 percent of normal.
Very Severe COPD or Stage 4—Very severe or End-Stage COPD with a lower FEV1 than Stage 3, or people with low blood oxygen levels and a Stage 3 FEV1.This patient has a FEV1 percent of 37 which falls within the stage 3 or severe COPD.
During stage 3 COPD, you will likely experience significant lung function impairment. Many patients will experience an increase in COPD flare-ups or exacerbations. For some people, the increase in flare-ups means they could need to be hospitalized at times as well.Inhaled corticosteroid (ICS) use in combination with long-acting β2-agonists (LABAs) was shown to provide improved reductions in exacerbations, lung function, and health status. ICS-LABA combination therapy is currently recommended for patients with a history of exacerbations despite treatment with long-acting bronchodilators alone. The presence of eosinophilic bronchial inflammation, detected by high blood eosinophil levels or a history of asthma or asthma–COPD overlap, may define a population of patients in whom ICSs may be of particular benefit.
The Towards a Revolution in COPD Health (TORCH) trial was a pivotal, double-blind, placebo-controlled, randomized study comparing salmeterol plus fluticasone propionate (50 and 500 µg, respectively, taken twice daily) with each component alone and placebo over 3 years.26 Patients with COPD were enrolled if they had at least a 10-pack-year smoking history, FEV1 <60% predicted, and an FEV1:FVC ratio ≤0.70.26 Among 6,184 randomized patients, the risk of death was reduced by 17.5% with the ICS-LABA combination vs placebo (P=0.052). ICS-LABA significantly reduced the rate of exacerbations by 25% compared with placebo (P<0.001) and improved health status and FEV1 compared with either component alone or placebo.
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This question is part of the following fields:
- Respiratory
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Question 14
Incorrect
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A 73 year old woman presents with severe emphysema. She is on maximal therapy including high dose Seretide and tiotropium. She tells you that she is so unwell that she can barely manage the walk the 160 metres to the bus stop. On examination she looks short of breath at rest. Her BP is 158/74 mmHg, pulse is 76 and regular. There are quiet breath sounds, occasional coarse crackles and wheeze on auscultation of the chest. Investigations show: Haemoglobin 14.2 g/dl (13.5-17.7) White cell count 8.4 x 109/l (4-11) Platelets 300 x 109/l (150-400) Sodium 137 mmol/l (135-146) Potassium 4.1 mmol/l (3.5-5) Creatinine 127 micromole/l (79-118) pH 7.4 (7.35-7.45) pCO2 7.5 kPa (4.8-6.1) pO2 9.7 kPa (10-13.3) Chest x-ray – Predominant upper lobe emphysema. FEV1 – 30% of predicted. Which of the features of her history, examination or investigations would preclude referral for lung reduction surgery?
Your Answer: Severe limitation of exercise capacity
Correct Answer: pCO2 7.4
Explanation:Nice guidelines for lung reduction surgery:
FEV1 > 20% predicted
PaCO2 < 7.3 kPa
TLco > 20% predicted
Upper lobe predominant emphysemaThis patient has pCO2 of 7.4 so she is unsuitable for referral for lung reduction surgery.
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This question is part of the following fields:
- Respiratory
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Question 15
Incorrect
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A 78 year old male presents to the emergency department with shortness of breath that has developed gradually over the last 4 days. His symptoms include fever and cough productive of greenish sputum. Past history is notable for COPD for which he was once admitted to the ICU, 2 years back. He now takes nebulizers (ipratropium bromide) at home. The patient previously suffered from myocardial infarction 7 years ago. He also has Diabetes Mellitus type II controlled by lifestyle modification. On examination, the following vitals are obtained. BP : 159/92 mmHg Pulse: 91/min (regular) Temp: Febrile On auscultation, there are scattered ronchi bilaterally and right sided basal crackles. Cardiovascular and abdominal examinations are unremarkable. Lab findings are given below: pH 7.31 pa(O2) 7.6 kPa pa(CO2) 6.3 kPa Bicarbonate 30 mmol/L, Sodium 136 mmol/L, Potassium 3.7 mmol/L, Urea 7.0 mmol/L, Creatinine 111 μmol/L, Haemoglobin 11.3 g/dL, Platelets 233 x 109 /l Mean cell volume (MCV) 83 fl White blood cells (WBC) 15.2 x 109 /l. CXR shows an opacity obscuring the right heart border. Which of the following interventions should be started immediately while managing this patient?
Your Answer: Intravenous hydrocortisone
Correct Answer: Salbutamol and ipratropium bromide nebulisers
Explanation:Acute exacerbations of chronic obstructive pulmonary disease (COPD) are immediately treated with inhaled beta2 agonists and inhaled anticholinergics, followed by antibiotics (if indicated) and systemic corticosteroids. Methylxanthine therapy may be considered in patients who do not respond to other bronchodilators.
High flow oxygen would worsen his symptoms. Usually titrated oxygen (88 to 92 %) is given in such patients to avoid the risk of hyperoxic hypercarbia in which increasing oxygen saturation in a chronic carbon dioxide retainer can inadvertently lead to respiratory acidosis and death. -
This question is part of the following fields:
- Respiratory
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Question 16
Correct
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A 65 year old retired postman has been complaining of a two-month history of lethargy associated with dyspnoea. He has never smoked and takes no medication. The chest X-ray shows multiple round lesions increasing in size and numbers at the base. There is no hilar lymphadenopathy. What condition does he most likely have?
Your Answer: Pulmonary metastases
Explanation:Pulmonary metastasis is seen in 20-54% of extrathoracic malignancies. The lungs are the second most frequent site of metastases from extrathoracic malignancies. Twenty percent of metastatic disease is isolated to the lungs. The development of pulmonary metastases in patients with known malignancies indicates disseminated disease and places the patient in stage IV in TNM (tumour, node, metastasis) staging systems.
Chest radiography (CXR) is the initial imaging modality used in the detection of suspected pulmonary metastasis in patients with known malignancies. Chest CT scanning without contrast is more sensitive than CXR.
Breast, colorectal, lung, kidney, head and neck, and uterus cancers are the most common primary tumours with lung metastasis at autopsy. Choriocarcinoma, osteosarcoma, testicular tumours, malignant melanoma, Ewing sarcoma, and thyroid cancer frequently metastasize to lung, but the frequency of these tumours is low. -
This question is part of the following fields:
- Respiratory
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Question 17
Incorrect
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Which treatment of chronic obstructive pulmonary disease (COPD) increases the long-term prognosis in patients?
Your Answer: Inhaled β2-agonists
Correct Answer: Long-term domiciliary oxygen therapy
Explanation:COPD is commonly associated with progressive hypoxemia. Oxygen administration reduces mortality rates in patients with advanced COPD because of the favourable effects on pulmonary hemodynamics.
Long-term oxygen therapy improves survival 2-fold or more in hypoxemic patients with COPD, according to 2 landmark trials, the British Medical Research Council (MRC) study and the US National Heart, Lung and Blood Institute’s Nocturnal Oxygen Therapy Trial (NOTT). Hypoxemia is defined as PaO2 (partial pressure of oxygen in arterial blood) of less than 55 mm Hg or oxygen saturation of less than 90%. Oxygen was used for 15-19 hours per day.
Therefore, specialists recommend long-term oxygen therapy for patients with a PaO2 of less than 55 mm Hg, a PaO2 of less than 59 mm Hg with evidence of polycythaemia, or cor pulmonale. Patients should be evaluated after 1-3 months after initiating therapy, because some patients may not require long-term oxygen.
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This question is part of the following fields:
- Respiratory
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Question 18
Incorrect
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Briefly state the mechanism of action of salbutamol.
Your Answer: Beta2 receptor agonist which decreases cAMP levels and leads to muscle relaxation and bronchodilation
Correct Answer: Beta2 receptor agonist which increases cAMP levels and leads to muscle relaxation and bronchodilation
Explanation:Salbutamol stimulates beta-2 adrenergic receptors, which are the predominant receptors in bronchial smooth muscle (beta-2 receptors are also present in the heart in a concentration between 10% and 50%).
Stimulation of beta-2 receptors leads to the activation of enzyme adenyl cyclase that forms cyclic AMP (adenosine-mono-phosphate) from ATP (adenosine-tri-phosphate). This increase of cyclic AMP relaxes bronchial smooth muscle and decrease airway resistance by lowering intracellular ionic calcium concentrations. Salbutamol relaxes the smooth muscles of airways, from trachea to terminal bronchioles.
Increased cyclic AMP concentrations also inhibits the release of bronchoconstrictor mediators such as histamine and leukotriene from the mast cells in the airway.
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This question is part of the following fields:
- Respiratory
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Question 19
Incorrect
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Which of the following is not a known cause of occupational asthma?
Your Answer: Platinum salts
Correct Answer: Cadmium
Explanation:Occupational asthma (OA) could be divided into a nonimmunological, irritant-induced asthma and an immunological, allergy-induced asthma. In addition, allergy-induced asthma can be caused by two different groups of agents: high molecular weight proteins (>5,000 Da) or low molecular weight agents (<5,000 Da), generally chemicals like the isocyanates.
Isocyanates are very reactive chemicals characterized by one or more isocyanate groups (–N=C=O). The main reactions of this chemical group are addition reactions with ethanol, resulting in urethanes, with amines (resulting in urea derivates) and with water. Here, the product is carbamic acid which is not stable and reacts further to amines, releasing free carbon dioxide.Diisocyanates and polyisocyanates are, together with the largely nontoxic polyol group, the basic building blocks of the polyurethane (PU) chemical industry, where they are used solely or in combination with solvents or additives in the production of adhesives, foams, elastomers, paintings, coatings and other materials.
The complex salts of platinum are one of the most potent respiratory sensitising agents having caused occupational asthma in more than 50% of exposed workers. Substitution of ammonium hexachlor platinate with platinum tetra amine dichloride in the manufacture of catalyst has controlled the problem in the catalyst industry. Ammonium hexachlorplatinate exposure still occurs in the refining process.
Rosin based solder flux fume is produced when soldering. This fume is a top cause of occupational asthma.
Bakeries, flour mills and kitchens where flour dust and additives in the flour are a common cause of occupational asthma.
Cadmium was not found to cause occupational asthma.
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This question is part of the following fields:
- Respiratory
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Question 20
Correct
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How should DVT during pregnancy be managed?
Your Answer: Dalteparin
Explanation:Subcutaneous low molecular weight heparin (LMWH) is the preferred treatment for most patients with acute DVT, including in pregnancy. A large meta-analyses comparing LMWH to unfractionated heparin (UFH) showed that LMWH decreased the risk of mortality, recurrent veno-thrombo embolism (VTE), and haemorrhage compared with heparin. Other advantages of LMWH may include more predictable therapeutic response, ease of administration and monitoring, and less heparin-induced thrombocytopenia. Disadvantages of LMWH include cost and longer half-life compared with heparin.
Warfarin, which is administered orally, is used if long-term anticoagulation is needed. The international normalized ratio (INR) is followed, with a target range of 2-3. Warfarin crosses the placenta and is teratogenic, causing a constellation of anomalies known as warfarin embryopathy, with greatest risk between the sixth and twelfth week of gestation.
Other options are not indicated for use. -
This question is part of the following fields:
- Respiratory
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