This practice set contains high-yield board review questions covering key concepts in Infection, Pharmacology & VTE. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 141
Topic: Infection, Pharmacology & VTE
A 70-year-old woman undergoes a total hip arthroplasty. Four days postoperatively, she experiences sudden onset pleuritic chest pain and dyspnea. An ECG shows sinus tachycardia and an S1Q3T3 pattern. What is the most appropriate initial diagnostic imaging test for the suspected condition?
Correct Answer & Explanation
. CT pulmonary angiography
Explanation
The clinical presentation strongly suggests a pulmonary embolism. CT pulmonary angiography is the gold standard and most appropriate initial imaging test to diagnose a PE in this setting.
Question 142
Topic: Infection, Pharmacology & VTE
A 36-year-old woman with systemic sclerosis develops breathlessness on exertion. Her pulmonary function tests show normal spirometry but a decreased gas transfer factor (Tlco, transfer factor for carbon monoxide) and transfer coefficient (Kco). Which of the following is the most likely explanation for this abnormality?
Correct Answer & Explanation
. Pulmonary vascular disease
Explanation
Correct Answer: C- Pulmonary vascular disease Explanation Pulmonary vascular disease Isolated decreases in gas transfer are typical of pulmonary vascular diseases such as vasculitis and recurrent pulmonary embolism. Interstitial lung disease Interstitial lung disease is incorrect. In interstitial lung disease you would also expect to see decreased lung volumes with a restrictive ratio (> 80%) on spirometry. Pleural involvement Pleural involvement is incorrect. In pleural involvement these investigations would give a picture of extrapulmonary restriction, with a restrictive ratio, lowTlco but normal/high Kco (ie the same cardiac output is going through a smaller alveolar volume). Respiratory muscle weakness Respiratory muscle weakness is incorrect. In respiratory muscle weakness, these investigations would give a picture of extrapulmonary restriction, with a restrictive ratio, low Tlco but normal/high Kco (ie the same cardiac output is going through a smaller alveolar volume). Severe thoracic skin thickening Severe thoracic skin thickening is incorrect. In severe thoracic skin thickening these investigations would give a picture of extrapulmonary restriction, with a restrictive ratio, low Tlco but normal/high Kco (ie the same cardiac output is going through a smaller alveolar volume).
Question 143
Topic: Infection, Pharmacology & VTE
You are trying to introduce D-dimer testing into your Emergency Department to reduce the number of patients who are admitted for suspected pulmonary embolus who are heparinized unnecessarily. Which of the following is true regarding the use of D-dimer measurement in the diagnosis of pulmonary embolus (PE)?
Correct Answer & Explanation
. It is not useful for confirming PE when the clinical probability is high
Explanation
Correct Answer: E - It is not useful for confirming PE when the clinical probability is high. D-dimer measurements should not be performed if: 1. An alternative diagnosis is likely, 2. The clinical probability is high, 3. There is a probable massive PE. The D-dimer test misses 10% of patients with pulmonary embolism, while only 30% of patients with positive D-dimer findings have a confirmatory diagnosis of pulmonary embolism (i.e., the negative predictive value is greater than the positive predictive value). D-dimer measurement should not be used as a screening test for PE because D-dimers can be positive in hospitalized patients, obstetric patients, patients with peripheral vascular disease, cancer, inflammatory conditions, and with increasing age.
Question 144
Topic: Infection, Pharmacology & VTE
A 58-year-old woman has been admitted with pulmonary embolism. After 7 days she develops an arterial thrombosis in her left leg. The platelet count is 40 × 10^9/l. Which drug is most likely to be responsible?
Correct Answer & Explanation
. Intravenous heparin for acute treatment
Explanation
Intravenous heparin for acute treatment. Heparin-induced thrombocytopenia (HIT) is caused by IgG antibodies that recognize multimolecular complexes of platelet factor 4 and heparin. Typically, the fall in platelet count begins 5–10 days after starting heparin. Most patients with HIT develop venous or arterial thrombosis. The thrombocytopenia is typically moderate in severity.
Question 145
Topic: Infection, Pharmacology & VTE
A 64-year-old mechanic and lifelong smoker noticed haemoptysis a few days after he had a cold. Clinical examination is unremarkable. His chest X-ray shows bilateral hilar enlargement and mediastinal widening. What is the next step in obtaining a diagnosis?
Correct Answer & Explanation
. Computed tomography of the thorax
Explanation
Correct Answer: B- Computed tomography of the thorax Explanation Computed tomography of the thorax Where a chest X-ray has been requested in primary or secondary care and is incidentally suggestive of lung cancer, a second copy of the radiologist's report should be sent to a designated member of the lung cancer multidisciplinary team (MDT), usually the chestphysician. The MDT should have a mechanism in place to follow up these reports to enable the patient’s GP to have a management plan in place. Patients with known or suspected lung cancer should be offered a contrast-enhanced chest computed tomographic (CT) scan to further define the diagnosis and stage the disease. The scan should also include the liver and adrenals. Bronchoscopy Bronchoscopy is incorrect. Chest CT should be performed before an intended fibre-optic bronchoscopy or any other biopsy procedure. d-Dimer d- Dimer is incorrect. d-Dimer is an appropriateinvestigation for pulmonary embolus. The history here is suggestive of lung carcinoma. Sputum sample Sputum sample is incorrect. Sputum sampling would not reveal the correct diagnosis here. This is not a history suggestive of respiratory infection. Ventilation/perfusion scan Ventilation/perfusion scan is incorrect. Ventilation/perfusion scans are used to investigate for pulmonary emboli in patients who cannot have CT pulmonary angiograms, eg owing to contrast allergy or severe renal impairment. This is not a history suggestive of pulmonary embolism.
Question 146
Topic: Infection, Pharmacology & VTE
A 56-year-old woman with rheumatoid arthritis complains that she has had recurrent haemoptysis for over 5 years. She has never smoked and her only medication is a non-steroidal anti-inflammatory agent. She tells you that she coughs up phlegm every day and at times this contains streaks of fresh blood. She has no known respiratory disease, but tends to get frequent chest infections that are relieved by a course of antibiotics. What is the most likely diagnosis?
Correct Answer & Explanation
. Bronchiectasis
Explanation
Correct Answer: B- Bronchiectasis Explanation Bronchiectasis Some 3–4% of patients with rheumatoid arthritis develop bronchiectasis. This is characterised by recurrent haemoptysis. The history of expectorating phlegm on most days and frequent chest infections is suggestive of the diagnosis. A high-resolution computed tomography scan of her lungs will establish the diagnosis. Atypical pneumonia Atypical pneumonia is incorrect. This lady may indeed acquire infections with atypical organisms but the history suggests there is an underlying chronic respiratory disorder leaving her vulnerable to recurrent chest infections. Therefore, bronchiectasis is the most appropriate answer. Lung cancer Lung cancer is incorrect. Her lack of smoking history coupled with a history of rheumatoid arthritis and long (5-year) history of chronic productive cough with recurrent respiratory infections is more in keeping with bronchiectasis than malignancy. Pulmonary embolism Pulmonary embolism is incorrect. Although pulmonary emboli can be associated with haemoptysis, there are features in this history such as duration of symptoms, presence of daily sputum production and history of recurrent chest infections which make pulmonary embolism an unlikely cause of her haemoptysis. Tuberculosis Tuberculosis is incorrect. Tuberculosis can cause productive cough and haemoptysis. However, the duration of symptoms is too long to consider tuberculosis as a likely diagnosis. In addition, Mycobacterium tuberculosis would not respond to typical antibiotics used for respiratory tract infections.
Question 147
Topic: Infection, Pharmacology & VTE
A 26-year-old woman arrives in the Arabic Gulf area from Australia. A few days later she presents to hospital with pleuritic chest pain and breathlessness. She is not on the oral contraceptive pill and has no family or personal history of deep vein thrombosis (DVT) or pulmonary embolism (PE). A pulmonary embolus is confirmed radiologically and she is started on warfarin. How long would you continue warfarin therapy in these circumstances?
Correct Answer & Explanation
. 3 months
Explanation
Correct Answer: B-3 months Explanation 3 months This young woman’s only risk factor is the long-haul flight, which is only a temporary risk factor. That being said, this would be considered a provoked PE, as such 3 months’ anti-coagulation is sufficient. 4–6 weeks 4–6 weeks is incorrect. Previous guidelines suggested that a duration of 4–6 weeks’ anticoagulation is adequate when a DVT has occurred post surgery. However, 2012 guidelines suggest a minimum of 3 months’ anticoagulation for all provoked DVTs. 6 months 6 months is incorrect. Patients with unprovoked PE should be treated initially for 3 months, with review at the 3 month stage for consideration of extension to 6 months, where there is thought to be increased risk of a recurrence. 6 months of anticoagulation is recommended for DVT or PE in the presence of active malignancy. The decision to stop or continue anticoagulation after 6 months in such patients should be made on an individual basis. 1 year 1 year is incorrect. Patients with unprovoked PE should be treated initially for 3 months, with review at the 3 month stage for consideration of extension to 6 months, where there is thought to be increased risk of a recurrence. 6 months of anticoagulation is recommended for DVT or PE in the presence of active malignancy. The decision to stop or continue anticoagulation after 6 months in such patients should be made on an individual basis. Lifelong Lifelong is incorrect. Lifelong anticoagulation is generally only recommended for a history or recurrent DVT/PE.
Question 148
Topic: Infection, Pharmacology & VTE
A 50-year-old man has been referred by his GP because of a long-standing history of persistent cough productive of mucopurulent sputum. The patient was treated several times for recurrent chest infections. What is the most appropriate diagnostic step to confirm the diagnosis?
Correct Answer & Explanation
. High-resolution computed tomography
Explanation
Correct Answer: C- High-resolution computed tomography Explanation High-resolution computed tomography The gold standard for the diagnosis of bronchiectasis is thin-section high-resolution computed tomography (HRCT) of the chest, which has replaced the more invasive investigation of bronchography. The diagnostic criteria for bronchiectasis on HRCT depend on finding both dilatation and thickening of the affected bronchi, dilatation being present if the internal diameter of the bronchus is greater than the diameter of its accompanying pulmonary artery. The classic appearance of a cross-section of a thick-walled dilated bronchus next to the accompanying pulmonary artery is the ‘signet ring’ sign. Bronchial dilatation is also recognised when airways are seen in longitudinal section on CT and there is a failure of tapering as the bronchus courses towards the periphery. Bronchoscopy Bronchoscopy is incorrect. Bronchoscopy in bronchiectasis may demonstrate larger than expected bronchi with visible mucopurulent secretions, but it will not detect bronchiectasis affecting distal airways. Given the test is invasive and not always diagnostic, it is not routinely used in diagnosing bronchiectasis. Bronchoscopy is indicated in cases of localised bronchiectasis to rule out a foreign body or obstructing lesion, eg carcinoma. Chest X-ray Chest X-ray is incorrect. The chest radiograph can be normal in at least 50% of patients with computed tomographic or bronchographic evidence of bronchiectasis. If it is abnormal the findings reflect thickened and dilated bronchi, which produce tramline opacities and ring shadows. Retained mucus might be seen as tubular opacities, and there can be associated volume loss of the affected lobe. Spirometry Spirometry is incorrect. Spirometry is normal or obstructive in bronchiectasis, depending on the severity, but spirometry alone is not a sufficient diagnostic test for bronchiectasis. Ventilation/perfusion scan Ventilation/perfusion scan is incorrect. Ventilation/perfusion scans are used in the diagnosis of pulmonary embolism. They are not used to investigate for bronchiectasis.
Question 149
Topic: Infection, Pharmacology & VTE
A 74-year-old man with previously stable emphysema presents to the emergency department with right-sided pleuritic chest pain and sudden increase in shortness of breath. There are no other associated symptoms and no signs to suggest acute infection. There appears to be decreased vocal resonance over the upper right side of the chest. Which is the most likely diagnosis in this case?
Correct Answer & Explanation
. A spontaneous pneumothorax
Explanation
Correct Answer: C - A spontaneous pneumothorax. Explanation: Underlying COPD is the usual cause of pneumothorax in patients of this age group. The sudden onset of shortness of breath associated with pleuritic chest pain and the absence of infective symptoms make pneumothorax more likely than COPD exacerbation or pneumonia. Decreased vocal resonance is a classic sign of pneumothorax.
Question 150
Topic: Infection, Pharmacology & VTE
A 40-year-old African American female presents with sausage-like swelling of her digits (dactylitis). Hand radiographs demonstrate multiple well-defined, cyst-like radiolucencies in the phalanges with a lace-like trabecular pattern. Chest X-ray shows bilateral hilar lymphadenopathy. What is the most likely diagnosis?
Correct Answer & Explanation
. Sarcoidosis
Explanation
Sarcoidosis can cause osseous involvement in 5-10% of patients, classically presenting as cyst-like lesions in the phalanges and dactylitis. This correlates strongly with the bilateral hilar lymphadenopathy seen on chest radiography.
Question 151
Topic: Infection, Pharmacology & VTE
A 64-year-old woman is referred to the medical team from the orthopaedic ward. She underwent a right total hip replacement 6 days ago. She is known to suffer from mild chronic obstructive pulmonary disease and is on regular inhaled steroids and a short-acting β2-agonist. She now complains of left-sided chest pain and is also dyspnoeic. Your clinical diagnosis is pulmonary embolism. Which one of the following would not be a feature of pulmonary embolism in this patient?
Correct Answer & Explanation
. Bradycardia
Explanation
Bradycardia is not a feature of pulmonary embolism. The clinical features of pulmonary embolism include dyspnoea, tachypnoea (respiratory rate > 20/min), tachycardia, atrial flutter/fibrillation, and fever.
Question 152
Topic: Infection, Pharmacology & VTE
You are called to see a 50-year-old woman who is having difficulty breathing after undergoing a laparoscopic cholecystectomy. She is making a lot of noisy inspiratory effort with stridor. You notice that she is on long-term warfarin for thromboembolic disease, salbutamol and inhaled steroids for asthma and penicillamine for severe rheumatoid arthritis. Which of the following tests would be the most helpful in diagnosing her current problem?
Correct Answer & Explanation
. Spirometry with flow–volume loop
Explanation
Correct Answer: D- Spirometry with flow–volume loop Explanation Spirometry with flow–volume loop This woman has stridor due to cricoarytenoid arthritis. This is seen in studies in up to 75% of patients with rheumatoid arthritis. It can cause sore throat, hoarse voice and stridor, but is often asymptomatic. However, symptoms can rapidly worsen in the post-operative period. It is unrelated to any lung fibrosis. The flow– volume loop can be abnormal, as can direct laryngoscopy and high- resolution computed tomography of the larynx. Patients can need urgent tracheostomy and steroids, both orally and via joint injection. Chest X-ray Chest X-ray is incorrect. Chest X-ray may well be normal and therefore unhelpful here. Computed tomography scan of the chest Computed tomography (CT) scan of the chest is incorrect. CT chest would not show the cricoarytenoid arthritis. CT imaging of the larynx would be required. Peak flow Peak flow is incorrect. Peak flow measurement is useful in assessing the severity of an exacerbation of asthma.The presence of stridor makes an acute exacerbation of this lady’s asthma unlikely. Spirometry with transfer factor measurement Spirometry with transfer factor measurement is incorrect. This lady has stridor due to cricoarytenoid arthritis; this will not affect her transfer factor. The most appropriate and helpful combination of pulmonary function tests is spirometry with flow–volume loop.
Question 153
Topic: Infection, Pharmacology & VTE
A 48-year-old woman is admitted with a 2-day history of fever with rigors and breathlessness. On examination, she looks extremely unwell and is confused and cyanosed. She has a respiratory rate of 36/min and a systolic blood pressure of 86 mmHg. There is dullness on percussion and bronchial breathing at her right base. The chest X-ray reveals consolidation. Which of the following would be the most appropriate antibiotic regimen to use?
Correct Answer & Explanation
. Intravenous co-amoxiclav and intravenous clarithromycin
Explanation
This woman has severe pneumonia as defined by the British Thoracic Society (BTS) guidelines, which requires the presence of any two of the following features: Confusion, Urea > 7 mmol/l, Respiratory rate > 30/min, Hypotension (systolic BP < 90 mmHg, diastolic BP < 60 mmHg). Appropriate treatment (as recommended by BTS) is with intravenous antimicrobials: Co-amoxiclav 1.2 g three times daily or cefuroxime 1.5 g three times daily or cefotaxime 1 g three times daily or ceftriaxone 2 g once daily together with: Erythromycin 500 mg four times daily or clarithromycin 500 mg twice daily.
Question 154
Topic: Infection, Pharmacology & VTE
A 70-year-old woman with a history of rheumatoid arthritis comes to the clinic for review. Recently she has been suffering from increased shortness of breath. She takes diclofenac and methotrexate for her arthritis. Other history of note includes smoking of ten cigarettes per day. On examination, her blood pressure is 145/82 mmHg and she is mildly clubbed. On auscultation there are inspiratory crackles throughout both lung fields.
FVC 81% Gas transfer coefficient (Kco) Reduced pO2 7.8 kPa
pCO2 3.5 kPa What is the most likely diagnosis?
Correct Answer & Explanation
. Methotrexate pneumonitis
Explanation
Correct Answer: C- Methotrexate pneumonitis Explanation Methotrexate pneumonitis The lung function picture, coupled with bibasal crackles and the patient taking a medication known to be capable of causing pneumonitis is consistent with methotrexate pneumonitis. Management includes cessation of methotrexate, cessation of smoking and supplemental oxygen therapy. Corticosteroids may also be of value. Other drugs which can lead to pulmonary fibrosis include bleomycin, busulfan, amiodarone, gold, penicillamine, crack cocaine and heroin. Asthma Asthma is incorrect. Asthma would be associated with bilateral wheeze rather than crackles and obstructive spirometry with a likely normal Kco. Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease is incorrect.Although this woman smokes, the forced expiratory volume in 1 s (FEV1) is not disproportionately reduced, so fibrosis rather than obstruction is the more likely cause. Pulmonary embolus Pulmonary embolus is incorrect. This is not a presentation of pulmonary embolus, where one might suspect a clear chest to auscultation, pleurituc chest pain +/- evidence of deep vein thrombosis (DVT). The presence of crackles along with the pulmonary functiontest results and the medication history make methotrexate pneumonitis the most likely option. Pulmonary haemorrhage Pulmonary haemorrhage is incorrect. The reduced gas transfer coefficient (Kco) and anti-glomerular basement membrane (anti-GBM) antibody negativity make pulmonary haemorrhage less likely.
Question 155
Topic: Infection, Pharmacology & VTE
A 68-year-old female undergoes a right total knee arthroplasty. On postoperative day 4, she experiences sudden-onset pleuritic chest pain and dyspnea. Her ECG shows sinus tachycardia with an S1Q3T3 pattern. CT pulmonary angiography confirms a pulmonary embolism. Which of the following is the most appropriate initial treatment?
Correct Answer & Explanation
. Intravenous unfractionated heparin
Explanation
In the acute postoperative period following major orthopedic surgery, a hemodynamically stable patient with a PE should be started on unfractionated heparin. This allows for rapid reversal if surgical site bleeding occurs, compared to DOACs or LMWH.
Question 156
Topic: Infection, Pharmacology & VTE
A 35-year-old farmer sustains a Gustilo-Anderson Type IIIA open tibia fracture heavily contaminated with soil. He has no known drug allergies. According to current evidence-based guidelines, which of the following is the most appropriate initial antibiotic regimen?
Correct Answer & Explanation
. Intravenous cefazolin and high-dose penicillin
Explanation
For heavily contaminated agricultural wounds (high risk for Clostridium species), the addition of penicillin to a first-generation cephalosporin (or aminoglycoside combination) is recommended. This high-dose penicillin specifically helps prevent severe gas gangrene infections.
Question 157
Topic: Infection, Pharmacology & VTE
A 72-year-old male with a history of recurrent deep vein thrombosis and a known Factor V Leiden mutation is scheduled for an elective total hip arthroplasty. According to AAOS guidelines, which of the following is the most appropriate chemoprophylaxis strategy for this high-risk patient?
Correct Answer & Explanation
. Low molecular weight heparin for up to 35 days
Explanation
In patients at high risk for venous thromboembolism (VTE), such as those with known hypercoagulable states or prior DVT, aggressive pharmacologic prophylaxis like LMWH for up to 35 days postoperatively is recommended. Aspirin alone is insufficient for high-risk profiles.
Question 158
Topic: Infection, Pharmacology & VTE
A 20-year-old woman complains of a sudden onset of dyspnoea associated with pleuritic chest pain. She takes the oral contraceptive pill, and has a BMI of 31. Her O2 saturation is 92% on air. Chest X- ray is reported as normal, pregnancy test is negative. Which of the following methods of assessment is the most appropriate to confirm your diagnosis of pulmonary embolism?
Correct Answer & Explanation
. CTPA
Explanation
Correct Answer: A- CTPA Explanation CTPA CT pulmonary angiogram (CTPA), widely available in most Emergency units, is now seen as the diagnostic test of choice for for pulmonary embolus. d-Dimer d- Dimer is incorrect. A negative d-dimer test is useful for excluding pulmonary embolism (PE) in patients who are clinically thought to be at low risk, but a ‘positive’ result does not establish the diagnosis. We do not have full clinical information here to calculate this lady’s Well’s score, but it is likely she would be classed as high risk and therefore d-dimer testing would be inappropriate. Echocardiography Echocardiography is incorrect. Echocardiography might show right ventricular dilatation and evidence of pulmonary hypertension, which, in the proper clinical setting, might strengthen the clinical impression that a PE has occurred; however, a CTPA is the most likely test to give a definitive diagnosis here. Right heart catheterisation Right heart catheterisation is incorrect. Right heart catheterisation is not available in all hospitals and is an invasive investigation that should not be used to diagnose PE. If PE is present, this test will show elevated right heart pressures and pulmonary hypertension. In a small number of patients with massive PE, right heart catheterisation may be used to perform percutaneous thrombectomy to administer local thrombolysis to the site of the PE if there are contraindications to systemic thrombolysis. Ventilation perfusion scan Ventilation perfusion scan is incorrect. Ventilation/perfusion scans have been superceded by CTPA in the diagnostic work up of PE. Their use should now be restricted to individuals with contrast allergy or where the risk from radiation from CTPA is high.
Question 159
Topic: Infection, Pharmacology & VTE
You are asked to see a 57-year-old smoker, who complains of shortness of breath some 7 days after a total hip replacement. On examination, he is obese and has a swollen left leg. He is also visibly short of breath. There appears to be increased prominence of vascular markings at the right hilum on the chest X-ray. His calculated alveolar–arterial (A–a) gradient is 34 mmHg (10-24 normal range). Which of the following fits best with his diagnosis?
Correct Answer & Explanation
. Pulmonary embolus
Explanation
The alveolar–arterial (A–a) gradient is affected primarily by ventilation/perfusion (V/Q) mismatch and shunting. Pulmonary embolus is the most likely diagnosis given the clinical presentation of a swollen leg (DVT) and shortness of breath post-surgery.
Question 160
Topic: Infection, Pharmacology & VTE
A 70-year-old female is recovering from a total knee arthroplasty. On post-operative day 5, she develops a confirmed deep vein thrombosis and her platelet count drops from 250,000 to 90,000. She is currently on subcutaneous unfractionated heparin. What is the most appropriate immediate pharmacological management?
Correct Answer & Explanation
. Stop heparin and start a direct thrombin inhibitor like argatroban
Explanation
The patient has developed heparin-induced thrombocytopenia (HIT). All heparin products (including LMWH) must be stopped immediately, and anticoagulation should be continued with a non-heparin agent such as a direct thrombin inhibitor (e.g., argatroban) or fondaparinux.
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