Question 1

A 29-year-old intravenous heroin abuser is admitted to the Emergency Department with a severe cough, fever and rigors. He says that he has suffered progressively increasing shortness of breath on exertion over the past few days. On examination he has a pyrexia of 37.9 °C, his blood pressure is 122/75 mmHg and his body mass index (BMI) is 17 kg/m2. You hear mild crackles and wheeze on auscultation of his chest.

Investigation:

Hb 10.9 g/dl

WCC 6.1 x 109/l

PLT 245 x 109/l

Sodium 141 mmol/l

Potassium 4.0 mmol/l

Creatinine 90 µmol/l Lactate dehydrogenase (LDH) 420 U/l (normal range 70- 250 U/l) Oxygen saturations 92% on air, 89% after a walk test The chest X-ray shows diffuse bilateral infiltrates. Which of the following is the most likely diagnosis?

Explanation

Correct Answer: C- Pneumocystis jirovecii pneumonia Explanation Pneumocystis jirovecii pneumonia The clinical picture seen here, with relatively little to find on auscultation, but with chest X-ray changes and desaturation on exercise, is very typical of Pneumocystis jirovecii infection. This can be diagnosed on the basis of a sputum sample, although bronchoalveolar lavage (BAL) might be required to obtain a suitable sample (the yield for BAL samples is over 90%). Co-trimoxazole or pentamidine are both effective treatments for the condition. Given the possible diagnosis, he should be screened for HIV. Endocarditis Endocarditis is incorrect. Intravenous drug users are at risk of right-sided endocarditis. However, the history given here is more in keeping with a primary respiratory infection. Klebsiella pneumoniae pneumonia Klebsiella pneumoniae pneumonia is incorrect. Intravenous drug users are at risk of Klebsiella and Staphylococcus aureus pneumonia. However, these typically cause a cavitating pneumonia and one would expect to find more on clinical examination given the degree of hypoxia. Staphylococcus aureus pneumonia Staphylococcus aureus pneumonia is incorrect. Intravenous drug users are at risk of Klebsiella and S. aureus pneumonia. However, these typically cause a cavitating pneumonia and one would expect to find more on clinical examination given the degree of hypoxia. Tuberculosis Tuberculosis is incorrect. Intravenous drug users are at risk of tuberculosis but the history would normally be longer than a few days, as is mentioned here. The relatively normal auscultation findings and desaturation on exercise are more in keeping with Pneumocystis pneumonia.

Question 2

A 50-year-old lawyer attended a clinic with a 15-day history of dyspnoea and weight loss over the past 6 months. He reports his sputum to be clear. On examination, a diagnosis of pleural effusion was made that was confirmed on chest X-ray. A pleural tap revealed few red cells and lymphocytes and a protein level of 40 g/l. What should be the next investigative step?

Explanation

Correct Answer: B- Computed tomography of the thorax Explanation Computed tomography of the thorax BTS guidelines from 2010 recommend contrast computed tomography (CT) as the most appropriate next

investigation here. Bronchoscopy Bronchoscopy is incorrect. Bronchoscopy would only be indicated if investigations such as contrast CT and pleural biopsy were non-diagnostic and a lung mass amenable to bronchoscopic sampling was seen on CT. Percutaneous pleural biopsy Percutaneous pleural biopsy is incorrect. Pleural biopsy would be indicated following CT using radiological guidance, under local anaesthetic thoracoscopy or via a video-assisted thoracoscopic surgery (VATS). ‘Blind’ percutaneous pleural biopsies are essentially obsolete now, given their poor diagnostic yield. Sputum examination for tubercle bacilli Sputum examination for tubercle bacilli is incorrect. It is justifiable to test sputum for tuberculosis in this case, but this is not a history highly suggestive of TB and the next most appropriate investigation is CT. Thoracoscopic pleural biopsy Thoracoscopic pleural biopsy is incorrect. A thoracoscopic pleural biopsy allows the physician to perform directed pleural biopsies, remove the pleural fluid and carry out pleurodesis to prevent recurrence.

Question 3

Which one of the following statements about the peak expiratory flow rate (PEFR) is true?

Explanation

Correct Answer: B- It is a parameter which relates to the degree of airway obstruction Explanation It is a parameter which relates to the degree of airway obstruction The PEFR is a sensitive measurement of airway obstruction, although the maximal mid-expiratory flow rate is more changed in mild disease. A PEFR of less than 50% of normal is an indication for aminophylline therapy as the next step in patients with acute asthma A PEFR of less than 50% of normal is an indication for aminophylline therapy as the next step in patients with acute asthma is incorrect. Aminophylline is not routinely recommended for acute severe asthma. Intravenous magnesium may be considered in acute asthma with PEFR less than 50% of normal if there has been a failure to respond to nebulised bronchodilators. It is more related to age than to height It is more related to age than to height is incorrect. PEFR is more related to height than to age. It is not a sensitive parameter for assessing improvement in response to therapy in patients with acute bronchial asthma It is not a sensitive parameter for assessing improvement in response to therapy in patients with acute bronchial asthma is incorrect. The PEFR is a sensitive measurement of airway obstruction. It is usually effort- dependent, in people who have practised the test It is usually effort-dependent, even in people who have practised the test is incorrect. PEFR is effort- independent if the proper technique is used, which is more likely if the patient has practiced the test.

Question 4

A 50-year-old man who has a history of intravenous drug use is admitted with a productive cough, fevers and rigors. Examination and chest X-ray show a right-sided effusion and right lower-lobe consolidation. Pleural aspiration of the fluid shows it to be a clear and straw- coloured, with a protein level of 35 g/l and a pH of 7.12. It has been sent for culture, along with blood cultures. Which of the following would be the most appropriate course of management?

Explanation

Correct Answer: A- Start intravenous benzylpenicillin and oral clarithromycin and insert a chest drain into the effusion Explanation Start intravenous benzylpenicillin and oral clarithromycin and insert a chest drain into the effusion This man has pneumonia and an empyema. He has an exudative acidic effusion, with a pH of below 7.2. This therefore needs drainage as well as antibiotic treatment, with intravenous benzylpenicillin and clarithromycin being reasonable choices. Start intravenous cefuroxime and oral metronidazole and arrange a medical thoracoscopy Start intravenous cefuroxime and oral metronidazole and arrange a medical thoracoscopy is incorrect. Medical thoracoscopy is not indicated in this setting. The first-line management of empyema is intravenous antibiotics and chest drain insertion. Start intravenous cefuroxime and oral metronidazole and reassess the size of the effusion in 3 days Start intravenous cefuroxime and oral metronidazole and reassess the size of the effusion in 3 days is incorrect. If the effusion was parapneumonic and not an empyema (ie

pH > 7.2 and culture- negative), treatment with antibiotics and reassessment of the effusion would be a reasonable course of management. However, if the patient’s fever, white cell count or inflammatory markers fail to settle, this course should be employed together with repeated aspiration to ensure empyema has not subsequently developed. Start oral amoxicillin and oral metronidazole and refer to the thoracic surgeons for debridement Start oral amoxicillin and oral metronidazole and refer to the thoracic surgeons for debridement is incorrect. Empyemas which fail to resolve with medical management alone might indicate the need for surgical intervention with debridement. Surgical management is not a first-line treatment, nor are oral antibiotics (intravenous antibiotics are required). Start oral amoxicillin and oral metronidazole and repeat a pleural tap the next day Start oral amoxicillin and oral metronidazole and repeat a pleural tap the next day is incorrect. Empyema would be inadequately treated by oral antibiotics and repeat pleural tap the following day would be highly unlikely to add any valuable clinical information to guide management.

Question 5

A 45-year-old woman visits the surgery with her 15- year-old son, who has recently been diagnosed with asthma. She has researched the pathology of asthma and has a number of questions about potential causative factors. Which of the following responses best describes the pathology of asthma?

Explanation

Correct Answer: A- Asthma occurs due to a combination of airway hyper-responsiveness, airflow limitation and airway inflammation Explanation Asthma occurs due to a combination of airway hyper- responsiveness, airflow limitation and airway inflammation This is a ‘know it or you don’t’ question. In many Western countries the prevalence of asthma is increasing, particularly during the second decade of life, where it can affect up to 10–15% of the population. The pathogenesis can be described as having three components:

• Asthma is characterised by airflow limitation that is usually reversible spontaneously or with treatment,

although later on in the disease there may be an irreversible component to airflow limitation. • There is also airway hyper-responsiveness to a wide range of external stimuli. • A predominantly eosinophilic pattern of inflammation occurs, with associated plasma exudates, oedema, mucus-plug formation, bronchial smooth muscle hypertrophy and long- term epithelial damage. Asthma predominantly occurs due to airflow limitation Asthma predominantly occurs due to airflow limitation is incorrect. Asthma occurs due to a combination of airway hyper-responsiveness, airflow limitation and airway inflammation. Asthma predominantly occurs due to airway hyper- responsiveness Asthma predominantly occurs due to airway hyper- responsiveness is incorrect. Asthma occurs due to a combination of airway hyper-responsiveness, airflow limitation and airway inflammation. Asthma predominantly occurs due to airway hyporesponsiveness Asthma predominantly occurs due to airway hyporesponsiveness is incorrect. Asthma occurs due to a combination of airway hyper-responsiveness, airflow limitation and airway inflammation. Asthma predominantly occurs due to airway inflammation Asthma predominantly occurs due to airway inflammation is incorrect. Asthma occurs due to a combination of airway hyper-responsiveness, airflow limitation and airway inflammation.

Question 6

A 60-year-old man presents to the Emergency medical take as a GP referral. He has had a non- productive niggling cough over the past few weeks, and most recently severe headaches and swelling of his face and arms. He smokes 20 cigarettes per day and has done so for 40 years. Examination reveals a blood pressure of 155/85 mmHg; you notice dilated veins over his arms and upper chest, his face looks plethoric, and there is evidence of oedema. Auscultation of the chest reveals poor air entry and wheeze consistent with COPD. Investigations:

Hb 13.8 g/dl

WCC 9.9 × 109/l

PLT 188 × 109/l

Na+ 137 mmol/l

K+ 4.5 mmol/l

Creatinine 112 μmol/l

CXR Large right hilar mass

CT scan Right hilar mass suspicious of bronchial carcinoma, leading to SVC compression Which of the following is the most appropriate intervention?

Explanation

Correct Answer: D- Stenting Explanation Stenting This patient has Superior Vena Cava (SVC) obstruction as a result of extrinsic compression from an underlying bronchial carcinoma. A NICE review has concluded that stenting offers a greater degree of success in terms of relief of symptoms than radiotherapy, and is therefore, the intervention of choice here. Chemotherapy Chemotherapy is incorrect. Chemotherapy may be a first- line option in cases of histologically proven small-cell cancer. Corticosteroids Corticosteroids is incorrect. Corticosteroids are most useful where the cause of compression is an underlying haematological malignancy. Radiotherapy Radiotherapy is incorrect. Radiotherapy may be an option later; if radiotherapy is used initially then stenting becomes significantly more difficult due to local fibrosis. Surgical bypass Surgical bypass is incorrect. Surgical bypass is only really an option for benign tumours, and there is little evidence to indicate that it confers any better benefit than stenting.

Question 7

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?

Explanation

Correct Answer: C- Intravenous co-amoxiclav and intravenous clarithromycin Explanation Intravenous co-amoxiclav and intravenous clarithromycin This woman has severe pneumonia as defined by the British Thoracic Society (BTS) guidelines, which requires the presence 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 orceftriaxone 2 g once daily together with:

• Erythromycin 500 mg four times daily or clarithromycin 500 mg twice daily Intravenous cefotaxime and intravenous ciprofloxacin Intravenous cefotaxime and intravenous ciprofloxacin is incorrect. This is not the treatment recommended by the BTS guideline. Intravenous ceftazidime and intravenous vancomycin Intravenous ceftazidime and intravenous vancomycin is incorrect. This is not the treatment recommended by the BTS guideline. Oral amoxicillin Oral amoxicillin is incorrect. This is not the treatment recommended by the BTS guideline. Oral amoxicillin and oral clarithromycin Oral amoxicillin and oral clarithromycin is incorrect. This is not the treatment recommended by the BTS guideline.

Question 8

Which one of the following features is encountered least frequently in patients with sleep apnoea syndrome?

Explanation

Correct Answer: B- Female gender Explanation Female gender Typically patients are male, middle aged and obese. Daytime sleepiness Daytime sleepiness is incorrect. Daytime sleepiness is a cardinal feature of obstructive sleep apnoea syndrome (OSAS). Other symptoms include night sweats, personality change, morning confusion and headache. Hypertension Hypertension is incorrect. Hypertension is commonly associated with OSAS. There might be an associated increased risk of pulmonary hypertension and cardiac arrhythmias. Large neck size Large neck size is incorrect. Large neck size (typically collar size > 17 inches) is classically associated with OSAS. Snoring Snoring is incorrect. Snoring is another cardinal feature of OSAS.

Question 9

A 26-year-old patient admitted with suspected pneumonia and an abnormal chest X-ray mentions to the attending physician that he has an azygos lobe. Where would you visualise the azygos lobe on an anterior–posterior chest X-ray?

Explanation

Correct Answer: E- Right upper zone Explanation Right upper zone This is a ‘know it or you don’t’ question. An azygos lobe is seen in about 0.5% of routine chest X-rays and is a normal variant. It is seen as a ‘reverse comma sign’ behind the medial end of the right clavicle. Left lower zone Left lower zone is incorrect. An azygos lobe is seen as a ‘reverse comma sign’ behind the medial end of the right clavicle. Left upper zone Left upper zone is incorrect. An azygos lobe is seen as a ‘reverse comma sign’ behind the medial end of the right clavicle. Right lower zone Right lower zone is incorrect. An azygos lobe is seen as a 'reverse comma sign' behind the medial end of the right clavicle. Right middle zone Right middle zone is incorrect. An azygos lobe is seen as a 'reverse comma sign' behind the medial end of the right clavicle.

Question 10

Which one of the following features is most accurate regarding Pneumocystis jirovecii pneumonia (PJP)?

Explanation

Correct Answer: A- Auscultation of the lungs usually reveals no abnormality Explanation Auscultation of the lungs usually reveals no abnormality Pneumocystis jirovecii pneumonia (PJP) is a pulmonary disease characterised by dyspnoea, tachypnoea and hypoxaemia. On examination patients usually show signs of respiratory distress (tachypnoea, dyspnoea). Auscultation of the lung usually reveals no abnormalities. Blood culture is positive in a third of cases Blood culture is positive in a third of cases is incorrect. The trophozoite does not enter the blood; the organism is identified in pulmonary secretions. Previously diagnosis relied on bronchoalveolar lavage or lung biopsy and staining with methenamine silver or Giemsa stain. Now the diagnsosis is usually made by PCR of sputum of bronchoalveolar lavage fluid. Metronidazole is the treatment of choice Metronidazole is the treatment of choice is incorrect. Co- trimoxazole is the recommended treatment; alternatively, pentamidine isethionate can be used. Metronidazole is not effective in the treatment of PJP. Occurs exclusively in people with AIDS Occurs exclusively in people with AIDS is incorrect. P. jirovecii pneumonia occurs in patients who are deficient in immunoglobulin G (IgG) and IgM and in patients deficient in cell-mediated immunity. The vast majority of adult patients with this pneumonia have AIDS, but it can also occur in patients who have received chemotherapy for a haematological malignancy or after an organ transplant. It can also occur in malnourished or premature infants. Pleural effusion is frequently bilateral Pleural effusion is frequently bilateral is incorrect. Pleural effusions are uncommon in PJP, occurring in < 5% cases. Where they are present they are usually unilateral.

Question 11

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.

Investigation:

Hb 12.2 g/dl

WCC 5.6 x 109/l

PLT 200 x 109/l

Sodium 139 mmol/l

Potassium 4.9 mmol/l

Creatinine 139 µmol/l Anti-GBM antibodies Negative

FEV1 84%

FVC 81% Gas transfer coefficient (Kco) Reduced pO2 7.8 kPa

pCO2 3.5 kPa What is the most likely diagnosis?

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 function

test 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 12

Which one of the following statements about the FEF25%–75% (forced expiratory flow rate between 25% and 75% of the forced vital capacity) in pulmonary function tests is true?

Explanation

Correct Answer: E- It reflects the status of the small airways Explanation It reflects the status of the small airways The forced expiratory flow rate between 25% and 75% of the forced vital capacity (FEF25%–75%) primarily reflects the status of the small airways. It is more sensitive than the forced expiratory volume in 1 second (FEV1) for identifying early airway obstruction. It is effort-dependent It is effort-dependent is incorrect. FEF25%–75% is effort-independent. This portion of the flow volume curve is the most effort independent portion. It is not affected in smokers It is not affected in smokers is incorrect. FEF25%–75% is impaired in smokers and in patients with graft versus host disease who have associated lung pathology. It is not impaired in bronchiolitis obliterans It is not impaired in bronchiolitis obliterans is incorrect. FEF25%–75% is impaired in bronchiolitis obliterans. It is useful to identify tracheal obstruction It is useful to identify tracheal obstruction is incorrect. FEF25%–75% is not useful for identifying large airway disease.

Question 13

A 44-year-old woman who is known to have brittle asthma is admitted to the Emergency Department. She is started on a Venturi mask designed to deliver 40% O2. How does the Venturi mask achieve this?

Explanation

Correct Answer: A- Air entrainment Explanation The Venturi effect is the reduction in pressure when a fluid flows through a constricted portion of pipe, probably related to an increase in its velocity. The effect is employed in the development of Venturi masks, where the reduction in pressure along a narrowed portion of the mask leads to entrainment of air, mixing inspired O2 with room air to deliver a specific percentage of O2 at a specific flow rate. Intermittent positive pressure Intermittent positive pressure (Option B) is incorrect. In Venturi masks the reduction in pressure along a narrowed portion of the mask leads to entrainment of air. Passive mixing of air and O2 Passive mixing of air and O2 (Option C) is incorrect. Rebreathing delivered O2 Rebreathing delivered O2 (Option D) is incorrect. In Venturi masks the reduction in pressure along a narrowed portion of the mask leads to entrainment of air. Turbulent flow Turbulent flow (Option E) is incorrect. In Venturi masks the reduction in pressure along a narrowed portion of the mask leads to entrainment of air.

Question 14

A 51-year-old lifelong smoker, who has worked for many years in a shipyard, presents with a 7- month history of increasing breathlessness. On examination, he has a blood pressure of 145/85 mmHg and a pulse of 75 bpm; his body mass index (BMI) is 31 kg/m2 and he also appears to have finger clubbing. Auscultation of the chest reveals bibasal inspiratory crackles. The chest X- ray is reported as showing evidence of pleural plaques. Pulmonary function testing reveals a mixed obstructive/restrictive picture. Which of the following is the most likely cause of his breathlessness?

Explanation

Correct Answer: A- Asbestosis Explanation Asbestosis Shipbuilding, car manufacture, boiler making and plumbing industries are all associated with a risk of asbestos exposure. Hence this man’s occupation puts him at significant risk. The findings on auscultation of the chest, coupled with the finger clubbing and the restrictive component seen on pulmonary function testing all point towards asbestos-related pulmonary fibrosis (asbestosis). Asbestos-related pleural plaques Asbestos-related pleural plaques is incorrect. Although this man does indeed have asbestos-related pleural plaques seen on chest X-ray, plaques themselves are not thought to contribute to breathlessness. Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease is incorrect. The crackles, clubbing and evidence of airflow restriction are not in keeping with breathlessness secondary to chronic obstructive pulmonary disease. Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis is incorrect. There is a clear occupational history here suggesting asbestos exposure. Therefore asbestosis is more likely than idiopathic pulmonary fibrosis. Obesity Obesity is incorrect. There is clearly more than obesity going on here to account for his breathlessness given the auscultation and investigation findings.

Question 15

A 73-year-old woman presents with weight loss and a chronic cough. Her husband has noticed that her pupil is constricted and her right eyelid is drooping. She has had pain in her right shoulder for some months, which her GP has described as ‘probable rheumatism’. Her chest X- ray reveals a mass in the right lung apex with possible lymphadenopathy at the right hilum. What is the most likely diagnosis in this case?

Explanation

Correct Answer: C- Horner syndrome caused by a Pancoast tumour Explanation Horner syndrome caused by a Pancoast tumour Horner syndrome is caused by an apical (Pancoast) lung tumour, which leads to spinal cord damage between spinal nerve root levels C8 and T1. Symptoms are pupil constriction, ptosis and facial anhidrosis. Aspergilloma Aspergilloma is incorrect. Aspergillomas are fungal balls that develop within a lung cavity. Chest X- ray will show a cavity containing a mass with a visible rim of air surrounding the mass. Eaton–Lambert syndrome Eaton–Lambert syndrome is incorrect. Eaton–Lambert syndrome is a paraneoplastic syndrome associated with proximal myopathy that is related to a deficient action of cholinergic neurones. Small-cell carcinoma Small-cell carcinoma is incorrect. Pancoast tumours are mostly squamous or adenocarcinomas, only 3–5% are said to be owing to small-cell tumours; this is because small-cell carcinoma of the bronchus is more likely to occur centrally and so would not be expected to present like this. Tuberculosis Tuberculosis is incorrect. This lady’s presentation is in keeping with an invasive mass causing Horner syndrome. This in conjuction with a solid mass seen on chest imaging is more in keeping with lung cancer than tuberculosis.

Question 16

A 50-year-old man patient was referred by his GP because of a long-standing history of persistent cough productive of mucopurulent sputum. He also noticed increasing shortness of breath. The patient has been treated several times for recurrent chest infections. What is the most likely diagnosis?

Explanation

Correct Answer: B- Bronchiectasis Explanation Bronchiectasis Bronchiectasis should be suspected when there is a history of persistent cough productive of mucopurulent or purulent sputum throughout the year. Patients have frequently been treated for recurrent chest infections and labelled as ‘bronchitic’, often despite the absence of a history of smoking. Patients can produce mucoid sputum early in their disease, developing purulent sputum when they suffer an exacerbation associated with a viral upper respiratory tract infection. Such exacerbations can be associated with pleuritic chest pain, haemoptysis, fever and sometimes wheeze. People who present as adults often recall a chesty cough or wheezy bronchitis associated with upper respiratory tract infections in childhood, followed by complete resolution of symptoms in their teens and early adult life before these return after a viral trigger. Upper respiratory tract symptoms such as nasal drip are common, and in about 30% of cases there is a history of chronic sinusitis. Patients with bronchiectasis also suffer from undue tiredness, which many find more troublesome than the productive cough. Asthma Asthma is incorrect. Asthma is not associated with chronic sputum production; cough in asthma is dry unless there is an intercurrent infection. Chronic cardiac failure Chronic cardiac failure is incorrect. Where cough is present in cardiac failure it is usually associated with frothy sputum. The description here of chronic purulent sputum is suggestive of bronchiectasis. Extrinsic allergic alveolitis Extrinsic allergic alveolitis (EAA) is incorrect. EAA is not associated with a chronic productive cough. Furthermore, there is no mention of any potential allergen to induce EAA. Lung cancer Lung cancer is incorrect. Lung cancer can be associated with cough, but would not usually be a cough persistently productive of mucopurulent sputum. Given that no smoking history or other ‘red flag’ symptoms are mentioned (eg haemoptysis), bronchiectasis is a more likely diagnosis.

Question 17

Which is the most common malignant tumour found in the lung?

Explanation

Correct Answer: C- Metastatic carcinoma Explanation Metastatic carcinoma Malignant metastases to the lung can present as a solitary enlarging nodule, as multiple nodules or with diffuse lymphatic involvement. Solitary metastasis represents some 10% of round lesions in general, but some 70% of round lesions in patients with a known malignancy. Colorectal cancer is reported to be the most common tumour of origin. A diagnosis can usually be secured by percutaneous computed tomography- (CT-) guided biopsy. In rare cases, surgical excision prolongs survival or results in cure, depending on the state of the primary tumour and the likelihood of other occult metastases. In general, the longer the interval between resection of the primary tumour and the appearance of the metastases, the better is the prognosis. Multiple metastases range enormously in size and number, from cannon balls to miliary shadowing, and can be accompanied by hilar lymphadenopathy or pleural effusion. Breast, colon, renal and lung primaries are probably the most common underlying tumours, but other tumours amenable to chemotherapy (eg testicular cancer, choriocarcinoma) and sarcomas also metastasise in this way. A diagnosis might be made on the basis of cytology or histology on various samples from the pleura or lung and can occasionally be made from cytology on expectoration or induced sputum. It is particularly important to accurately identify tumours that are suitable for chemotherapy or for endocrine manipulation (eg breast). Solitary or multiple Kaposi’s sarcoma is a feature of AIDS, and can involve the bronchi and pleura as well as lung tissue. Lymphangitis carcinomatosa is most commonly due to breast and primary lung tumours (usually adenocarcinomas). Patients can be asymptomatic when the disease is first suspected on the basis of an X-ray showing diffusely increased interstitial markings accompanied by Kerley B lines, hilar lymphadenopathy or pleural effusion.

Although the diagnosis can be established by cytology from sputum or pleural fluid, it often requires a bronchoscopic or transbronchial lung biopsy. Later, progressive and severe breathlessness with hypoxaemia often develops, and patients require vigorous palliative relief with opiates and oxygen. Metastases are sometimes confined to a bronchus and will not be visible on a plain chest X-ray – diagnosis requires bronchoscopy. These metastases tend to present with haemoptysis, which can usually be effectively controlled by radiotherapy. Renal carcinoma and malignant melanoma are recorded causes. Adenocarcinoma of the bronchus Adenocarcinoma of the bronchus is incorrect. Metastatic carcinoma is the most common malignant tumour found in the lung. Carcinoid tumour Carcinoid tumour is incorrect. Metastatic carcinoma is the most common malignant tumour found in the lung. Oat-cell carcinoma Oat-cell carcinoma is incorrect. Metastatic carcinoma is the most common malignant tumour found in the lung. Squamous-cell carcinoma of the bronchus Squamous-cell carcinoma of the bronchus is incorrect. Metastatic carcinoma is the most common malingnant tumour found in the lung.

Question 18

A 38-year-old school teacher from an inner city primary school comes for review in the Emergency Department. She has a chronic cough, night sweats and has lost weight over the past few weeks. Over the past few days she has begun to suffer increasing occipital headaches and drowsiness. She smokes 15 cigarettes per day. On examination in the Emergency Department she is pyrexial 37.9 °C, her BP is 122/70 mmHg; pulse is 75/min and regular. There are scattered crackles and wheeze on auscultation of the chest.

Investigations:

Hb 10.9 g/dl

WCC 12.9 × 109/l

PLT 201 × 109/l

Na+ 133 mmol/l

K+ 4.9 mmol/l

Creatinine 105 μmol/l CSF Lymphocytosis, opening pressure 24 cm H2O, protein 1.5 g/l TB PCR Positive Which of the following is the optimal initial drug regimen?

Explanation

Correct Answer: C- Isoniazid, pyrazinamide, rifampicin, ethambutol, prednisolone Explanation Isoniazid, pyrazinamide, rifampicin, ethambutol, prednisolone NICE guidelines recommend the following:

• Patients with active meningeal tuberculosis (TB) should be offered:

• a treatment regimen, initially lasting for 12 months, comprising isoniazid, pyrazinamide, rifampicin and a fourth drug (for example, ethambutol) for the first 2 months, followed by isoniazid and rifampicin for the rest of the treatment period • a glucocorticoid at the normal dose range (in adults equivalent to prednisolone 20–40 mg if on rifampicin, otherwise 10–20 mg) • with gradual withdrawal of the glucocorticoid considered, starting within 2–3 weeks of initiation. Amikacin, isoniazid, levofloxacin, rifampicin Amikacin, isoniazid, levofloxacin, rifampicin is incorrect. Amikacin and levofloxacin are potential second-line agents used for the treatment of resistant TB. They are not used first line. Additionally, given the evidence of meningeal TB, prednisolone would be indicated. Isoniazid, pyrazinamide, levofloxacin, ethambutol, prednisolone Isoniazid, pyrazinamide, levofloxacin, ethambutol, prednisolone is incorrect. Levofloxacin is a second- line agent used for the treatment of resistant TB. It is not used first line. Isoniazid, rifampicin, azithromycin, ethambutol Isoniazid, rifampicin, azithromycin, ethambutol is incorrect. Azithromycin is a potential second-line agent used for the treatment of resistant TB. It is not used first line. Additionally, given the evidence of meningeal TB, prednisolone would be indicated. Isoniazid, rifampicin, azithromycin, ethambutol, prednisolone Isoniazid, rifampicin, azithromycin, ethambutol, prednisolone is incorrect. Azithromycin is a potential second-line agent used for the treatment of resistant TB. It is not used first line.

Question 19

A 25-year-old man with a known history of alcohol and drug abuse presents with a 14-day history of fever, dry cough and tiredness. He is emaciated. His temperature is 39.4°C and he has cervical and axillary lymphadenopathy. His chest X-ray shows bilateral pulmonary shadowing. What is the most likely cause for his illness?

Explanation

Correct Answer: C- Pneumocystis pneumonia Explanation Pneumocystis pneumonia The history is suggestive that the patient is immunocompromised. Pneumocystis pneumonia can present with a normal X-ray or bilateral interstitial shadowing, which is often perihilar in distribution. Both tuberculosis and Pneumocystisinfection are likely in an immunocompromised patient, but the X- ray findings (i.e. the bilateral nature of the changes) are more suggestive of Pneumocystis rather than tuberculous infection. Alcoholic cardiomyopathy Alcoholic cardiomyopathy is incorrect. The clinical picture is one of infective pneumonia rather than of alcoholic cardiomyopathy. Pneumococcal pneumonia Pneumococcal pneumonia is incorrect. Pneumococcal pneumonia usually presents with lobar consolidation. Pulmonary tuberculosis Pulmonary tuberculosis is incorrect. Pulmonary tuberculosis, which is increasing in prevalence (especially in immunocompromised patients), might manifest as consolidation, cavitation, fibrosis and calcification on a chest X-ray but does not usually present with such a high fever. Tricuspid endocarditis Tricuspid endocarditis is incorrect. The clinical picture is one of infective pneumonia rather than of tricuspid endocarditis.

Question 20

A 45-year-old man, presenting with weight loss and cough, is found to have small-cell lung cancer. Which of the following best describes the additional biochemical and clinical features that can occur in this condition?

Explanation

Correct Answer: D- Hypertrophic pulmonary osteoarthropathy is a very rare feature Explanation Hypertrophic pulmonary osteoarthropathy is a very rare feature Hypertrophic pulmonary osteoarthropathy is very rare in small-cell carcinoma of the lung. Acidosis is commonly seen Acidosis is commonly seen is incorrect. Acidosis is rarely seen. Cushing syndrome, if present, is characterised by buffalo hump, striae and central obesity Cushing syndrome, if present, is characterised by buffalo hump, striae and central obesity is incorrect. Due to the short natural history of this type of cancer, Cushing syndrome in small-cell carcinoma does not manifest classically by buffalo hump, striae or central obesity. Its presence is suspected by arterial hypertension, hyperglycaemia, hypokalaemia, alkalosis and muscle weakness. Chemotherapy is the treatment of choice. Hypercalcaemia is commonly seen Hypercalcaemia is commonly seen is incorrect. Small- cell carcinoma is rarely associated with hypercalcaemia despite the high incidence of lytic bone metastases. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) occurs in > 60% of cases Syndrome of inappropriate antidiuretic hormone secretion (SIADH) occurs in > 60% of cases is incorrect. SIADH occurs in 5–10% of cases.

Question 21

A 24-year-old male is admitted with a closed midshaft femur fracture. 36 hours post-injury, he develops progressive tachypnea, confusion, and a petechial rash over his axilla. Arterial blood gas reveals a PaO2 of 55 mmHg. What is the most appropriate initial management for this patient's condition?

Explanation

This patient has classic Fat Embolism Syndrome (FES) manifesting with hypoxia, confusion, and petechial rash. The mainstay of treatment for FES is supportive care, particularly maintaining adequate oxygenation and ventilation. Corticosteroids have not been proven to change mortality once FES develops.

Question 22

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?

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 23

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?

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 24

A 28-year-old male presents with a closed tibial plateau fracture. He complains of pain out of proportion to his injury and worsening paresthesia in his first web space. His diastolic blood pressure is 80 mmHg. Intracompartmental pressure monitoring reveals an anterior compartment pressure of 55 mmHg. What is the delta pressure, and what is the indicated treatment?

Explanation

Delta pressure is calculated as diastolic blood pressure minus intracompartmental pressure (80 - 55 = 25 mmHg). A delta pressure of less than 30 mmHg is highly indicative of acute compartment syndrome and necessitates emergent four-compartment fasciotomy.

Question 25

A 42-year-old male with multiple pelvic and lower extremity fractures develops acute respiratory distress syndrome (ARDS) on postoperative day 3. His chest radiograph shows diffuse bilateral infiltrates. Which of the following mechanical ventilation strategies is most appropriate to minimize ventilator-induced lung injury?

Explanation

The ARDSnet protocol recommends low tidal volumes (6 mL/kg predicted body weight) to prevent volutrauma and appropriately high PEEP to recruit alveoli and prevent atelectrauma. This lung-protective strategy has been shown to significantly reduce mortality in ARDS patients.

Question 26

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?

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 27

A 31-year-old male with a severe traumatic brain injury undergoes open reduction and internal fixation of an acetabular fracture. To prevent heterotopic ossification (HO), indomethacin is prescribed. What is the primary mechanism of action by which indomethacin prevents HO?

Explanation

Indomethacin is an NSAID that prevents heterotopic ossification by inhibiting the cyclooxygenase (COX) enzymes, thereby decreasing the synthesis of prostaglandins (specifically PGE2). PGE2 is a crucial mediator in the differentiation of mesenchymal stem cells into osteoblasts.

Question 28

An 82-year-old female undergoes intramedullary nailing for an intertrochanteric femur fracture. On postoperative day 2, she becomes acutely confused, agitated, and experiences visual hallucinations. Her vital signs are stable, and her laboratory results are unremarkable. What is the most appropriate initial pharmacological intervention if non-pharmacological measures fail?

Explanation

The patient is experiencing postoperative delirium. If non-pharmacological measures fail and the patient requires pharmacological management, a low-dose typical antipsychotic such as haloperidol is the treatment of choice. Benzodiazepines can worsen delirium in the elderly.

Question 29

A 65-year-old female on alendronate for 10 years presents with a non-traumatic, transverse subtrochanteric fracture of her left femur. Radiographs show cortical thickening and a lateral cortical beak. During surgical planning for intramedullary nailing, what specific technical consideration must be accounted for?

Explanation

Atypical femur fractures (AFF) are often associated with an increased anterior and lateral bowing of the femur. Surgeons must account for this by using a nail with a smaller radius of curvature, over-reaming, or using a smaller diameter nail to avoid iatrogenic fracture during insertion.

Question 30

A 45-year-old male presents with severe low back pain, bilateral sciatica, and new-onset urinary retention. Post-void residual volume is 400 mL. An emergent MRI reveals a massive L4-L5 disc herniation compressing the thecal sac. What is the maximum recommended time frame for surgical decompression to optimize functional recovery?

Explanation

Cauda equina syndrome with urinary retention is a surgical emergency. Decompression should ideally be performed within 24 to 48 hours to maximize the chances of recovery of motor, sensory, and sphincter function.

Question 31

A 40-year-old female complains of burning pain, swelling, and color changes in her right hand 6 weeks after cast removal for a distal radius fracture. Radiographs reveal patchy osteopenia. What is the most effective initial intervention to prevent progression of this condition?

Explanation

The patient is presenting with Complex Regional Pain Syndrome (CRPS) Type I. Early recognition and aggressive physical therapy (emphasizing active range of motion and load-bearing exercises) are the most effective first-line treatments to maintain function and prevent progression.

Question 32

A 55-year-old diabetic male presents with a rapidly expanding area of erythema, swelling, and extreme pain out of proportion to exam on his right lower leg. Crepitus is palpated, and a plain radiograph shows gas in the soft tissues. What is the most critical immediate step in management?

Explanation

The clinical picture and gas in the soft tissues are pathognomonic for necrotizing fasciitis. While broad-spectrum antibiotics are necessary, emergent and aggressive surgical debridement is the definitive and life-saving treatment and must not be delayed for imaging.

Question 33

A 32-year-old male presents 8 months after intramedullary nailing of a closed tibial shaft fracture. He reports persistent pain with weight-bearing. Radiographs demonstrate a hypertrophic nonunion at the fracture site. What is the most appropriate surgical treatment?

Explanation

Hypertrophic nonunions possess adequate biology but lack sufficient mechanical stability. Exchange nailing with a larger, reamed intramedullary nail provides the necessary biomechanical stability and stimulates osteogenesis via the reamings, leading to high union rates.

Question 34

A 72-year-old female presents with chronic, intractable shoulder pain and profound weakness in elevation. Radiographs show superior migration of the humeral head with severe glenohumeral osteoarthritis and acetabularization of the coracoacromial arch. What is the most appropriate surgical option?

Explanation

The patient has cuff tear arthropathy. Reverse total shoulder arthroplasty (RTSA) is the treatment of choice as it medializes and lowers the center of rotation, increasing the deltoid moment arm and allowing it to compensate for the deficient rotator cuff.

Question 35

A 24-year-old male sustains a closed comminuted diaphyseal femur fracture. 36 hours post-admission, he develops progressive hypoxia, a petechial rash over his axillae, and confusion. Which of the following is the primary pathophysiological mechanism responsible for his respiratory compromise?

Explanation

Fat embolism syndrome (FES) is characterized by hypoxia, petechiae, and neurological decline. The primary pathogenesis involves circulating free fatty acids causing toxic endothelial damage, leading to an ARDS-like pulmonary compromise.

Question 36

A 14-year-old female with Adolescent Idiopathic Scoliosis is evaluated for spinal fusion. Her curve measures 75 degrees in the thoracic spine. Which of the following pulmonary function test (PFT) parameters is most likely to be decreased and best correlates with her preoperative respiratory status?

Explanation

Severe thoracic scoliosis primarily causes a restrictive lung disease pattern. This is best indicated by a proportional decrease in both FEV1 and FVC with a notably decreased Total Lung Capacity (TLC).

Question 37

A 68-year-old male undergoes a total hip arthroplasty. On postoperative day 3, he complains of sudden-onset pleuritic chest pain and dyspnea. His heart rate is 115 bpm, and oxygen saturation is 88% on room air. An ECG shows sinus tachycardia with an S1Q3T3 pattern. What is the most appropriate next step in management?

Explanation

In a patient with a high clinical probability of pulmonary embolism (tachycardia, hypoxia, recent major surgery), CTPA is the gold standard diagnostic test. A D-dimer is not useful postoperatively due to expected elevation from surgical trauma.

Question 38

A 24-year-old male sustains a closed femoral shaft fracture in a motor vehicle collision. Twenty-four hours later, he develops unexplained tachycardia, a petechial rash over his anterior axillary folds, and sudden confusion. Arterial blood gas shows a PaO2 of 55 mmHg on room air. According to Gurd and Wilson's criteria, which of the following clinical features in this patient is considered a major criterion for the most likely diagnosis?

Explanation

The patient is presenting with Fat Embolism Syndrome. Gurd and Wilson's major criteria include a petechial rash, respiratory insufficiency, and cerebral involvement. Tachycardia, pyrexia, and a drop in hematocrit are considered minor criteria.

Question 39

A 35-year-old male is brought to the emergency department after a high-speed motorcycle collision. His blood pressure is 70/40 mmHg and heart rate is 135 bpm. A pelvic radiograph shows an anteroposterior compression type III (APC-III) pelvic ring injury. A pelvic binder is applied correctly, but he remains hemodynamically unstable despite aggressive blood product resuscitation. A FAST scan is negative. What is the most appropriate next step in his management?

Explanation

In a hemodynamically unstable patient with a pelvic ring injury and a negative FAST scan, the bleeding is typically retroperitoneal from the presacral venous plexus or internal iliac branches. Preperitoneal pelvic packing or angioembolization is the standard life-saving next step after binder application.

Question 40

A 45-year-old male presents to the clinic with severe low back pain, bilateral sciatica, and new-onset urinary incontinence. Physical examination reveals perianal anesthesia and significantly decreased anal sphincter tone. An urgent MRI confirms a massive L4-L5 central disc herniation. What is the most critical factor influencing the functional recovery of this patient's normal bladder function?

Explanation

This patient has cauda equina syndrome, which is an absolute surgical emergency. The time to surgical decompression (ideally within 24 to 48 hours of symptom onset) is the most critical prognostic factor for the recovery of bladder and bowel function.

Question 41

A 13-year-old obese boy presents with a 4-week history of left knee pain and an antalgic gait. Physical examination of the left hip reveals restricted internal rotation, and the hip obligatorily externally rotates during passive flexion. Radiographs demonstrate a widening and irregularity of the left proximal femoral physis. Following definitive surgical management, what is the most devastating common complication this patient faces?

Explanation

Slipped capital femoral epiphysis (SCFE) is treated with in situ pinning. Avascular necrosis of the femoral head is the most devastating complication, often resulting from unstable slips or iatrogenic injury to the retinacular vessels during hardware placement.

Question 42

A 22-year-old male falls onto an outstretched hand and presents with swelling and severe anatomical snuffbox tenderness. Radiographs confirm a displaced fracture of the proximal pole of the scaphoid. Why is this specific fracture pattern at a significantly high risk for nonunion and avascular necrosis?

Explanation

The scaphoid receives its primary blood supply in a retrograde fashion from the dorsal carpal branch of the radial artery, which enters the bone distally. Proximal pole fractures disrupt this intraosseous vascular supply, leading to high rates of ischemia, AVN, and nonunion.

Question 43

A 15-year-old boy presents with progressive distal thigh pain that awakens him at night. Radiographs of the distal femur reveal an ill-defined, destructive, bone-forming lesion in the metaphysis accompanied by a sunburst periosteal reaction and a Codman's triangle. A core needle biopsy confirms a high-grade conventional osteosarcoma. What is the current standard of care sequence for this patient?

Explanation

The standard treatment for high-grade conventional osteosarcoma includes neoadjuvant chemotherapy, followed by wide surgical resection (limb-salvage or amputation), and subsequent adjuvant chemotherapy. This multidisciplinary approach significantly improves overall survival and limb preservation rates.

Question 44

A 21-year-old female collegiate soccer player sustains a twisting knee injury, feeling a pop followed by immediate hemarthrosis. An MRI reveals a complete tear of the anterior cruciate ligament (ACL) and a peripheral longitudinal tear of the medial meniscus. Which of the following statements is true regarding meniscal repair performed concurrently with ACL reconstruction?

Explanation

Meniscal repairs performed concurrently with ACL reconstruction demonstrate significantly higher healing rates than isolated repairs. The intra-articular bleeding and pluripotent marrow elements released during the bony tunnel reaming enhance the biological healing environment.

Question 45

A 68-year-old female undergoes a primary total hip arthroplasty (THA) via a posterior approach for severe osteoarthritis. Six weeks postoperatively, she sustains a posterior dislocation of the THA while bending forward to tie her shoes. Recurrent posterior dislocations are most strongly associated with which of the following technical component malpositioning errors?

Explanation

Acetabular cup retroversion or insufficient femoral anteversion severely limits impingement-free internal rotation and flexion. This technical error predisposes a total hip arthroplasty to posterior dislocation when the hip is flexed, adducted, and internally rotated.

Question 46

A 25-year-old male is admitted with a closed diaphyseal femur fracture. Thirty-six hours after admission, he becomes agitated and confused. Examination reveals a petechial rash over his axillae and conjunctivae. His oxygen saturation is 86% on room air. What is the most appropriate initial management?

Explanation

This patient presents with classic signs of fat embolism syndrome (hypoxia, confusion, petechial rash) following a long bone fracture. The mainstay of treatment is supportive care, primarily focusing on maintaining adequate oxygenation and hemodynamics.

Question 47

A 28-year-old male polytrauma patient presents with bilateral femur fractures, a pulmonary contusion, and a closed head injury. His serum lactate is 4.5 mmol/L, base deficit is -8, and pH is 7.21. Which of the following is the most appropriate orthopedic management strategy?

Explanation

This patient is physiologically unstable as indicated by elevated lactate, significant base deficit, and acidosis, making him a poor candidate for early total care. Damage control orthopedics (DCO) using temporary external fixation minimizes the systemic inflammatory response and secondary hits.

Question 48

According to the Musculoskeletal Infection Society (MSIS) criteria, which of the following is considered a major definitive criterion for the diagnosis of a periprosthetic joint infection?

Explanation

According to the MSIS criteria, the two major criteria for periprosthetic joint infection are a sinus tract communicating with the joint or two positive periprosthetic cultures with phenotypically identical organisms. The other options are considered minor diagnostic criteria.

Question 49

A 34-year-old male sustains a closed spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture). On initial presentation, his radial nerve function is intact. Following a closed reduction and application of a coaptation splint, the patient is unable to extend his wrist or fingers. What is the most appropriate next step in management?

Explanation

A secondary radial nerve palsy that develops immediately after closed reduction of a humeral shaft fracture strongly suggests nerve entrapment within the fracture site. This is an absolute indication for immediate surgical exploration.

Question 50

A 45-year-old male presents with a closed tibial plateau fracture. He complains of pain out of proportion to his injury that is exacerbated by passive stretch of his toes. Compartment pressure monitoring reveals an anterior compartment pressure of 35 mmHg. His diastolic blood pressure is 60 mmHg. What is the most appropriate action?

Explanation

The diagnosis of acute compartment syndrome is supported by a delta pressure (diastolic blood pressure minus compartment pressure) of less than 30 mmHg. In this case, the delta pressure is 25 mmHg, which is a strong indication for an urgent four-compartment fasciotomy.

Question 51

A 14-year-old boy presents with progressive thigh pain and a low-grade fever. Radiographs show a permeative, lytic lesion in the femoral diaphysis with an "onion-skin" periosteal reaction. A biopsy reveals small, round, blue cells. Which chromosomal translocation is most characteristically associated with this pathology?

Explanation

Ewing sarcoma is characterized by small, round, blue cells and a classic "onion-skin" periosteal reaction. It is strongly associated with the t(11;22)(q24;q12) chromosomal translocation, resulting in the EWS-FLI1 fusion gene.

Question 52

A 6-year-old girl sustains a severely displaced, extension-type supracondylar fracture of the humerus. On examination, the hand is pink but the radial pulse is non-palpable. Capillary refill is less than 2 seconds. What is the most appropriate initial management?

Explanation

In a "pink, pulseless" hand following a displaced supracondylar humerus fracture, the first step is urgent closed reduction and percutaneous pinning to restore alignment, which often relieves kinking of the brachial artery. Vascular exploration is generally reserved for hands that remain persistently ischemic (white) after fracture reduction.

Question 53

A 65-year-old female with long-standing rheumatoid arthritis presents with progressive hand clumsiness and gait instability. Lateral flexion-extension radiographs of the cervical spine demonstrate an anterior atlantodens interval (ADI) of 11 mm. Which of the following is the most likely pathological mechanism for her symptoms?

Explanation

An ADI greater than 9-10 mm in adults indicates disruption of the transverse and accessory ligaments with a high likelihood of spinal cord compression. This manifests clinically as myelopathy, presenting with hand clumsiness and gait instability.

Question 54

A 40-year-old male is brought to the trauma bay after a high-speed motorcycle collision. His blood pressure is 80/50 mmHg. Pelvic radiographs reveal an "open book" (APC-III) pelvic ring disruption. A pelvic binder is applied, and he receives 2 units of packed red blood cells, but his blood pressure remains 85/55 mmHg. What is the next most appropriate step?

Explanation

In a hemodynamically unstable patient with an APC-III pelvic fracture despite mechanical stabilization (binder) and initial volume resuscitation, the primary source of bleeding is likely venous or arterial from the presacral plexus. Pelvic packing or angiography with embolization is the standard next step to achieve hemostasis.

Orthopedic Prometric MCQs - Chapter 4 Part 1

Orthopedic Prometric MCQs - Chapter 4 Part 2

Orthopedic Prometric MCQs - Chapter 4 Part 2

Chapter Index