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CSHK Part 1 MCQ study materials
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CSHK Part 1 MCQ practice questions

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Question 1General Surgery

A 24-year-old man presents with a 6-hour history of central abdominal pain that has migrated to the right iliac fossa. He has anorexia and low-grade fever. Which single finding on examination is most specific for acute appendicitis?

  1. Rebound tenderness at McBurney's point
  2. Pain in the right lower quadrant on internal rotation of the flexed right hip Correct answer.
  3. Positive Rovsing's sign
  4. Pain on percussion in the right iliac fossa

Explanation

Pain elicited in the right lower quadrant when the flexed right hip is internally rotated indicates irritation of the obturator internus muscle and is the obturator sign, a localising sign of a pelvic appendix. The other listed signs are sensitive markers of peritoneal irritation but are less specific because they can occur with other causes of right iliac fossa inflammation.

Question 2General Surgery

A 58-year-old woman has a 2 cm firm, painless lump in the upper outer quadrant of the right breast that is tethered to skin. Which feature on history most strongly suggests malignancy rather than a benign lesion?

  1. Nipple discharge that is green and multiductal
  2. A lump that fluctuates in size during the menstrual cycle
  3. A lump that has enlarged steadily over 8 weeks Correct answer.
  4. Cyclical tenderness related to menses

Explanation

Progressive, unremitting enlargement of a painless, hard, tethered lump is the classic presentation of breast carcinoma, and skin tethering reflects invasion of Cooper's ligaments. Benign disease such as fibroadenoma or fibrocystic change tends to be cyclical, tender, or stable in size over time.

Question 3General Surgery

Which structure forms the medial boundary of the femoral canal and is the key landmark dividing femoral from inguinal herniae?

  1. Lacunar ligament Correct answer.
  2. Inguinal ligament
  3. Femoral vein
  4. Pectineal line of the pubis

Explanation

The femoral ring is bounded medially by the lacunar ligament, laterally by the femoral vein, anteriorly by the inguinal ligament and posteriorly by the pectineal ligament. The lacunar ligament is the critical medial structure that causes femoral herniae to strangulate and must be divided during surgical repair.

Question 4General Surgery

A 45-year-old man with a 12-hour history of severe epigastric pain has a rigid abdomen with absent bowel sounds. Erect chest radiograph shows free gas under both hemidiaphragms. What is the most appropriate immediate management step?

  1. Nasogastric decompression with observation for 24 hours
  2. Oral contrast study to confirm the site of perforation
  3. Immediate upper gastrointestinal endoscopy to locate the perforation
  4. Urgent laparotomy after resuscitation with intravenous fluids and antibiotics Correct answer.

Explanation

Pneumoperitoneum with generalised peritonitis indicates a perforated viscus, most commonly a perforated peptic ulcer, and requires resuscitation followed by urgent laparotomy or laparoscopic repair. Delay for further imaging or endoscopy worsens sepsis and mortality.

Question 5General Surgery

Which of the following is the most common cause of acute pancreatitis in the United Kingdom?

  1. Alcohol excess
  2. Gallstones Correct answer.
  3. Endoscopic retrograde cholangiopancreatography
  4. Hypertriglyceridaemia

Explanation

Gallstones and alcohol are the two leading causes of acute pancreatitis, with gallstones the commonest overall in the UK population. Hypertriglyceridaemia and post-ERCP pancreatitis are recognised but far less frequent causes.

Question 6General Surgery

A 62-year-old man has painless visible haematuria. Which investigation is the initial imaging of choice for suspected upper urinary tract urothelial malignancy?

  1. Renal ultrasound alone
  2. Magnetic resonance imaging of the kidneys
  3. Intravenous urogram
  4. Multiphasic computed tomography urogram Correct answer.

Explanation

CT urography is the recommended first-line imaging for painless visible haematuria in adults because it detects renal and ureteric urothelial tumours as well as stones with high sensitivity. Ultrasound is reserved for patients who cannot undergo CT or for follow-up.

Question 7General Surgery

A 70-year-old woman presents with a painful, irreducible lump in the groin below and lateral to the pubic tubercle, with overlying skin erythema. What is the most likely diagnosis?

  1. Femoral hernia Correct answer.
  2. Inguinal hernia
  3. Psoas abscess
  4. Saphena varix

Explanation

A lump below and lateral to the pubic tubercle is a femoral hernia, and its narrow neck through the femoral ring predisposes to irreducibility and strangulation. Inguinal herniae lie above and medial to the pubic tubercle.

Question 8General Surgery

Which of the following is a recognised risk factor for the development of colorectal carcinoma?

  1. Ulcerative colitis of more than 10 years' duration Correct answer.
  2. Peutz-Jeghers syndrome
  3. Coeliac disease
  4. Chronic pancreatitis

Explanation

Long-standing extensive ulcerative colitis is a well-established risk factor for colorectal carcinoma, with surveillance colonoscopy recommended after 8 to 10 years of disease. Coeliac disease and chronic pancreatitis do not predispose to colorectal cancer.

Question 9General Surgery

A 55-year-old man with a 3-day history of right lower quadrant pain and a tender mass is found to have a pericolic abscess complicating diverticulitis. Which statement best describes the Hinchey classification stage III?

  1. Pericolic abscess confined to the mesentery
  2. Generalised faecal peritonitis
  3. Pelvic abscess Correct answer.
  4. Generalised purulent peritonitis

Explanation

The Hinchey classification stages complicated diverticulitis as I (pericolic abscess), II (pelvic or distant abscess), III (generalised purulent peritonitis) and IV (generalised faecal peritonitis). Pelvic abscess corresponds to stage II.

Question 10General Surgery

A 68-year-old man develops a wound infection 5 days after elective open right hemicolectomy. Which single measure most effectively reduces the incidence of surgical site infection in colorectal surgery?

  1. Prolonged postoperative antibiotic course
  2. Intravenous antibiotic prophylaxis within 60 minutes of incision Correct answer.
  3. Delayed primary closure in all patients
  4. Wound irrigation with hydrogen peroxide at closure

Explanation

Timely intravenous prophylactic antibiotics, administered within 60 minutes before skin incision and covering aerobic and anaerobic organisms, are the single most effective intervention for reducing surgical site infection in colorectal surgery. Prolonged postoperative antibiotics confer no added benefit and promote resistance.

Question 11General Surgery

A 32-year-old woman has a 1.5 cm thyroid nodule with a normal TSH. Fine needle aspiration cytology is reported as Bethesda category III (atypia of undetermined significance). What is the most appropriate next step?

  1. Radioactive iodine ablation
  2. Total thyroidectomy
  3. Repeat fine needle aspiration or molecular testing Correct answer.
  4. Observation with annual ultrasound alone

Explanation

Bethesda III nodules carry an indeterminate risk of malignancy of roughly 10 to 30 percent, so repeat fine needle aspiration or molecular testing is recommended to refine risk before surgery. Immediate total thyroidectomy is overtreatment without further risk stratification.

Question 12General Surgery

A 48-year-old man has a 4 cm right-sided renal mass on CT with no evidence of metastasis. Which factor is the most important determinant of the choice between partial and radical nephrectomy?

  1. Presence of a solitary kidney or chronic kidney disease Correct answer.
  2. Patient's age
  3. Tumour histology on biopsy
  4. Serum calcium level

Explanation

Partial nephrectomy is preferred whenever technically feasible, particularly in patients with a solitary kidney, bilateral tumours or pre-existing chronic kidney disease, to preserve renal function. In a patient with two normal kidneys and a 4 cm tumour, partial nephrectomy is also the standard where expertise allows.

Question 13General Surgery

A 40-year-old woman has a 3 cm thyroid nodule with compressive symptoms and a fine needle aspirate showing follicular proliferation. Which investigation is most useful in distinguishing follicular adenoma from follicular carcinoma?

  1. Serum thyroglobulin
  2. Histological examination for capsular and vascular invasion after excision Correct answer.
  3. Radioiodine uptake scan
  4. Repeat fine needle aspiration cytology

Explanation

Follicular carcinoma is diagnosed by histological evidence of capsular or vascular invasion, which cannot be assessed on cytology alone. This is why follicular lesions usually require diagnostic hemithyroidectomy.

Question 14General Surgery

A 60-year-old man with a 20-pack-year smoking history presents with painless jaundice and a palpable gallbladder (Courvoisier's law). Which diagnosis is most likely?

  1. Sclerosing cholangitis
  2. Carcinoma of the head of pancreas Correct answer.
  3. Gallstone impacted in the cystic duct
  4. Acute cholecystitis

Explanation

Courvoisier's law states that a palpable, nontender gallbladder with painless jaundice is unlikely to be due to stones and suggests malignant obstruction, most commonly pancreatic head carcinoma. Chronic stone disease fibroses the gallbladder and prevents distension.

Question 15General Surgery

A 25-year-old man has a 2 cm indirect inguinal hernia. Which anatomical structure lies immediately lateral to the inferior epigastric vessels at the deep inguinal ring?

  1. The femoral canal
  2. The deep inguinal ring Correct answer.
  3. The lacunar ligament
  4. The superficial inguinal ring

Explanation

The deep inguinal ring lies lateral to the inferior epigastric vessels and is the site of an indirect inguinal hernia. Direct herniae protrude medial to these vessels through Hesselbach's triangle.

Question 16General Surgery

A 70-year-old woman has a 2-day history of a tense, tender, irreducible groin lump with vomiting. At operation the bowel is dusky but viable after release of the constriction. What is the most appropriate management of the bowel and the hernia?

  1. Return of the bowel to the abdomen and mesh repair
  2. Resection of the bowel and primary suture repair
  3. Resection of the bowel and mesh repair
  4. Return of the bowel to the abdomen and primary suture repair Correct answer.

Explanation

Viable bowel after release of a strangulating constriction is returned to the abdomen without resection. In a contaminated field created by an obstructed strangulated hernia, permanent mesh is avoided and a tissue repair is performed to reduce the risk of infection.

Question 17General Surgery

A 35-year-old woman has a 1.5 cm papillary thyroid carcinoma confined to one lobe with no lymph node involvement. What is the most appropriate surgical management?

  1. Total thyroidectomy alone
  2. Total thyroidectomy with central neck dissection and radioiodine ablation
  3. Radioactive iodine ablation without surgery
  4. Hemithyroidectomy alone Correct answer.

Explanation

For a low-risk papillary carcinoma of 4 cm or less without nodal disease, hemithyroidectomy is an accepted option that avoids the morbidity of total thyroidectomy. Completion thyroidectomy can be performed later if histology reveals higher-risk features.

Question 18General Surgery

A 52-year-old man has a 2 cm well-differentiated rectal adenocarcinoma 6 cm from the anal verge with no distant metastasis. Which factor most strongly determines the need for neoadjuvant chemoradiotherapy?

  1. Serum CEA level
  2. Distance from the anal verge and T stage on MRI Correct answer.
  3. Patient's age
  4. Tumour grade

Explanation

Neoadjuvant chemoradiotherapy is offered for locally advanced rectal cancer, defined by MRI features such as T3 or T4 disease and threatened circumferential resection margin, particularly for low rectal tumours. MRI staging and tumour height are the key determinants of preoperative treatment.

Question 19General Surgery

A 45-year-old man has acute severe pancreatitis with a modified Glasgow score of 5 at 48 hours. Which single intervention has the strongest evidence for reducing mortality in severe acute pancreatitis?

  1. Urgent ERCP in all patients
  2. Nasogastric suction
  3. Early enteral nutrition Correct answer.
  4. Prophylactic antibiotics

Explanation

Early enteral nutrition within 72 hours reduces infectious complications and mortality in severe acute pancreatitis by maintaining gut mucosal integrity. Prophylactic antibiotics and routine nasogastric suction are not supported by evidence.

Question 20General Surgery

A 35-year-old woman has a recurrent, painful lump in the upper outer quadrant of the breast that fluctuates with menses. Ultrasound shows a well-defined 1.5 cm hypoechoic lesion. Which of the following is the most appropriate management?

  1. Excision biopsy
  2. Reassurance and review Correct answer.
  3. Mastectomy
  4. Core needle biopsy

Explanation

A well-defined hypoechoic lesion in a young woman with cyclical symptoms is most likely a fibroadenoma or a simple cyst, and if ultrasound features are benign, reassurance with review is appropriate. Biopsy is reserved for suspicious or indeterminate lesions.

Question 21General Surgery

A 66-year-old man has a 3 cm renal cell carcinoma with a tumour thrombus extending into the inferior vena cava below the hepatic veins. Which of the following is the most appropriate surgical approach?

  1. Radical nephrectomy alone
  2. Radical nephrectomy with caval thrombectomy under vascular control Correct answer.
  3. Systemic targeted therapy alone
  4. Palliative radiotherapy

Explanation

Renal cell carcinoma with level II inferior vena cava thrombus is potentially curable with radical nephrectomy and caval thrombectomy under vascular control. Systemic therapy alone is reserved for metastatic disease, and radiotherapy has no curative role.

Question 22General Surgery

A 60-year-old woman has a 2 cm distal rectal tumour 4 cm from the anal verge with no sphincter involvement on MRI. Which of the following is the most appropriate surgical procedure?

  1. Hartmann's procedure
  2. Anterior resection Correct answer.
  3. Abdominoperineal resection
  4. Local excision

Explanation

Anterior resection with total mesorectal excision is appropriate for a distal rectal tumour where a clear distal margin and sphincter preservation can be achieved. Abdominoperineal resection is reserved for tumours invading the sphincter complex or where a clear margin cannot be obtained.

Question 23General Surgery

A 55-year-old man has a 1 cm papillary thyroid carcinoma with a single 1 cm ipsilateral central compartment node metastasis. What is the most appropriate operation?

  1. Total thyroidectomy with therapeutic central neck dissection Correct answer.
  2. Total thyroidectomy with modified radical neck dissection
  3. Hemithyroidectomy alone
  4. Radioactive iodine ablation alone

Explanation

Papillary carcinoma with proven central compartment nodal metastasis is treated with total thyroidectomy and therapeutic central neck dissection. Modified radical neck dissection is reserved for lateral compartment disease.

Question 24General Surgery

A 50-year-old woman has a 3 cm well-differentiated liposarcoma of the thigh. Which of the following is the most important principle of surgical management?

  1. Amputation of the limb
  2. Wide local excision with a clear margin Correct answer.
  3. Simple enucleation of the tumour
  4. Excision biopsy with observation of the margin

Explanation

Soft tissue sarcomas require wide local excision with a clear margin, usually combined with radiotherapy for high-grade or deep lesions. Enucleation leaves microscopic disease and leads to local recurrence.

Question 25General Surgery

A 30-year-old man has a 5 cm indirect inguinal hernia and a history of previous open appendicectomy through a lower midline incision. Which approach is most appropriate?

  1. Open tissue repair without mesh
  2. Laparoscopic totally extraperitoneal mesh repair
  3. Laparoscopic transabdominal preperitoneal repair
  4. Open mesh repair via an anterior approach Correct answer.

Explanation

An anterior open mesh repair is appropriate for a primary unilateral indirect hernia, and previous lower abdominal surgery is not a contraindication. Laparoscopic approaches are best reserved for bilateral or recurrent hernias or where the anterior approach is unsuitable.

Question 26General Surgery

A 45-year-old man is admitted with a deep partial-thickness burn. According to the Parkland formula, which fluid regimen is most appropriate for the first 24 hours after the burn?

  1. 1 mL/kg per % total body surface area of Ringer's lactate, with all given in the first 8 hours
  2. 4 mL/kg per % total body surface area of 5% dextrose, with half given in the first 8 hours
  3. 4 mL/kg per % total body surface area of Ringer's lactate, with half given in the first 8 hours Correct answer.
  4. 2 mL/kg per % total body surface area of Ringer's lactate, given evenly over 24 hours

Explanation

The Parkland formula calculates 4 mL/kg per % total body surface area of Ringer's lactate in the first 24 hours from the time of injury, with half administered in the first 8 hours and the remainder over the next 16 hours. Ringer's lactate is preferred because it approximates physiological electrolyte composition, whereas dextrose solutions do not replace the sodium and volume losses seen in major burns.

Question 27General Surgery

A 38-year-old woman is found to have a solitary 2.5 cm nodule in the left lobe of the thyroid. Fine needle aspiration cytology is reported as Bethesda category IV (follicular neoplasm). Which statement best describes the limitation of cytology in this situation?

  1. Cytology cannot reliably distinguish a follicular adenoma from a follicular carcinoma because capsular or vascular invasion cannot be assessed on aspirated cells Correct answer.
  2. Cytology is diagnostic of malignancy in this category, so the reported result already confirms carcinoma
  3. Cytology is unreliable because follicular neoplasms almost never yield adequate cellular material for interpretation
  4. Cytology can distinguish benign from malignant lesions only when the nodule exceeds 4 cm in diameter

Explanation

The diagnosis of follicular carcinoma rests on demonstrating capsular or vascular invasion at the interface between the nodule and surrounding thyroid tissue, a feature that requires examination of the intact surgical specimen. Aspirated cells can show a follicular pattern but cannot show whether invasion is present, so Bethesda IV is managed by diagnostic hemithyroidectomy rather than by cytology alone.

Question 28General Surgery

A 58-year-old man has a 3 cm adenocarcinoma of the sigmoid colon. Staging CT shows no distant metastases. Which single feature most strongly predicts a poor prognosis and therefore guides the decision for adjuvant chemotherapy?

  1. Absence of visible peritumoural inflammation
  2. Patient age of 58 years
  3. Tumour diameter of 3 cm
  4. Presence of lymphovascular invasion in the resected specimen Correct answer.

Explanation

Lymphovascular invasion is a recognised high-risk histological feature in node-negative colorectal cancer and, along with perineural invasion, poor differentiation, T4 stage and perforation, supports offering adjuvant chemotherapy. Tumour size, patient age and the absence of peritumoural inflammation are not validated prognostic determinants used to select adjuvant treatment in this setting.

Question 29General Surgery

A 55-year-old man is undergoing a laparoscopic totally extraperitoneal inguinal hernia repair. Which anatomical landmark defines the boundary between the direct and indirect hernia spaces in this approach?

  1. The inferior epigastric vessels Correct answer.
  2. The deep inguinal ring
  3. The iliopubic tract
  4. The lacunar ligament

Explanation

The inferior epigastric vessels divide the myopectineal orifice into a medial direct space and a lateral indirect space, and this relationship is used to classify hernias during laparoscopic repair. The deep inguinal ring is the entry point of an indirect hernia, while the iliopubic tract and lacunar ligament are distinct structures of the posterior inguinal floor.

Question 30Cardiothoracic Surgery

A 24-year-old man sustains a blunt left chest injury in a road traffic collision. He is hypotensive with distended neck veins, muffled heart sounds and a systolic blood pressure that falls further on inspiration. Which bedside finding is most consistent with cardiac tamponade?

  1. Pulsus parvus et tardus
  2. Pulsus paradoxus Correct answer.
  3. Pulsus alternans
  4. Pulsus bisferiens

Explanation

Cardiac tamponade raises intrapericardial pressure so that right ventricular filling is impaired during inspiration, producing an exaggerated fall in systolic pressure of more than 10 mmHg, which is pulsus paradoxus. The other pulse abnormalities reflect left ventricular dysfunction, aortic regurgitation or aortic stenosis rather than pericardial constraint.

Question 31Cardiothoracic Surgery

Which coronary artery is most commonly injured during an uncomplicated orthotopic heart transplantation when the standard biatrial technique is used?

  1. Left anterior descending artery
  2. Circumflex artery
  3. Left main coronary artery
  4. Right coronary artery Correct answer.

Explanation

During excision of the recipient heart the right coronary artery is the vessel most vulnerable to injury because of its anterior course in the atrioventricular groove close to the transection lines. Injury to this vessel is a recognised cause of early right ventricular dysfunction after transplantation.

Question 32Cardiothoracic Surgery

A 62-year-old smoker presents with haemoptysis and a 2 cm peripheral lung nodule. Staging CT shows no mediastinal lymphadenopathy and no distant metastases. What is the most appropriate next step in management?

  1. Repeat CT in six months
  2. Perform mediastinoscopy before any imaging
  3. Start empirical antituberculous therapy
  4. Refer for surgical resection after cardiopulmonary assessment Correct answer.

Explanation

A solitary peripheral nodule suspicious for malignancy with no evidence of nodal or distant spread should be assessed for curative surgical resection once fitness is established. Delay for empirical treatment or repeat imaging risks progression of an early curable cancer.

Question 33Cardiothoracic Surgery

Which finding on transthoracic echocardiography best supports a diagnosis of infective endocarditis in a patient with a prosthetic aortic valve?

  1. Mild aortic regurgitation
  2. Left atrial dilatation
  3. A mobile echodense mass attached to the valve Correct answer.
  4. Increased left ventricular wall thickness

Explanation

A mobile echodense mass on a prosthetic valve represents a vegetation and is a major echocardiographic criterion for infective endocarditis. Regurgitation, hypertrophy and atrial dilatation are non-specific and can occur without infection.

Question 34Cardiothoracic Surgery

A patient develops sudden hypotension and a falling haemoglobin level two hours after coronary artery bypass grafting, with chest drain output of 300 mL per hour. What is the most appropriate immediate action?

  1. Perform pericardiocentesis
  2. Increase intravenous fluids and observe for another four hours
  3. Return to theatre for re-exploration Correct answer.
  4. Start a nitrate infusion

Explanation

Chest drain loss exceeding 200 mL per hour for two consecutive hours, or a sudden large loss with haemodynamic compromise, indicates likely surgical bleeding and warrants urgent re-exploration. Observation risks unrecognised tamponade and haemorrhagic shock.

Question 35Cardiothoracic Surgery

Which of the following is the most common congenital cardiac anomaly overall?

  1. Atrial septal defect
  2. Coarctation of the aorta
  3. Tetralogy of Fallot
  4. Bicuspid aortic valve Correct answer.

Explanation

Bicuspid aortic valve is the most common congenital cardiac anomaly, occurring in roughly 1 to 2 percent of the population. Many other lesions are individually rarer, and tetralogy of Fallot and coarctation are far less frequent.

Question 36Cardiothoracic Surgery

In a patient with a type B aortic dissection who has an uncomplicated course with adequate blood pressure control, what is the preferred initial management?

  1. Thoracic endovascular aortic repair
  2. Medical management with anti-impulse therapy Correct answer.
  3. Immediate open surgical repair
  4. Thrombolysis

Explanation

Uncomplicated type B dissection is managed medically with strict blood pressure and heart rate control to reduce aortic wall stress. Intervention is reserved for complications such as malperfusion, rupture or refractory pain.

Question 37Cardiothoracic Surgery

Which statement best describes the physiological consequence of a large left-to-right shunt through an atrial septal defect?

  1. Reduced pulmonary blood flow
  2. Left ventricular volume overload
  3. Right ventricular volume overload Correct answer.
  4. Systemic hypoxaemia from the outset

Explanation

A left-to-right shunt at atrial level increases pulmonary blood flow and returns a larger volume to the right atrium and ventricle, producing right ventricular volume overload. Systemic oxygenation remains normal until shunt reversal occurs.

Question 38Cardiothoracic Surgery

A 68-year-old man has severe symptomatic aortic stenosis with a mean gradient of 50 mmHg and preserved ejection fraction. Coronary angiography shows no significant coronary disease. Which procedure offers the best long-term outcome?

  1. Balloon aortic valvuloplasty
  2. Percutaneous coronary intervention
  3. Surgical aortic valve replacement Correct answer.
  4. Medical therapy with statins

Explanation

Symptomatic severe aortic stenosis is an indication for valve replacement, and surgical replacement offers durable long-term outcomes in a suitable candidate. Balloon valvuloplasty provides only temporary palliation.

Question 39Cardiothoracic Surgery

Which feature on chest radiography is most characteristic of a tension pneumothorax?

  1. Mediastinal shift away from the affected side Correct answer.
  2. Bilateral hilar enlargement
  3. Basal pleural thickening
  4. Mediastinal shift towards the affected side

Explanation

Tension pneumothorax raises intrathoracic pressure on the affected side and pushes the mediastinum away from it, often with depression of the hemidiaphragm. This is a clinical diagnosis requiring immediate decompression, not waiting for imaging.

Question 40Cardiothoracic Surgery

Which vessel is most commonly used for coronary artery bypass grafting because of its long-term patency?

  1. Radial artery
  2. Saphenous vein
  3. Gastroepiploic artery
  4. Left internal thoracic artery Correct answer.

Explanation

The left internal thoracic artery grafted to the left anterior descending artery has the best documented long-term patency and survival benefit, making it the conduit of choice. Vein grafts degenerate more rapidly.

Question 41Cardiothoracic Surgery

A patient with a flail chest and pulmonary contusion becomes hypoxaemic despite oxygen. What is the most important initial ventilatory strategy?

  1. Immediate surgical fixation before any ventilation
  2. Chest strapping to stabilise the segment
  3. Non-invasive ventilation or intubation with positive pressure support Correct answer.
  4. High-dose corticosteroids

Explanation

Positive pressure ventilation splints the flail segment and improves oxygenation in pulmonary contusion, so non-invasive or invasive support is the mainstay. Chest strapping impairs ventilation and increases the risk of pneumonia.

Question 42Cardiothoracic Surgery

Which of the following best explains why the modified Blalock-Taussig shunt relieves cyanosis in tetralogy of Fallot?

  1. It closes the ventricular septal defect
  2. It increases pulmonary blood flow from a systemic artery Correct answer.
  3. It reduces systemic vascular resistance
  4. It relieves right ventricular outflow obstruction

Explanation

The modified Blalock-Taussig shunt connects a systemic artery to the pulmonary artery, increasing pulmonary blood flow and thus oxygenation in cyanotic patients with reduced pulmonary perfusion. It does not correct the intracardiac anatomy.

Question 43Cardiothoracic Surgery

A patient is being assessed for lung volume reduction surgery. Which feature predicts the greatest benefit?

  1. Active cigarette smoking
  2. Upper lobe predominant emphysema with low exercise capacity Correct answer.
  3. Severe pulmonary hypertension
  4. Homogeneous emphysema with preserved diffusion capacity

Explanation

The National Emphysema Treatment Trial showed greatest benefit from lung volume reduction surgery in patients with upper lobe predominant emphysema and low baseline exercise capacity after rehabilitation. Homogeneous disease and pulmonary hypertension carry higher risk.

Question 44Cardiothoracic Surgery

Which is the most appropriate initial investigation for suspected acute pulmonary embolism in a haemodynamically stable patient with normal renal function?

  1. CT pulmonary angiography Correct answer.
  2. Transthoracic echocardiography
  3. Ventilation-perfusion scintigraphy
  4. D-dimer measurement

Explanation

CT pulmonary angiography is the first-line imaging test in stable patients with suspected pulmonary embolism when renal function permits contrast. D-dimer is useful mainly to exclude the diagnosis in low-probability patients.

Question 45Cardiothoracic Surgery

Which of the following is a recognised indication for emergency thoracotomy in penetrating chest trauma?

  1. Cardiac tamponade with witnessed cardiac arrest and ongoing resuscitation Correct answer.
  2. Subcutaneous emphysema alone
  3. Stable small haemothorax
  4. Isolated rib fracture

Explanation

Emergency thoracotomy may be indicated in penetrating trauma with witnessed arrest and signs of life during ongoing resuscitation, offering a chance of survival. The other findings do not warrant such an invasive emergency procedure.

Question 46Cardiothoracic Surgery

What is the most common cause of a late complication requiring reoperation after mitral valve repair with an annuloplasty ring?

  1. Ring dehiscence or recurrent mitral regurgitation Correct answer.
  2. Tricuspid atresia
  3. Acute valve thrombosis
  4. Aortic dissection

Explanation

Late failure after mitral repair most often results from ring dehiscence or progressive leaflet disease causing recurrent regurgitation. Valve thrombosis is more typical of mechanical prostheses, and the other conditions are unrelated.

Question 47Cardiothoracic Surgery

Which finding on spirometry is characteristic of a patient with a large pleural effusion before drainage?

  1. Obstructive pattern with reduced forced expiratory volume in one second to forced vital capacity ratio
  2. Normal spirometry
  3. Increased diffusion capacity
  4. Restrictive pattern with reduced forced vital capacity Correct answer.

Explanation

A large pleural effusion compresses the lung and reduces lung volumes, producing a restrictive pattern with reduced forced vital capacity and preserved or increased ratio. Drainage typically improves these values.

Question 48Cardiothoracic Surgery

A 70-year-old woman has a 3 cm solitary pulmonary nodule with mediastinal lymph node enlargement on CT. What is the most appropriate next step to complete staging?

  1. Immediate lobectomy
  2. Endobronchial ultrasound-guided transbronchial needle aspiration Correct answer.
  3. Repeat CT in three months
  4. Bronchoalveolar lavage

Explanation

Enlarged mediastinal nodes require tissue sampling to stage the mediastinum before any resection, and endobronchial ultrasound-guided aspiration is a minimally invasive method. Proceeding directly to surgery risks futile resection in N2 disease.

Question 49Cardiothoracic Surgery

Which statement about the Fontan circulation is correct?

  1. It requires a systemic-to-pulmonary shunt
  2. It is performed in the first week of life
  3. A systemic ventricle pumps blood directly into the pulmonary arteries
  4. Systemic venous pressure drives pulmonary blood flow without a subpulmonary ventricle Correct answer.

Explanation

In the Fontan circulation, systemic venous return is directed to the pulmonary arteries so that central venous pressure drives pulmonary blood flow, with no subpulmonary pumping chamber. This places the burden on the single systemic ventricle.

Question 50Cardiothoracic Surgery

Which of the following is the most common site of metastasis from a primary lung carcinoma?

  1. Spleen
  2. Skin
  3. Pancreas
  4. Brain Correct answer.

Explanation

The brain is a frequent site of haematogenous metastasis in lung cancer, particularly with small cell and adenocarcinoma histology, and staging often includes brain imaging. The other organs are much less commonly involved.