10 - surgery mcqs - 61 to 70

61. Infantile hypertrophic pyloric stenosis

a. Occurs with a male : female ratio of 4:1.

b. Sons of affected mothers have a 20% risk of developing the lesion

c. Invariably presents between six and eights months of age

d. Typically presents with bile stained projectile vomiting

e. Surgical treatment is by Heller's Cardiomyotomy

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only a and b are true . it usually presents between 3 and 6 weeks of age . vomit is not usually bile stained . operation done to treat is called ramstedt's pyloromyotomy . heller's cardiomyotomy is done for achalasia cardia .

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62. Oesophageal atresia

a. Is often associated with a distal trachea-oesophageal fistula

b. Polyhydramnios is often present late in pregnancy

c. 50% have other associated congenital abnormalities

d. Contrast X-ray studies are necessary to confirm the diagnosis

e. Post-operatively over 30% develop oesophageal strictures

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a , b , c , e are true . 80 % cases are associated with distal TOF . fallot's tetralogy and VSD often occur with oesophageal atresia . contrast studies are dangerous as it can lead to aspiration . ( contrast media can be aspirated ) . diagnosis can be confirmed by failure to pass a radio opaque nasogastric tube .

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63. The following are features of Fallot's Tetralogy

a. An atrial septal defect

b. Pulmonary stenosis

c. Right ventricular hypertrophy

d. A left to right cardiac shunt

e. Cyanotic attacks during feeding and crying

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b , c , e are the right answers . right to left shunt . features of TOF are PS , VSD , RVH , OVER-RIDING OF AORTA .

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64. Phaeochromocytomas

a. Are neuroendocrine tumours of the adrenal cortex

b. Are benign in 90% of cases

c. Occur as part of the MEN type I syndrome

d. Can be imaged with a meta-iodobenzylguanidine scan

e. Require only beta-blockade prior to surgery

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only b and d are true . 90 % pheochromocytomas arise in adrenal medulla . occur as part of MEN II a and MEN II b syndromes. pre- operative alpha and beta blockade is essential .

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65. Regarding Cushing's Syndrome

a. 80% of cases are due to pituitary adenomas (Cushing's Disease)

b. Most ACTH secreting pituitary adenomas are more than 2 cm in diameter

c. Is characterised by loss of the diurnal rhythm of cortisol secretion

d. Cortisol production is suppressed by low-dose dexamethasone

e. Adrenal carcinomas are more common than adrenal adenomas

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only a and c are true . most microadenomas are less than 1 cm in diameter . adrenal adenomas are three times more common than adrenal carcinomas .Dexamethasone suppression tests are intended to mimic the physiology of the pituitary, which in the presence of steroids decreases the release of ACTH causing a fall in plasma and urine cortisol level. In Cushing syndrome, a loss of sensitivity to glucocorticoids occurs and ACTH is therefore not suppressed and adrenal production of cortisol is not affected. The overnight 1-mg dexamethasone suppression test requires administration of 1 mg of dexamethasone at 11 pm with subsequent measurement of cortisol level at 8 am. In healthy individuals, the serum cortisol level should be less than 2-3 mcg/dL. To enhance the sensitivity of the test, a cutoff value of less than 1.8 mcg/dL (50 nmol/L) excludes Cushing syndrome. Its ease of administration makes the 1-mg dexamethasone suppression test a widely used screening tool.

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66. The following are complications of parenteral nutrition

a. Hyperglycaemia

b. Hypoglycaemia

c. Hypokalaemia

d. Hyperkalaemia

e. Hypercalcaemia

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all can occur .

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67. The functions of a tracheostomy are to

a. Bypass an upper airway obstruction

b. Increase the anatomical dead space

c. Increase airway resistance

d. Protect against aspiration

e. Allow frequent airway suction

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a , d , e are true ... it reduces the anatomical dead space by approximately 15 % . it decreases airway resistance .

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68. Regarding Hydatid disease

a. Is due to Entamoeba histolytica

b. Man is an accidental intermediate host

c. The liver is the commonest site of infection

d. Can be diagnosed by the Casoni test

e. Is resistant to treatment by metronidazole

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hydatid cyst is due to echinococcus granulosus . it is sensitive to metronidazole . liver infection is characterised by a characteristic three layered cyst .

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69. Medullary carcinoma of the thyroid

a. Is a tumour of the parafollicular C cells

b. Produce thyroxine as the principle hormone

c. 10% of cases are sporadic

d. Can occur as part of the MEN type II syndrome

e. Total thyroidectomy is the surgical treatment of choice

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a , d , e are true . produce calcitonin as the principal hormone . 90 % cases are sporadic .

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70. The following are features of thyrotoxicosis

a. Weight gain

b. Palpitations

c. Proximal myopathy

d. Increased skin pigmentation

e. Pretibial myxoedema

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b , c , d , e are all the features . thyrotoxicosis presents with weight loss.

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