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Preguntas y Respuestas 6 Cirugía General

Preguntas y Respuestas 6

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Preguntas y RespuestasPreparación para el examen USMLE y ENARM

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Page 1: Preguntas y Respuestas 6

Preguntas y Respuestas 6

Cirugía General

Page 2: Preguntas y Respuestas 6

1. A postoperative patient with protracted vomiting is like to have: A. Metabolic acidosis.

B. Respiratory acidosis.

C. Metabolic alkalosis.

D. Lactic acidosis.

E. Microcytic anemia.

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1. Answer: C. Protracted vomiting leads to loss of hydrogen ions and a metabolic alkalosis.

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9. The most lateral femoral structure in the anatomic position of the groin is: A. Artery.

B. Lymphatics.

C. Empty space.

D. Nerve.

E. Vein.

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9. Answer: D. One can use the mnemonic NAVEL (nerve, artery, veil, empty space, lymphatic) to remember the position of groin structures from lateral to medial.

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10. A hernia that arises lateral to the inferior epigastric vessels is which of the following? A. Indirect inguinal hernia.

B. Direct inguinal hernia.

C. Femoral hernia.

D. Obturator hernia.

E. Sliding hernia.

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10. Answer: A. An indirect inguinal hernia arises lateral to the epigastric vessels, a direct hernia arises medial to the vessels, a femoral hernia is found through the femoral canal, an obturator hernia protrudes through the obturator canal, and a sliding hernia is any hernia where a portion of the sac is made up of the wall of an intra-abdominal organ.

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12. The borders of the Hesselbach triangle do not include: A. The lateral border of the rectus muscle.

B. The inguinal ligament inferiorly.

C. The semilunar line superiorly.

D. The inferior epigastric vessels.

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12. Answer: C. The structure not included in the borders of the triangle is the semilunar line. The semilunar line is related to Spigelian hernias.

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15. Mallory–Weiss syndrome: A. Is usually fatal.

B. Is best treated with surgery.

C. Requires CT scanning for diagnosis.

D. Can usually be treated endoscopically.

E. Mandates Helicobacter pylori testing.

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15. Answer: D. Mallory–Weiss Syndrome, a condition of bleeding from a mucosal rent at the gastroesophageal junction, has a fairly benign course and can almost always be diagnosed and treated with endoscopic hemostatic maneuvers. It is not associated with H. pylori infection.

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26. A 40-year-old woman with a long history of oral contraceptive use complains of chronic abdominal pain. Ultrasound reveals a well circumscribed 3-cm lesion in the right lobe of the liver. Angiography of the mass reveals hypervascularity. Liver biopsy reveals normal hepatocytes without evidence of hemorrhage or necrosis. Which of the following laboratory findings would be expected in this patient? A. Elevated AST.

B. Elevated ALT.

C. Elevated alkaline phosphatase.

D. Elevated lipase.

E. Normal amylase.

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26. Answer: E.

This patient likely has hepatocellular adenoma. This tumor is common in women who take oral contraceptives. Pathology reveals normal hepatocytes. Laboratory studies in these patients reveal normal liver function testing. Angiography is present from hypervascularity.

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31. A 65-year-old man is seen in the clinic with a history of central abdominal pain, jaundice, and weight loss. A CT scan shows an irregular mass in the head of pancreas. Which of the following is NOT indicated? A. Serum CA 19-9 and CEA assay.

B. Percutaneous image-guided biopsy of the mass for tissue diagnosis.

C. Endoscopic ultrasound to assess respectability.

D. ERCP with CBD stent placement for relief of obstructive jaundice.

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31. Answer: B. CA 19-9 is a tumor marker sensitive for pancreatic cancer. Endocopic ultrasound can help in identifying locally advanced disease and is also useful for obtaining biopsies. Percutaneous biopsies of pancreatic masses can seed tumor in the biopsy.

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33. A 52-year-old woman with chronic diarrhea, weight loss, and lower abdominal pain undergoes exploratory laparotomy. Findings include an intense desmoplastic reaction causing fibrosis, intestinal kinking, and obstruction at the level of the cecum and appendix. The lesion measures 3 cm in size. Preoperatively, her laboratory values included elevated urinary levels of 5-hydroxyindoleacetic acid in 24-hour urine and serum chromogranin A. What is the most appropriate treatment for this patient? A. Segmental intestinal resection.

B. Wide excision of bowel and mesentery.

C. Right hemicolectomy.

D. Local excision.

E. Pancreaticduodenectomy.

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33. Answer: B.

This patient has pathologic evidence of a large small-bowel carcinoid tumor. Treatment for tumors larger than 1 cm, multiple tumors, or lymph node involvement is wide excision of bowel and mesentery. Tumors less than 1 cm without evidence of metastatic disease can be treated with segmental intestinal resection. Tumors in the terminal ileum are managed with right hemicolectomy, while large duodenal tumors are managed with pancreaticoduodenectomy

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34. A 45-year-old white man complains of fatigue and weight gain during the past few months. He is worried because his first cousin was diagnosed as having thyroid carcinoma last year. Physical examination reveals a nodule in the upper lobe of the right thyroid gland. Serum electrolytes are as follows: sodium 135 mEq/L, potassium 5 mEq/L, chloride 104 mEq/L, and calcium-6.1 mg/dL. What is the most likely diagnosis? A. Anaplastic carcinoma of the thyroid gland.

B. Follicular carcinoma of the thyroid gland.

C. Hashimoto thyroiditis.

D. Medullary carcinoma of the thyroid gland.

E. Papillary carcinoma of the thyroid gland.

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34. Answer: D.

This patient most likely has medullary carcinoma of the thyroid. The medulla of the thyroid produces calcitonin, which inhibits osteoclast destruction of bone and helps to keep blood calcium levels low. This patient’s calcium level was 6.1, which is below the normal range of 8.4 to 10.2, and makes a calcitonin-producing tumor of the thyroid most likely.

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39. A 65-year-old man presents to his physician with a lesion present on his nose. Examination reveals a raised, shiny, papular lesion with small blood vessels. What is the most likely diagnosis? A. Basal cell carcinoma.

B. Squamous cell carcinoma.

C. Malignant melanoma.

D. Merkel cell carcinoma.

E. Histiocytosis X.

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39. Answer: A.

Basal cell carcinomas are the most common skin tumors. They tend to involve skin-exposed areas most often in the head and neck. Grossly, they are characterized by a pearly papule with overlying telangiectatic vessels. The lower lip is actually the most common site for a tobacco user to develop squamous cell carcinoma. Malignant melanomas are the most likely primary skin tumors to metastasize systemically.

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42. The most significant risk factor for abdominal aortic aneurysm rupture is: A. Male sex.

B. Obesity.

C. History of smoking.

D. Aneurysm diameter.

E. Aneurysm length.

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42. Answer: D. The risk of abdominal aortic aneurysm rupture is most dependent upon its diameter, with diameter greater than 5.5 cm at higher risk.

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49. A 7-year-old boy presents to the emergency department with a history of passing a large, bloody bowel movement. Vital signs are stable. Further workup using a technetium scan localizes ectopic gastric mucosa in the lower abdomen. Failure to obliterate which structure in the developing fetus gives rise to this anomaly? A. Cardinal veins.

B. Ductus venosus.

C. Vitelline duct.

D. Omphalomesenteric duct.

E. Stenson duct.

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49. Answer: C.

Meckel diverticulum is a congenital sacculation of the distal ileum. It is usually located within 2 feet of the ileocecal valve and varies in length from 1 to 6 inches. Normal obliteration of the vitelline duct usually occurs around the seventh week of fetal development. If the ileal portion of this structure is not obliterated, a Meckel diverticulum forms. It is a true congenital diverticulum and therefore contains heterotopic tissue of the digestive tract. Bleeding is often profuse but not life threatening. The most severe complication is intestinal obstruction. Treatment involves surgical resection.

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53. A 16-year-old boy presents to the emergency department with severe acute onset of right testicular pain that began 2 hours ago. There was no history of trauma to the testicle and the patient reports being in good health with no recent illness. Upon examination, the patient was afebrile, and the right testicle was swollen, painful, and high riding with a horizontal lie. Elevation of the testicle by the examiner provided some relief of pain. What is the most likely diagnosis? A. Epididymitis.

B. Bacterial prostatitis.

C. Henoch–Schönlein purpura.

D. Testcular carcinoma.

E. Testicular torsion.

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53. Answer: E.

Testicular torsion is indeed a urologic emergency. A high-riding testicle in a horizontal lie in which elevation of the testicle provides relief.

The critical time of ischemia for testicular torsion is 4 hours and if a gangrenous testicle is missed, the patient will be at a high risk of sterility due to his body mounting an autoimmune response to his own sperm.

Appropriate management is immediate bilateral orchiopexy because the contralateral testicle is also at an increased risk of torsion. Some examiners would still use a sonogram of the testicle to rule out testicular torsion.

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54. On the second postoperative day you notice that one of the patients you are caring for while on surgery rotation sounds hoarse. He recently underwent a thyroidectomy to remove a cancerous lesion. Throughout his hospital stay you observe that his voice remains hoarse and does not improve with time. Which of the following structures was most likely injured during the operation? A. Superficial branch of the laryngeal nerve.

B. Cricothyroid nerve.

C. Superior thyroid nerve.

D. Recurrent laryngeal nerve.

E. Accessory laryngeal nerve.

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54. Answer: D.

The recurrent laryngeal nerve has been injured. Thyroidectomy is the treatment of choice for patients diagnosed with thyroid cancer. Although this is a rare complication (occurring in only 1% of patients), it soon becomes apparent when the patient assumes a husky and hoarse voice. This injury may cause temporary voice pathology lasting 6 to 12 months or it may be a permanent issue.

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61. A 52-year-old executive and heavy smoker tells you in the emergency room that he developed sudden overwhelming epigastric pain at 8:15 AM. His skin feels clammy and he is tachycardic, and his abdomen is rigid. The most likely diagnosis is: A. Appendicitis.

B. Pelvic inflammatory disease.

C. Perforated peptic ulcer.

D. Acute cholecystitis.

E. Right lower lobe pneumonia.

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61. Answer: C.

Perforated peptic ulcer. Patients who perforate a hollow viscus can often remember the exact time it occurs, based on the suddenness of onset and intensity of pain. The other choices would have more gradual onset of pain and associated symptoms.

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64. The safest time to operate on a pregnant patient for acute appendicitis is: A. First trimester.

B. After an induced delivery, even if premature.

C. Second trimester.

D. Third trimester.

E. Early morning.

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64. Answer: C.

The second trimester is the safest interval to operate on a pregnant woman.