Surgery USMLE (523-626)

A 25-year-old woman presents to the emergency room complaining of redness and pain in her right foot up to the level of the midcalf. She reports that her right lower extremity has been swollen for at least 15 years, but her left leg has been normal. On physical examination, she has a temperature of 39°C (102.2°F) and the right lower extremity is nontender with nonpitting edema from the groin down to the foot. There is cellulitis of the right foot without ulcers or skin discoloration. The left leg is normal. Which of the following is the most likely underlying problem?

A blond, blue-eyed, 69-year-old sailor has a non-healing, indolent, 1.5-cm ulcer on the lower lip, arising from the vermilion border. The ulcer has been present and growing for the past 8 months. He is a pipe smoker, but has no history of alcohol or drug abuse. Physical examination shows "weather-beaten" facial skin, but no other ulcers. There are no enlarged lymph nodes in his neck. Which of the following is the most likely diagnosis?

A 30-year-old woman presents with hypertension, weakness, bone pain, and a serum calcium level of 15.2 mg/dL. Hand films below show osteitis fibrosa cystica. Which of the following is the most likely cause of these findings?

A 35-year-old woman presents with a serum calcium level of 15.2 mg/dL and an elevated parathyroid hormone level. Following correction of the patient’s hypercalcemia with hydration and furosemide, which of the following is the best therapeutic approach?

A 65-year-old man presents to the emergency department with sudden onset of pain and weakness of the left lower extremity of 2-hour duration. Past history reveals chronic atrial fibrillation following a myocardial infarction 12 months ago. On examination, he is found to have a cool, pale left lower extremity with decreased strength and absent popliteal and pedal pulses. The opposite leg has a normal appearance with palpable pulses. Following successful treatment for an embolus to the left femoral artery with no evidence of a reperfusion injury (anticoagulation with heparin and thromboembolecctomy), which of the following long-term treatments would most likely decrease the chance of recurrent embolus ?

A 65-year-old man presents to the emergency department with an abrupt onset of excruciating chest pain 1 hour ago. The pain is localized to the anterior chest, but radiates to the back and neck. On examination, the patient is afebrile, with a BP of 210/110 mmHg, pulse rate of 95/min, and a respiratory rate of 12/min. He appears pale and sweaty. Unequal carotid, radial, and femoral pulses are noted. An electrocardiogram (ECG) shows nonspecific ST-T segment changes. Chest x-ray shows a slightly widened mediastinum and normal lung fields. Which of the following is the preferred modality in establishing the diagnosis?

A 63-year-old man has a chylothorax that after 2 weeks of conservative therapy appears to be persistent. The chest tube output is approximately 600 mL/day. Appropriate management at this time includes which of the following procedures?

A 32-year-old woman has a CXR screening, and a 1.5-cm mass is noted in the right lower lobe. She is a nonsmoker. Bronchoscopy shows a mass in the right lower lobe orifice, covered with mucosa. Biopsy indicates this is compatible with a carcinoid tumor. Imaging suggests ipsilateral mediastinal lymph node involvement but no extrathoracic disease. Which of the following is the most appropriate treatment plan?

A 55-year-old woman presents with a 6-month history of weight loss, abdominal cramps, and intermittent nonbloody diarrhea. On examination, her abdomen is mildly distended and there is a palpable mass in the right lower quadrant. Stool cultures yield normal fecal flora. CT scan with oral contrast demonstrates an inflammatory mass in the right lower quadrant, with thickening of the terminal ileum and ileocecal valve. Initial management should include which of the following?

A 13-year-old boy is brought to the emergency department at midnight with a 4-hour history of right scrotal pain that was sudden in onset and associated with nausea and one episode of vomiting. On examination, he is in obvious distress. He has mild right lower abdominal tenderness, and high-riding, tender right testes. CBC and urinalysis are normal. Which of the following is the most appropriate next step in management?

A 33-year-old woman is found to have a palpable thyroid nodule during a routine medical checkup. A sonogram confirms the presence of a solid, 1.5-cm nodule in the right lobe of the thyroid gland. Fine needle aspirate cytology (FNA) is reported as "follicular tumor, otherwise unspecified." At surgery, a frozen section is read as follicular carcinoma. With the neck open, the surgeon can feel for enlarged jugular and peritracheal lymph nodes, and finds none. Which of the following is the most appropriate treatment?

A 63-year-old woman with chronic obstructive pulmonary disease (COPD) presents with a several-week history of fever, night sweats, weight loss, and cough. Her CXR is noted to have a density in the left upper lobe with a relatively thin-walled cavity. Bronchoscopy and computed tomographic (CT) scan are suggestive of a lung abscess rather than a malignant process. Which of the following is the most appropriate initial management of this patient?

A 50-year-old salesman is on a yacht with a client when he has a severe vomiting and retching spell punctuated by a sharp substernal pain. He arrives in your emergency room 4 hours later and has a chest film in which the left descending aorta is outlined by air density. Which of the following is the most appropriate next step in his workup?

An elderly man is involved in a rear end automobile collision in which he hyperextends his neck. He develops paralysis and burning pain of both upper extremities, while maintaining good motor function in his legs. Which of the following is the most likely diagnosis?

A 4-year-old previously healthy girl presents to the emergency department with a 24-hour history of rectal bleeding and dizziness. She has no other gastrointestinal symptoms. On examination, she appears pale. Her heart rate is 140 beats/min, and she has a 20 mmHg postural drop in systolic blood pressure. The child’s abdomen is nondistended and nontender, and fresh blood and clots are in the rectal vault on rectal examination. Which of the following is the most appropriate diagnostic study to order for this patient?

A 4-year-old previously healthy girl presents to the emergency department with a 24-hour history of rectal bleeding and dizziness. She has no other gastrointestinal symptoms. On examination, she appears pale. Her heart rate is 140 beats/min, and she has a 20 mmHg postural drop in systolic blood pressure. The child’s abdomen is nondistended and nontender, and fresh blood and clots are in the rectal vault on rectal examination. Definitive management of this child should include which of the following?

A 29-year-old nonhelmeted motorcycle driver is involved in a single vehicular crash, resulting in a significant closed-head injury. He is intubated in the field and transported to a level 1 trauma center. On arrival, he is oxygenating well with assisted ventilation and has a normal blood pressure and moderate tachycardia. His Glasgow Coma Score is 7, and his pupils are equal and sluggishly reactive. After stabilization in the emergency department, the patient undergoes a CT scan of the head that demonstrates a small amount of subarachnoid blood and a right frontal lobe contusion with edema with no midline shift. CT scan of the abdomen is normal. The patient is transferred to the ICU. The optimal initial management of this patient’s intracranial pressure (ICP) would be which of the following?

A 53-year-old woman presents with weight loss and a persistent rash to her lower abdomen and perineum. She is diagnosed with necrolytic migrating erythema and additional workup demonstrates diabetes mellitus, anemia and a large mass in the tail of the pancreas. Which of the following is the most likely diagnosis?

A 49-year-old obese man has become irritable, his face has changed to a round configuration, he has developed purplish lines on his flanks, and he is hypertensive. A 24-hour urine collection demonstrates elevated cortisol levels. This is confirmed with bedtime cortisol measurements of 700 ng/mL. Which of the following findings is most consistent with the diagnosis of Cushing disease?

A 70-year-old man presents with back pain and increasing difficulty with initiating a urinary stream. On rectal examination, he is found to have a hard, irregularly enlarged prostate. He has an elevated prostate-specific antigen (PSA), and osteoblastic lesions in the vertebral column and bones of the pelvis. A needle biopsy of the prostate shows well-differentiated adenocarcinoma. Which of the following is the treatment of choice?

A 25-year-old previously healthy man is scheduled for elective inguinal hernia repair under general anesthesia. After induction of anesthesia and initial inguinal incision, the patient develops tachycardia, muscle rigidity, fever of 38.5°C, and elevated end-tidal carbon dioxide. Which of the following is the most likely diagnosis?

A 66-year-old woman presents with severe right lower extremity claudication. Surgery is considered, but her hypertension, smoking, and diabetes puts her at risk for associated coronary heart disease. What test is most predictive of postoperative ischemic cardiac events following surgery?

A 5-week-old infant presents with a 1-week history of progressive nonbilious emesis, associated with a 24-hour history of decreased urine output. The infant continues to be active and eager to feed. On examination, the infant has a sunken fontanels and decreased skin turgor. The abdomen is scaphoid, and with a test feed, there is a visible peristaltic wave in the epigastrium. Electrolytes and a urinalysis are evaluated. Which of the following laboratory findings are most likely to be seen in this patient?

A 5-week-old infant presents with a 1-week history of progressive nonbilious emesis, associated with a 24-hour history of decreased urine output. The infant continues to be active and eager to feed. On examination, the infant has a sunken fontanelle and decreased skin turgor. The abdomen is scaphoid, and with a test feed, there is a visible peristaltic wave in the epigastrium. Which of the following is the most appropriate next step in management of this infant?

A 49-year-old woman has a firm, 2-cm mass in the right breast that has been present for 3 months. Mammogram has been read as "cannot rule out cancer," but it cannot diagnose cancer either. A fine-needle aspiration of the mass (FNA) and cytology do not identify any malignant cells. Which of the following is the most appropriate next step in management?

A 60-year-old man sees a urologist for what he describes as bloody urine. A urine sample is positive for cytologic evidence of malignancy. Cystoscopy confirms the presence of superficial transitional cell carcinoma. Which of the following is the recommended treatment for stage A (superficial and submucosal) transitional cell carcinoma of the bladder ?

A 36-year-old man presents to the emergency room with renal colic. His vital signs are normal and a urinalysis shows microscopic hematuria. A radiograph reveals a 1.5-cm stone. Which of the following is the most appropriate management of this patient?

An 8-month-old boy is seen by a pediatrician for the first time. The physician notes that there are no testes in the scrotum. Which of the following is the optimal management of bilateral undescended testicles in an infant?

A 55-year-old man presents to the emergency department with left lower quadrant abdominal pain. The pain has been present for 1 week, but has increased in intensity over the last 2 days associated with nausea, constipation, and dysuria. Past history is unremarkable. Examination reveals a temperature of 101°F, pulse rate of 95/min, BP of 130/70 mmHg, and normal heart and lung examinations. Abdominal examination reveals fullness and marked tenderness in the left lower quadrant, with voluntary guarding and decreased bowel sounds. Laboratory tests reveal a WBC count of 18,000 with a left shift and 20–50 WBCs in the urinalysis. A CT scan of the abdomen reveals a thickened sigmoid colon with pericolonic inflammation. He is admitted to the hospital for treatment. Which of the following is the most likely diagnosis?

A 55-year-old man presents to the emergency department with left lower quadrant abdominal pain. The pain has been present for 1 week, but has increased in intensity over the last 2 days associated with nausea, constipation, and dysuria. Past history is unremarkable. Examination reveals a temperature of 101°F, pulse rate of 95/min, BP of 130/70 mmHg, and normal heart and lung examinations. Abdominal examination reveals fullness and marked tenderness in the left lower quadrant, with voluntary guarding and decreased bowel sounds. Laboratory tests reveal a WBC count of 18,000 with a left shift and 20–50 WBCs in the urinalysis. A CT scan of the abdomen reveals a thickened sigmoid colon with pericolonic inflammation. He is admitted to the hospital for treatment. Which of the following is the most appropriate management of this patient?

A 39-year-old woman completed her last course of postoperative adjuvant chemotherapy for breast cancer 6 months ago. She now comes to the clinic complaining of constant back pain for about 3 weeks. She is tender to palpation over two well-circumscribed areas in the thoracic and lumbar spine. Which of the following is the most appropriate next step in management?

A 56-year-old woman presents to the clinic for routine health screening. Her concern is the development of breast cancer. She has no current breast-related complaints. Past history is pertinent for fibrocystic changes with atypical ductal hyperplasia and a single fibroadenoma, both diagnosed by open biopsy 5 years ago. She smokes one pack per day and drinks one can of beer daily. Family history is positive for breast cancer in her mother, diagnosed at the age of 85. Current medications include a cholesterol-lowering agent, an antihypertensive, and HRT, which she has taken for 5 years. Physical examination is unremarkable. Mammograms show dense breasts, decreasing the accuracy of the study, but no suspicious findings were noted. Which of the following is the most common risk factor in evaluating women for breast cancer?

A 42-year-old woman returns to the clinic following an uneventful biopsy for a well- defined, mobile mass. The pathology report describes the mass as a fibro adenoma, but LCIS is identified in the breast parenchyma adjacent to the fibro adenoma and extending to the margin of resection. She has no current illnesses, is on no medications, and her family history is negative for breast cancer. Breast imaging studies show fatty breasts with no abnormal findings except for the fibro adenoma. Which of the following is the most appropriate management option?

A 56-year-old woman has been treated for 3 years for wheezing on exertion, which was diagnosed as asthma. Chest radiograph, shown here, reveals a midline mass compressing the trachea. Which of the following is the most likely diagnosis?

A 59-year-old man is found to have a 6-cm thoracoabdominal aortic aneurysm which extends to above the renal arteries for which he desires repair, but he is concerned about the risk of paralysis postoperatively. Which of the following maneuvers should be employed to decrease the risk of paraplegia after repair?

A 77-year-old man becomes "senile" over a period of 3 or 4 weeks. He used to be active and managed all of his financial affairs. Now, he stares at the wall, barely talks, and sleeps most of the day. His daughter recalls that he fell from a horse about a week before the mental changes began. Which of the following would a CT scan of his head most likely show?

A man who weighs 65 kg sustains second and third degree burns over both of his lower extremities when his pants catch on fire. When examined shortly thereafter, it is ascertained that virtually all of the skin from both groins to the tip of the toes, front and back, has been burned. According to the modified Parkland formula, which of the following is the approximate total amount of IV fluid that he can be expected to require during the first 24hours post-burn?

A 65-year-old man presents to the emergency department with sudden onset of pain and weakness of the left lower extremity of 2-hour duration. Past history reveals chronic atrial fibrillation following a myocardial infarction 12 months ago. On examination, he is found to have a cool, pale left lower extremity with decreased strength and absent popliteal and pedal pulses. The opposite leg has a normal appearance with palpable pulses. Which of the following is the most appropriate first step in management of this patient?

A 50-year-old man presents with intractable peptic ulcer disease, severe esophagitis, and abdominal pain. Which of the following is most consistent with the diagnosis of Zollinger-Ellison syndrome?

A 29-year-old woman with a history of difficulty becoming pregnant presents to her primary care physician and is diagnosed with Grave disease on iodine uptake scan; her thyrotropin (TSH) level is markedly suppressed and her free thyroxine (T4) level is elevated. She desires to conceive as soon as possible and elects to undergo thyroidectomy. After she is rendered euthyroid with medications preoperatively, which of the following management strategies should also be employed to reduce the risk of developing thyroid storm in the operating room?

A postoperative patient with swelling and pain in his right calf is suspected of having a deep venous thrombosis. Prior to initiating treatment with anticoagulants, he requires a confirmatory examination. Which of the following is a limitation of the duplex ultrasound in evaluating a DVT?

A 72-year-old woman with severe COPD who requires home oxygen is unable to ambulate inside her home without experiencing severe left hip pain. She was hospitalized 1 year ago for a viral pneumonia and was ventilator-dependent at that time for 6 weeks. On examination, her blood pressure is 165/80 mm Hg. She has weakly palpable bilateral femoral pulses. An angiogram demonstrates severe aortoiliac disease involving bilateral iliac vessels. Which of the following is the most appropriate vascular procedure for this patient?

A 25-year-old man was admitted to the ICU with severe head injury with a basal skull fracture. Eighteen hours after the injury, he developed polyuria. Urine osmolality was 150 mOsm/Land serum osmolality was 350 mOsm/L. IV fluids were stopped, and 1 hour later urine output and urine osmolality remained unchanged. Five units of vasopressin were administered intravenously, and urine osmolality increased to 300 mOsm/L. Select the most likely diagnosis of the patients with polyuria.

A 70-year-old man was admitted to the ICU with severe pancreatitis. During his ICU course, he underwent several CT scans with IV contrast and was also treated with an aminoglycoside for a urinary tract infection. The patient required a prolonged course of TPN, and developed Candida sepsis treated with amphotericin. He subsequently developed polyuria with urine osmolality of 250 mOsm/L and serum osmolality of 350 mOsm/L. After receiving 5 units of vasopressin intravenously, there is no change in urine osmolality or urine output. Select the most likely diagnosis of the patients with polyuria

A 42-year-old man describes intermittent episodes of severe, crushing chest pain that extends to the back and the jaw and last anywhere from a few seconds to several minutes. Many times the pain is accompanied by dysphagia and triggered by the ingestion of very cold or very hot liquids. However, sometimes the pain occurs for no apparent reason. There is no history of regurgitation, and, although the problem has been present for many years, there has been no progression of the symptoms. Repeated ECGs and cardiac enzymes have always been negative. Barium swallow shows an area of "corkscrew" appearance. Manometry shows that about one half of wet swallows produce repetitive simultaneous esophageal contractions of the esophageal body, and that the lower esophageal sphincter has normal pressures and exhibits normal relaxation. Which of the following is the most likely diagnosis?

A 52-year-old woman has terminal cervical cancer with extensive pelvic invasion, and requires strong opiate analgesia to control severe pain. Intermittent nausea and vomiting have precluded the use of oral agents. She was on fentanyl patches but she developed allergic skin reactions to the adhesive and now requests to be switched to parenteral medication. Because of prior chemotherapy treatments she has no available venous access, but she is willing to have her family administer intramuscular injections. Assuming equianalgesic dosages, which of the following would be the most appropriate pharmacotherapy?

A 29-year-old man presents to the ER with persistent vomiting and abdominal pain for the last 24 hours. The pain is crampy, diffuse, and has been getting worse. He had a normal bowel movement two days ago and denies diarrhea. The emesis appears green without blood or coffee grounds. He has not eaten since the onset of the pain due to nausea. On exam, his temperature is 36.8° C (98.2° F}, pulse is 91/min, and blood pressure is 116/75 mmHg while sitting and 94/65 mmHg while standing. His abdomen is distended with hyperactive bowel sounds. Percussion reveals tympany and he is diffusely tender to palpation. There is no rebound tenderness or guarding. Laboratory studies reveal: WBC count 9,600/mm3 Hematocrit 45% Sodium 147 mEq/L Potassium 3.1 mEq/L Creatinine 1.0 mg/dL AST 20 U/L ALT 12 U/L Bilirubin 0.8 mg/dL Which of the following historical findings would you most expect in this patient?

A 71-year-old woman with a 40-year smoking history is noted to have a peripheral nodule in her left upper lobe on chest x-ray. Workup is consistent with small cell lung cancer with ipsilateral mediastinal lymph node involvement but no extrathoracic disease. What is the best treatment option for this patient?

A 42-year-old homeless man presents with a 3-week history of shortness of breath, fevers, and pleuritic chest pain. Chest x-ray (CXR) reveals a large left pleural effusion. Thoracentesis reveals thick, purulent-appearing fluid, which is found to have glucose less than 40 mg/dL and a pH of 6.5. A chest tube is placed, but the pleural effusion persists. Which of the following is the most appropriate management of this patient?

A 75-year-old man is brought to the emergency department for severe pain in the left flank and back of 1hour duration. He has a prior history of a myocardial infarction and coronary artery bypass grafting 8 years ago. On examination, he is found to have a BP of 80/50 mmHg, pulse rate of 110/min, respiratory rate of 15/min, and a pulsatile, tenderabdominal mass. He has had two large-bore IV lines placed by the paramedics. He is alert and oriented, and gives consent for surgery. On postoperative day 3, the patient develops dark-colored diarrhea but remains normotensive, on full mechanical ventilation, and is awake. Laboratory analysis reveals normal electrolytes, blood urea nitrogen (BUN), and creatinine; hematocrit of 30; and WBC of 15,000. Which is the most appropriate next step in management?

A pedestrian is hit by a car. The paramedics report that he was unconscious at the site, and he arrives at the emergency department in coma, strapped to a head board with sandbags on either side of his head. Initial survey shows stable vital signs, and his pupils are of equal size and reactive to light. He is rapidly intubated by the nasotracheal route over a flexible bronchoscope and then sent for CT scans of the head. As he is being positioned on the table, it is noted that there is a sizable hematoma behind his right ear and that clear fluid is dripping from the ear canal.Which of the following is most advisable, considering this new finding?

During a campaign appearance, a political candidate is shot point blank in the right chest with a .22 caliber revolver. The entrance wound is well above the nipple line, just under the third rib, at the level of the anterior axillary line. His motorcade brings him to the emergency department, but he makes it a point to walk in, holding his right chest with a bloody hand and waving for the news media. A chest x-ray shows a hemothorax on the right, and the bullet is seen to be embedded in the right paraspinous muscles. A chest tube is placed in the right pleural cavity, and 650 mL blood is recovered. Over the ensuing 4 hours, he continues to drain between 250 and 350 mL blood per hour. Which of the following is the most appropriate next step in management?

A 76-year-old man is admitted to the coronary care unit after an episode of substernal chest pain. His other medical problems include hypertension, hyperlipidemia, and type 2 diabetes mellitus. He has a history of a diverticular bleed 2 years ago. After initial workup, cardiac catheterization is performed and shows 50% left main coronary artery stenosis, 90% proximal left anterior descending artery stenosis, and 65% right coronary artery stenosis. Antiplatelet agents are stopped, and the patient is continued on a heparin drip in preparation for coronary artery bypass surgery the next day. Five hours after the catheterization, his blood pressure is 75/60 mm Hg and pulse is 120/min and regular. He complains of some generalized weakness and back pain but denies chest pain, shortness of breath, nausea, and abdominal discomfort. He appears to be diaphoretic and clammy. Neck veins are flat. Heart sounds are normal, and the chest is clear to auscultation. The groin site for arterial puncture is mildly tender, without subcutaneous hematoma. He receives 1000 ml of normal saline, with symptomatic improvement. His blood pressure is 96/60 mm Hg and pulse is 85/min. His ECG seems to be unchanged. Which of the following is the most appropriate next step in managing this patient?

A 63-year-old obese female undergoes an elective cholecystectomy after two episodes of acute calculous cholecystitis. Three days after surgery, her blood pressure is 150/100 mmHg, her heart rate is 90/min, and her arterial oxygen saturation is 91 % on room air. She is afebrile. Which of the following would most likely increase her functional residual lung capacity?

A 65-year-old woman presents to the physician’s office for a second opinion on the management options for recently diagnosed breast cancer. She presents with a 2.5-cm mass in the upper outer quadrant of the left breast associated with a palpable axillary node suspicious for metastatic disease. The remainder of her examination is normal. Mammography demonstrates the cancer and shows no other suspicious lesions in either breast. Chest x-ray, bone scan, and blood test panel, including liver function tests, are normal. Family history is positive for breast cancer diagnosed in her sister at age 65. Past history is unremarkable. The first physician recommended modified radical mastectomy. Which of the following is the most appropriate management option for locoregional control yielding results equally effective as mastectomy?

A 65-year-old woman presents to the physician’s office for a second opinion on the management options for recently diagnosed breast cancer. She presents with a 2.5-cm mass in the upper outer quadrant of the left breast associated with a palpable axillary node suspicious for metastatic disease. The remainder of her examination is normal. Mammography demonstrates the cancer and shows no other suspicious lesions in either breast. Chest x-ray, bone scan, and blood test panel, including liver function tests, are normal. Family history is positive for breast cancer diagnosed in her sister at age 65. Past history is unremarkable. The first physician recommended modified radical mastectomy. The patient has read about SLN biopsy. She avidly wants to avoid the risk of lymphedema that her sister must endure. She asks the question “Am I a candidate for a SLN biopsy instead of a complete axillary dissection?” Which of the following is the most appropriate answer to her question?

During a hunting trip, a young man is bitten by a coyote. The animal is captured and brought to the authorities alive. Which of the following is the most important criterion to determine the patient's need for rabies prophylaxis?

A 62-year-old woman had an abdominal hysterectomy and salpingo-oophorectomy 3 days ago. She had an indwelling bladder catheter during the procedure, which was removed in the recovery room. She has been voiding at will since then. She also had compression pneumatic stockings on both lower extremities during the operation. She began ambulation on the 1st postoperative day, and has been as active as possible under the circumstances, including faithful adherence to a prescribed program of incentive spirometry. On the evening of the 3rd postoperative day, she spikes a fever, with a temperature to 39.4 C (103 F). Which of the following is the most likely source of the fever?

A 44-year-old male is found unresponsive and hypotensive at the scene of a high-speed motor vehicle accident. He is intubated and immediately rushed to the emergency department. The passenger in his car is pronounced dead at the scene. Physical examination in the ED shows large bruises over the entire chest wall and collapsed neck veins bilaterally. Lung exam reveals decreased breath sounds on the left side. Chest x-ray shows a large left hemothorax and a widened, rightward deviating mediastinum. The most likely diagnosis is:

An 85-year-old male is placed on mechanical ventilation after a complicated elective hernia repair. After five days of endotracheal intubation with mechanical ventilation, the ratio of the rate of carbon dioxide produced to the rate of oxygen uptake is 1.05. What is the best explanation for these findings?

A 64-year-old man with a history of a triple coronary artery bypass 2 years ago presents with peripheral arterial occlusive disease. His only medication is a thiazide diuretic. Which of the following medications would be most appropriate in the medical management of his atherosclerosis?

A patient who has had angina as well as claudication reports feeling light-headed on exertion, especially when lifting and working with his arms. The subclavian steal syndrome is associated with which of the following hemodynamic abnormalities?

A 75-year-old woman is admitted to the hospital from a nursing home for abdominal pain and pneumonia. She was noted to be short of breath with increasing cough for 2 days before admission. Treatment, consisting of supplemental oxygen, IV antibiotics, and pulmonary toilet, is instituted, with improvement within 2 days. On the third hospital day, her abdominal pain worsens. Examination reveals a mildly distended abdomen with bowel sounds but no signs of peritonitis. Remainder of examination reveals a tender bulge in the medial left thigh below the inguinal ligament. Gentle pressure causes more pain but does not change the size or shape of the bulge. Abdominal films show a nonspecific bowel gas pattern. Laboratory analysis shows a WBC of 13,000, decreased from 18,000 at the time of admission. Which of the following is the most likely diagnosis?

A 66-year-old woman picks up a bag of groceries out of the supermarket cart to place it in the trunk of her car. As she does so, she feels sharp, sudden pain in the middle of her arm, and her humerus suddenly breaks. She arrives at the emergency department cradling her arm; the deformity leaves no doubt that the bone is broken. Which of the following is the most likely reason for the fracture?

A 62-year-old man has had gastroesophageal reflux disease diagnosed by pH monitoring, and present for several years. He has been less than totally compliant with medical management, which he follows when the pain is bad, but discontinues when he feels better. Endoscopy and biopsies show severe peptic esophagitis, with Barrett's esophagus and early dysplastic changes, but no overt carcinoma. Additional tests show good esophageal motility, with low pressure in the lower esophageal sphincter and normal gastric emptying. Which of the following is the most appropriate treatment at this time?

An 18-year-old male comes to the physician's office because of dull aching and fullness of the scrotum. Examination shows soft left-sided scrotal swelling; transillumination testing is negative. The scrotal swelling increases when the patient performs the Valsalva maneuver. The physical examination is otherwise unremarkable. Which of the following is the most likely cause of his condition?

A 72-year-old man underwent surgical repair of an aneurysm of the infrarenal aorta. He received perioperative prophylaxis with a second-generation cephalosporin antibiotic. On the first postoperative day he complains of progressive abdominal pain and bloody diarrhea. His temperature is 38.5° C (101° F), blood pressure is 110/65 mm Hg, pulse is 11 O/min and respirations are 22/min. His abdomen is mildly distended and tender to palpation. The tenderness is mostly in the left lower quadrant without rebound. Femoral pulses are full and symmetric. His white blood cell count is 12,000/mm3. Which of the following is the most likely diagnosis?

A 32-year-old male comes to the emergency department because of a 3 day history of increasing lower abdominal pain, mild diarrhea and rectal pain on defecation. Ten days ago he had right lower quadrant (RLQ) pain for about 24 hours that resolved spontaneously. Since then, he has had malaise and low-grade fever. His temperature is 38.7° C (101.6° F), blood pressure is 150/90 mm Hg, pulse is 11 0/min and respirations are 15/min. Examination shows lower abdominal tenderness without rebound. No masses are palpable, and bowel sounds are decreased. Rectal examination shows a very tender, boggy and fluctuant bulging mass on palpation with the tip of the finger anteriorly. Laboratory studies show: Complete blood count Hemoglobin Platelets Leukocyte count 14.0 g/L 270,000/mm 15,500/mm His current condition is most likely a complication of?

A 4-year-old boy is seen 1 hour after ingestion of a lye drain cleaner. No oropharyngeal burns are noted. The CXR is normal, but the patient continues to complain of significant chest pain. Which of the following is the most appropriate next step in his management?

A previously healthy 20-year-old man is admitted to the hospital with acute onset of left- sided chest pain. Electrocardiographic findings are normal, but CXR shows a 40% left pneumothorax. Appropriate treatment consists of which of the following procedures?

A 22-year-old professional basketball player falls on his outstretched hand during a scrimmage game. He has mild swelling at the wrist and tenderness to palpation in the anatomic snuffbox. No fracture is visible on multiple radiographs of the wrist and hand. Which of the following is the most appropriate management of this patient?

A 44-year-old man complains of vague right upper abdominal discomfort that he has had for about 1 month. He describes no other symptoms, and, except for enucleation of one eye at age 21 "for a tumor," he has been in excellent health all his life. He exercises regularly and neither smokes nor drinks. The only findings on physical examination include the artificial eye and a tender, enlarged, and nodular liver. CT scan of the upper abdomen demonstrates multiple masses within the liver. Which of the following will most likely be found on biopsy of these masses?

A 71-year-old West Texas farmer of Irish ancestry has a nonhealing, indolent, punched out, clean-looking 2-cm ulcer over the left temple. The ulcer has been slowly growing over the past 3 years. There are no enlarged lymph nodes in the head and neck. Which of the following would best dictate proper management?

Ten days after undergoing liver transplantation, a patient's levels of gamma-glutamyl transferase (GGT), alkaline phosphatase, and bilirubin begin to rise. Which of the following is the most appropriate next step in diagnosis?

A previously healthy, intoxicated, 19-year-old man is driving a car without using a seat belt. He crashes the car into the back of a parked truck. In the process he slams his abdomen into the steering wheel and ruptures his spleen. Which of the following is the most important problem associated with this type of injury?

After suitable calculations have been made using the modified Parkland formula, a 70-kg man with extensive third-degree burns is receiving Ringer's lactate at the calculated rate, which happens to be 750 mL/hr. The infusion was started within 30 minutes of the time when the burn occurred. Over the next 3 hours, his urinary output is recorded as 15 mL, 22 mL, and 18 mL. It is verified that the Foley catheter is open and draining freely. The urine is dark yellow, without blood, and has a specific gravity of 1040 and a sodium concentration of 10 mEq/L. The patient's blood pressure is 100/70 mm Hg, his pulse is 98/min, and his central venous pressure is 2 cm H2O. On the basis of these findings, which of the following is the most appropriate next step in management?

A 27-year-old immigrant from El Salvador has a 14 × 12 × 9 cm mass in her left breast. It has been present for 7 years and has slowly grown to its present size. The mass is firm, nontender, rubbery, and completely movable, and it is not attached to the overlying skin or the chest wall. There are no palpable axillary nodes or skin ulceration. Which of the following is the most likely diagnosis?

A 32-year-old woman in the 2nd month of pregnancy is found to have a 5-cm mass in the upper outer quadrant of her left breast. Mammogram shows no other lesions, and core biopsy reveals infiltrating ductal carcinoma. Which of the following would be the best course of action at this time?

In the course of a robbery, a young woman is stabbed repeatedly. On arrival at the emergency department, she is shivering and asks for a blanket and a drink of water; she is noted to be pale and perspiring. Her blood pressure is 72/50 mm Hg and her pulse is 130/min. Her neck and forehead veins are large and distended. A quick initial survey reveals entry wounds in her left chest and upper abdomen. She has bilateral breath sounds and a scaphoid, nontender abdomen. As IV infusions of Ringer's lactate are started, her systolic blood pressure drops further to 40 mm Hg, no distal pulses can be felt, and she loses consciousness. Her central venous pressure at that time is 28 cm H2O. Which of the following is the most appropriate next step in management?

A 62-year-old man reports an episode of gross, painless hematuria. There is no history of trauma, and further questioning determines that he had total hematuria, rather than initial or terminal hematuria. The man does not smoke and has had no other symptoms referable to the urinary tract. He has no known allergies. Physical examination, including rectal examination, is unremarkable. His serum creatinine is 0.8 mg/dL, and, except for the presence of many red cells, his urinalysis is normal and shows no red cell casts. His hematocrit is 46%. Which of the following is the most appropriate initial step in the workup?

A 63-year-old man, who weighs 65 kg, is in his 2nd postoperative day after an abdominoperineal resection for cancer of the rectum. An indwelling Foley catheter was left in place after surgery. The nurses are concerned because, even though his vital signs have been stable, his urinary output in the past 2 hours has been zero. In the preceding 3 hours, they had collected 56 mL, 73 mL, and 61 mL. Which of the following is the most likely diagnosis?

A 37-year-old woman undergoes a lumpectomy and axillary dissection for a 3-cm infiltrating ductal carcinoma, diagnosed by core biopsies, located on the upper outer quadrant of her left breast. The pathology report of the surgical specimen is received 3 days after the operation. It indicates that all margins around the tumor are clear, and that 4 of 17 axillary lymph nodes have metastatic tumor. The tumor is reported to be estrogen and progesterone receptor negative. Which of the following should further therapy most likely include?

A 45-year-old man with alcoholic cirrhosis is bleeding from a duodenal ulcer. He has required 6 units of blood over the past 8 hours, and all conservative measures to stop the bleeding, including irrigation with cold saline, IV vasopressin, and endoscopic use of the laser have failed. He is being considered for surgical intervention. Laboratory studies done at the time of admission, when he had received only one unit of blood, showed a bilirubin of 4.5 mg/dL, a prothrombin time of 22 seconds, and a serum albumin of 1.8 g/dL. He was mentally clear when he came in, but has since then developed encephalopathy and is now in a coma. Which of the following best describes his operative risk?

A 55-year-old woman falls in the shower and hurts her right shoulder. She shows up in the emergency department with her arm held close to her body, but the forearm rotated outward as if she were going to shake hands. She is in pain and will not move the arm from that position. Her shoulder looks "square" in comparison with the rounded unhurt opposite side, and there is numbness in a small area of her shoulder over the deltoid muscle. Which of the following is the most likely diagnosis?

A 22-year-old convenience store clerk is shot once with a .38 caliber revolver. The entry wound is in the left midclavicular line, 2 inches below the nipple. There is no exit wound. He is hemodynamically stable. A chest x-ray film shows a small pneumothorax on the left, and demonstrates the bullet to be lodged in the left paraspinal muscles. In addition to the appropriate treatment for the pneumothorax, which of the following will this patient most likely need?

A 68-year-old man is brought to the emergency department with excruciating back pain that began suddenly 45 minutes ago. The pain is constant and is not exacerbated by sneezing or coughing. He is diaphoretic and has a systolic blood pressure of 90 mm Hg. There is an 8-cm pulsatile mass deep in his epigastrium, above the umbilicus. A chest x-ray film is unremarkable. Two years ago, he was diagnosed with prostatic cancer and was treated with orchiectomy and radiation. At that time, his blood pressure was normal, and he had a 6-cm, asymptomatic abdominal aortic aneurysm for which he declined treatment. Which of the following is the most likely diagnosis?

A middle-aged homeless man is brought to the emergency department because of very severe pain in his forearm. He had passed out after drinking a bottle of cheap wine, and then slept on a park bench for an indeterminate time, probably more than 12 hours. Shortly after he woke up and began to walk, the pain began. There are no signs of trauma, but the muscles in his forearm are very firm and tender to palpation, and passive motion of his fingers and wrist elicits excruciating pain. Pulses at the wrist are normal. Which of the following is the most appropriate next step in management?

A 54-year-old obese man gives a history of burning retrosternal pain and heartburn that is brought about by bending over, wearing a tight belt, or lying flat in bed at night. He gets symptomatic relief from over-the-counter antiacids or H2 blockers, but has never been formally studied or treated. The problem has been present for many years and seems to be progressing. Which of the following is the most appropriate next step in management?

A pedestrian is hit by a car and knocked unconscious. Within a few minutes, he starts to move around and moan. When the ambulance arrives, he is moving all four extremities and mumbling that his neck hurts. Shortly thereafter, he lapses again into a deep coma. In the emergency department, it is noted that his left pupil is fixed and dilated, and he has clear fluid dripping from the left ear. The trauma team intubates him nasally over a fiberoptic bronchoscope and does a quick initial survey that reveals no other obvious injuries. He is hemodynamically stable. Which of the following is the most appropriate next step in management?

While working at a bookbinding shop, a young man suffers a traumatic amputation of his index finger. The finger was cleanly severed at its base. The patient and the finger are brought to a first-aid station, from which both are to be transported to a highly specialized medical center for replantation to be done. Which of the following is the correct way to prepare and transport the severed finger?

An out-of-shape, recently divorced, 42-year-old man is trying to impress a young woman by challenging her to a game of tennis. In the middle of the game, a loud "pop" (like a gunshot) is heard, and the man falls to the ground clutching his ankle. He limps off the court with pain and swelling in the back of the lower leg. Although he can still weakly plantar-flex his foot, he seeks medical help the next day because of persistent pain, swelling, and limping. He can put weight on that foot with no exacerbation of the pain, but the motion of taking a step is painful. Which of the following would be the most likely finding on physical examination?

A 66-year-old man with diabetes and generalized arteriosclerotic occlusive disease notices a gradual loss of erectile function over several years. Initially, he can get erections, but they do not last long enough. Later, he notices a decrease in the quality of his erections, and more recently he becomes, by his own criteria, completely impotent. He has occasional, brief nocturnal erections, but "he can never get an erection when he needs one." Which of the following is the most appropriate initial step in management?

A 54-year-old woman has a severe ureteral colic. An intravenous pyelogram shows a 7- mm ureteral stone at the ureteropelvic junction. She has a normal coagulation profile. Which of the following would most likely be the best therapy in this case?

A 68-year-old woman presents with an obviously incarcerated umbilical hernia. She has gross abdominal distention, is clinically dehydrated, and reports persistent fecaloid vomiting for the past 3 days. Although tired, weak, and thirsty, she is awake and alert and her sensorium is not particularly affected. Laboratory analysis reveals a serum sodium concentration of 118 mEq/L. Which of the following is the most likely physiologic explanation for the serum sodium?

A 31-year-old woman smashes her car against a bridge abutment. She sustains multiple injuries, including upper and lower extremity fractures. She is fully awake and alert, and she reports that she was not wearing a seat belt and distinctly remembers hitting her abdomen against the steering wheel. Her blood pressure is 135/75 mm Hg, and her pulse is 88/min. Physical examination shows that she has a rigid, tender abdomen, with guarding and rebound in all four quadrants. She has no bowel sounds. Which of the following would be the most appropriate step in evaluating potential intraabdominal injuries?

A 27-year-old man sustained penetrating injuries of the chest and abdomen when he was repeatedly stabbed with a long ice-pick. At the time of admission, he had a right pneumothorax, for which a chest tube was placed prior to undergoing a general anesthetic for exploratory laparotomy. The operation revealed no intraabdominal injuries and was terminated sooner than had been anticipated. The patient remained intubated, waiting for the anesthetic to wear off. Because he was not moving enough air, he was placed on a respirator. Then, he suddenly went into cardiac arrest and died. All through this time he had been hemodynamically stable, and never had any signs of hypotension or arrhythmias. Which of the following was the most likely cause of the cardiac arrest?

A 13-year-old, obese boy complains of persistent knee pain for several weeks. The family brings him in because he has been limping. He sits in the examining table with the sole of the foot on the affected side pointing to the other leg. Physical examination is normal for the knee, but shows limited hip motion. As the hip is flexed, the leg goes into external rotation and cannot be rotated internally. Which of the following is the most likely diagnosis?

A 72-year-old man has a 3-mm ureteral stone impacted at the ureterovesical junction. He has been having mild ureteral colicky pain for about 12 hours, and he has been given fluids and analgesics in the expectation that he will spontaneously pass the stone. He then has shaking chills, and spikes a temperature of 40 C (104 F). When seen shortly thereafter, he has flank pain and looks quite ill. Which of the following is the most appropriate next step in management?