Surgery USMLE (1-100)

1.A 23-year-old woman comes to the physician because of a 4-week history of a whistling noise during respiration. She underwent a difficult rhinoplasty a few months ago. The noise is getting louder and is annoying. Which of the following is the most likely diagnosis?

2.A 32-year-old female presents with intermittent blood staining of her bra from her left breast. She has not felt any lumps on either breast. Physical examination shows no breast mass or axillary lymphadenopathy. Ultrasonogram of the breast is within normal limits. Which of the following is the most likely diagnosis?

3.A 22-year-old man is stabbed in the right chest with a 5-cm-long knife blad On arrival at the emergency department, he is wide awake and alert. He is speaking with a normal tone of voice but complaining of shortness of breath. The right hemithorax is hyperresonant to percussion and has no breath sounds; the rest of the initial survey is negativ His blood pressure is 110/75 mm Hg, pulse is 86/min, and venous pressure is 3cm H2O. Pulse oximetry shows a saturation of 85%. Which of the following is the most appropriate next step in patient care?

4.A 48-year-old woman develops constipation postoperatively and self-medicates with milk of magnesi She presents to clinic, at which time her serum electrolytes are checked, and she is noted to have an elevated serum magnesium level. Which of the following represents the earliest clinical indication of hypermagnesemia?

5.A 68-year-old man is brought to the emergency department following a high-speed automobile accident. He is alert and complains of chest pain and mild back pain. His blood pressure is 80/60 mm Hg. Chest x-ray shows a widened mediastinum, tracheal deviation, bronchial displacement, and loss of the aortic kno Which of the following is the most likely diagnosis?

6.A one-year-old boy is brought to the emergency department with scalds on both the buttocks and thighs. His mother states that the child was burned because she accidentally drew a bath for the child with water that was too hot. She states the injury occurred 2 days ago. On examination, the child is irritabl Second-degree burns are noted on the buttocks, genitalia, waist, proximal thighs and feet. There is an abrupt demarcation between the burned and unaffected skin. A faint yellow patch of discoloration is noted on the left thorax with a slight violaceous hu The child has not yet had his 1-year vaccinations. Which of the following is the most appropriate next step in management?

7.A 47-year old woman comes to the clinic because of worsening left breast swelling and pain. She had mastitis when she nursed her first child 20 years ago. She has not seen a doctor since that tim She is afebril Breast examination shows the left breast is enlarged with a 7 x 6 cm area of edema and erythem A poorly localized mass without fluctuation is palpated in that are Scant non-bloody discharge is noted on the nipple, and several large axillary nodes are palpate Which of the following is the most appropriate next step in management?

8.A 35-year-old man comes to the physician because of persistent dull perineal pain and dysuria for 6 months. The patient denies urinary tract infections or urethral discharg His temperature is 37 C (98.6 F). On digital rectal examination, the prostate is slightly tender and boggy but not enlarged or indurate Urinalysis is normal. Expressed prostatic secretions show the following: Leukocytes 30 cells/high power field Bacteria None Cultures of prostatic secretion and urine are negative for bacteri Which of the following is the most likely diagnosis?

9.An otherwise healthy 28-year-old man comes to his physician because of painless enlargement of the right testis. He began to feel a sensation of heaviness in the right hemiscrotum approximately 6 months ago. Physical examination reveals diffuse enlargement of the right testis, but it is difficult to determine whether this is due to an intratesticular or extratesticular lesion. Which of the following is the most appropriate next step in diagnosis?

10.A man involved in a high-speed, head-on automobile collision arrives at the emergency department in a deep com His pupils react poorly to light but are of equal siz An airway is placed, and the patient is sent for CT scan of the head with extension to the neck. The study shows no cervical spine fractures, but does reveal a small, crescent-shaped hematoma on the right side, with no deviation of the midline structures. Which of the following is the most appropriate next step in management?

11.A 19-year-oldgangmemberisshotintheabdomenwith a .38 caliber revolver. The entry wound is in the epigastrium, to the left of the midlin The bullet is lodged in the psoas muscle on the right. He is hemodynamically stable, and the abdomen is moderately tender. Which of the following is the most appropriate next step in diagnosis?

12.Five days after an uneventful cholecystectomy, an asymptomatic middle-aged woman is found to have a serum sodium level of 125 mEq/L. Which of the following is the most appropriate management strategy for this patient?

13.A 50-year-old patient presents with symptomatic nephrolithiasis. He reports that he underwent a jejunoileal bypass for morbid obesity when he was 39. Which of the following is a complication of jejunoileal bypass?

14.Following surgery a patient develops oliguri You believe the oliguria is due to hypovolemia, but you seek corroborative data before increasing intravenous fluids. Which of the following values supports the diagnosis of hypovolemia?

15.A football player is tackled, and he develops severe knee swelling and pain. On physical examination with the knee flexed at 90 degrees, the leg can be pulled anteriorly, like a drawer being opene A similar finding can be elicited with the knee flexed at 20 degrees by grasping the thigh with one hand, and pulling the leg with the other. Which of the following is the most likely injured structure?

16.A 33-year-old woman is undergoing a diagnostic work-up because she appears to have Cushing syndrom She has elevated levels of cortisol, which are not suppressed when she is given high- dose dexamethason ACTH levels are greater than 200 pg/ mL. A chest x-ray film shows a central, 3-cm round mass on the hilum of the right lung. Bronchoscopy and biopsies confirm a diagnosis of small cell carcinoma of the lung. Which of the following is the preferred treatment for this woman?

17.A 53-year-old woman comes to the physician because of a "lump" in her neck. She says that her masseuse noticed it 1 month ago. There is no associated pain, pressure, or hoarseness. She feels fine and has no other complaints. She has no history of radiation exposur Examination reveals a palpable thyroid nodule that is approximately 3 cm. Which of the following is the most appropriate next step in diagnosis?

18.A 56-year-old man has been having bloody bowel movements on and off for the past several weeks. He reports that the blood is bright red, it coats the outside of the stools, and he can see it in the toilet bowl even before he wipes himself. When he does so, there is also blood on the toilet paper. After further questioning, it is ascertained that he has been constipated for the past 2 months and that the caliber of the stools has change They are now pencil thin, rather the usual diameter of an inch or so that was customary for him. He has no pain. Which of the following is the most likely diagnosis?

19.A multiple trauma patient receives 14 units of packed red cells and several liters of Ringer's lactate solution during a laparotomy for multiple intra-abdominal injuries. The surgeons note that blood is oozing from all dissected raw surfaces, as well as from his TV line sites. His core temperature is normal. Which of the following is the most appropriate next step in management?

20.A 75-year-old man slips and falls at home, hitting his right chest wall against the kitchen counter. He has an area of exquisite pain to direct palpation over the seventh rib, at the level of the anterior axillary lin A chest x-ray film confirms the presence of a rib fracture, with no other abnormal findings. Which of the following is the most appropriate initial step in management?

21.A 45-year-old woman with Crohn disease and a small intestinal fistula develops tetany during the second week of parenteral nutrition. The laboratory findings include: Na: 135 mEq/L K: 3.2 mEq/L Cl: 103 mEq/L HCO3: 25 mEq/L Ca: 8.2 mEq/L Mg: 1.2 mEq/L PO4: 2.4 mEq/L Albumin: 2.4 An arterial blood gas sample reveals a pH of 7.42, PCO2 of 38 mm Hg, and PO2 of 84 mm Hg. Which of the following is the most likely cause of the patient’s tetany?

22.A patient with a nonobstructing carcinoma of the sigmoid colon is being prepared for elective resection. Which of the following reduces the risk of postoperative infectious complications?

23.A 75-year-old man with a history of myocardial infarction 2 years ago, peripheral vascular disease with symptoms of claudication after walking half a block, hypertension, and diabetes presents with a large ventral herni He wishes to have the hernia repaire Which of the following is the most appropriate next step in his preoperative workup?

24.A young man is shot with a .45 caliber revolver, point blank in the lower abdomen, just above the pubis. The entrance wound is at the midline, and there is no exit wound. X-ray films show the bullet embedded in the sacral promontory, to the right of the midline. Digital rectal examination and proctoscopic examination are negative, but he has gross hematuri He is hemodynamically stable. Which of the following is the most appropriate next step in management?

25.A front-seat passenger in a car involved in a head-on collision relates that he hit the dashboard with his knees, however, he is specifically complaining of severe pain in his right hip, rather than knee pain. He lies in the stretcher in the emergency department with the right lower extremity shortened, adducted, and internally rotated. Which of the following is the most likely injury?

26.A 71-year-old woman is brought to the physician by her distressed daughter. The daughter relates that, 3 days ago, her mother began to complain of right upper quadrant abdominal pain. She did not want to eat and "took to her bed sick." The daughter recalls that she complained of chills, nausea, and some vomiting. Physical examination reveals an obtunded, hypotensive, and obviously very sick elderly woman. She has impressive pain to deep palpation in the right upper quadrant, along with muscle guarding and rebound. Her temperature is 40 C (104 F), and laboratory analysis shows a white cell count of 22,000/mm3 with multiple immature forms, a bilirubin of 5 mg/dL and alkaline phosphatase of 840 U/L. The serum amylase is normal. An emergency sonogram shows multiple stones in the gallbladder, normal thickness of the gallbladder wall without pericholecystic fluid, dilated intrahepatic ducts, and common duct with a diameter of 2.1 cm. The sonographer cannot identify stones in the common duct. In addition to IV fluids and antibiotics, which of the following is the most appropriate next step in management?

27.A 25-year-old man is shot with a .22 caliber revolver. The entrance wound is in the anteromedial aspect of his upper thigh, and the exit wound is about 3 inches lower, in the posterolateral aspect of the thigh. He has a large, expanding hematoma in the upper inner thigh. There are no palpable pulses in the foot. The bone is intact by physical examination and x-ray films. Which of the following is the most appropriate next step in management?

28.A 7-year-old boy passes a large, bloody bowel movement. He is hemodynamically stable, and he has a hemoglobin of 14 g/dL. Nasogastric aspiration yields clear, greenish fluid. Physical examination, including anoscopy, is unremarkable. Which of the following is the most appropriate next diagnostic test?

29.An 81-year-old man with Alzheimer disease who lives in a nursing home undergoes surgery for a fractured femoral neck. On the 5th postoperative day, it is noted that his abdomen is grossly distended and tense, but not tender. He has occasional bowel sounds. The rectal vault is empty on digital examination, and there is no evidence of occult blood. X-ray films show a few distended loops of small bowel and a very distended colon. The cecum measures 9 cm in diameter, and the gas pattern of distention extends throughout the entire large bowel, including the sigmoid and rectum. No stool is seen in the films. Other than the abdominal distention, and the ravages of his mental disease, he does not appear to be ill. Vital signs are normal for his age. Which of the following is the most likely diagnosis?

30.A 46-year-old woman was applying her make-up while also drinking her morning cup of coffee. She noticed in the mirror that a round, 2-cm mass would move up and down in the lower part of her neck whenever she swallowed. Her physician confirms that she has a single, firm, thyroid nodule in the right lobe. There are no other abnormalities in the history or physical examination. Her pulse is 82/min and regular. Thyroid stimulating hormone (TSH) is within normal limits. Which of the following is the most appropriate next step in management?

32.A 55-year-old, HIV-positive man has a fungating mass growing out of the anus. He can feel it when he wipes himself after having a bowel movement, but it is not painful. For the past 6 months, he has noticed blood on the toilet paper, and from time to time there has also been blood coating the outside of the stools. He has lost weight, and he looks emaciated and ill. On physical examination, the mass is easily visible. It measures 3.5 cm in diameter, is fixed to surrounding tissues, and appears to grow out of the anal canal. He also has rock-hard, enlarged lymph nodes on both groins, some of them as large as 2 cm in diameter. Which of the following is the most likely diagnosis?

33.A 79-year-old man with atrial fibrillation develops an acute abdomen. When seen 2 days after the onset of the abdominal pain, he has a silent abdomen, with diffuse tenderness and mild rebound. There is a trace of blood on the rectal examination. He also has acidosis and looks quite sick. X-ray films show distended small bowel and distended right colon, up to the middle of the transverse colon. Which of the following is the most likely diagnosis?

34.A 42-year-old, right-handed man has had a history of progressive speech difficulties and right hemiparesis for 5 months. He has had progressively severe headaches for the past 2 months, which are worse in the mornings. At the time of admission, he is confused and vomiting, and has blurred vision, papilledema, and diplopi Shortly thereafter, his blood pressure increases to 190/110 mm Hg, and he develops bradycardi Which of the following is most likely the significance of the hypertension and the bradycardia?

35.After a grand mal seizure, a 32-year-old epileptic woman notices pain in her right shoulder, and she cannot move it. She goes to a minor emergency clinic, where she has a limited physical examination and anteroposterior (AP) x-ray films of her shoulder. The films are read as negative, and she is diagnosed as having a sprain and given pain medication. The next day, she still has the same pain and is unable to move her arm. She comes to the emergency department holding her arm close to her body, with her hand resting on her anterior chest wall. Which of the following is the most likely diagnosis?

36.A 69-year-old man who smokes and drinks and has rotten teeth, has a hard, fixed, 4-cm mass in his left neck. The mass is just medial to and in front of the sternomastoid muscle, at the level of the upper notch of the thyroid cartilage. It has been there for at least 6 months, and it is growing. Which of the following is the most appropriate next step in diagnosis?

37.On the 5th postoperative day, it is noticed that large amounts of clear, pink, salmon-colored fluid are soaking the wound dressings of a patient who had a negative exploratory laparotomy for a stab wound of the abdomen. The laparotomy was done through a midline supraumbilical and infraumbilical incision. When seen by the surgical staff, the patient is lying in bed in the supine position, with the dressings removed. In the dim light of his hospital room, the incision appears intact and not particularly red or inflamed, but there are indeed traces of the clear pink fluid on his skin. He has no specific complaints. He is still NPO and on IV fluids, but has already been passing gas per rectum, and plans had been made to feed him today. The abdomen is not distended, and he has normal bowel sounds. He is afebrile. Which of the following is the most appropriate next step in management?

38.A 2-year-old child has been shot in the arm in a drive-by shooting. His brachial artery was partially transected, and there was copious bleeding. The EMTs control the site of bleeding by local pressure, and the child is no longer losing blood; however, he is hypotensive and tachycardic. IV fluid resuscitation is urgently needed, but several attempts at starting peripheral IV lines have been unsuccessful. Which of the following would be the best alternative route in this situation?

39.A 24-year-old woman sustains multiple injuries in a car accident, including a pelvic fracture. She is hemodynamically stable. Initial assessment shows no vaginal or rectal injuries; however, when a Foley catheter is inserted, bloody urine is recovered. Which of the following would be the best way to evaluate her urologic injury?

41.A 54-year-old man, who 5 years ago underwent a laparotomy for a gunshot wound to the abdomen, is admitted to the hospital because of protracted vomiting and progressive abdominal distention. The symptoms began 5 days earlier, and since then he has not had a bowel movement or passed any gas. At the time of hospitalization, he has hyperactive bowel sounds and some abdominal discomfort, but does not have an acute abdomen. His abdominal x-ray films show dilated loops of small bowel, multiple air-fluid levels, and no free air under the diaphragms. He is placed on nasogastric suction and IV fluids. After 6 hours, he develops fever, leukocytosis, abdominal tenderness, and rebound tenderness, and his abdomen is silent. Which of the following is the most appropriate next step in management?

42.While running to catch a bus, and old man twists his ankle and falls on his inverted foot. Anteroposterior (AP), lateral, and mortise x-ray films show displaced fractures of both malleoli. Which of the following would be the preferred form of treatment?

43.A 19-year-old man sustains multiple injuries in a high-speed automobile collision. There is a pneumothorax on the left, for which he has a chest tube placed. Over the next several days, a large amount of air drains continuously through the tube (a large "air leak"), and daily chest x- rays show that his collapsed left lung is not expanding. The patient is not on a respirator. Which of the following is the most likely cause of these findings?

44.A 54-year-old woman is brought to the emergency department after a head-on automobile accident. On arrival, she is breathing well. She has multiple bruises over the chest and multiple sites of point tenderness over the ribs. X-ray films show multiple rib fractures on both sides, but the lung parenchyma is clear, and both lungs are expanded. Two days later she is in respiratory distress, and her lungs "white out" on repeat chest x-ray films. Which of the following is the most likely diagnosis?

45.Renal ultrasound and intravenous pyelography (IVP) in a 65-year-old man evaluated for urinary incontinence reveal bilateral hydronephrosis. Which of the following is the most likely condition leading to this complication?

46.A 57-year-old man is undergoing a femoral-popliteal bypass of his right lower extremity because of severe peripheral vascular disease. This patient has a longstanding history of claudication and shortness of breath. He had a myocardial infarction 3 years ago and has had progressive limitation of his exercise capacity because of his peripheral vascular disease. He has not had any risk stratification after his infarction. Two weeks ago, he underwent a lower extremity arterial study that showed severe diffuse disease of his right leg arterial system. The patient is brought to the operating room, and, during the procedure, his right lower extremity is made bloodless by application of a thigh tourniquet for 1.5 hours. The surgeons complete their bypass and are preparing to restore blood flow. Which of the following is an expected consequence of this maneuver?

47.A previously healthy 55-year-old man undergoes elective right hemicolectomy for a stage I (T2N0M0) cancer of the cecum. His postoperative ileus is somewhat prolonged, and on the fifth postoperative day his nasogastric tube is still in place. Physical examination reveals diminished skin turgor, dry mucous membranes, and orthostatic hypotension. Pertinent laboratory values are as follows: Arterial blood gases: pH 7.56, PCO2 50 mm Hg, PO2 85 mm Hg. Serum electrolytes (mEq/L): Na+ 132, K+ 3.1, Cl- 80; HCO-3 42. Urine electrolytes (mEq/L): Na+ 2, K+ 5, Cl- 6. What is the patient’s acid–base abnormality?

48.A 52-year-old man with gastric outlet obstruction secondary to a duodenal ulcer presents with hypochloremic, hypokalemic metabolic alkalosis. Which of the following is the most appropriate therapy for this patient?

49.A 23-year-old woman is brought to the emergency room from a halfway house, where she apparently swallowed a handful of pills. The patient complains of shortness of breath and tinnitus, but refuses to identify the pills she ingested. Pertinent laboratory values are as follows: Arterial blood gases: pH 7.45, PCO2 12 mm Hg, PO2 126 mm Hg. Serum electrolytes (mEq/L): Na+ 138, K+ 4.8, Cl− 102, HCO3− 8. An overdose of which of the following drugs would be most likely to cause the acid–base disturbance in this patient?

50.A 31 -year-old man is brought to the emergency department after a motor vehicle accident. He sustained a severe head injury and, on arrival to the emergency department, has a Glasgow coma score of 8. His blood pressure is stable, and an urgent CT scan of the head reveals a large subdural bleed with evidence of a midline shift and cerebellar tonsillar compression. The patient is breathing spontaneously without any respiratory assistance and is not intubated. Which of the following is the most appropriate next step in management?

51.A 40-year-old retired professional football player complains of the sudden onset of palpitations and shortness of breath 5 days after having knee replacement surgery. His pulse is 100/min and regular. Oxygen saturation is 90% room air. An ECG reveals sinus tachycardia. A chest x-ray film is unremarkable. Which of the following is the most appropriate next step in management?

52.A 19-year-old man is involved in a motorcycle accident in which he sustains a closed fracture of his right femur and a pelvic fracture. In addition to the obvious deformity in his leg, physical examination is remarkable for the presence of a scrotal hematoma and blood at the meatus. There is no blood in the rectal exam, but the prostate cannot be felt. The patient states that he feels the need to void, but cannot do it. Which of the following is the most appropriate next step in diagnosis?

53.A 65-year-old man undergoes a low anterior resection for rectal cancer. On the fifth day in hospital, his physical examination shows a temperature of 39°C (102°F), blood pressure of 150/90 mm Hg, pulse of 110 beats per minute and regular, and respiratory rate of 28 breaths per minute. A computed tomography (CT) scan of the abdomen reveals an abscess in the pelvis. Which of the following most accurately describes his present condition?

54.A victim of blunt abdominal trauma has splenic and liver lacerations as well as an unstable pelvic fracture. He is hypotensive and tachycardic with a heart rate of 150 despite receiving 2 L of crystalloid en route to the hospital. He was intubated prior to arrival due to declining mental status. He is taken emergently to the operating room for exploratory laparotomy and external fixation of his pelvic fracture. Which of the following is the best resuscitative strategy?

55.In the first postoperative day after an open abdominal procedure, a patient develops a temperature of 38.9 C (102 F). He is encouraged to ambulate, cough, and breathe deeply, but he is noncompliant. On the second day, he is still febrile. Incentive spirometry and postural drainage are instituted, but his participation is less than enthusiastic. He lies in bed all day and hardly moves. By the third day, he is still spiking fevers in the same range, although efforts to improve his ventilation continue, resolution of his problem will most likely require which of the following?

56.A middle-aged man with symptomatic carotid stenosis underwent a carotid endarterectomy on the right side. The area of significant stenosis extended from die carotid bifurcation up into the internal carotid, requiring a very high dissection and clamping of the vessel. The endarterectomy was done with an in situ shunt and closed with a Dacron patch. In the postoperative period, the patient has persistent difficulty swallowing solids and even more difficulty swallowing liquids. Any attempt to do so results in violent coughing and aspiration. His lips look symmetric and move normally, he speaks in a normal tone of voice without tiring, and he has no trouble breathing. When he is asked to stick his tongue out, he does so without deviation to either side. His symptoms are due to intraoperative damage of which of the following nerves?

58.A 62-year-old man who had a motorcycle accident has been in a coma for several weeks. He is on a respirator, has had pneumonia on and off, has been on pressors, and shows no signs of neurologic improvement. The family inquires about brain death and possible organ donation. An independent neurologic evaluation confirms that the patient is brain dead. What advice should be given to his family?

59.A 3-year-old boy is brought to the emergency room after spilling bleach onto his lower extremities. He is diagnosed with a chemical burn and all involved clothing are removed. In addition to resuscitation, which of the following is the most appropriate initial management of this patient?

60.A 35-year-old man with new diagnosis of Crohn disease presents with rapidly enlarging painful ulcerations on the lower extremities. Cultures of the lesion are negative, and skin biopsy reveals no evidence of malignancy. Which of the following is the most appropriate treatment option?

61.Following a weekend of snowmobiling, a 42-year-old man comes to the emergency department with pain, numbness, and discoloration of his right forefoot. You diagnose frostbite. Which of the following is the proper initial treatment?

62.A 23-year-old man is admitted to the hospital after being struck by a motor vehicle. The patient sustained a compound fracture of his left femur in the accident and has had moderate blood loss. He was admitted to the hospital, has been stabilized over the past few days, and is now preparing for physical therapy. His hematocrit is 24%. The man feels weak and fatigued and easily gets short of breath with mild exertion. Which of the following is the most appropriate next step in management?

63.A 24-year-old man comes to the physician 24 hours after sustaining an injury to the right knee while playing soccer. He can walk, but he limps on the right side. He reports that he was hit by another player on the lateral side of his right knee, but did not feel a snap or pop at the time of the accident. On examination, the right knee appears normal, but palpation elicits tenderness along the medial aspect of the joint line. Increased laxity is observed when a valgus stress is applied to the knee flexed at 30 degrees, but not when the knee is in full extension. Lachman's test and posterior drawer tests are negative. Which of the following is the most likely diagnosis?

64.A 54-year-old man sees you because of a growth on his lower lip. He smokes tobacco, has a fair complexion, and works outdoors. The biopsy report confirms a carcinoma. Which of the following is the most common diagnosis for tumors involving the lips?

65.A 40-year-old woman complains of mild, intermittent pain and paresthesias in her right wrist. She reports the pain is worse at night and with driving. On physical examination hyperflexion of the right wrist reproduces the paresthesia. With regard to her diagnosis, which of the following is the most appropriate initial treatment?

66.A 60-year-old diabetic man undergoes incision and drainage of an infected boil on his back. The wound is left open and packed daily. Week by week, the wound grows smaller and eventually heals. Which of the following terms describes the method of wound closure by the patient?

67.A 24-year-old woman is brought to the emergency department after being stabbed by her boyfriend. The examining physician notes a 1.5-cm puncture wound lateral to her sternum. She has a blood pressure of 70/palpable, distended neck veins, and muffled heart sounds. Which of the following is the most appropriate next step in management?

68.A 55-year-old-woman of Asian descent goes to the emergency department because of vomiting and severe abdominal cramping of 3 days' duration. Her pain is centered on the umbilicus. She denies being exposed to a viral or bacterial illness. Her medical history includes a previous cholecystectomy and an appendectomy after which she developed an infection. Her abdomen is not tender, but hyperactive, high-pitched peristalsis with rushes coincides with palpable bowel cramping. Abdominal x-ray films taken in the supine and upright positions demonstrate a ladder- like series of distended small bowel loops. Which of the following is the most likely explanation for these findings?

69.A 60-kg, 53-year-old man with no significant medical problems undergoes lysis of adhesions for a small-bowel obstruction. Postoperatively, he has high nasogastric output and low urine output. What is the most appropriate management of his fluids?

70.Four days after surgical evacuation of an acute subdural hematoma, a 44-year-old man becomes mildly lethargic and develops asterixis. He has received 2400 mL of 5% dextrose in water intravenously each day since surgery, and he appears well hydrated. Pertinent laboratory values are as follows: Serum electrolytes (mEq/L): Na+ 118, K+ 3.4, Cl− 82, HCO3− 24 Serum osmolality: 242 mOsm/L Urine sodium: 47 mEq/L Urine osmolality: 486 mOsm/L Which of the following is the best treatment of his hyponatremia?

71.A 35-year-old man had a splenectomy 8 days ago, following a motor vehicle accident. He is now complaining of left shoulder pain. His temperature is 39.0 C (102.2 F), blood pressure is 110/80 mm Hg, pulse is 110/min, and respirations are 30 min and shallow, Physical examination shows clear lungs with equal breath sounds bilaterally and mild tenderness to palpation in the left upper quadrant with a well-healing midline laparotomy incision. Laboratory studies show: Hemoglobin 15 g/dL Hematocrit 45% Leukocyte counts 15,000/mm3 A chest x-ray film shows no infiltrates or effusions. Which of the following is the most likely diagnosis?

72.A 42-year-old man is diagnosed with an osteosarcoma. His family history is significant for a 37-year-old sister with breast cancer and an uncle with adrenocortical carcinoma. His family physician suspects that he may have Li-Fraumeni syndrome and suggests genetic testing. Which of the following genes is most likely to be mutated if he has the syndrome?

73.A patient with a solid malignancy discusses chemotherapy with his oncologist. He is interested in the risks of the treatment. What is the primary toxicity of doxorubicin (Adriamycin)?

74.A 22-year-old woman has a known family history of breast cancer in her first-degree relatives. She undergoes genetic testing and is found to be a BRCA1 mutation carrier. She does not currently desire bilateral prophylactic mastectomy. Which of the following is the next best option to manage her risk for breast cancer?

75.A 56-year-old woman is undergoing chemotherapy. She presents today with complaints of burning on urination and bloody urine. Which of the following agents causes hemorrhagic cystitis?

76.A 30-year-old woman comes to the physician 6 hours after falling on her outstretched right hand. She has pain and limitation of movement in her wrist, but denies sensations of tingling or numbness. The right wrist is mildly swollen, and its range of passive motion is limited compared with the left side. Palpation elicits maximal tenderness in the area of the anatomic snuffbox, between the tendons of the extensor pollicis longus and abductor pollicis muscles. Ulnar and radial pulses are normal, and Tinel's and Phalen's tests are negative. Further examination rules out signs of nerve or vascular damage. Plain x-ray films performed in the anteriorposterior, lateral, and oblique views fail to show any evidence of fractures. At this time, which of die following is the most appropriate next step in management?

77.A 72-year-old woman undergoes a partial colectomy for adenocarcinoma of the sigmoid colon. She receives appropriate antibiotic coverage and low-dose heparin prophylaxis. On the 5th hospital day, the patient begins complaining of right chest pain, difficulty in breathing, and dry cough. Her temperature is 37.9 C (100.2 F), blood pressure is 134/78 mm Hg, pulse is 115/min and regular, and respirations are 20/rnin. Examination shows crackles in the right chest, but no tenderness or edema in the legs. A chest x-ray film reveals areas of opacification in the right lung. ECG reveals sinus tachycardia with nonspecific ST changes. Laboratory studies show: Arterial blood gas analysis PaQ2 74 mm Hg Pa C 0 2 37 mm Hg pH 7.35 Blood/serumHematocrit 40% Leukocytes 8300/mm3 Lactate dehydrogenase 350 U/L Fibrin D-dimer 600 ng/mL (normal upper limit 500 ng/mL) Which of the following is the most appropriate step in diagnosis?

78.A 65-year-old man complains of blood in his urine for the past 2 months. He has had no similar episodes in the past. He is otherwise healthy and denies abdominal pain, any trauma, fever, chills, anorexia, or dysuria. He reports having a good urinary stream and no nocturia or dribbling. He is not sexually active. He has no other medical problems and is not taking any medications. His vital signs are stable. Lung, heart, abdominal, and groin examination are unremarkable. Rectal exam reveals a nontender prostate with no masses or enlargement- Urinalysis reveals packed red cells, a few white cells, and no casts. Which of the following is the most appropriate management?

79.A 65-year-old man undergoes a technically difficult abdominal–perineal resection for a rectal cancer during which he receives 3 units of packed red blood cells. Four hours later, in the intensive care unit (ICU), he is bleeding heavily from his perineal wound. Emergency coagulation studies reveal normal prothrombin, partial thromboplastin, and bleeding times. The fibrin degradation products are not elevated, but the serum fibrinogen content is depressed and the platelet count is 70,000/μL. Which of the following is the most likely cause of his bleeding?

80.A 78-year-old man with a history of coronary artery disease and an asymptomatic reducible inguinal hernia requests an elective hernia repair. Which of the following would be a valid reason for delaying the proposed surgery?

81.A 68-year-old man is admitted to the coronary care unit with an acute myocardial infarction. His postinfarction course is marked by congestive heart failure and intermittent hypotension. On the fourth day in hospital, he develops severe midabdominal pain. On physical examination, blood pressure is 90/60 mm Hg and pulse is 110 beats per minute and regular; the abdomen is soft with mild generalized tenderness and distention. Bowel sounds are hypoactive; stool Hematest is positive. Which of the following is the most appropriate next step in this patient’s management?

82.A 30-year-old woman in her last trimester of pregnancy suddenly develops massive swelling of the left lower extremity. Which of the following would be the most appropriate workup and treatment at this time?

83.A 20-year-old woman with a family history of von Willebrand disease is found to have an activated partial thromboplastin time (aPTT) of 78 (normal = 32) on routine testing prior to cholecystectomy. Further investigation reveals a prothrombin time (PT) of 13 (normal = 12), a platelet count of 350,000/mm3, and an abnormal bleeding time. Which of the following should be administered in the perioperative period?

84.A pedestrian is hit by a car. Physical examination shows the leg to be angulated midpoint between the knee and the ankle. X-ray films confirm fractures of the shaft of the tibia and fibula. Satisfactory alignment is achieved by external manipulation, and a long leg cast applied. In the ensuing 8 hours, the patient complains of increasing pain. When the cast is removed, the pain persists, the muscle compartments feel tight, and there is excruciating pain with passive extension of the toes. Which of the following is the most appropriate next step in management?

85.A 27-year-old man is shot point blank with a .22-caliber revolver. The entrance wound is in the anterior chest wall, just to the left of the sternal border, at the level of the 4th intercostal space. There is no exit wound. He is diaphoretic, cold, shivering, and anxious, and is asking for a blanket and a drink of water. His blood pressure is 65/40 mm Hg, and his pulse is 145/min and barely perceptible. He has large, distended veins in his neck and forehead. He is breathing adequately and has bilateral breath sounds. He is neurologically intact. Which of the following is the most likely diagnosis?

86.A 75-year-old thin cachectic woman undergoes a tracheostomy for failure to wean from the ventilator. One week later, she develops significant bleeding from the tracheostomy. Which of the following would be an appropriate initial step in the management of this problem?

87.A 53-year-old woman has been intubated for several days after sustaining a right pulmonary contusion after a motor vehicle collision as well as multiple rib fractures. Which of the following is a reasonable indication to attempt extubation?

88.A 19-year-old man receives un-cross-matched blood during resuscitation after a gunshot wound to the abdomen. He develops fever, tachycardia, and oliguria during the transfusion and is diagnosed as having a hemolytic reaction. Which of the following is the most appropriate next step in the management of this patient?

89.A 74-year-old woman with a history of a previous total abdominal hysterectomy presents with abdominal pain and distention for 3 days. She is noted on plain films to have dilated small-bowel and air-fluid levels. She is taken to the operating room for a small-bowel obstruction. Which of the following inhalational anesthetics should be avoided because of accumulation in air-filled cavities during general anesthesia?

90.A 61-year-old alcoholic man presents with severe epigastric pain radiating to his back. His amylase and lipase are elevated, and he is diagnosed with acute pancreatitis. Over the first 48 hours, he is determined to have 6 Ranson’s criteria, including a PaO 2 less than 60 mm Hg. His chest x-ray reveals bilateral pulmonary infiltrates, and his wedge pressure is low. Which of the following criteria must be met to make a diagnosis of adult respiratory distress syndrome (ARDS)?

91.A 50-year-old man has respiratory failure due to pneumonia and sepsis after undergoing splenectomy for a traumatic injury. Which of the following management strategies will improve tissue oxygen uptake (ie, shifting the oxygen dissociation curve, depicted here, to the right)?

92.A 64-year-old man with history of severe emphysema is admitted for hematemesis. The bleeding ceases soon after admission, but the patient becomes confused and agitated. Arterial blood gases are as follows: pH 7.23; PO2 42 mm Hg; PCO2 75 mm Hg. Which of the following is the best initial therapy for this patient?

93.A 62-year-old woman has an eczematoid lesion in the areola of her right breast that has been present for 3 months. She has self-medicated with skin lotions and over-the-counter steroid ointments, but the area has not improved. On physical examination, the nipple is inverted, the skin of the areola is reddish and desquamated, and the entire area feels firm, with no discrete mass demarcated from the rest of the breast. Which of the following is the most appropriate next step in management?

94.A 35-year-old woman has dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, cough, and hemoptysis. The symptoms have been slowly progressive for about 5 years. She looks thin and cachectic, and has atrial fibrillation and a low-pitched, rumbling diastolic apical heart murmur. At age 15, she had rheumatic fever. Surgery has been recommended. Which of the following is the most appropriate management?

95.A 74-year-old man presents with sudden onset of extremely severe, tearing precordial chest pain that radiates to the back and migrates downward shortly after its onset. As far as the man can tell, there was no precipitating event. He is seen within an hour and is in obvious distress. He is afebrile, but his blood pressure is 220/110 mm Hg and his pulses in the upper extremities are unequal at 102/min. Chest x-ray shows a wide mediastinum. Which of the following could best establish the diagnosis?

96.A 16-year-old adolescent boy with a history of severe hemophilia A is undergoing an elective inguinal hernia repair. Which of the following is the best option for preventing or treating a bleeding complication in the setting of this disease?

97.A 59-year-old man is planning to undergo a coronary artery bypass. He has osteoarthritis and consumes nonsteroidal anti-inflammatory drugs (NSAIDs) for the pain. Which of the following is the most appropriate treatment prior to surgery to minimize his risk of bleeding from his NSAID use?

98.A 63-year-old man undergoes a partial gastrectomy with Billroth II reconstruction for intractable peptic ulcer disease. He presents several months postoperatively with a megaloblastic anemia. Which of the following is the best treatment for this surgical complication?

99.A 52-year-old woman undergoes a sigmoid resection with primary anastomosis for recurrent diverticulitis. She returns to the emergency room 10 days later with left flank pain and decreased urine output; laboratory examination is significant for a white blood cell (WBC) count of 20,000/mm3. She undergoes a CT scan that demonstrates new left hydronephrosis, but no evidence of an intra-abdominal abscess. Which of the following is the most appropriate next step in management?

100.A 23-year-old woman undergoes total thyroidectomy for carcinoma of the thyroid gland. On the second postoperative day, she begins to complain of a tingling sensation in her hands. She appears quite anxious and later complains of muscle cramps. Which of the following is the most appropriate initial management strategy?