152. A 62-year-old woman undergoes a pancreaticoduodenectomy for a pancreatic head cancer. A jejunostomy is placed to facilitate nutritional repletion as she is expected to have a prolonged recovery. What is the best method for delivering postoperative nutrition?

153. A 65-year-old woman has a life-threatening pulmonary embolus 5 days following removal of a uterine malignancy. She is immediately heparinized and maintained in good therapeutic range for the next 3 days, then passes gross blood from her vagina and develops tachycardia, hypotension, and oliguria. Following resuscitation, an abdominal CT scan reveals a major retroperitoneal hematoma. Which of the following is the best next step in management?

154. A 71-year-old man develops dysphagia for both solids and liquids and weight loss of 60 lb over the past 6 months. He undergoes endoscopy, demonstrating a distal esophageal lesion, and biopsies are consistent with squamous cell carcinoma. He is scheduled for neoadjuvant chemoradiation followed by an esophagectomy. Preoperatively he is started on total parenteral nutrition, given his severe malnutrition reflected by an albumin of less than 1. Which of the following is most likely to be a concern initially in starting total parenteral nutrition in this patient?

155. A 39-year-old woman presents with generalized malaise and lymphadenopathy. Biopsy of a supraclavicular lymph node reveals non-Hodgkin lymphoma. Fortyeight hours after initiation of chemotherapy, she develops a high-grade fever and her laboratory studies demonstrate hyperkalemia, hyperphosphatemia, and hypocalcemia. Which of the following cells mediate this syndrome?

157. A 24-year-old woman presents with lethargy, anorexia, tachypnea, and weakness. Laboratory studies reveal a BUN of 150 mg/dL, serum creatinine of 16 mg/dL, and potassium of 6.2 mEq/L. Chest x-ray shows increased pulmonary vascularity and a dilated heart. Which of the following is the most appropriate management of this patient?

159. A 56-year-old woman is undergoing a cadaveric renal transplant. After revascularization of the transplanted kidney, the transplanted renal parenchyma becomes swollen and blue. The surgeon suspects hyperacute rejection. What is the treatment of choice for this patient?

160. A 57-year-old man has end-stage heart failure due to atherosclerosis. His cardiologist refers him for evaluation for heart transplantation. Which of the following is an absolute contraindication for heart transplantation?

161. A 38-year-old woman who underwent a cadaveric renal transplant 8 years ago presents with fevers, fatigue, and weight loss. Evaluation included CT scans of the head, neck, chest, abdomen, and pelvis; she is noted to have diffuse lymphadenopathy and pulmonary nodules. A biopsy and histologic examination of a lymph node is performed. Which of the following viruses is most likely to be present in the lymph node?

162. A 41-year-old man underwent a successful living-related kidney transplantation 1 year ago with good results. Preoperatively, he was noted to have an elevated calcium level; post- transplantation, he continues to have elevated calcium levels and associated symptoms. Which of the following is the most appropriate next step in management?

163. A 53-year-old man presents with constipation and a 20-lb weight loss over the course of 6 months. Colonoscopy reveals a fungating mass in the sigmoid colon; biopsy is consistent with adenocarcinoma. His metastatic workup is negative. A CEA level is obtained and is 4-fold greater than normal. Which of the following is the appropriate use of this test?

168. A 62-year-old, right-handed man has transient episodes of paralysis of the right arm and inability to express himself. There is no associated headache. The episodes have sudden onset, last about 5-10 minutes, and leave no neurologic sequela. The patient is overweight and sedentary. He smokes one pack of cigarettes per day and has high cholesterol, but he is not hypertensive. The only abnormality in the physical examination is a bruit over the left carotid bifurcation. Which of the following is the most appropriate initial step in diagnosis?

169. Eight hours after undergoing a transnasal, transsphenoidal resection of a prolactinoma, a young lady becomes lethargic, confused, and eventually comatose. Review of the record shows that her urinary output since surgery has averaged 600 mL/hr, while her intake of IV fluids (5% dextrose in 0.45% saline) has been 100 mL/hr. Her blood pressure is 110/75 mm Hg, and her pulse is 88/min. Which of the following would most likely yield the correct diagnosis?

170. A 42-year-old man has had a rocky course for the 3 days following a bowel resection for intestinal perforation due to inflammatory bowel disease. His CVP had been 12 to 14 but is now 6, in the face of diminished blood pressure and oliguria. Which of the following is the most likely etiology of his hypotension?

171. Acute renal failure occurs following aortic angiography in a 72-year-old man. His weight has been rising, his lungs show rales at both bases, and he is dyspneic. His fractional excretion of sodium is greater than 1. He has eosinophilia on his peripheral smear, an elevated erythrocyte sedimentation rate, and proteinuria with microscopic hematuria. Which of the following is the most likely cause of his renal failure?

172. A 55-year-old woman has been hospitalized because of recurrent pancreatitis, ARDS, prolonged ileus, and need for parenteral nutrition. She demonstrates weakness, lassitude, orthostatic hypotension, nausea, and fever. Which of the following abnormalities is most likely to explain these symptoms?

173. A young man is shot in the upper part of the neck with a .22 caliber revolver. Inspection of the entrance and exit wounds indicates that the trajectory of the bullet is all above die level of the angle of the mandible, but below the skull. He is fully conscious and neurologically intact. A steady trickle of blood flows from both wounds, and it does not seem to respond to local pressure. He is hemodynamically stable. Which of the following is the most appropriate next step in diagnosis?

174. A 21-year-old college student undergoes surgery to remove a small cyst in his palm at the base of his third digit. He receives an axillary regional block prior to die procedure but still has discomfort post-operatively. Injection of anesmetic in which of the following sites may be used to treat his pain?

175. A 26-year-old man is resuscitated with packed red blood cells following a motor vehicle collision complicated by a fractured pelvis and resultant hemorrhage. A few hours later the patient becomes hypotensive with a normal central venous pressure (CVP), oliguric, and febrile. Upon examination, the patient is noted to have profuse oozing of blood from his intravenous (IV) sites. Which of the following is the most likely diagnosis?

176. A 62-year-old man is suffering from arrhythmias on the night of his triple coronary bypass. Potassium has been administered. His urine output is 20 to 30 mL/h. Serum potassium level is 6.2. Which of the following medications counteracts the effects of potassium without reducing the serum potassium level?

177. An in-hospital workup of a 78-year-old hypertensive, mildly asthmatic man who is receiving chemotherapy for colon cancer reveals symptomatic gallstones. Preoperative laboratory results are notable for a hematocrit of 24% and urinalysis with 18 to 25 WBCs and gram-negative bacteria. On call to the operating room, the patient receives intravenous penicillin. His abdomen is shaved in the operating room. An open cholecystectomy is performed and, despite a lack of indications, the common bile duct is explored. The wound is closed primarily with a Penrose drain exiting a separate stab wound. On postoperative day 3, the patient develops a wound infection. Which of the following changes in the care of this patient could have decreased the chance of a postoperative wound infection?

179. A 45-year-old woman undergoes an uneventful laparoscopic cholecystectomy for which she receives 1 dose of cephalosporin. One week later, she returns to the emergency room with fever, nausea, and copious diarrhea and is suspected of having pseudomembranous colitis. She is afebrile and has no peritoneal signs on abdominal examination. She has a mild leukocytosis with a left shift. Which of the following is the appropriate initial management strategy?

180. An 18-year-old woman develops urticaria and wheezing after an injection of intravenous contrast for an abdominal CT scan. Her blood pressure is 120/60 mm Hg, heart rate is 155 beats per minute, and respiratory rate is 30 breaths per minute. Which of the following is the most appropriate immediate therapy?

181. A patient develops a fever and tachycardia during a blood transfusion after a redo coronary artery bypass procedure. The nurse subsequently discovers that there was a mix-up in the cross-match because of a labeling error. Which of the following is diagnostic in a patient with an immediate hemolytic reaction secondary to a blood transfusion?

182. A 72-year-old man with diabetes, renal insufficiency, and coronary artery disease presents in septic shock from emphysematous cholecystitis. His oxygen saturation is 100% on 6- L nasal cannula and his hemoglobin is 7.2 mg/dL. His mixed venous oxygen saturation is 58%. Which of the following treatment options will improve his oxygen delivery the most?

184. A 65-year-old man who had a 25-lb weight loss over the previous 6 months is diagnosed with adenocarcinoma of the distal esophagus. He undergoes a transhiatal esophagectomy complicated by a cervical leak. He is receiving enteral feeds through a jejunostomy tube. After a week, his physicians wish to assess his nutritional resuscitation. Which of the following is the most accurate measure of adequacy of his nutritional support?

185. A 47-year-old man with hypertensive nephropathy develops fever, graft tenderness, and oliguria 4 weeks following cadaveric renal transplantation. Serum creatinine is 3.1 mg/dL. A renal ultrasound reveals mild edema of the renal papillae but normal flow in both the renal artery and the renal vein. Nuclear scan demonstrates sluggish uptake and excretion. Which of the following is the most appropriate next step?

186. Approximately 6 weeks following a kidney transplant, a 59-year-old woman develops fever, malaise, and myalgias and is found to have a cytomegalovirus (CMV) infection. Which of the following is a potential sequela of CMV infection?

187. A kidney transplant recipient presents with severe acute rejection that does not respond to steroid treatment. Administration of which of the following agents is the best step in her management?

188. A 24-year-old woman develops moderate, generalized abdominal pain of sudden onset and shortly thereafter faints. At the time of evaluation in the emergency department, she has regained consciousness, is pale, and has a blood pressure of 95/70 mm Hg and a faint pulse rate of 90/min. The abdomen is mildly distended and tender, with normal bowel sounds. Her hemoglobin is 7 g/dL. There is no history of trauma, but it is suspected that she might be bleeding into her abdomen, and a diagnostic peritoneal lavage is performed. The study shows that there is free blood in the peritoneal cavity. She denies the possibility of pregnancy because she has been on birth control pills since the age of 14 and has never missed taking them. Pelvic examination is normal, and a pregnancy test is negative. At laparotomy, the surgeons are likely to find which of the following?

189. A 56-year-old man presents to his urologist for continued evaluation of hypertension and hematuria. The patient has a 10-year history of hypertension and recent onset of painless hematuria for which he sought the attention of an urologist 3 months ago. On detailed questioning, the man states that he has been having severe headaches that are refractory to narcotic analgesics. Three days ago, a renal ultrasound was obtained that demonstrated bilaterally enlarged kidneys with multiple cysts. Which of the following is the most appropriate next step in diagnosis?

190. A patient involved in a high-speed automobile collision arrives in the emergency department unconscious, with multiple facial fractures; brisk bleeding into his nose, mouth, and throat; and gurgly, irregular, noisy breathing. Which of the following would be the best method to secure an airway in this patient?

191. A 30-year-old man is scheduled for a laparoscopic cholecystectomy for biliary colic. He reports a family history of prolonged paralysis during general anesthesia. Which of the following medications should be avoided during his procedure?

192. A 63-year-old man with multiple rib fractures and a pulmonary contusion requires prolonged intubation. He is unable to be weaned from the ventilator and is on a volume control mode. He has a tracheostomy and a percutaneous gastrotomy in place through which he is being fed. The surgeon orders a respiratory quotient (RQ), which is the ratio of the rate of carbon dioxide production over the rate of oxygen uptake. The RQ is 1. Based on this information, which of the following is the next step in his management?

193. A 22-year-old woman is involved in a major motor vehicle accident and receives a tracheostomy during her hospitalization. Five days after placement of the tracheostomy she has some minor bleeding around the tracheostomy site. Which of the following is the most appropriate immediate therapy?

194. A 42-year-old man is undergoing chemotherapy after resection of a cecal adenocarcinoma with positive lymph nodes. You are asked to see him regarding a potential surgical complication. Which of the following potentially operable complications is a common occurrence among patients receiving systemic chemotherapy?

195. A 28-year-old medical student seeks your attention because of a testicular mass. Biopsy is consistent with pure seminoma. There is no evidence of enlarged retroperitoneal lymph nodes on CT scan. Which of the following is the best treatment strategy for this patient?

196. A 25-year-old woman with end-stage renal disease is exploring the benefits of renal transplantation. Which of the following is an advantage of dialysis over renal transplantation?

197. A 30-year-old previously healthy man presents with refractory hypertension on four medications. Urinalysis is positive for metanephrines. He was adopted as an infant and therefore does not know his family history. Which of the following inherited syndromes is not associated with this disease?

198. A 48-year-old man with alcoholic cirrhosis has several episodes of massive hematemesis. Upper gastrointestinal endoscopy confirms that he is bleeding from esophageal varices. Sclerosing injections fail to control the bleeding. After the patient has been transfused 7 units of packed red cells, he is subjected to an emergency side-to-side portacaval shunt. At the time of surgery he has a serum albumin level of 3.1 g/dL, a total bilirubin of 1,7 mg/dL, and a prothrombin time (PT) 2 seconds above the control After surgery, the bleeding stops, and the patient wakes up briefly from the anesthetic but then lapses into a coma. The reason for his neurologic deterioration would most likely be revealed by a laboratory determination of which of the following?

199. A 57-year-old man is returned to the post-surgical recovery unit after an open cholecystectomy. The patient had an uneventful, but prolonged, operative course in a very cold operating room. His past medical history is unremarkable. The only attempt at patient warming was raising the ambient temperature of the room. His urine output since arrival in the post- anesthesia care unit (PACU) has been 5 mL/hr. Which of the following is most likely to confirm the diagnosis?

200. A 25-year-old man presents to the same day surgical center for repair of an old injury to his lateral collateral ligament. The anesthesiologist wants to perform an axillary block for local pain control. If the posterior wall of the axillary artery is pierced during placement of the block, which of the following nerves will most likely be affected?

201. A 55-year-old man is diagnosed with benign prostatic hyperplasia. The patient declines pharmacologic treatment and elects to undergo transurethral resection of the prostate (TURP). Which of the following is the most common complication of this procedure?

202. A 33-year-old woman is brought to the emergency room from the scene of a severe motor vehicle accident. She is combative, confused, uncooperative, and appear dusky and dyspneic. Which of the following is the most appropriate management of her airway?

203. Following a boating injury in an industrial-use river, a patient begins to display fever, tachycardia, and a rapidly expanding area of erythema, blistering, and drainage from a flank wound. An x-ray shows gas in the soft tissues. Which of the following measures is most appropriate?

204. Following pelvic gynecologic surgery, a 34-year-old woman becomes dyspneic, her peripheral arterial O2 saturation falls from 94% to 81%, and her measured PaO2 is 52 on a 100% non-rebreather mask. She is hemodynamically stable. A CT angiogram is consistent with a right lower lobe pulmonary embolus. Which of the following is the next step in her management?

205. A 72-year-old woman who is planning to undergo ventral hernia repair is on warfarin for atrial fibrillation. She is advised to cease her warfarin several days before her surgery and is hospitalized preoperatively for heparinization. During her hospital stay, she complains of severe abdominal and flank pain. Her prothrombin time (PT) is normal, but her activated partial thromboplastin time (aPTT) is elevated. An abdominal CT scan demonstrates a large retroperitoneal hematoma. Which of the following should be administered to reverse the effects of the heparin?

206. A 42-year-old man who was in a house fire is transferred to your burn unit. He has singed nose hairs and facial burns. Direct laryngoscopy in the emergency room demonstrates pharyngeal edema and mucosal sloughing. He has 60% total body surface area burns. Which of the following is the next step in the management of this patient?

208. A 24-year-old man whose father was just diagnosed with colon cancer presents to his family physician to discuss screening colonoscopy. His physician suspects that he has hereditary nonpolyposis colon cancer (HNPCC) or Lynch syndrome and recommends screening colonoscopy beginning at age 25. Which of the following is most supportive of a clinical diagnosis of HNPCC?

209. A 53-year-old woman presents with bright red blood per rectum, increased abdominal distention, and weight loss. She is found to have a large fungating mass 8 cm from the anal verge. No other lesions are identified. Biopsy is consistent with invasive rectal adenocarcinoma. Endorectal ultrasound shows invasion of the tumor into the perirectal fat and multiple enlarged lymph nodes. CT scans of the chest, abdomen, and pelvis do not show any metastases. She would like to preserve her sphincter if possible. Which of the following is the best treatment option for this patient given her preferences?

210. A 35-year-old woman presents with a right breast mass. You perform a thorough history and physical examination as well as a core biopsy of the right breast mass. In which of the following circumstances would a sentinel lymph node biopsy be indicated?

211. A patient requires both cardiac and renal transplantation. Preparation for the procedures has begun. How do cardiac allografts differ from renal allografts?

212. A patient with colon cancer has a mass in the upper lobe of his left lung 2.5 years following resection of his colon cancer and subsequent 12 months of chemotherapy. His CEA level is rising. Which of the following predicts a 5-year survival rate of greater than 20% following resection of pulmonary metastases?

213. A 70-year-old man is concerned when his dentist finds a white patch on his oral mucosa during a routine examination. Proper management should include which of the following?

214. A 60-year-old man presents with a 6-mm basal cell carcinoma on the tip of his nose. He is scheduled to undergo excision of the tumor in the operating room with repair of the defect using skin and subcutaneous tissue from his earlobe. Which of the following terms most appropriately describes this form of reconstructive surgery?

215. A 40-year-old woman undergoes an incisional biopsy of a pigmented lesion on her right thigh. Pathologic examination reveals malignant melanoma with a thickness of 3 mm. Findings on examination of the groin are normal. Which of the following is the most appropriate next step in her management?

217. A 49-year-old woman undergoes surgical resection of a malignancy. The family asks about the prognosis. The histopathology is available for review. For which of the following malignancies does histologic grade best correlate with prognosis?

219. A 61-year-old man undergoes upper endoscopy for evaluation of weight loss and is identified to have a submucosal mass in the stomach. Biopsy is consistent with a gastrointestinal stromal tumor (GIST). Workup reveals the presence of liver metastases. Which of the following is the best initial treatment for this patient?

220. A 57-year-old woman develops bony metastases 1 year after right modified radical mastectomy for breast cancer. The tumor was estrogen receptor-negative, progesterone receptor- negative, and Her-2/neu positive. Which of the following agents is indicated for treatment of her metastatic disease?

221. A 61-year-old man with severe three-vessel coronary disease and diabetes mellitus is scheduled for abdominal surgery. The patient has a long history of coronary disease and had a q- wave myocardial infarction 2 years ago. He has had type 1 diabetes mellitus for 12 years. His medications include atenolol, insulin, and captopril. His last hemoglobin Alc, 3 months ago, was 9.2%. Which of the following is the most predictive of a perioperative complication in this patient?

222. A 44-year-old woman has a 2-cm firm palpable mass in the upper outer quadrant of her right breast. The mass is freely movable, and her breast is of normal, rather generous size. There are no palpable axillary nodes. Mammogram shows no other lesions. A core biopsy establishes a diagnosis of infiltrating ductal carcinoma. She has no neurologic or skeletal symptoms, and a chest x-ray film and liver enzymes are normal. She understands that systemic therapy may eventually be needed once the full extent of her disease is known. Although she wants the best chance for cure, she is very concerned about cosmetic deformity and wants to know what can be done about the breast itself. Which of the following is the most appropriate management?

223. A 26-year-old, drug-addicted man develops congestive heart failure over a period of a few days. He is febrile, has a loud, diastolic murmur at the right second intercostal space, and has a blood pressure of 120/20 mmHg. A physical examination performed a few weeks ago, when he attempted to enroll in a detoxification program, was completely normal. His blood pressure at that time was 120/80 mm Hg, and no murmurs were noted. In addition to long-term antibiotic therapy, which of the following is the most appropriate next step in management?

224. A 45-year-old woman with breast cancer undergoes a modified radical mastectomy with lymph node dissection. Six weeks later, she returns complaining of decreased mobility of her shoulder. On physical examination, the scapula protrudes from the body when pressing her outstretched arm on the wall. Which of the following nerves was most likely injured during the operation?

225. A 12-year-old boy is in a motor vehicle collision in which the car caught fire. He sustains significant inhalation injury and a circumferential burn without fractures or other soft tissue trauma to his left lower extremity during extrication from the burning vehicle. He is intubated and aggressively resuscitated in the intensive care unit. Which of the following is the most appropriate method of assessing for compartment syndrome of the left lower extremity?

226. During a bar brawl, a 19-year-old man sustains a 4-in laceration on his left arm from glass and presents to the emergency room the following morning, 10 hours later. He is neurovascularly intact and the wound is deep, extending down to fascia. Which of the following is the most appropriate management of the wound?

227.A 59-year-old woman undergoes an exploratory laparotomy for peritonitis and is found to have perforated diverticulitis. She undergoes a sigmoid resection with an end colostomy. She is administered a third-generation cephalosporin within 1 hour prior to the incision and the antibiotic is continued postoperatively. One week later, she develops an intra-abdominal abscess, which is percutaneously drained. Bacteroides fragilis is isolated from the cultures. Which of the following statements regarding her perioperative antibiotic regimen is most accurate?

228. A 30-year-old man with a history of Crohn disease develops an enterocutaneous fistula and is placed on total parenteral nutrition through a right subclavian central venous catheter. After 5 days, the patient develops a fever and leukocytosis; CT scan of the abdomen reveals no intra- abdominal abscess. The subclavian catheter insertion site is inspected and noted to be erythematous and painful. Blood cultures are positive. Which of the following organisms is the most likely cause of his fever?

229. A 32-year-old woman has an episode of upper gastrointestinal bleeding after a night of heavy alcoholic intake followed by ingestion of multiple aspirin tablets for the hangover. There was no prior vomiting until the time when she felt nauseated, went to the bathroom, and "filled the wash basin with vomiting of bright red bloody fluid." When she arrives in the emergency department, an upper gastrointestinal endoscopy is promptly performed, which confirms a diagnosis of acute erosive gastritis. She has no duodenal ulcer and no esophageal varices. Gastric lavage with ice-cold saline is performed and the bleeding stops. Laser photocoagulation or electrocautery are not used, neither is pitressin infused. She remains hemodynamically stable throughout the procedure, and she has a normal hemoglobin. She is sent home 2 hours later. Four hours after discharge, she returns complaining of severe, constant chest pain. She is in acute distress, has a temperature of 39.0 C (102.2 F), is having chills, and looks quite ill. Physical examination is remarkable for the presence of crepitation to palpation in the upper chest and lower neck, and chest x-rays confirm the presence of air in the mediastinum and the subcutaneous tissues. Which of the following is the most likely diagnosis?

230. A 45-year-old man comes to the emergency department because of severe right flank pain that began abrupdy 3 hours ago. The pain comes in waves and radiates down to the ipsilateral testis. The patient is nauseated and extremely restless. His temperature is 37.0 C (98.6 F). Dipstick examination of urine is positive for hematuria. Urinary pH is 5.8. Which of die following is the most appropriate next step in diagnosis?

232. A 19-year-old college student presents with a testicular mass, and after treatment he returns for regular follow-up visits. Which of the following is the most useful serum marker for detecting recurrent disease after treatment of nonseminomatous testicular cancer?

233. An edentulous 72-year-old man with a 50-year history of cigarette smoking presents with a nontender, hard mass in the lateral neck. Which of the following is the best diagnostic test for establishing a diagnosis of malignancy?

234. A 78-year-old man comes to the physician because of a bloody urethral discharge for 3 days. He has had increasing frequency of urination and hesitancy for the past 2 years, but these symptoms have never been severe enough to require medical attention. Digital rectal examination reveals a slightly enlarged and firm prostate. Expressed prostatic secretions are negative for bacteria and leukocytes. Collection of a clean-catch urine in separate aliquots reveals initial hematuria, with blood present in the first 5 mL. Which of the following is the most likely diagnosis?

235. While playing football, a college student injures his shoulder. He comes in with his arm held close to his body, complaining of pain over the clavicle, rather than the shoulder joint. Physical examination shows a normal shoulder, but there is point tenderness at the junction of the middle and distal thirds of the clavicle. Gentle pressure elicits a gritty feeling of bone crunching on bone. He has normal pulses on that arm. After appropriate x-ray studies are performed, which of the following is the most appropriate initial step in management?

236. A 38-year-old immigrant from Latin America sustained a third-degree burn in the lateral aspect of her lower leg when she was 14. The burn was untreated. Ever since the incident, she has had shallow ulcerations at the scar site that heal and break down all the time. In the past few months she has developed an indolent, dirty-looking, deeper ulcer at the site, with "heaped up" tissue growth around the edges. The ulcer is steadily growing and showing no signs of healing. Which of the following is the most appropriate next step in diagnosis?

237. A 50-year-old man complains of loss of libido and impotence after starting treatment with leuprolide for prostatic hyperplasia. An alpha-blocker and finasteride have also been tried, but with similar adverse effects. So far, the patient has not experienced any episodes of urinary tract infection or hematuria, but he is excessively bothered by his symptoms without any medication. Digital rectal examination shows mild prostatic enlargement. At this time, his prostate-specific antigen (PSA) is 4.5 ng/mL, and his creatinine is 0.7 mg/dL. Dipstick examination shows no hematuria. Which of the following is the most appropriate alternative to his current pharmacologic treatment?

238. A 65-year-old man sustains a 50% TBSA burn while burning trash in the backyard. The patient is resuscitated with lactated Ringer (LR) solution using the Parkland formula and a weight of 80 kg. What is the rate of LR given in the first 8 hours?

239. A 67-year-old man presents to his primary care physician with a 1-cm skin lesion on his left forearm. On examination, it has a waxy appearance with rolled pearly borders surrounding a central ulcer. Which of the following is the most appropriate management of this patient?

241. A 39-year-old woman with a known history of von Willebrand disease has a ventral hernia after a previous cesarean section and desires to undergo elective repair. Which of the following should be administered preoperatively?

242. You are the physician on call for the extracorporeal membrane oxygenation (ECMO) service. There are 5 calls today, but only one machine and one technologist available. Which of the following patients is the most appropriate recipient of this service?

243. A 45-year-old man shows up in the emergency department with a pale, pulseless, paresthetic, painful, and paralytic right lower extremity. The process began suddenly 2 hours ago. On examination, no pulses are apparent in the right lower extremity. Pulse at the wrist is 95/min and grossly irregular. Treatment would likely be based on which of the following?

244. A 69-year-old man, who smokes and drinks heavily, complains of an earache on his left side. The earache has been present for 6 weeks and is not getting any better despite systemic antibiotics and ear drops. On physical examination, he is found to have very poor oral hygiene, only a few remaining stumps of rotten teeth, and big tonsils that are hard to see because he gags easily. Otoscopic examination shows a perfectly normal right tympanic membrane, although the left is distorted by what appears to be a serous otitis media. Tuning fork testing shows conductive hearing loss on the left but equal bone conduction on both sides. He is afebrile. Which of the following will most likely confirm the diagnosis?

245. Shortly after the administration of an inhalational anesthetic and succinylcholine for intubation prior to an elective inguinal hernia repair in a 10-year-old boy, he becomes markedly febrile, displays a tachycardia of 160, and his urine changes color to a dark red. Which of the following is the most appropriate treatment at this time?

246. A 19-year-old man sustains severe lower-extremity trauma, including a femur fracture and a crush injury to his foot. He requires vascular reconstruction of the popliteal artery. On the day after surgery, he becomes dyspneic and hypoxemic and requires intubation and mechanical ventilation. Which of the following is the most likely etiology of his decompensation?

247. An 18-year-old gang member is stabbed in the back, just to the right of the midline. Physical examination shows paralysis and loss of proprioception distal to the injury on the right side, and loss of pain perception distal to the injury on the left side. Which of the following is the most likely diagnosis?

248. A 31-year-old man is brought by helicopter to the trauma center after a motor vehicle accident in which he sustained massive lower extremity crush injury. The patient is alert and awake but in tremendous pain. His blood pressure is 140/80 mm Hg, and his pulse is 110/min. There is copious ongoing blood loss from the sites of injury. Urgent laboratory data will most likely show which of the following electrolyte abnormalities?

249. A neonate does not pass any meconium during the first day of life. On day 2 he is brought for evaluation because of repeated green vomiting and progressive abdominal distention. X-ray films of the abdomen show multiple dilated loops of small bowel and no gas in the colon. A contrast enema shows a normally positioned microcolon, and the contrast material refluxes freely into the small bowel, filling some of the more distal distended loops. Exploratory laparotomy is done. There is no malrotation, the small bowel does not have any atretic or obstructed segments, and there is no inspissated meconium in it. Which of the following is most appropriate next step in management?

250. A 62-year-old woman with a history of coronary artery disease presents with a pancreatic head tumor and undergoes a pancreaticoduodenectomy. Postoperatively, she develops a leak from the pancreaticojejunostomy anastomosis and becomes septic. A Swan-Ganz catheter is placed, which demonstrates an increased cardiac output and decreased systemic vascular resistance. She also develops acute renal failure and oliguria. Which of the following is an indication to start dopamine?

251. A 37-year-old woman is brought to the surgical floor after undergoing a routine vaginal hysterectomy that morning. She had been fasting since midnight the night prior to her surgery. She has no past medical history except for uterine fibroids and takes only oral contraceptive pills regularly. During the procedure, she was reported to lose approximately 300 mL of blood. On the floor, she appears well but complains of some fatigue. Her blood pressure is 110/60 mm Hg, and her pulse is 100/min. She is not taking food or water yet because of persistent nausea and vomiting postoperatively. Which of the following is the most appropriate next step in management?

252. A window cleaner falls from a third-story scaffold and lands on his feet. Physical examination and x-rays show comminuted fractures of both calcaneus. He is tender to palpation over multiple bruises and abrasions in other parts of his trunk and extremities, but he has normal vital signs and a normal neurologic exam. Given the mechanism of injury, which of the following is the most appropriate next step in diagnosis?

253. On the second postoperative day after an abdomino-perineal resection for cancer of the rectum, a 72-yearold man complains of severe retrosternal pain. The pain is crushing in nature and radiates to the left arm. He also becomes short of breath and tachycardic. Except for his fresh surgical wounds and postoperative discomfort, physical examination is unremarkable. He does not have distended neck veins. Which of the following is the most appropriate next step in diagnosis?

254. A 14-year-old girl has a firm, movable, rubbery mass in her left breast. The mass was first noticed 6 months ago and has since grown to about 6 cm in diameter. Which of the following is the most likely diagnosis?

255. A 3-week-old infant is brought in because of 2 days of protracted bilious vomiting. He looks acutely ill, and plain x-rays show two large air fluid levels in the upper abdomen, the larger one on the left side and a smaller one on the right side. The radiologist describes the finding as a "double bubble sign." He also reports that there is intraluminal gas distal to those two air fluid levels, but that it is sparse and does not outline distended loops. Which of the following is the most likely tentative clinical diagnosis?

256. A 43-year-old man with a gangrenous gallbladder and gram-negative sepsis agrees to participate in a research study. An assay of tumor necrosis factor (TNF) is performed. Which of the following is the origin of this peptide?

257. A 49-year-old man who underwent liver transplantation 5 years ago for alcoholic cirrhosis presents with a gradually increasing bilirubin level. He undergoes a liver biopsy, which demonstrates a paucity of bile ducts. Which of the following is his best option for treatment?

258. An otherwise healthy 24-year-old man presents in the emergency department with very severe pain of recent onset in his right scrotum. The pain is constant and began about 3 hours prior to his arrival. Physical examination shows a temperature of 39.4 C (103 F) but is otherwise unremarkable, except for the scrotal area. The testis on the affected side is in the normal position; however, it appears to be swollen and is exquisitely tender to palpation. The cord above the testis is equally painful and tender. Urinalysis shows pyuria. Which of the following is the most appropriate next step in management?

259. A 16-year-old boy is persuaded by his older brother to accompany him and his friends on a beer-drinking binge. This is the first such experience for the boy, and it leads to the development of severe colicky left flank pain. When rescued by his parents, he is diaphoretic and doubled up in pain. He relates that he began to urinate frequently and profusely after the third or fourth beer and that the pain seized him shortly thereafter. He is tender to fist percussion over the left costovertebral angle but is afebrile. Which of the following is the most likely diagnosis?

260. A 25-year-old man is found on a pre-employment chest x-ray film to have a 3-cm peripheral coin lesion. The patient has never smoked, and a chest x-ray film that he had 2 years ago when he enrolled in graduate school had been normal. Prompted by this finding, he undergoes a more thorough physical examination, which discloses the presence of a firm, 2-cm testicular mass of which he was not previously aware. There are also palpable inguinal nodes on the same side. Which of the following is the most appropriate next step in management?

261. A 53-year-old man is brought to the emergency department by his wife because of headache and visual changes. Approximately 3 hours ago, he had the acute onset of an extremely severe posterior headache that was non-radiating but was associated with nausea and vomiting. This headache subsided, but over the past hour he has developed mild neck stiffness and pain on flexion of his neck. The patient is not cooperative, so no additional history is known; however, his wife states that he was feeling well until recently and has no allergies. The patient appears moderately uncomfortable and is complaining of the worst headache he has ever experienced. Which of the following is the most likely cause for hissymptoms?

262. A 25-year-old man is shot with a .22-caliber revolver. The entrance wound is in the anterior, lateral aspect of his thigh, and the bullet is seen on x-ray films to be embedded in the muscles posterolateral to the femur. The emergency department physician cleans the wound thoroughly. Which of the following is the most appropriate next step in management?

263. A patient sustained third-degree burns on both his arms when his shirt caught on fire while he was lighting the backyard barbecue. The burned areas are dry, white, leathery, anesthetic, and circumferential all around the arms and forearms. Which of the following parameters should be very closely monitored?

264. A previously healthy 60-year-old man is referred for urologic evaluation of macroscopic hematuria. Urinary cytology is positive for malignant cells, and cystoscopic examination reveals an exophytic multifocal tumor. A biopsy of die tumor demonstrates papillary fronds lined by ccfls similar to transitional epithelium but showing nuclear atypia, mitoses, and necrosis. Which of the following is the most important risk factor in the U.S. For the development of this type of tumor?

265. A young man is brought to the emergency department following a head-on collision at 30 miles per hour. He is awake and alert. Other than a forehead laceration, physical examination is normal and laboratory values are within normal limits. Chest x-ray films are unremarkable. Which of the following is the most appropriate next step in diagnosis?

266. A 52-year-old woman in renal failure is listed as a transplant candidate. In order to assess the propriety of the transplant, which of the following combinations represents how a cross-match is performed?

267. A 25-year-old man presents with a painless, hard, 3-cm testicular mass that he discovered serendipitously while taking a shower. Physical examination confirms that the mass arises from the testicle itself, is not part of the epididymis, and is solid rather than a fluid collection. The rest of the physical examination is unremarkable. Which of the following would be the most appropriate next step?

268. A 72-year-old man has a 4-cm hard mass in the left supraclavicular area. The mass is movable and nontender and has been present and steadily growing for the past 3 months. On direct questioning the only additional findings include a 20-pound weight loss and a vague feeling of epigastric discomfort over the past 2 months. Physical examination shows evidence of the weight loss but no other significant findings in the abdominal examination. The supraclavicular mass is obvious, but no other masses can be felt anywhere else in the neck, axillas, or groins. There is occult blood in the stool, and his hemoglobin is 10.5 g/dL. Which of the following would a biopsy of the supraclavicular mass most likely reveal?

269. A 65-year-old man comes to the physician for a health maintenance examination. Which of the following screening methods would allow the highest detection rate of prostatic carcinoma in early stages?

270. A 22-year-old woman is brought to the emergency department after a motorcycle accident in which she sustained severe crush injuries of her lower extremities. In the field, her Glasgow Coma Score was 14. She is awake and alert on arrival after having been given morphine for pain control. Any details of her past medical history are unknown. Initial examination shows a blood pressure of 140/80 mm Hg and pulse of 100/min. Her oxygen saturation on room air is 95% by pulse oximeter. An ECG is obtained and shows very large, peaked T-waves in leads V1-V6. Which of the following is the most appropriate initial step in patient care?

271. A 53-year-old woman sustains multiple injuries in a head-on automobile collision. She was driving the car and wearing a seat belt. At the moment of impact, she was held in place by the belt, but she hit the windshield with her face, the dashboard with her arms, and the steering wheel with her abdomen. Initial survey reveals closed fractures in both upper extremities, facial lacerations, and abdominal bruises. She is breathing well and is neurologically intact, but she is complaining of severe abdominal pain. Her blood pressure is 75/55 mm Hg, pulse is 110/min, and central venous pressure is zero. Physical examination of the abdomen shows tenderness, guarding, and rebound tenderness on all quadrants. There is no evidence of pelvic fracture. Which of the following would be the most appropriate study to evaluate her abdominal injuries?

272. A 42-year-old man sustains a gunshot wound to the abdomen and is in shock. Multiple units of packed red blood cells are transfused in an effort to resuscitate him. He complains of numbness around his mouth and displays carpopedal spasm. An electrocardiogram demonstrates a prolonged QT interval. Which of the following is the most appropriate treatment?

273. A 6-year-old boy has insidious development of limping with decreased motion in one hip. He complains occasionally of knee pain on that side. He walks into the office with an antalgic gait. Examination of the knee is normal, but passive motion of the hip is guarded. The child is afebrile, and the parents indicate that his gait and level of activity were completely normal all his life until this recent problem. He has not had a recent febrile illness. Which of the following is the most likely diagnosis?

274. A 39-year-old woman is involved in a head-on, highspeed automobile collision. She arrives at the emergency department in a deep coma, with bilaterally fixed dilated pupils. She has normal blood pressure and pulse rate. CT scan of the head shows diffuse blurring of the gray- white interface and multiple small punctate hemorrhages. There is no single large hematoma or displacement of the midline structures. Extension of the CT to include the neck shows no cervical spine fractures. Which of the following is the most appropriate initial step in management?

276. An 82-year-old man develops severe abdominal distention, nausea, vomiting, and colicky abdominal pain. He has not passed any gas or stools for the past 12 hours. His vital signs are normal, and his pulse is regular. He has a distended, tympanitic abdomen, with hyperactive, highpitched bowel sounds. There are no signs of peritoneal irritation. Rectal examination is negative for masses or occult blood, and trie rectal vault is empty. Abdominal xray films show distended loops of small and large bowel, as well as a very large round gas shadow that is located in the right upper quadrant and tapers toward the left lower quadrant in the shape of a parrot's beak. The patient has never had any abdominal surgery, and he does not have any palpable hernias. Which of the following is the most appropriate next step in management?

277. A 42-year-old woman drops a hot iron on her lap while doing the laundry. She comes in with the shape of the iron clearly delineated on her upper thigh. The area is white, dry, leathery, and anesthetic. Which of the following is the most appropriate next step in management?

279. A 72-year-old man has multiple injuries and an altered sensorium after a high-speed motor vehicle collision. He is intubated for his decreased mental status. During intubation, a large amount of gastric contents are noted in the posterior pharynx and he aspirates. Which of the following is the appropriate initial treatment?

280. A patient with severe neurological devastation after head trauma has a prolonged course in the intensive care unit. He has been mechanically ventilated for his entire hospital stay. Which of the following clinical findings is diagnostic of a ventilator-associated pneumonia?

281. A 40-year-old obese woman, mother of five children, presents with progressive jaundice that she first noticed 4 weeks ago. She has a total bilirubin of 22 mg/dL, with 16 mg/dL direct (conjugated) and 6 mg/dL indirect (unconjugated). Her transaminases (AST and ALT) are minimally elevated, but her alkaline phosphatase is about 6 times the upper limit of normal. She has no anemia or occult blood in the stools. She has a history of multiple episodes of colicky right upper quadrant abdominal pain, brought about by the ingestion of fatty food; the last episode occurred a few days before her jaundice was first noted. She currently has no pain and is afebrile. A sonogram of her upper abdomen shows a contracted gallbladder full of stones, as well as dilated intrahepatic and extrahepatic biliary ducts; however, no stone can be identified in die common duct. Which of the following is the most appropriate next step in diagnosis?

283. A 51-year-old man is undergoing abdominal surgery and becomes hypotensive while under general anesthesia. The patient had been doing well during most of the procedure but now has a blood pressure of 80/40 mm Hg. His past medical history is significant for coronary artery disease and diabetes mellitus. A pulmonary artery catheter placed prior to the procedure gives the following data: Central venous pressure 10 mmHg, Pulmonary artery pressure 60/30 mmHg, Pulmonary capillary occlusion 24 mm Hg pressure Cardiac output 2.3 L/min. Which of the following is the most likely diagnosis?

284. A 62-year-old man complains of perineal discomfort and reports that there are streaks of fecal soiling in his underwear. Four months ago, he had a perirectal abscess drained surgically. Physical examination shows a perineal opening in the skin lateral to the anus, and a cord-like tract can be palpated going from the opening toward the inside of the anal canal. Brownish purulent discharge can be expressed from the tract. Which of the following is the most likely diagnosis?

285. A 29-year-old woman presents with a 6-month history of erythema and edema of the right breast with palpable axillary lymphadenopathy. A punch biopsy of the skin reveals neoplastic cells in the dermal lymphatics. Which of the following is the best next step in her management?

286. A 50-year-old woman with a history of essential hypertension presents to the emergency department with sudden onset of a severe headache, nausea and vomiting, and photophobia. On examination, her BP is 160/100 mmHg. She is mildly confused and has nuchal rigidity, without focal neurologic signs. Which of the following is the most likely diagnosis?

287. A 50-year-old woman with a history of essential hypertension presents to the emergency department with sudden onset of a severe headache, nausea and vomiting, and photophobia. On examination, her BP is 160/100 mmHg. She is mildly confused and has nuchal rigidity, without focal neurologic signs. Once the diagnosis has been confirmed, Rupture cerebral aneurysm, which of the following is the next most important step in patient management?

288. A 35-year-old woman presents with a lump in the left breast. Her family history is negative for breast cancer. On examination the mass is rubbery, mobile, and nontender to palpation. There are no overlying skin changes and the axilla is negative for lymphadenopathy. An ultrasound demonstrates a simple 1-cm cyst in the area of the palpable mass in the left breast. Which of the following represents the most appropriate management of this patient?

289. A 55-year-old woman presents with a slow-growing painless mass on the right side of the neck. A fine-needle aspiration of the nodule shows a well-differentiated papillary carcinoma. A complete neck ultrasound demonstrates a 1-cm nodule in the right thyroid without masses in the contralateral lobe or lymph node metastasis in the central and lateral neck compartments. With regards to this patient, which of the following is associated with a poor prognosis?

290. Following significant head trauma, a 34-year-old woman undergoes a CT scan that demonstrates bilateral frontal lobe contusions of the brain. There is no midline shift. She has a GCS of 14. Which of the following is the best initial management of this patient?

291. A 72-year-old man of Norwegian ancestry has a contracted hand that can no longer be extended and placed flat on a table. The problem developed gradually, over many years. He complains of no pain or neurologic abnormalities and, to the extent that the deformity allows, can move his fingers at will. Physical examination demonstrates the deformity described and in addition shows the presence of palpable fascial nodules. Which of the following is the most likely diagnosis?

292. A 50-year-old man is admitted to the hospital with a UGI bleed from acute erosive gastritis, secondary to chronic nonsteroidal anti-inflammatory use. His hematocrit is 28%. With fluid resuscitation, his blood pressure normalizes, but he has a persistent hyperdynamic precordium, tachycardia, and flow murmur on auscultation. He complains of shortness of breath on ambulation. An ECG shows depressed ST-T segments. Which of the following is the next appropriate step in management?

293. A previously healthy 28-year-old woman develops significant postpartum hemorrhage, with a rapid drop in hematocrit to 18%. Despite aggressive IV fluid resuscitation, the patient has a persistent tachycardia, labile systolic blood pressure, and poor urine output. Ongoing resuscitation includes emergency transfusion with 2 units of O-negative packed red blood cells. During transfusion of the second unit, the patient develops chills, fever, vomiting, and hypertension. These symptoms are most likely the result of which of the following?

294. A 45-year-old man with poorly controlled hypertension presents with severe chest pain radiating to his back. An ECG demonstrates no significant abnormalities. A CT scan of the chest and abdomen is obtained, which demonstrates a descending thoracic aortic dissection extending from distal to the left sub-clavian take off down to above the iliac bifurcation. A Foley catheter is placed, and urine output is 30 to 40 cc/h. His feet are warm, with less than 2-second capillary refill. Which of the following is the most appropriate initial management?

296. A 45-year-old woman underwent elective surgery for an inguinal hernia. In the postoperative recovery room, she developed nausea, vomiting, and acute abdominal pain. She has a history of systemic lupus erythematosus, pernicious anemia, type-1 diabetes, chronic low back pain, and uterine fibroids. Her preoperative medications include monthly vitamin B-12 injections, insulin, prednisone, hydroxychloroquine, and acetaminophen. Her blood pressure is 70/40 mm Hg and heart rate is 110/min. Initial laboratory studies show a blood glucose of 50 mg/dl. Which of the following is the most likely cause of her condition?

297. A 57-year-old man comes to the physician for a routine checkup. He complains of right- sided leg cramps accompanied by fatigue while walking. He also complains of occasional right thigh pain. He denies chest pain, syncope, nausea, and abdominal pain. His sexual performance has decreased over the past 1 year. His other medical problems include stage 3 chronic kidney disease, type 2 diabetes mellitus, hypertension, hyperlipidemia, gout, and gastroesophageal reflux disease. His blood pressure is 144/92 mm Hg, pulse is 67/min, and BMI is 29 kg/m2. Peripheral pulses are bilaterally palpable. There is a small ulcer at the base of the right great toe. The ankle- brachia! index (ABI) is 1.0 (normal: 1.0 - 1.3). His laboratory values are significant for a serum creatinine level of 2.2 mg/dl and an HbA1c level of 7.5% but otherwise unremarkable. Which of the following is the most appropriate next step in managing this patient's leg pain?

298. A 34-year-old woman is admitted to the hospital because of septic shock secondary to a urinary tract infection. In the intensive care unit, she receives intravenous fluids and antibiotics. Her initial ECG shows sinus tachycardia but is otherwise unremarkable. Chest x-ray shows no abnormalities. An internal jugular vein catheter is placed on the right side using ultrasound guidance to locate the vein. The patient is properly draped, and the skin is cleaned with chlorhexidine solution. Blood is freely aspirated from all ports after insertion. Vital signs are stable, and oxygenation is maintained. Which of the following is the most appropriate next step in managing this patient?

299. A 45-year-old woman, who wears high-heeled, pointed shoes, complains of pain in the forefoot after prolonged standing or walking. Occasionally, she also experiences numbness, a burning sensation, and tingling in the area. Physical examination shows no obvious deformities and a very tender spot in the third interspace, between the third and fourth toes. There is no redness, limitation of motion, or signs of inflammation. Which of the following is the most likely diagnosis?

300. A 22-year-old gang member arrives in the emergency department with multiple gunshot wounds to the chest and abdomen. He has labored breathing and is cyanotic, diaphoretic, cold, and shivering. He is wide awake, and in a normal tone of voice he tells everyone that he is going to die. An initial survey reveals a blood pressure of 60/40 mm Hg. His pulse is 150/min and barely perceptible. He is in obvious respiratory distress and has big distended veins in his neck and forehead. His trachea is deviated to the left, and the right side of his chest is hyperresonant to percussion, with no breath sounds. Which of the following is the most appropriate initial step in management?