USLME surgery

A 48 - year - old woman develops constipation postoperatively and self - medicates with milk of magnesia. 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 follo wing represents the earliest clinical indication of hypermagnesemia?`

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 opened. 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?

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/LK: 3.2 mEq/LCl: 103 mEq/LHCO3: 25 mEq/LCa: 8.2 mEq/LMg: 1.2 mEq/LPO4: 2.4 mEq/LAlbumin: 2.4An 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?

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 diplopia. Shortly thereafter, his blood pressure increases to 190/110 mm Hg, and he develops bradycardia. Which of the following is most likely the significance of the hypertension and the bradycardia?

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?

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?

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?

A 52-year-old man has been impotent ever since he had an abdominoperineal resection for cancer of the rectum. The tumor was staged as T3, NO, MO. He gets no nocturnal erections, and his impotence extends to all situations, regardless of sexual partner, and includes inability to masturbate. His erectile dysfunction is most likely due to which of the following?

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?

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?

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)?

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?

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?

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?

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?

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?

A 65-year-old man has an enterocutaneous fistula originating in the jejunum secondary to inflammatory bowel disease. Which of the following would be the most appropriate fluid for replacement of his enteric losses?

A 45-year-old woman is seen with wasting of the intrinsic muscles of the hand, weakness, and pain in the wrist. Which of the following nerves has most likely been injured?

A 68-year-old woman presents with a pigmented lesion on the trunk. Upon further examination the lesion has an irregular border, darkening coloration, and raised surface. An incisional biopsy is performed and confirms a melanoma with a thickness of 0.5 mm. The patient is scheduled for a wide local excision of the melanoma in the operating room. Which of the following is the smallest margi recommended for excision?

A 25-year-old woman presents with a benign nevus on the right upper arm. She desires removal and undergoes a clean incision and then closure of the incision without complication. With regard to the healing process, which of the following cell types are the first infiltrating cells to enter the wound site, peaking at 24 to 48 hours?

A 35-year-old woman undergoes an elective laparoscopic cholecystectomy for symptomatic cholelithiasis. Which of the following wound classes best describes her procedure?

A 65-year-old woman presents with a 1-cm lesion with a pearly border on her nose, and punch biopsy is consistent with a basal cell carcinoma. She is scheduled to undergo Mohs surgery. Which of the following is a benefit of Mohs surgery over wide local excision?

A 55-year-old man presents with worsening cirrhosis. After evaluation by a hepatologist, he presents for evaluation for hepatic transplantation. He is informed that prioritization for transplantation is based on the Model of End-stage Liver Disease (MELD) score, and that patients with higher MELD scores have a greater benefit from transplantation. Which of the following contributes to the MELD score?

A young woman who has received a transplant has posttransplant fever and malaise. Graft-versus-host disease (GVHD) is diagnosed. This has occurred most commonly with the transplantation of which of the following?

A 55-year-old woman who has end-stage liver disease is referred to a hepatologist for evaluation. Which of the following would prevent her from being a transplantation candidate?

A 63-year-old man with a 40-pack per year smoking history undergoes a low anterior resection for rectal cancer and on postoperative day 5 develops a fever, new infiltrate on chest x-ray, and leukocytosis. He is transferred to the ICU for treatment of his pneumonia because of clinical deterioration. Which of the following is a sign of early sepsis?

A 43-year-old trauma patient develops acute respiratory distress syndrome (ARDS) and has difficulty oxygenating despite increased concentrations of inspired O2. After the positive end-expiratory pressure (PEEP) is increased, the patient’s oxygenation improves. What is the mechanism by which this occurs?

An 80-year-old man comes to the physician because of a slowly growing ulcerated mass on the glans penis. A biopsy is positive for squamous cell carcinoma. Which of the following conditions is usually present in association with this tumor?

A 33-year-old woman seeks assistance because of a swelling of her right parotid gland. Biopsy is performed and reveals acinar carcinoma. You consent the patient for resection and inform her that at the very least, she will require superficial parotidectomy. Which of the following intraoperative findings would require sacrifice of the facial nerve?

A college student is tackled while playing football and develops severe knee pain. When examined shortly thereafter, the knee is swollen and the patient has pain on direct palpation over the lateral aspect of the knee. With the knee flexed 30 degrees, passive adduction elicits pain on the same area, and the leg can be adducted further than in the normal contralateral leg (varus stress test). The anterior drawer test, posterior drawer test, and Lachman test are negative. Which of the following is the most likely site of injury?

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?

A 33-year-old diabetic man receives a renal allograft. The physicians choose cyclosporine as one of the antirejection medications. Which of the following functions does cyclosporine A primarily inhibit?

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?

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?

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?

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?

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?

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

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?

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?

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?

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?

A 72-year-old man undergoes resection of an abdominal aneurysm. He arrives in the ICU with a core temperature of 33°C (91.4°F) and shivering. Which of the following is a physiologic consequence of the shivering?

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?

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?

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?

54-year-old woman presents to her physician for an opinion regarding additional therapy following curative resection of recently diagnosed colon cancer. She underwent uncomplicated sigmoid resection for invasive colon cancer 4 weeks ago. The pathology revealed carcinoma invading into, but not through, the muscularis propria, with one of eight positive mesenteric nodes. There was no evidence of liver metastases at the time of operation. Preoperative chest x-ray and CT scan of the abdomen showed no evidence of distant disease. Preoperative carcinoembryonic antigen (CEA) level was normal. Past history is positive for diabetes and mild hypertension. Examination is unremarkable except for a healing abdominal incision. Which of the following is the correct stage of this patient’s colon cancer?

Which of the following patients with primary hyperparathyroidism should undergo parathyroidectomy?

A 49-year-old woman presents to her physician with dysphagia, regurgitation of undigested food eaten hours earlier, and coughing over the last 6 months. She was hospitalized 1 month ago for aspiration pneumonia and successfully treated with antibiotics. Examination reveals a thin-appearing woman with normal vital signs and unremarkable chest, heart, and abdominal examination. A UGI contrast study is performed and reveals a pharyngoesophageal (Zenker’s) diverticulum. Which of the following statements is true regarding Zenker’s diverticula?

36-year-old woman whose mother has just undergone treatment for breast cancer is asking about how this affects her and what can be done to lessen her chances of having the disease. Which of the following has the lowest risk factor for breast cancer?

39-year-old woman presents to the physician’s office for evaluation of a palpable nodule in the neck of 2 years’ duration. Her past history is pertinent for Hashimoto’s disease diagnosed 5 years ago, for which she takes thyroid hormone. She has a history of low-dose chest irradiation for an enlarged thymus gland during infancy. On examination, a 2.5-cm nodule is palpable in the left lobe of the thyroid and is firm and nontender. Which of the following portions of her history increases the risk for thyroid cancer?

While playing with his children, a 44-year-old man falls and lands on his right shoulder. There is immediate pain and deformity. In an uncomplicated dislocation of the glenohumeral joint, the humeral head usually dislocates primarily in which of the following directions?

A 29-year-old construction worker fell 15 ft from a roof and broke his right humerus, as depicted in the accompanying radiograph. Given his injury, which of the following nerves is most at risk?

In a failed suicide gesture, a depressed student severs her radial nerve at the wrist. Which of the following is her expected disability?

A 52-year-old woman presents with hypertension, obesity, and new skin striae. You are concerned about possible Cushing syndrome. Which of the following is the most common cause of Cushing syndrome?

A 62-year-old woman presents with invasive ductal carcinoma of the right breast. Which of the following findings would still allow her to receive breast conservation surgery (partial mastectomy)?

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

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

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

A 27-year-old basketball player jumps to block a shot with his right hand. As his hand contacts the ball, he feels severe pain in his right shoulder. He presents to the emergency department with continuing shoulder pain. You note that he holds his right arm in slight external rotation, supporting its weight with his left hand. On physical examination, he resists internal rotation of his right arm. Which of the following nerves is most likely to be injured in this patient?

A 23-year-old male is found at the scene of a motor vehicle accident with bilateral lower extremity fractures. You also note extensive abdominal bruising and scalp lacerations. At the scene, the patient's blood pressure is 80/60 mmHg and his heart rate is 120/min. He is given 2 liters of IV fluids wide open. On the way to the hospital he becomes progressively drowsy, and he develops progressive weakness on the right side of his body. This patient is also likely to show deficits in the functioning of which of the following nerves?

A 34-year-old man is brought to the emergency department after being involved in a motorbike accident. Examination shows a hematoma on the forehead and bleeding from his leg. His pupils are bilateral round and eactive; he has papilledema. He responds to pain, has decorticated posture and speaks incoherently. After the initial resuscitation you start the treatment with intravenous fluids, hyperventilation, head elevation and intravenous mannitol. Which of the following is the mechanism of action of hyperventilation in this patient?

A 40-year-old female is brought to the emergency department following a motor vehicle accident in which she was the front seat passenger. She reports hitting her head against the windshield and hurting her right leg. She appears completely alert and oriented. Glasgow Coma Scale = 15/ 15. Her pupils are equal and reactive to light. There is a bruise over the right forehead, but no tenderness is present on palpation of the cranial bones. Examination of the right leg reveals a hematoma over the thigh. Knee extension on the right is markedly reduced when compared to the left. Sensory examination reveals decreased sensory perception to both sharp and dull stimuli over the right lower medial leg. All other dermatomes are intact. What nerve injury is most likely present in this patient?

A 74-year-old woman is admitted with upper gastrointestinal (GI) bleeding. She is started on H 2 blockers, but experiences another bleeding episode. Endoscopy documents diffuse gastric ulcerations. Omeprazole is added to the H2 antagonists as a therapeutic approach to the management of acute gastric and duodenal ulcers. Which of the following is the mechanism of action of omeprazole?

A 38-year-old woman who underwent total thyroidectomy for multinodular goiter 6 months ago presents with persistent hoarseness. Which of the following nerves was most likely injured during her operation?

A 52-year-old man with a family history of multiple endocrine neoplasia type 1 (MEN1) has an elevated gastrin level and is suspected to have a gastrinoma. Which of the following is the most likely location for his tumor?

A 73-year-old woman presents to the emergency room complaining of severe epigastric pain radiating to her back, nausea, and vomiting. CT scan of the abdomen demonstrates inflammation and edema of the pancreas. A right upper quadrant ultrasound demonstrates the presence of gallstones in the gallbladder. Which of the following is an important prognostic sign in acute pancreatitis according to Ranson’s criteria?

A 24-year-old man presents to the emergency room with abdominal pain and fever. CT scan of the abdomen reveals inflammation of the colon. He is referred to a gastroenterologist to be evaluated for inflammatory bowel disease (Crohn disease versus ulcerative colitis). Which of the following indications for surgery is more prevalent in patients with Crohn disease?

A newborn has a midline defect in the anterior abdominal wall. The parents ask what, if anything, should be done. Spontaneous closure of which of the following congenital abnormalities of the abdominal wall generally occurs by the age of 4?

A neonate is found to have an imperforate anus. As the pediatric surgeon you recommend studies to search for other anomalies. Which of the following is an associated abnormality?

A 45-year-old man is examined for a yearly executive physical. A mass is palpated in the rectum, and a biopsy suggests carcinoid. Which of the following findings is most likely to be associated with the carcinoid syndrome?

A 31-year-old biker is involved in a motor vehicle accident after attending a party where he drank a lot of soda drinks. He describes a direct blow to his lower abdomen and pelvis during the accident. He complains of diffuse abdominal pain that refers to his left shoulder. Which of the following injuries most likely accounts for this patient's current symptoms?

Your hospital is conducting an ongoing research study involving the hormonal response to trauma. Blood is drawn regularly (with Institutional Review Board [IRB] approval) for various studies. Which of the following values are likely to be seen after a healthy 36-year-old man is hit by a bus and sustains a ruptured spleen and a lacerated small bowel?

A 45-year-old man was an unhelmeted motorcyclist involved in a high-speed collision. He was ejected from the motorcycle and was noted to be apneic at the scene. After being intubated, he was brought to the ER, where he is noted to have a left dilated pupil that responds only sluggishly. What is the pathophysiology of his dilated pupil?

A 25-year-old man comes to the physician because of a mass in his mouth. He has had the lump for many years. He denies weight loss. He was in a motor vehicle accident several years ago and sustained a concussion of the brain. He does not use tobacco, alcohol, or illicit drugs. Physical examination shows a nontender 2 x 2-cm mass located on the hard palate of the mouth that is immobile and has a bony hard consistency. Which of the following is the most likely cause of this patient's oral finding?

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?

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 knob. Which of the following is the most likely diagnosis?

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 discharge. His temperature is 37 C (98.6 F). On digital rectal examination, the prostate is slightly tender and boggy but not enlarged or indurated. 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 bacteria. Which of the following is the most likely diagnosis?

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 changed. 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?

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?

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 much 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?

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?

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?

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?

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?

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; HCO3- 42.Urine electrolytes (mEq/L): Na+ 2, K+ 5, Cl- 6What is the patient’s acid–base abnormality?

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?

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?

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 39.0C (102.2F), 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?

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?

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 PaO2 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)?

60-year-old woman presents with the skin lesion shown here. She reports a history of a burn injury to the hand while cooking a few years ago. She reports the wound has never healed completely. You are concerned about the skin lesion and perform a punch biopsy. Which of the following is the most accurate diagnosis given the patient’s history?

A 31-year-old accounting student presents with a persistent headache that began approximately 4 months ago. The headache has been gradually increasing in intensity, and is worse in the mornings. Thinking that she might need new glasses, she sought help from her optometrist, who discovered that she has bilateral papilledema and sent her in for medical evaluation. On direct questioning, she admits to repeat vomiting for the past 3 weeks, with no heaving, straining, or preceding nausea. "I would just open my mouth, and the stuff would hit the wall," she explains. She denies any other neurological symptoms. Which of the following is the most likely diagnosis?

A brain-dead potential donor has become available. You must plan for the dispersal of the thoracic organs. Which of the following will necessitate a heart-lung transplant?

A 55-year-old woman requires an abdominoperineal operation for rectal cancer. She has a history of stable angina. Which of the following clinical markers is most likely to predict a cardiac event during her noncardiac surgery and should prompt further cardiac workup prior to her operation?

An 18-year-old man was traveling at a high speed when his car slammed into a wall. He is brought into the emergency department by ambulance. His blood pressure is 60/40 mmHg, pulse is 115/min and weak, respirations are 18/min, and central venous pressure is 2 cmH2O. He is responsive only to painful stimuli. Breath sounds are equal bilaterally, and cardiac auscultation reveals only tachycardia. The abdomen is soft, nondistended, and nontender with active bowel sounds. A chest x-ray film shows a widened mediastinum. Which of the following is the most likely diagnosis?

A 22-year-old woman is taken to the emergency department after she injures her foot. She had been standing on a chair changing a light bulb, when she accidentally stepped off the chair backward. She heard a cracking sound when she fell and developed pain and swelling behind the ankle. Her symptoms worsened when she tried to descend the stairs in her house. Physical examination demonstrates marked swelling behind her ankle, and her pain is exacerbated by plantar flexion and dorsiflexion of the hallus. Which of the following is the most likely diagnosis?

A 60-year-old man complains of anal itching and discomfort, particularly toward the end of the day. He works as a salesman in a department store, where he has to be on his feet all day. When he goes home in the evening, he finds himself sitting sideways to avoid the discomfort. He has no fever, rectal bleeding, or soiling of his underwear, and he has never had surgery in that area. Which of the following is the most likely diagnosis?

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?

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?