NBME 15- Block 1

Two days after operative repair of a right hip fracture, an 82-year-old woman is somnolent. Her initial postoperative course was uncomplicated. She has a 10-year history of osteoporosis. Her current medications are enoxaparin, morphine, and temazepam. She has never smoked cigarettes. Prior to the hip fracture, she was able to walk short distances with a walker. She is 157 cm (5 ft 2 in) tall and weighs 54 kg (120 lb); BMI is 22 kg/m2. She responds to painful stimuli only. Her temperature is 37.2°C (99°F), pulse is 88/min and regular, respirations are 10/min, and blood pressure is 132/82 mm Hg. There are jugular venous pulsations 4 cm above the sternal angle. Examination shows severe kyphoscoliosis. The lungs are clear to auscultation. Examination of the right lower extremity shows ecchymoses and edema of the proximal thigh; there is trace ankle edema and no palpable cord. Examination of the left lower extremity shows no edema or palpable cord. Arterial blood gas analysis on room air shows:

An x-ray of the chest shows a normal cardiac silhouette, no pleural effusions, and a small area of atelectasis at the right lung base. An ECG shows a normal sinus rhythm and no ischemic changes. Which of the following is the most appropriate pharmacotherapy?

A 30-month-old boy is brought to the emergency department by his parents because of progressive difficulty bearing weight on his left leg. He now refuses to walk. His parents say that he used to walk with no problems. During the past week, he had two nosebleeds and required direct pressure for 20 minutes before they stopped. He was born at 38 weeks’ gestation after an uncomplicated pregnancy and vaginal delivery. He was 51 cm (20 in) long at birth and weighed 2495 g (5 lb 8 oz). There is no personal or family history of serious illness. Immunizations are up-to-date. On arrival, he appears listless. His temperature is 39.5°C (103.1°F). Examination shows several large blue ecchymoses over the back and abdomen. The patient cries vigorously when the physician attempts to move the patient’s left lower extremity. The neck is supple. The lungs are clear to auscultation. The spleen tip is palpated. The remainder of the examination shows no abnormalities. Laboratory studies show:

AP and lateral x-rays of the pelvis and left lower extremity show a permeative osteolytic lesion at the diaphysis of the proximal femur. Which of the following is the most appropriate next step in management?

A previously healthy 47-year-old man comes to the physician because of progressive difficulty swallowing during the past 3 months. He reports that both solid foods and liquids seem to “get hung up” behind the lower part of his breast bone. He has had to take smaller bites, chew better, and eat more slowly than he has in the past. He has not had any change in weight. Physical examination shows no abnormalities. A barium swallow is shown. Which of the following is the most likely cause of this patient’s symptoms?

A 47-year-old man comes to the physician 24 hours after the onset of fever and nausea. He has a 4-week history of diarrhea that has increased in volume and frequency. The diarrhea has not responded to use of over-the-counter medications, and he now passes watery brown stools 8 to 10 times daily. During the past 5 days, he has had mild abdominal cramps that are relieved by bowel movements. Prior to the onset of his symptoms, he went on a 2-week vacation to Mexico and took ciprofloxacin daily. He has not had fecal incontinence or any other symptoms. He has no history of serious illness. His temperature is 38.6°C (101.5°F), pulse is 86/min, and blood pressure is 130/80 mm Hg. The abdomen is soft. There is right upper quadrant tenderness with no rebound tenderness. Bowel sounds are increased in all quadrants. The liver is tender and enlarged. Rectal examination shows no abnormalities. Test of the stool for occult blood is positive. Laboratory studies show:

Examination of the stool shows leukocytes. Test of the stool for Clostridium difficile toxin is negative. A CT scan of the abdomen shows an 8-cm cystic mass in the right lobe of the liver. Which of the following is the most likely explanation for this patient’s CT scan findings?

A 62-year-old woman comes to the physician because of a 3-day history of low-grade fever, cough productive of green sputum, and progressive shortness of breath. Initially, her shortness of breath occurred only with exertion, but last night she had to sleep in a chair to breathe. She has type 2 diabetes mellitus treated with diet and glipizide and mild congestive heart failure treated with lisinopril. Her temperature is 37.5°C (99.5°F), pulse is 110/min, respirations are 24/min, and blood pressure is 140/60 mm Hg. Breath sounds are decreased over the left lower lung field, and there is dullness to percussion. A grade 2/6 midsystolic murmur is heard. An x-ray of the chest shows a large left pleural effusion. A thoracentesis is performed. Laboratory studies show:

Which of the following is the most likely diagnosis?

An 8-month-old boy is brought to the physician because his parents are concerned about his development. They report that he had learned to stand with support at the age of 4 months but has been unable to stand with or without support during the past 2 weeks. During this period, he has cried when held around his chest. His parents add that he has not grown much during the past 2 months. He was born at term following an uncomplicated pregnancy and delivery. He receives no medications. His diet consists of breast milk, rice cereal, and pureed fruits. His family lives in a cold climate. At his last examination 2 months ago, he was at the 25th percentile for length and weight. Today, he is at the 3rd percentile for length and 10th percentile for weight. He is alert and mildly irritable. Vital signs are within normal limits. Examination shows a dark complexion. Cardiopulmonary examination shows no abnormalities. The abdomen is soft. The wrists are widened and tender. He screams when picked up and when placed in a standing position. X-rays of the right wrist and left knee are shown. Which of the following is the most likely diagnosis?

A 47-year-old man comes to the emergency department because of fever during the past 8 hours. Two days ago, he sustained a small puncture wound to his lower abdomen while repairing a fence in a barnyard. He did not seek treatment at that time. He has a 10-year history of type 2 diabetes mellitus treated with glargine insulin. He appears lethargic. His temperature is 40°C (104°F), pulse is 130/min, and blood pressure is 90/60 mm Hg. Abdominal examination shows an exquisitely tender puncture wound over the right lower quadrant and surrounding erythema and warmth. During the next hour, the physician notices a 3-cm extension of the erythema. In addition to administration of intravenous fluids and broad-spectrum antibiotics, which of the following is the most appropriate next step in management?

A 57-year-old woman with cirrhosis secondary to chronic hepatitis C is hospitalized because of tense ascites. Her medications are propranolol, furosemide, and spironolactone. On admission, her serum creatinine concentration is 1 mg/dL. Five liters of ascitic fluid is removed on therapeutic paracentesis. Intravenous furosemide and oral spironolactone therapy are begun. During the next 2 days, the patient has a 3.6-kg (8-lb) weight loss. Her pulse is 85/min and regular, and blood pressure is 100/65 mm Hg. Examination shows scleral icterus. Breath sounds are decreased at both lung bases. Abdominal examination shows moderate ascites. Laboratory studies show:

In addition to discontinuing spironolactone and furosemide, which of the following is the most appropriate next step in management?

A previously healthy 20-year-old man is brought to the emergency department because of a 12-hour history of increasing fever and confusion. He has never seen a physician. He takes no medications. His temperature is 40°C (104°F), pulse is 110/min, respirations are 18/min, and blood pressure is 100/70 mm Hg. On arrival, he is delirious. Examination shows a diffuse rash over the body. A photograph of the rash is shown. There is moderate nuchal rigidity. The remainder of the examination shows no abnormalities. Immunization against which of the following is most likely to have prevented this patient’s condition?

A 62-year-old woman comes to the physician because of a 2-day history of moderate left-sided lower abdominal pain. She also has had nausea and loss of appetite during this time. She has not had vomiting. She has hypertension well controlled with hydrochlorothiazide. Her temperature is 38.4°C (101.1°F), pulse is 98/min, respirations are 14/min, and blood pressure is 120/78 mm Hg. Abdominal examination shows tenderness to palpation of the left lower quadrant; there is no guarding or rebound. Bowel sounds are decreased. Rectal examination shows no abnormalities. Test of the stool for occult blood is negative. Laboratory studies show:

Results of other laboratory studies are within the reference ranges. Chest and abdominal x-rays show no abnormalities. Which of the following is the most appropriate next step in management?

A 47-year-old man comes to the physician for a follow-up examination. He has hypertension treated with ramipril and gout treated with allopurinol. He has not had a gout flare during the past 6 months. His only other medication is aspirin. He is 180 cm (5 ft 11 in) tall and weighs 109 kg (240 lb); BMI is 34 kg/m2. His blood pressure is 152/95 mm Hg. Examination shows truncal obesity. Six months ago, his serum creatinine concentration was 1.4 mg/dL. Serum studies today show:

Which of the following is the most appropriate additional pharmacotherapy?

A 21-year-old woman is brought to the emergency department because of a 3-day history of vomiting and malaise and a 6-day history of abdominal cramping. One week ago, she had a medically induced abortion at 44 days’ gestation, with use of oral mifepristone and vaginal misoprostol. She has no history of serious illness and takes no medications. She follows a vegetarian diet. She appears ill. Temperature is 39.0°C (102.0°F), pulse is 151/min, respirations are 32/min, and blood pressure is 89/56 mm Hg. Physical examination discloses coarse breath sounds, a soft, nondistended abdomen, and 1+ pitting edema. Results of laboratory studies are shown:

Blood cultures grow gram-positive rods. Which of the following infectious agents is the most likely cause of these findings?

A 65-year-old woman is admitted to the hospital because of a 1-day history of fever, and edema and erythema of the right arm. She says that overnight her right arm began throbbing and the redness worsened. She also had chills and increasingly severe arm pain throughout the night. Her temperature reached 38.9°C (102°F) at home. One year ago, she had stage II breast cancer treated with right partial mastectomy, lymphadenectomy, and radiation therapy. She was treated with a compression sleeve for lymphedema of the right upper extremity postoperatively. She has osteoarthritis of the shoulders and hands, which limits the use of her upper extremities. She says her symptoms have always been present since the operation, but the swelling has worsened since yesterday. Her temperature is 38.3°C (101°F), pulse is 88/min, respirations are 14/min, and blood pressure is 150/80 mm Hg. Examination shows a bright red, well-demarcated area from 3 cm below the elbow to 3 cm above the ulnar prominence; it is exquisitely tender to light touch. The patient has moderate tenderness to palpation of the right upper extremity. There are no open areas over the skin or fingers. Laboratory studies show:

Which of the following is the most likely infectious agent?

A 25-year-old woman comes to the office for a follow-up examination 4 weeks after being diagnosed with HIV infection. She feels well. She used intravenous drugs for 5 years but stopped 2 years ago. She has been sexually active with one male partner during the past year; they use condoms consistently. Results of PPD skin testing 6 months ago were negative. She has no other history of serious illness and takes no medications. Her pulse is 68/min, respirations are 14/min, and blood pressure is 105/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Examination shows no abnormalities. Laboratory studies show:

Which of the following is the most appropriate next step in diagnosis?

An 82-year-old woman with hypertension comes to the office because of a 2-month history of easy fatigability and shortness of breath with mild exertion. She says she has to use two pillows to sleep and breathe comfortably. She had a myocardial infarction at the age of 75 years. Her medications are hydrochlorothiazide, fosinopril, and potassium supplementation. She has never smoked cigarettes. Her pulse is 100/min, and blood pressure is 150/100 mm Hg. Crackles are heard at the lung bases bilaterally. There is pitting edema of the lower extremities. No other abnormalities are noted. Which of the following is the most likely set of findings in this patient?

A 19-year-old man comes to the office because of a 10-hour history of shortness of breath and sharp, retrosternal chest pain radiating to his neck and left shoulder. The pain is worse with movement or swallowing. He also has a 1-week history of fever, malaise, myalgia, diarrhea, cough, and a scratchy sore throat. He has been unable to work as a summer lifeguard during this period. He smokes two packs of cigarettes daily. His temperature is 38°C (100.4°F), pulse is 70/min, respirations are 16/min, and blood pressure is 110/60 mm Hg. Examination and x-rays of the chest show normal findings. An ECG is shown. Which of the following is the most appropriate next step in diagnosis?

A 63-year-old man comes to the office because of chronic intermittent mild chest pain that usually occurs when he walks up two flights of stairs. He is otherwise asymptomatic. He has hypertension and coronary artery disease. He is adherent to his medication regimen of atorvastatin, clopidogrel, carvedilol, and aspirin. He has a sedentary lifestyle. He smoked two packs of cigarettes daily for 25 years but now smokes five cigarettes daily. He is 173 cm (5 ft 8 in) tall and weighs 91 kg (200 lb); BMI is 30 kg/m2. Blood pressure is 130/65 mm Hg. Examination shows no other abnormalities. The patient asks about undergoing revascularization. The physician is aware of a randomized controlled trial in which aggressive lifestyle management is comparable to percutaneous coronary intervention (PCI) in terms of meaningful cardiovascular outcomes. Which of the following statistical features of the study is most supportive of a recommendation for lifestyle management in this patient?