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?