CK- NBME 9 – Block 3

A 42-year-old man is brought to the emergency department by the staff of a homeless shelter after they found him unconscious outside the shelter. He has alcohol use disorder, schizophrenia, hepatitis C, and cirrhosis. He has been treated for hepatic encephalopathy and ascites. On arrival, he is responsive only to painful stimuli. He is 188 cm (6 ft 2 in) tall and weighs 68 kg (150 lb); BMI is 19 kg/m2. Temperature is 37.7°C (99.9°F), pulse is 130/min, respirations are 24/min, and blood pressure is 86/40 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 92%. Examination shows jaundice and conjunctival icterus. There are multiple ecchymoses over all the extremities. Abdominal examination shows ascites and a fluid wave. The patient moans on palpation of the abdomen. There is trace edema of the ankles. All extremities are warm. Urine output has been 60 mL/h during the past 4 hours. In addition to obtaining a complete blood count, serum electrolyte concentrations, and urinalysis, which of the following is most likely to confirm the diagnosis?

A 2-year-old boy is admitted to the intensive care unit through the emergency department 20 minutes after his parents found him at the bottom of the backyard swimming pool. The parents report that when they pulled their son from the pool, he was not breathing and had no pulse. They are unsure of the duration of the submersion. They administered cardiopulmonary resuscitation for 10 minutes until emergency medical technicians arrived. En route to the emergency department, the patient was intubated and mechanically ventilated with 100% oxygen at a rate of 20 breaths per minute, after which his pulse returned at a rate of 150/min. On arrival in the emergency department, vital signs were temperature 36.5°C (97.7°F), pulse 150/min, and blood pressure 100/60 mm Hg. Pulse oximetry on 100% oxygen showed an oxygen saturation of 100%. Now, in the intensive care unit, his vital signs are unchanged. He has spontaneous respirations, and he is reaching for his endotracheal tube. His parents want to know if he will survive. Which of the following factors would most strongly suggest a good prognosis in this patient?

An 18-year-old woman comes to the physician in the fall because of episodes of coughing and wheezing since she moved from the Midwest to New England to attend college 3 weeks ago. The episodes have been occurring several times daily and are associated with a sensation of tightness in her chest. During this period, she has had decreased stamina during exercise. She has had one episode of bronchitis each winter for 3 years. She has no history of serious illness and takes no medications. She does not smoke cigarettes. She is not in respiratory distress. Vital signs are within normal limits. The lungs are clear to auscultation. Spirometry shows no abnormalities. Which of the following is the most appropriate next step in management?

A 44-year-old woman comes to the physician because of a 2-week history of nonproductive cough that worsens at night. She says occasionally she has coughed so hard that she vomited or had loss of urine. Between these episodes, she feels well. She has not had fever, night sweats, shortness of breath, wheezing, chills, weight loss, or cough productive of bloody sputum. She says her symptoms began as a cold with sore throat and runny nose and seemed to improve by the end of the first week, but then she began coughing. Use of over-the-counter cold medicine has not provided relief of her cough. Results of a PPD skin test 1 year ago were negative. The patient has no history of asthma, hypertension, or allergies. She takes no medications. She does not smoke cigarettes. Her three children recently had similar illnesses, but she says their symptoms resolved within 1 week. They attend school, and their vaccinations are up-to-date. The patient volunteers at a homeless shelter twice monthly. Her temperature is 37.2°C (99°F), pulse is 72/min and regular, respirations are 16/min, and blood pressure is 122/76 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Examination shows no abnormalities. Which of the following is the most appropriate next step in diagnosis?

An 82-year-old woman is brought to the emergency department by her daughter because of shortness of breath. Each night for the past week, the patient has awakened with shortness of breath; she has found that using three pillows instead of one allows her to breathe more easily at night. Two days ago, she had shortness of breath with exertion, and 8 hours ago, she had the sudden onset of mild shortness of breath at rest. She also has a 4-day history of swelling of her ankles and feet. Her only medication is 81-mg aspirin. On arrival, she is in mild respiratory distress but able to speak in complete sentences. Her temperature is 37°C (98.6°F), pulse is 86/min, respirations are 16/min, and blood pressure is 162/88 mm Hg. Examination shows jugular venous distention. Bilateral basilar crackles are heard over the lower quarter of the lung fields. Cardiac examination shows a regular rhythm. A grade 2/6 holosystolic murmur is heard best at the apex with the patient in the left lateral decubitus position. There is 2+ pitting edema of the ankles. In addition to furosemide, administration of which of the following is the most appropriate next step in pharmacotherapy?

A 62-year-old woman is brought to the emergency department by paramedics 30 minutes after the onset of sharp, anterior chest pain. She is otherwise asymptomatic. Administration of nitroglycerin en route to the hospital has not relieved her symptoms. She has type 2 diabetes mellitus, hypertension, and peripheral artery disease. She underwent laparoscopic cholecystectomy 1 year ago. Her medications are insulin, ramipril, hydrochlorothiazide, atorvastatin, and aspirin. Her pulse is 96/min, respirations are 12/min, and blood pressure is 124/76 mm Hg. The lungs are clear to auscultation. A normal S1 and S2 are heard. Peripheral pulses are decreased bilaterally. An ECG shows a left bundle branch block; review of her medical records shows that a routine ECG 1 year ago showed no abnormalities. Her serum troponin I and myoglobin concentrations are within the reference ranges. The patient is admitted to the hospital. Which of the following is the most appropriate next step in diagnosis?

A 52-year-old man is brought to the emergency department because of a 6-hour history of thirst and fatigue and a 2-hour history of light-headedness. He has been working outside during the past 2 days in temperatures reaching 90.0°F. He has no history of serious illness and takes no medications. On arrival, he is lethargic and disoriented. His temperature is 37.2°C (99.0°F), pulse is 150/min and irregular, respirations are 16/min, and blood pressure is 78/50 mm Hg. The lungs are clear to auscultation; no bruits are heard. No murmurs are noted on cardiac examination. The abdomen is nontender. ECG is shown. In addition to administration of 0.9% saline, which of the following is the most appropriate next step in management?

A 27-year-old woman comes to the physician because of a 3-day history of temperatures to 39.4°C (103°F). She has not had any other symptoms. She underwent splenectomy at the age of 17 years because of injuries she sustained in a motor vehicle collision. She has no history of serious illness and takes no medications. Her father died of alcoholic hepatitis and cirrhosis. She is sexually active with multiple partners and does not use condoms. She has smoked one pack of cigarettes daily for 15 years. She occasionally drinks alcohol. She has an 8-year history of frequent crack cocaine use and daily intravenous heroin use. She appears ill. Her temperature is 39.8°C (103.7°F), pulse is 120/min and regular, respirations are 24/min, and blood pressure is 80/60 mm Hg. Examination shows no other abnormalities. Laboratory studies show:

Hematocrit: 33%

Leukocyte count: 21,000/mm³

Segmented neutrophils: 85%

Bands: 9%

Lymphocytes: 6%

Platelet count: 490,000/mm³

Urine:

RBC: 10/hpf

WBC: 2/hpf

Bacteria: negative

Serum studies show no abnormalities. Results of blood cultures are pending. A chest x-ray and transthoracic echocardiography show no abnormalities. Which of the following is the most appropriate initial antibiotic therapy for this patient?

A 62-year-old woman comes to the physician because of a 6-month history of increasingly severe left knee pain and a “giving-way” sensation while walking. The pain occurs in the front of the knee and is exacerbated by walking up stairs or sitting in a car for prolonged periods of time. There is no history of trauma. Five years ago, she underwent a discectomy for herniation of L3-4. She is 158 cm (5 ft 2 in) tall and weighs 113 kg (250 lb); BMI is 46 kg/m2. Examination of the left knee shows no joint effusion. There is tenderness to palpation along the patella. Muscle strength in both lower extremities is 5/5. Sensation to light touch is decreased over the left hallux. Pedal pulses are 2+ bilaterally. Which of the following is the most likely diagnosis?

A previously healthy 7-year-old boy is brought to the physician because of a 3-week history of pain in his left shoulder and arm. He has difficulty raising his left arm over his head. The pain is worse with motion and at night; it often awakens him from sleep. Over-the-counter medications have not relieved the pain. There is no history of trauma. Examination of the left shoulder shows diffuse tenderness of the greater tuberosity involving the entire humoral head. Passive range of motion of the left shoulder is limited to 90 degrees of abduction and 70 degrees of forward flexion. Extension and flexion of the left wrist are full. Muscle strength and sensation are intact. Radial pulses are palpable bilaterally. X-rays of the left upper extremity are shown. Which of the following is the most appropriate next step in management?

A 3-year-old girl is brought to the clinic because of a 3-day history of low-grade fever and sore throat. She also has a 12-hour history of rash that began on her hands; the rash is not itchy or painful. She has no history of serious illness and receives no medications. Her temperature is 38.4°C (101.2°F), pulse is 132/min, respirations are 34/min, and blood pressure is 93/48 mm Hg. Examination shows multiple ulcers on the soft palate and posterior aspect of the pharynx. The lungs are clear to auscultation. A grade 2/6 ejection murmur is heard on cardiac examination; S2 varies with inspiration. The abdomen is soft and nontender. The liver edge is palpated 2 cm below the right costal margin. There are multiple vesicles over the palms and digits. A dose of acetaminophen is administered. Which of the following is the most appropriate next step in management?

A 13-year-old girl with neurofibromatosis 2 is brought to the office for a follow-up examination. She feels well. Vital signs are within normal limits. Physical examination shows no abnormalities. In addition to audiometry, which of the following is most appropriate to include in the annual screening of this patient?

A 62-year-old man comes to the physician because he has been “slowing down” during the past 6 months. He has noticed that his gait is slower, he has difficulty rising from a chair, and his handwriting is smaller. He has a history of type 2 diabetes mellitus, insomnia, gastroparesis, hypertension, and hyperlipidemia. Medications are metformin, metoclopramide, lisinopril, atorvastatin, and zolpidem. His blood pressure is 140/80 mm Hg; other vital signs are within normal limits. During the examination, there is decreased facial expression and reduced eye blinking. Tone is increased in the axial and limb muscles. Muscle strength is 5/5 throughout, and deep tendon reflexes are 1+ bilaterally. Sensation to vibration is decreased over the toes bilaterally. His gait is shuffling, and there is decreased arm swing. Which of the following medications is most likely worsening this patient’s neurologic condition?

 A 24-year-old woman with sickle cell disease is admitted to the hospital for management of severe abdominal pain and diffuse muscle and bone pain of the arms and legs associated with a sickle cell crisis. Her pain is similar to that of her previous crises. Her medications are acetaminophen-hydrocodone and folic acid supplementation. She appears to be in moderate discomfort. Her temperature is 36.7°C (98.1 °F), pulse is 94/min, respirations are 22/min, and blood pressure is 116/68 mm Hg. The abdomen is diffusely tender; there is no guarding or rebound. The remainder of the examination shows no abnormalities. Her hemoglobin concentration is 6.8 g/dL, and leukocyte count is 14,000/mm3. Pulse oximetry on room air shows an oxygen saturation of 94%. Administration of intravenous fluids and hydromorphone is begun. Which of the following is the most appropriate next step in management?

An asymptomatic 27-year-old man comes to the physician 1 month after he received the diagnosis of HIV infection. He takes no medications. He has been sexually active with multiple male partners. Examination shows no abnormalities. Laboratory studies show:

CD4⁺ T-lymphocyte count: 479/mm³ (Normal ≥ 500)

Serum:

Cytomegalovirus (CMV) antibody: negative

Hepatitis B surface antibody: negative

Hepatitis C antibody: negative

Toxoplasma gondii antibody: negative

Plasma HIV viral load:  2000 copies/mL

Which of the following is the most appropriate pharmacotherapy during the next year?

A 4-year-old girl is brought to the physician because of cough and a 2.3-kg (5-lb) weight loss during the past 2 months. There is no history of serious illness, and she takes no medications. Immunizations are up-to-date. She is at the 50th percentile for height and 25th percentile for weight. Occasional crackles are heard over the right middle lung field. Intradermal skin testing with PPD, tetanus toxoid, and antigens for Candida albicans and Trichophyton tonsurans is nonreactive at 72 hours. Her leukocyte count is 5100/mm3. Nucleic acid hybridization testing of gastric aspirates shows Mycobacterium tuberculosis. Which of the following is the most likely explanation for this patient’s findings?

A 1-year-old boy is brought to the physician 24 hours after the onset of lethargy. He has a 2-day history of fever, vomiting, and decreased appetite. He was recently adopted from Russia. He attends day care five times weekly. His temperature is 39.4°C (103°F). Examination shows neck stiffness and decreased skin turgor. Which of the following vaccines is most likely to have prevented this patient’s condition?

Six hours after undergoing surgical excision of the distal colon for cancer, a 77-year-old man has decreased urine output. His urine output has been 10 mL/h during the past 3 hours. During the 4-hour operation, he lost 500 mL of blood and underwent transfusion of 1 unit of packed red blood cells. His initial postoperative course was uncomplicated. Two years ago, he had a myocardial infarction and underwent coronary artery bypass grafting. He has a 10-year history of hypertension well controlled with atenolol. Current medications include morphine and labetalol. He currently appears pale and diaphoretic. His temperature is 37°C (98.6°F), pulse is 85/min, respirations are 14/min, and blood pressure is 90/60 mm Hg. Pulse oximetry on 2 L/min of oxygen via nasal cannula shows an oxygen saturation of 89%. Cardiopulmonary examination shows no abnormalities. The abdomen is nondistended with mild tenderness over the incision. His hematocrit is 24%, serum sodium concentration is 140 mEq/L, and serum creatinine concentration is 2.1 mg/dL. The patient is switched to administration of 100% oxygen by a nonrebreathing face mask. The most appropriate next step in management is administration of which of the following?

A 47-year-old man has had marked shortness of breath during ambulation and at rest for 24 hours. He has no chest pain. He completed a required course of chemotherapy including doxorubicin for non-Hodgkin lymphoma 4 months ago. His resting pulse has increased from 80/min to 110/min during this period. Echocardiography shows a left ventricular ejection fraction of 40%. An ECG shows sinus tachycardia but is otherwise normal. Which of the following is the most likely explanation for these findings?

A 27-year-old man comes to the physician because of a 4-day history of pain and fullness in his left testicle and a 2-day history of mild pain with urination. He has been sexually active with one female sexual partner for the past 2 years. Examination shows mild left testicular and scrotal tenderness with no redness or edema. Urinalysis shows 3-5 WBC/hpf but no obvious organisms. Which of the following is the most likely causal organism?