CK- NBME 11 – Block 1

A 1-week-old boy is brought to the physician because of a 2-day history of fever and irritability. His temperature is 39°C (102.2°F). Examination shows decreased motion of the left hip with tenderness. An x-ray of the hip shows increased joint space. Aspiration of the hip joint yields 3 mL of purulent fluid. A culture of the fluid is most likely to grow which of the following organisms?

 A 27-year-old man with schizophrenia is brought to the emergency department by his mother because he says he has been unable to see anything for the past 3 hours. They have been on a car trip across the country for the past 6 days. Last night, he reported hearing voices, so they stopped in an emergency department by the highway; he was administered haloperidol and was released 1 hour later. He has no other history of serious illness. His only regularly scheduled medication is intramuscular fluphenazine every 3 weeks. His temperature is 37.1°C (98.8°F), pulse is 88/min, and blood pressure is 142/78 mm Hg. On examination, he is lying on a stretcher, moaning, with his upper extremities held rigidly to his side. The eyes are rotated superiorly. The neck is rigid. On mental status examination, he is alert but too distressed to answer questions. His leukocyte count is 9800/mm3. Which of the following is the most likely cause of this patient’s current visual problems?

 A 32-year-old man comes to the physician with his wife because of changes in his behavior during the past 2 weeks. Four weeks ago, he witnessed a close friend die in a motor vehicle collision. On the evening of the collision, the patient had offered to drive his friend home after they had had a few beers, but the friend declined. As the friend walked away from the patient’s car, he was struck by an oncoming vehicle. The patient states that he does not remember much about the incident. During the past 2 weeks, his wife reports that he has been awakening nightly in a sweat and shouting “Watch out!” She states that he has been more emotionally distant and that he has not wanted to socialize with friends. He has not driven his car for 10 days. The patient reports difficulty sleeping and concentrating and says that “things just don’t seem real at times.” He says he used to drink alcohol only rarely but has been drinking two beers nightly for 3 weeks to help him calm his mind and sleep. His temperature is 36.9°C (98.4°F), pulse is 82/min, respirations are 12/min, and blood pressure is 145/80 mm Hg. Physical examination shows no abnormalities. On mental status examination, he has a flat affect but is irritable. He says that he has not been feeling much of anything lately. He has thought about death frequently during the past 2 weeks but says he does not want to commit suicide. Results of laboratory studies are within the reference range. Which of the following is the most likely diagnosis?

A 12-year-old boy is brought to the physician because of a 1-year history of recurrent episodes of increased urinary urgency and frequency, increased thirst, and bed wetting. The episodes occur every 3 to 4 weeks and last 2 to 3 days; he does not wet the bed between episodes. He has not had abdominal pain or a burning sensation on urination. He was toilet trained at the age of 3 years and had not wet the bed since the age of 4 years. He has no history of serious illness and takes no medications. His parents divorced 1 year ago; his mother is the custodial parent, and he visits his father on occasional weekends. He is at the 50th percentile for height, at the 95th percentile for weight, and above the 95th percentile for BMI. Genital and pubic hair development are Tanner stage 1. Laboratory studies show:

Serum glucose:

85 mg/dL

Urine (first morning void):

Specific gravity: 1.015

Blood: negative

Glucose: negative

Protein: negative

Which of the following is the most likely diagnosis?

 A 17-month-old infant with sickle cell disease has a 1-day history of rectal temperatures to 40.6°C (105°F). He has had rhinorrhea and a cough for 3 days. He receives daily penicillin prophylaxis and has received all appropriate immunizations. He is slightly irritable and has clear rhinorrhea. His spleen is palpable 2 cm below the left costal margin. The remainder of the examination is normal. Laboratory studies show:

Hemoglobin: 9.8 g/dL

Leukocytes: 18,700/mm³

Segmented neutrophils: 65%

Lymphocytes: 30%

Bands: 3%

Monocytes: 2%

Which of the following is the most appropriate pharmacotherapy for this patient?

A 32-year-old primigravid woman at 27 weeks’ gestation is brought to the emergency department because of painless vaginal bleeding for 6 hours. She has to change sanitary pads every 2 hours. She has had no prenatal care. Ultrasonography at 16 weeks’ gestation showed a normal fetus and a posterior fundal placenta. Her pulse is 100/min, and blood pressure is 120/80 mm Hg. Pelvic examination shows normal external genitalia. The uterus measures 27 cm and is nontender. Speculum examination shows a 2-cm friable ulcer on the cervix. The cervix is long, the external os is 1 cm dilated, and the internal os is closed. Which of the following is the most likely cause of the bleeding?

 A 17-year-old girl is brought to the emergency department by her father after she had loss of consciousness and collapsed on the sidewalk during an afternoon run. Her father says that his daughter is overweight and has been trying to lose weight for the past 2 months. In addition to modifying her diet, she has been running 2 to 3 miles daily during the past month. She has no history of serious illness and takes no medications. On questioning, her father says that his daughter is a “good kid” but occasionally attends parties, where alcohol is served; he is unsure whether she has used illicit drugs. On arrival, she is somnolent but arousable and responsive. She is oriented to person but not to place or time. She is 168 cm (5 ft 6 in) tall and weighs 85 kg (187 lb); BMI is 30 kg/m2. Her temperature is 39°C (102.2°F), pulse is 140/min, respirations are 40/min, and blood pressure is 105/70 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 97%. Examination shows cool, clammy, dry skin. The pupils are equal and reactive to light. No other abnormalities are noted. Which of the following is the most likely diagnosis?

A 72-year-old man is brought to the emergency department 2 hours after a generalized tonic-clonic seizure that lasted 5 minutes. He has no other history of seizures. His wife reports that the patient has been increasingly forgetful during the past 3 months. He also has had increasingly frequent jerk-like movements of the arms and legs. Three times during the past week, he did not recognize his wife when he saw her enter a room, but he recognized her voice. He has hypercholesterolemia treated with atorvastatin. He drinks three to four beers nightly. Examination shows involuntary jerking of the head, trunk, and all extremities. There are fasciculations of all extremities. On mental status examination, he has a normal mood and affect. He is alert and is able to repeat six digits forward. He recalls two of five parts of a name and address after 5 minutes. When shown a sketch of a pretzel, he identifies it as a snake. Which of the following is the most likely diagnosis?

 A 37-year-old woman comes to the physician for a second opinion regarding a positive Chlamydia trachomatis DNA hybridization test done by her primary physician 2 weeks ago. The patient has been in a mutually monogamous heterosexual relationship for the past 7 years. She does not doubt her partner’s fidelity, and she disbelieves the results. She has no history of serious illness and takes no medications. Pelvic examination shows normal vaginal discharge, an IUD string at the cervical os, and normal cervical mucus. There is no pelvic tenderness. The physician is aware that the prevalence of C. trachomatis infection in this patient’s age group is less than 1%; the sensitivity of the test is 80%, and the specificity is 97%. Which of the following best explains the validity of the test results to this patient?

 A 7-month-old girl is brought to the physician because of a 2-day history of rapid breathing, sweating, pallor, decreased feeding, and increased fussiness. The mother says the patient had the same symptoms 3 weeks ago, but they were less severe and resolved spontaneously in less than 1 day. The patient is alert and fussy. She is at the 50th percentile for length and weight. Her temperature is 37.3°C (99.1 °F), pulse is 220/min, respirations are 48/min, and blood pressure is 62/42 mm Hg. Capillary refill time is 3 seconds. Examination shows pink skin. The liver edge is palpated 3 cm below the right costal margin. The remainder of the examination shows no abnormalities. An ECG shows narrow complex tachycardia. Which of the following is the most appropriate next step in management?

 A 67-year-old woman is brought to the physician because of a 2-week history of increasingly blurred vision. Two months ago, she was hospitalized for 10 days for management of tuberculous meningitis; treatment with ethambutol, isoniazid, prednisone, pyrazinamide, pyridoxine, and rifampin was started at that time. She had been feeling well since discharge. Her only other medication is lisinopril for hypertension. She has no other history of serious illness. Her blood pressure is 125/70 mm Hg. Examination shows a best- corrected visual acuity of 20/50 bilaterally. Visual field examination shows decreased vision in the center of each field. Peripheral vision is normal. A mild-to-moderate decrease in color vision is noted bilaterally. The remainder of the examination shows no abnormalities. Toxicity from which of the following is the most likely cause of this patient’s blurred vision?

A 45-year-old man with alcoholic cirrhosis comes to the physician for a routine examination. His medications are spironolactone and furosemide. He no longer drinks alcohol. He is alert and fully oriented. His temperature is 37°C (98.6°F), pulse is 86/min, respirations are 12/min, and blood pressure is 108/60 mm Hg. Examination shows scattered spider angiomas over the chest and upper abdomen. The abdomen is distended; there is dullness to percussion over the flanks. Which of the following is the most appropriate screening test for this patient?

A 19-year-old man is brought to the emergency department 30 minutes after he was involved in a motor vehicle collision. He was the unrestrained driver. A cervical collar and spinal board were placed at the scene. He has no history of serious illness and takes no medications. On arrival, he reports shortness of breath and difficulty breathing, especially in the right side of the chest. His temperature is 36.9°C (98.5°F), pulse is 126/min, respirations are 30/min, and blood pressure is 110/70 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 78%. Examination shows right-sided supraclavicular fossal distention with inspiration. Which of the following is the most likely diagnosis?

A previously healthy 67-year-old woman is brought to the emergency department because of a 2-hour history of severe upper abdominal pain, nausea, and vomiting. Her symptoms began when her 4-year-old grandson jumped on her abdomen while she was lying on the sofa. She is in acute distress. Her temperature is 37.7°C (99.9°F), pulse is 110/min, respirations are 20/min, and blood pressure is 150/60 mm Hg. Decreased breath sounds are heard in the lung bases bilaterally. Cardiac examination shows no other abnormalities. Abdominal examination shows diffuse tenderness to palpation; bowel sounds are decreased. Laboratory studies show:

Hemoglobin: 11 g/dL

Leukocyte count: 8500/mm³

Serum:

Ca²⁺: 7.5 mg/dL

Creatinine: 1.9 mg/dL

Total bilirubin: 0.9 mg/dL

AST: 30 U/L

ALT: 29 U/L

Amylase: 348 U/L

Lipase: 189 U/L (N = 14–280)

Which of the following is the most likely diagnosis?

Researchers would like to review the evidence on the association between cigarette smoking and cardiovascular disease. They review a sample of 500 studies published during the past 50 years and note that the increased risk for cardiovascular disease in patients positively correlates with the number of cigarettes smoked daily. The researchers also note that all of these studies are observational. They conclude that this type of study design cannot determine a causal link between smoking and cardiovascular disease, but these studies support one of the criteria for causality. Which of the following best represents the causation criterion met by this type of association?

A 23-year-old woman comes to the physician to learn the results of a PPD skin test performed 48 hours ago. The test is required before she begins her first year of nursing school. She feels well. She emigrated from Thailand at the age of 15 years. She received the bCG vaccine during infancy. She has no history of serious illness and takes no medications. She has no known exposure to anyone with tuberculosis or respiratory symptoms. She does not drink alcohol. Vital signs are within normal limits. Examination shows no abnormalities. The PPD skin test shows 15 mm of induration. An x-ray of the chest shows no abnormalities. Which of the following is the most appropriate next step in management?

 A 76-year-old woman is brought to the emergency department because of a 2-day history of severe, right-sided chest pain that increases with deep inspiration and coughing. She also has a 1-week history of intermittent fever, malaise, and loss of appetite. Ten days ago, she was diagnosed with pneumonia of the right lower lobe. Azithromycin therapy was begun at that time. She has no other history of serious illness and takes no other medications. On arrival, her temperature is 39.5°C (103.1°F), pulse is 92/min, and blood pressure is 120/75 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. On pulmonary examination, there is egophony and dullness to percussion over the right lower lobe. Breath sounds are decreased on the right. A chest x-ray shows a right pleural effusion. Thoracentesis is performed; pleural fluid analysis shows a leukocyte count of 16,000/mm3, glucose concentration of 50 mg/dl_, and pH of 7.12. Which of the following is the most appropriate next step in management?

A 45-year-old woman with type 2 diabetes mellitus comes to the physician because of a 6-month history of mild pain and swelling of her right hand; the pain radiates to her shoulder. During this time, she also has had episodes of numbness and tingling of her right thumb and index and ring fingers, especially after prolonged typing. She has not sustained any recent injury. She is right-hand dominant. Her medications are insulin and ibuprofen. Vital signs are within normal limits. The neck is nontender, and range of motion is full. Spurling test is negative. Muscle strength is 5/5 in the supraspinatus, infraspinatus, and subscapularis. Radial pulses are 2+ bilaterally. Motor and sensory testing of the radial, median, and ulnar nerves shows no abnormalities. There is no thenar atrophy. Phalen test is positive on the right and negative on the left. Impingement testing is negative. Which of the following is the most appropriate next step in management?

A 70-year-old woman is admitted to the hospital because of a 1 -hour history of severe right-sided chest pain, shortness of breath, and dizziness. During this time, she also has had several coughing episodes, one of which produced blood-tinged sputum. Eighteen hours ago, she returned home from a cross-country airplane trip to see her daughter and grandchildren. The patient has no history of serious illness and takes no medications. She does not smoke cigarettes or drink alcohol. She follows a vegetarian diet, is physically fit, and exercises daily. She appears anxious. She is 163 cm (5 ft 4 in) tall and weighs 45 kg (100 lb); BMI is 17 kg/m2. Her pulse is 98/min, respirations are 16/min, and blood pressure is 106/84 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 88%. Examination shows jugular venous distention. Breath sounds are normal. On cardiac examination, S2 is increased; no murmurs are heard. Examination of the left calf shows tenderness to palpation and a positive Homans sign. Which of the following is the strongest predisposing risk factor for this patient’s in-hospital mortality?

A 3-year-old boy is brought to the physician for a well-child examination. He is at the 50th percentile for height, weight, and head circumference. His appetite is good. His pulse is 85/min. His blood pressure is 140/75 mm Hg and 140/78 mm Hg in the right and left upper extremities, respectively. His blood pressure is 144/76 mm Hg and 145/79 mm Hg in the right and left lower extremities, respectively. Funduscopic, cardiopulmonary, and abdominal examinations show no other abnormalities. Results of a complete blood count; serum electrolyte, urea nitrogen, and creatinine concentrations; and urinalysis are within the reference ranges. Which of the following is the most appropriate next step in diagnosis?

A 57-year-old woman is brought to the emergency department by paramedics 15 minutes after she was found unresponsive on a park bench. She was examined in the same emergency department 2 weeks ago because of a 2-month history of episodic unilateral throbbing headaches that typically occurred on the right side of the head but intermittently occurred on the left. Examination at that time showed no abnormalities. She was diagnosed with migraine, received an intramuscular injection of ketorolac, and discharged with instructions to schedule a follow-up examination with her primary care physician. Review of her medical records from that examination shows a 6-month history of chronic back pain, 15-year history of hypertension and type 2 diabetes mellitus, and 40-year history of post-traumatic complex partial seizures. Her other medications are oxycodone, lisinopril, metformin, and carbamazepine. On arrival, she is obtunded. Her pulse is 78/min, respirations are 6/min, and blood pressure is 160/92 mm Hg. On examination, the pupils are 1 mm and minimally reactive to light. There are intermittent, symmetrical, semipurposeful movements of all extremities. Deep tendon reflexes are 1+. Babinski sign is absent bilaterally. On ice-water caloric testing, the eyes move toward the ear in which the water is placed. Which of the following is the most likely cause of this patient’s decreased level of consciousness?

A 51 -year-old man, hospitalized for management of a proximal jejunal enterocutaneous fistula, has a 2-day history of fever and malaise. Four weeks ago, he underwent laparotomy for a gunshot wound to the abdomen; the fistula was noted 1 week after the operation. Since undergoing the laparotomy, he has received total parenteral nutrition through a left subclavian central catheter. During the past 2 weeks, he has participated in physical therapy; until today, he was able to ambulate 300 ft and walk up two flights of stairs without shortness of breath. He has no other history of serious illness. His medications are somatostatin and morphine. His temperature is 38.4°C (101.1 °F), pulse is 105/min, respirations are 20/min, and blood pressure is 110/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Examination shows the fistula opening with draining enteric contents. An ostomy pouching system is placed, and the surrounding skin is well protected. Fistula output is 400 mL daily. Three days ago, his leukocyte count was 8000/mm3; today, it is 14,000/mm3. Serum studies today show an albumin concentration of 2.7 g/dL and prealbumin concentration of 19 mg/dL (N=19.5-35.8). Which of the following is the most appropriate next step in management?

A study is conducted to investigate the attitude of patients with type 2 diabetes mellitus toward controlling their disease with lifestyle modifications, including diet and exercise. A total of 20 men and women aged 55 to 70 years are randomly selected from an outpatient diabetes clinic and are enrolled in the study. The male-to-female ratio among the patients is 1:1, and they are matched by age and BMI. Patients are assigned to groups led by a moderator who uses a standard set of scenarios to prompt discussion. The discussions are video recorded and reviewed to examine the patterns of the patients’ attitudes toward lifestyle modification in order to improve control of their disease. Which of the following best describes this study design?

 A 42-year-old man is brought to the emergency department by ambulance 20 minutes after sustaining a stab wound to his right anterior chest. On arrival, the patient is uncooperative, refusing to lie flat on the gurney. Medical history is unremarkable, and he takes no medications. He says he drank six 12-oz beers and used cocaine today. Vital signs are pulse 130/min, respirations 28/min, and blood pressure 66/40 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. The patient appears anxious. Physical examination discloses a single stab wound in the medial right anterior chest, 3 cm below the right nipple. The trachea is midline. Breath sounds are present bilaterally. Cardiac examination discloses distant but normal S1 and S2. Abdominal examination discloses no abnormalities. Which of the following is the most appropriate next step in management?

 A 37-year-old man comes to the clinic at the urging of his dentist 1 day after he was noted to have a blood pressure of 175/97 mm Hg following a dental extraction. The patient’s blood pressure was normal prior to the procedure. The patient reports pain at the site of extraction but does not have headache, change in vision, chest pain, or shortness of breath. Medical history is unremarkable, and he takes no medications. His father has hypertension and sustained a myocardial infarction at age 45 years. The patient has smoked one pack of cigarettes daily for 15 years. He drinks alcoholic beverages socially but does not use illicit drugs. He is 185 cm (6 ft 1 in) tall and weighs 79 kg (175 lb); BMI is 23 kg/m2. Blood pressure now is 133/74 mm Hg; remaining vital signs are normal. Physical examination discloses no abnormalities. Which of the following is the most appropriate next step in evaluation?

A 3-day-old male newborn is evaluated in the hospital nursery because of a 2-hour history of episodes of vomiting green material. He was well prior to the onset of these episodes. He was born at 41 weeks’ gestation following an uncomplicated pregnancy and cesarean delivery because of failure to progress. He appears listless. He is 50 cm (19.7 in; 50th percentile) long and weighs 3628 g (8 lb; 50th percentile). His temperature is 36.7°C (98.0°F), pulse is 170/min, respirations are 50/min, and blood pressure is 70/40 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Capillary refill time is 2 seconds. The abdomen is nondistended, and the patient cries when it is palpated. The remainder of the examination discloses no abnormalities. Which of the following is most likely to establish the diagnosis?

 A 66-year-old man comes to the office because of a 2-month history of right knee pain. He reports that the pain occurs for 5 to 10 minutes when he gets up in the morning, or after he walks for several blocks. He says his knee has not “given way” or “locked up.” Acetaminophen has not provided relief of the pain. He reports no recent trauma to the knee but fell on it after tripping over a step 1 year ago. Medical history also is remarkable for hypertension and hyperlipidemia. Medications are lisinopril and atorvastatin. He is 173 cm (5 ft 8 in) tall and weighs 63 kg (140 lb); BMI is 21 kg/m2. Blood pressure is 136/82 mm Hg. Examination of the lower extremities discloses normal flexion in both knees but decreased hyperextension in the right knee compared with the left knee. There is moderate medial joint line tenderness and a mild effusion of the right knee. Which of the following is the most appropriate recommendation at this time?

A 23-year-old man who is a US Army veteran comes to the clinic because of a 2-month history of depressed mood; difficulty concentrating; decreased appetite; and decreased interest in his usual activities, such as exercising and spending time with friends. He also has had difficulty sleeping during this period, including being unable to fall asleep for 2 hours and then waking up “for no reason” in the middle of the night; he does not feel rested in the morning. He says that he sometimes thinks he would be better off dead, but he does not have any plans to harm himself. Physical examination shows no abnormalities. He asks for treatment with a medication that will not interfere with his sexual function. Which of the following medications is most appropriate for this patient at this time?

A 23-year-old woman comes to the office because of a 1-week history of moderate abdominal cramps and bloody diarrhea. She has no history of serious illness and takes no medications. There is no family history of gastrointestinal disease. The patient has not traveled recently or had sick contacts. Temperature is 37.2°C (99.0°F). While lying flat, pulse is 110/min and blood pressure is 100/70 mm Hg; while standing, pulse is 120/min and blood pressure is 90/60 mm Hg. The abdomen is mildly distended and soft; there is mild, diffuse tenderness to palpation. Hematocrit is 36%, and leukocyte count is 13,000/mm3. Intravenous fluid therapy is begun. Stool culture results are negative. Colonoscopy shows inflamed mucosa and erythematous and raised mucosa over the rectum and sigmoid. The remainder of the colon appears normal. Colonic biopsy specimen shows crypt branching and abscesses. Which of the following is the most appropriate next step in pharmacotherapy?

A 21-year-old woman comes to student health services because of a 36-hour history of fever, sore throat, and headache. Two weeks ago, she was treated with a 5-day course of ibuprofen for muscle pain, fatigue, and malaise thought to be associated with a virus. She has no history of serious illness. Her only current medication is an oral contraceptive. Temperature is 38.3°C (101.0°F), pulse is 84/min, respirations are 12/min, and blood pressure is 115/75 mm Hg. Examination shows edema of the pharynx and tonsils. Multiple firm, mobile, tender lymph nodes are palpated in the cervical chain bilaterally. Cardiopulmonary examination shows no abnormalities. There is no abdominal tenderness. The spleen tip is palpated 5 cm below the left costal margin. Her leukocyte count is 14,000/mm3 (40% segmented neutrophils, 3% eosinophils, 55% lymphocytes, and 2% monocytes). Monospot test is positive. The patient lives in a college dormitory. Use of which of the following measures by the patient is most likely to prevent transmission of her illness?

An 11-year-old boy is brought to the emergency department 40 minutes after he was found slumped over in an alley. He appears somewhat disheveled and dirty. He is groggy and somewhat confused but smiling. He is unable to give coherent answers to most questions, and his speech is slurred. His pulse is 124/min, respirations are 10/min, and blood pressure is 100/62 mm Hg while supine and 82/48 mm Hg while sitting. Pupils are 5 mm and reactive to light. There is occasional nystagmus on lateral gaze. He falls asleep in the examining room. Intoxication with which of the following is the most likely cause of this patient’s condition?

A previously healthy 4-month-old boy is brought to the physician because of a 2-day history of fever and episodes of vomiting and crying. His temperature is 39.1°C (102.4°F), pulse is 142/min, respirations are 28/min, and blood pressure is 88/54 mm Hg. He is fussy but consolable. Examination shows an uncircumcised penis. The remainder of the examination shows no abnormalities. Laboratory studies show:

Hematocrit: 35%

Leukocyte count: 19,500/mm³

Platelet count: 250,000/mm³

Urine:

RBC: 10/hpf

WBC: 30/hpf

Urine culture grows greater than 100,000 colonies/mL of Escherichia coli. Blood culture is negative. Renal ultrasonography shows no abnormalities. Voiding cystourethrography shows a backflow of urine from the bladder to the renal pelvis. Which of the following is the most appropriate intervention to prevent future morbidity from this condition?

A 14-year-old girl is brought to the physician because of a generalized itchy rash for 4 days. During this period, she has also had abdominal cramps, joint pain, and fever; she has not had double vision. She received an intramuscular injection of botulism antitoxin 10 days ago because of an outbreak of botulism at a restaurant where she had eaten. Immunizations are up-to-date. She appears mildly ill. Her temperature is 38.2°C (100.8°F). Examination shows mild facial edema. There are scattered, edematous, soft nodules over the trunk and extremities. Abdominal examination shows tenderness to palpation without rebound. Active and passive range of motion of the wrists, knees, and ankles is limited by pain. Which of the following is the most likely diagnosis?

 A 25-year-old man comes to the physician for an examination prior to starting an exercise program consisting of swimming four times weekly. He feels well but wants to change his sedentary lifestyle. He has smoked one-half pack of cigarettes daily for 9 years. His father had a myocardial infarction at the age of 52 years. The patient is 178 cm (5 ft 10 in) tall and weighs 109 kg (240 lb); BMI is 34 kg/m2. His pulse is 76/min, and blood pressure is 138/76 mm Hg. The remainder of the examination and an ECG show no other abnormalities. In addition to obtaining serum lipid studies and recommending that the patient stop smoking, which of the following is the most appropriate next step in management?

A 32-year-old woman comes to an emergency department in New England because of a 5-day history of fever. She has not had any other symptoms. She has no history of serious illness and takes no medications. She has been sexually active with one male partner for 5 years, and they use condoms consistently. She has a healthy 2-year-old son. She immigrated to the USA from Kenya 6 weeks ago. She appears ill. Her temperature is 38.9°C (102°F), pulse is 90/min, and blood pressure is 110/70 mm Hg. The remainder of the examination shows no abnormalities. Her hematocrit is 29%, leukocyte count is 6000/mm3 (88% segmented neutrophils, 10% lymphocytes, and 2% monocytes), and serum lactate dehydrogenase activity is 450 U/L. Which of the following is the most likely causal organism?

A 42-year-old woman, gravida 2, para 2, comes to the physician because of a 10-month history of severe menstrual cramps and increased menstrual flow. Menses occur at regular 30- to 32-day intervals and last 4 to 6 days. She has severe cramps and heavy flow for the first 4 days of menses. She previously had heavy flow only for the first 2 days of menses. She has not had passage of clots or breakthrough bleeding. She has no history of serious illness. Her temperature is 37°C (98.6°F), pulse is 84/min, respirations are 18/min, and blood pressure is 130/80 mm Hg. Physical examination shows no abnormalities. Pelvic examination shows a smooth, globular-shaped, mobile uterus consistent in size with a 10-week gestation; there is mild tenderness to palpation with no contour abnormalities. Examination shows no adnexal tenderness or masses. Pelvic ultrasonography, including sonohysterography, shows diffuse uterine enlargement and a normal endometrial cavity. Which of the following is the most likely cause of this patient’s menstrual symptoms?

A study is conducted to assess the efficacy of a new medication to relieve pain. A total of 1000 patients with pain are enrolled and randomly assigned to receive either the new drug or the standard care. Results show that the new drug is more effective than the standard care, but 2.4% of patients receiving the new drug developed new-onset hypertension, compared with 1.6% of patients receiving the standard care. Based on these results, which of the following is the number needed to harm with the new drug to cause new-onset hypertension in one patient?

 A 42-year-old woman comes to the physician because of a 4-week history of progressive generalized weakness and urinary frequency. She says that she needs to stop and rest halfway up the stairs in her home and that she also has difficulty carrying grocery bags. She has no history of serious illness and takes no medications. Her younger sister and brother have hypertension. Her pulse is 88/min, respirations are 18/min, and blood pressure is 174/102 mm Hg. Funduscopic examination shows mild arteriovenous nicking. Muscle strength is 5/5 throughout, and reflexes are normal. Serum studies show:

Na⁺: 143 mEq/L

K⁺: 3.0 mEq/L

Cl⁻: 102 mEq/L

HCO₃⁻: 30 mEq/L

Which of the following additional serum findings are most likely in this patient?

 A previously healthy 16-year-old girl is admitted to the hospital because of a 4-day history of fever, malaise, headache, and abdominal pain. She was present at the site of a suspected bioterrorism attack 14 days ago. Her temperature is 40°C (104°F), pulse is 96/min, respirations are 16/min, and blood pressure is 110/70 mm Hg. After 1 day of supportive therapy, her fever subsides, but there are vesicular lesions at the same stage of development primarily over the mouth, face, and extremities with limited distribution across the trunk. Immunization of the patient’s contacts with which of the following is most likely to prevent the spread of this illness?

A 47-year-old man comes to the emergency department 12 hours after the onset of severe shortness of breath, dizziness, and generalized weakness. He has type 2 diabetes mellitus treated with metformin and insulin. He has had 19 visits to the emergency department during the past 3 years because of poor blood glucose control. He has smoked two packs of cigarettes daily for 30 years. His temperature is 38.6°C (101.4°F), pulse is 110/min, respirations are 34/min, and blood pressure is 90/70 mm Hg. A photograph of  Arterial blood gas analysis on room air shows:

Hemoglobin: 11.5 g/dL

Hematocrit: 35%

Leukocyte count: 26,000/mm³

Serum:

Na⁺: 132 mEq/L

K⁺: 5.4 mEq/L

Cl⁻: 95 mEq/L

HCO₃⁻: 13 mEq/L

Urea nitrogen: 29 mg/dL

Glucose: 733 mg/dL

Creatinine: 1.6 mg/dL

Arterial blood gas:

pH: 7.22

PCO₂: 21 mm Hg

PO₂: 98 mm Hg

Intravenous fluids, antibiotics, and insulin are administered. Which of the following is the most appropriate next step in diagnosis?

A 77-year-old woman, gravida 4, para 4, is admitted to the hospital for treatment of pneumonia. On hospital day 4, she has an episode of severe coughing, after which she states that she has had involuntary loss of urine. She states that she feels like “something is bulging” from her vagina. Her four pregnancies were uncomplicated and ended in spontaneous vaginal deliveries. Menopause occurred 25 years ago. She has not had postmenopausal bleeding and has never received hormone therapy. Her temperature is 37°C (98.6°F), pulse is 75/min, respirations are 18/min, and blood pressure is 140/90 mm Hg. Abdominal examination shows no abnormalities. The external genitalia are atrophic but otherwise normal. The anterior vaginal segment is descended halfway past the hymenal ring. Speculum examination shows a normal cervix. The uterus is small, nontender, and anteflexed, and there are no adnexal masses. Rectal examination shows no abnormalities. Which of the following is the most likely diagnosis?

A 1-day-old female newborn is examined in the nursery. She was born at term to a 31-year-old primigravid woman following an uncomplicated spontaneous vaginal delivery. The mother has systemic lupus erythematosus; she was asymptomatic during pregnancy, and her only medication was a prenatal vitamin. The patient’s Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. Her temperature is 37°C (98.6°F), pulse is 70/min, respirations are 50/min, and blood pressure is 75/45 mm Hg. Examination shows no abnormalities. An ECG is shown. Which of the following is the most appropriate next step in management?

A 6-month-old boy is brought to the physician because of dry scaly skin for 2 weeks. Over the past 3 months, he has had recurrent episodes of otitis media treated with amoxicillin. There are scattered petechiae over the entire body and mild generalized eczema. Examination shows cervical lymphadenopathy and hepatosplenomegaly. His platelet count is 25,000/mm3. Which of the following is the most likely diagnosis?

A previously healthy 4-year-old boy is brought to the emergency department by his parents 1 day after they noticed that he was not using his left arm. There is no known injury to the arm. He appears comfortable but resists any attempt to move the affected arm because of pain. He holds the left upper extremity with the elbow flexed and the forearm in pronation. There is no evidence of injury. Radial pulses are normal. Sensation is full over the affected extremity. Which of the following is the most appropriate next step in management?

A 57-year-old man comes to the physician because of an 8-month history of a nonproductive cough. He has had a 4.5-kg (10-lb) weight gain during the past 6 months despite no change in appetite. He has hypertension treated with atenolol. He has smoked one pack of cigarettes daily for 39 years. He is 175 cm (5 ft 9 in) tall and weighs 98 kg (216 lb); BMI is 32 kg/m2. His temperature is 37.1°C (98.8°F), pulse is 84/min, respirations are 16/min, and blood pressure is 152/98 mm Hg; one year ago, his blood pressure was 132/78 mm Hg. Examination shows purple striae over the abdomen. His serum potassium concentration is 3.4 mEq/L, and fasting serum glucose concentration is 119 mg/dL. An x-ray of the chest shows a right upper lobe nodule. In addition to a biopsy, which of the following is the most appropriate next step in diagnosis?

 A 67-year-old man comes to the physician because of a 6-month history of aching in his thighs and buttocks after he walks 200 feet. His temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 140/90 mm Hg. Femoral and distal pulses are absent bilaterally. Serum studies show a urea nitrogen concentration of 30 mg/dL and creatinine concentration of 1.5 mg/dL. He undergoes aortic arteriography. Three days later, his serum creatinine concentration is 2.8 mg/dL. Administration of which of the following prior to the arteriography is most likely to have prevented progression of this patient’s renal insufficiency?

A 2-month-old boy is brought to the physician for a well-child examination. He was born at term following an uncomplicated pregnancy, labor, and delivery. He has been breast-feeding six to eight times daily since birth. He smiles and lifts his head. He is at the 50th percentile for length, 75th percentile for weight, and 25th percentile for head circumference. Examination shows no abnormalities. His mother asks for nutritional recommendations. Which of the following is the most appropriate recommendation for the infant?

 A 37-year-old primigravid woman at 9 weeks’ gestation is admitted to the hospital because of progressive nausea and vomiting. Her symptoms began at 6 weeks’ gestation but have worsened so that she can no longer keep food or fluids down. Her temperature is 36.9°C (98.4°F), pulse is 105/min, respirations are 16/min, and blood pressure is 110/60 mm Hg. Examination shows a uterus consistent in size with a 9-week gestation. Her serum thyroid-stimulating hormone concentration is 0.4 pU/mL. Which of the following is the most appropriate next step in management?

A 22-year-old primigravid woman at 15 weeks’ gestation comes to the physician for her first prenatal visit. She has no history of serious illness, and pregnancy has been uncomplicated. Examination shows a uterus consistent in size with a 20-week gestation. Ultrasonography shows twins, both male, with a single placenta and no membrane between the fetuses. This patient should be advised that there is an increased risk for which of the following?

During a routine annual examination, an asymptomatic 46-year-old man is found to have a 1-cm prostatic nodule. Physical findings are otherwise normal. Which of the following is the most appropriate next step in management?