Two weeks following LASIK surgery in the right eye, a 70-year-old professional actor comes to the emergency department because of a 1-day history of blurry vision and “floaters” in his right eye. He says, “I feel like a curtain is covering my right visual field.” He has not had nausea or vomiting. He has not sustained any recent trauma. The patient has a history of systemic lupus erythematosus, prostate cancer, and hypertension. Medications include hydroxychloroquine and enalapril. Vital signs are temperature 37.5°C (99.5°F), pulse 88/min, respirations 18/min, and blood pressure 170/104 mm Hg. Visual acuity is 20/200 in the affected eye. One week ago during a follow-up examination, visual acuity was 20/25 in both eyes. Funduscopic examination with binocular indirect ophthalmoscopy is done while the right eye is dilated. Findings are shown. The patient’s condition is most likely caused by which of the following?

A 67-year-old man is brought to the office by his family to discuss whether he is a candidate for hospice care. The patient was discharged from the hospital 2 weeks ago after cancer metastatic to his liver was diagnosed. The primary site of the cancer is unknown. At discharge, the patient was prescribed long-acting morphine. The family was informed that the patient’s life expectancy was 3 to 6 months. Today, the family states that the patient has had increasing weakness and considerable pain since discharge. The patient’s wife says she can no longer provide adequate care for him at home, but the family is concerned about the cost of hospice care and wants to know what services would be covered. The patient has Medicare. Which of the following is the most appropriate statement to the patient’s family regarding his eligibility for hospice care?

A 32-year-old white woman, gravida 2, para 2, comes to the emergency department because of a 2-day history of acute back and abdominal pain. The pain is intermittent and lasts from 15 minutes to 4 hours. It starts below her rib cage in her back on the right side and comes through in waves to her right lower quadrant. When the pain is severe she is mildly nauseated. Vital signs are normal. Abdominal examination discloses diminished bowel sounds but is otherwise unremarkable. She indicates that the place where the pain occurs is the costovertebral area. Nephrolithiasis is suspected. A recent article compared helical CT scan of the abdomen with excretory urography (EXU) in the diagnosis of nephrolithiasis. In this study 54 of 80 consecutive patients who went to the emergency department with signs or symptoms of renal colic were examined by helical CT scan followed by EXU. Of the 54 patients studied using both tests, 40 were men and 14 were women. The average age was 40 years. The results are shown in the table:

Based on this information, which of the following is the most accurate statement?

A 12-year-old girl is brought to the office by her mother because of a 3-month history of gradual enlargement of the left breast compared with the right. She has not had pain in the breast, trauma to the breast, or fever. Menarche occurred at age 11 years. Medical history is otherwise unremarkable and the child takes no medications. Vital signs are normal. Physical examination shows the left breast to be larger than the right breast. Palpation of the left breast discloses a 3 × 5-cm firm, mobile mass. The skin overlying the mass shows no discoloration, erythema, or swelling. Sexual maturity rating for breast development is 2 bilaterally. Which of the following is the most likely diagnosis?

A 43-year-old woman is brought to the emergency department by ambulance 30 minutes after she was found unresponsive at home by her husband. The husband reports that during the past 8 to 10 days she has had periods of confusion and severe headaches that have not responded to aspirin or ibuprofen. Medical history is otherwise unremarkable and her only other medication is an oral contraceptive. Her last menstrual period ended 1 week ago. Vital signs are temperature 37.1°C (98.8°F), pulse 80/min, respirations 16/min, and blood pressure 130/76 mm Hg. She is minimally responsive to painful stimuli. Auscultation of the chest discloses normal S1 and S2. Abdominal examination discloses no abnormalities. There are multiple reddish-purple pinpoint lesions over both lower extremities that are more dense at the distal aspects. There is no edema. Reflexes are normal. Results of laboratory studies are shown:

Direct antiglobulin (Coombs) test is negative. Peripheral blood smears are shown. Which of the following is the most likely diagnosis?

A 68-year-old white woman comes to the office because she is concerned about her risk for osteoporosis. She says, “I don’t think I could handle the stress of a hip fracture like my mother had when she was 70.” Medical history is significant for hypertension and hypercholesterolemia. Medications include clonidine, atorvastatin, and daily ibuprofen. She has smoked one pack of cigarettes daily for the past 50 years, but she does not drink alcoholic beverages. In addition to the hip fracture in her mother, family history is significant for the mother’s death from a pulmonary embolism. The patient is 178 cm (5 ft 5 in) tall and weighs 73 kg (160 lb); BMI is 27 kg/m2. Vital signs are temperature 37.1°C (98.8°F), pulse 80/min, respirations 16/min, and blood pressure 148/76 mm Hg. Physical examination discloses kyphosis, enlargement of the distal interphalangeal joints of several fingers, and bony prominence of the first metatarsophalangeal joints bilaterally. Results of serum laboratory studies are shown:

Which of the following diagnostic studies is most appropriate to order at this time?

A 27-year-old woman comes to the office because of right knee pain since she returned from a ski trip yesterday. She appears anxious and requests hydromorphone for her pain, which she rates as a 9 on a 10-point scale. The patient’s medical history is remarkable for alcohol, marijuana, and dextroamphetamine use disorders; today she says she only uses those substances minimally. She takes no prescribed medications. She has never required inpatient rehabilitation, but she did receive outpatient chemical dependency treatment while in high school. She acknowledges close friendships with others who are dependent on heroin and other substances, but she insists she would never share her prescriptions with them. Family history is remarkable for alcohol use disorder in a grandfather and daily marijuana use in an uncle. The patient’s vital signs are temperature 37.0°C (98.6°F), pulse 80/min, respirations 14/min, and blood pressure 112/78 mm Hg. Physical examination discloses tenderness but no redness, warmth, or edema of the knees; range of motion of the knee joint is normal. After extensive discussion with the patient, which of the following is the most appropriate treatment option?

A 3-year-old boy is brought to the emergency department by his mother. She says, “Doctor, about 15 minutes ago my boy’s arms and legs were jerking and his eyes rolled up—it lasted about a minute. I was so scared!” She tells you that the child has been otherwise healthy and is up-to-date on his vaccinations. There is no family history of epilepsy. The boy’s vital signs now are temperature 40.0°C (104.0°F), pulse 98/min, respirations 32/min, and blood pressure 109/70 mm Hg. Physical examination shows bilateral immobile, bulging tympanic membranes and nasal congestion. Lungs are clear. There is no rash or organomegaly. Which of the following is the most appropriate next step?

A 50-year-old white man who is chief executive officer of a furniture corporation returns to the office 3 weeks after discharge from the hospital and 2 weeks after his initial follow-up visit. He was admitted to the hospital because of a non-Q-wave myocardial infarction, and 12 days prior to his last visit he had a coronary artery bypass graft operation. Medical history is also significant for hypertension and diabetes mellitus. His current medications include captopril, hydrochlorothiazide, aspirin, glipizide, and metoprolol; metoprolol was added to his medication regimen at his last visit. He has smoked one pack of cigarettes daily for the past 25 years and drinks alcoholic beverages socially. He is married. At his last visit, vital signs were normal. He was 6.8 kg (15 lb) overweight; the remainder of the physical examination showed no abnormalities. Today, he says he can now walk up stairs in his home without difficulty. He asks you when he can engage in sexual intercourse with his wife. Which of the following is the most appropriate advice?

A 19-year-old African American woman is brought to the emergency department by ambulance after she had a generalized tonic-clonic seizure 1 hour ago at home. Her mother accompanies her and says the patient is 35 weeks pregnant with her first child. The patient is unresponsive and has tonic-clonic movement. Vital signs are temperature 36.4°C (97.5°F), pulse 80/min, respirations 20/min, and blood pressure 190/115 mm Hg. Magnesium sulfate is administered, after which the seizure activity stops. The patient regains consciousness. An intravenous infusion of magnesium sulfate is continued and labor is begun by induction with oxytocin. Physical examination shows the cervix to be 4 cm dilated and 100% effaced. The fetus is at −1 station. After 8 hours, the patient is lethargic and difficult to arouse. Maternal vital signs now are temperature 37.4°C (99.3°F), pulse 80/min, respirations 12/min, and blood pressure 140/98 mm Hg. Auscultation of the lungs discloses crackles in both lower lung fields. There is 4+ pedal edema. Continuous fetal heart rate monitoring shows a baseline fetal heart rate of 140/min with minimal variability. Maternal deep tendon reflexes are absent. Intravenous intake during the past 8 hours has been 1200 mL and urinary output has been 200 mL. The finding on physical examination most indicative of magnesium sulfate administration as the cause of the patient’s drowsiness is which of the following?

A 25-year-old man comes to the office because of occasional chest pain and palpitations after exercise. He has no known history of medical problems. His family history is significant for an uncle who died suddenly at the age of 35 years from an unknown cause, but the patient thinks it had something to do with his heart. Today vital signs are normal. He is 185.5 cm (6 ft 1 in) tall and weighs 106.5 kg (235 lb); BMI is 31 kg/m2. Physical examination discloses a systolic murmur that does not radiate to the neck but is increased by handgrip. ECG shows tall R waves in leads V1 and V2. Laboratory studies show a serum total cholesterol concentration of 200 mg/dL and a serum LDL-cholesterol concentration of 145 mg/dL. At this time, which of the following is the most accurate statement regarding this patient?

Item 2 of 2

The patient also asks you about the pneumococcal vaccine. She says, “I think I had a pneumonia vaccination several years ago at a health fair, but I am not sure.” With respect to her risk for pneumococcal disease, which of the following is the most appropriate advice?

A 56-year-old African American bartender returns to the office for follow-up of chronic obstructive pulmonary disease. She believes she is coughing more often and has had more mucus production for the past 6 to 8 weeks. She takes over-the-counter cough lozenges for relief. Chest x-ray and blood studies 4 months ago were unchanged from 2 years ago. She smoked cigarettes for 20 years but stopped 4 years ago. She has no other history of pulmonary infection or abnormalities. She is 165 cm tall (5 ft 5 in) and weighs 64 kg (142 lb), which is a 4.5-kg (10-lb) increase in the past 4 months. Vital signs now are temperature 37.0°C (98.6°F), pulse 80/min, respirations 16/min, and blood pressure 126/70 mm Hg. Chest examination discloses rhonchi in both lungs that clear with deep breathing or coughing. The remainder of the physical examination shows no abnormalities. Forced expiratory volume in 1 second (FEV1) is 2.5 L compared with 3.05 L 4 months ago. The patient repeats that she is not smoking. She started work as a bartender 4 months ago. Which of the following is the most likely cause of her change in condition?

Item 1 of 2

Which of the following is the best indication that there were true differences between the intervention strategies?

Item 2 of 2

The 95% confidence intervals for the odds ratio are useful in interpreting the results because of which of the following?

An 87-year-old nursing home resident with multi-infarct dementia and hypertension is admitted to the hospital because of mental status changes. MRI of the brain is obtained and shows evidence of a new stroke. He is currently taking clopidogrel, metoprolol, and enalapril. He is receiving nutritional support via a nasogastric feeding tube. Insertion of a percutaneous gastrostomy (PEG) tube to provide more permanent access for nutritional support is recommended. The patient’s family asks whether he will live longer with a PEG tube. Results from a large retrospective analysis of an administrative database in the USA (N=18,976) found that patients over age 85 years, irrespective of diagnosis, had a mortality rate of 27% at 1 month following PEG tube placement and 70% at 1 year. In a different retrospective analysis in Europe involving patients with severe dementia (N=361), the 1-month and 1-year mortality rates following PEG tube placement were 54% and 90%, respectively. Which of the following is the most accurate interpretation of these data?

A 63-year-old white man comes to the office because of increasing shortness of breath and a productive cough since a respiratory illness 2 months ago. At that time he had temperatures to 37.8°C (100.0°F) and a sore throat for 4 days. He took acetaminophen and an over-the-counter cold medication but did not seek medical attention. The patient says he continues to cough up a moderate amount of cream-colored phlegm each morning. He does not have angina. He takes no medications. He smoked two packs of cigarettes daily for 35 years but quit 2 years ago. He drinks two beers every night; he does not exercise. The patient is 188 cm (6 ft 2 in) tall and weighs 100 kg (220 lb); BMI is 28 kg/m2. Vital signs are temperature 36.9°C (98.4°F), pulse 90/min, respirations 22/min, and blood pressure 158/64 mm Hg. Auscultation of the lungs discloses diminished breath sounds with few crackles and expiratory wheezing. There is no egophony. Heart sounds are distant but normal. Measurement of peak expiratory flow is 60% of predicted. X-rays of the chest are shown. Which of the following is the most likely diagnosis?

A 24-year-old woman, gravida 2, para 1, who is at 22 weeks’ gestation, comes to the office for a prenatal visit. Blood pressure is 100/56 mm Hg. Uterine fundal height is 22 cm and fetal heart rate is 150/min and regular. Urinalysis shows no albumin and no glucose. Toward the end of the visit, the patient asks, “Is it a problem that my husband has an Rh-negative blood type? My first baby had an Rh-negative blood type just like her father and she developed jaundice.” You note from her chart that the patient’s blood group is O, Rh-positive. Given this information, the most appropriate initial step is to do which of the following?

A 40-year-old man with HIV infection comes to the office because of a 7-day history of white patches around the edges of his tongue. He reports no pain or bleeding and says the patches have not interfered with his eating or swallowing. He is regularly seen by another physician, who monitors his HIV status, but he has refused to take any medications thus far because he has been asymptomatic. The patient’s last CD4+ cell count 4 months ago was 225/mm3. He is 183 cm (6 ft) tall and weighs 75 kg (165 lb); BMI is 22 kg/m2. Vital signs today are normal. Physical examination shows small, nontender lymph nodes palpated in his neck and groin. Examination of the mouth shows lesions on the tongue as shown. Which of the following is the most appropriate next step?

An 18-month-old boy is brought to the emergency department by his mother 30 minutes after a choking episode that began while he was eating a candy bar. The mother says that the choking resolved after 5 minutes. The child is not in respiratory distress. No retractions are noted. Vital signs are temperature 37.5°C (99.5°F), pulse 145/min, and respirations 32/min. Pulse oximetry on room air shows an oxygen saturation of 97%. Auscultation of the lungs discloses coarse rhonchi at both lung bases with an end-expiratory wheeze in the right mid lung field. The remainder of the physical examination shows no abnormalities. Chest x-ray is shown. Which of the following is the most appropriate next step in evaluation of this patient?

A 24-year-old woman comes to the office because of a 3-week history of nausea and a fluttering sensation in her chest. Medical history is significant for Graves disease diagnosed 3 years ago and successfully treated with medication. She discontinued the medication after 18 months and currently takes no medications. She is sexually active with one partner and uses condoms “most of the time.” Her last menstrual period was 8 weeks ago. She is alert and fully oriented. Vital signs are temperature 37.0°C (98.6°F), pulse 124/min and regular, respirations 12/min, and blood pressure 124/78 mm Hg. Physical examination discloses hyperreflexia. Results of laboratory studies are shown:

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

A randomized trial is conducted to assess the efficacy of probiotics in the prevention of necrotizing enterocolitis (NEC) in very low birth weight (VLBW) newborns. Of the 500 VLBW newborns enrolled, 250 newborns receive probiotics, and 250 newborns receive placebo. After 3 months, results show the development of NEC among five newborns in the probiotic group, compared with 15 newborns in the placebo group (p<0.05). Which of the following best represents the absolute risk reduction for NEC in VLBW newborns in the probiotic group?

A 43-year-old man with schizophrenia comes to the emergency department because of a 1-day history of auditory hallucinations, which he describes as voices talking about people following him. Medical history is otherwise unremarkable. The patient cannot recall the name of the medication he takes. He had been living in a group residential facility, but he was asked to leave 1 week ago after a physical altercation with another resident. Today, the patient describes his mood as “okay.” He has not had suicidal or homicidal ideation. He is alert and fully oriented, and speech is normal in rate and tone. He appears disheveled and his affect is restricted. BMI is 25 kg/m2. Vital signs are temperature 37.2°C (98.9°F), pulse 72/min, respirations 20/min, and blood pressure 110/80 mm Hg. Physical examination discloses no abnormalities. Urine toxicology screening is negative. Which of the following is the most appropriate pharmacotherapy at this time?

In a recent prospective randomized controlled trial of nonsteroidal anti-inflammatory drugs (NSAIDs), more than 1100 subjects receive aspirin or a placebo for a total of 3 years. At the end of the trial, the subjects undergo colonoscopy screening, which is repeated after a 3- to 5-year interval. The study shows that 27% of the aspirin users had at least one adenoma, whereas 40% of placebo users had at least one adenoma (P<.01). This translated into a relative risk of 0.62 of adenoma in aspirin users. Which of the following is the most accurate interpretation of this study?

A case-control study was conducted to investigate the association between sodium intake and hypertension. The study participants included 200 male and female nurses, ages 40 to 60 years, who are employed in a large health system. At the time of enrollment, each participant’s blood pressure was measured three times. Cases were defined as those with at least one of three blood pressure measurements greater than 140 mm Hg systolic or 90 mm Hg diastolic. The sodium intake of each participant was estimated based on results of a food frequency questionnaire (FFQ). Which of the following features of this study is most likely to compromise generalizability of its results?

A 68-year-old woman is admitted to the hospital because of severe right-sided weakness and declining mental status during the past 24 hours. Medical history is significant for adenocarcinoma of the lung treated with radiation therapy 8 months ago. The patient takes no medications. BMI is 33 kg/m2. Vital signs are temperature 37.1°C (98.8°F), pulse 84/min, respirations 16/min, and blood pressure 144/92 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 93%. The patient is lethargic but able to respond to commands. Physical examination discloses no lymphadenopathy. Cardiopulmonary and abdominal examinations disclose no abnormalities. Muscle strength is 2/5 in the right upper and lower extremities with increased deep tendon reflexes on the right. Strength and reflex testing on the left discloses no abnormalities. MRI of the brain is shown. Which of the following is the most appropriate immediate step in management?

A 14-year-old girl is brought to the office by her mother because of a 5-month history of episodic dizziness. The patient began her freshman year of high school 4 months ago. Since then, she frequently has visited the school nurse and been sent home because of light-headedness. The patient has missed 20 days this school year because of dizziness, headaches, stomachaches, or respiratory symptoms. She previously saw a physician who recently retired from the practice. The new physician reviews the patient’s medical record, which shows a long history of visits for a wide variety of symptoms; previous evaluations found no cause for her symptoms. The mother asks to speak with the physician alone. She is worried and says, “What should we do next? Maybe she needs another brain scan. She is asking to be homeschooled. What do you think?” In addition to expressing concern about the patient, which of the following is the most appropriate physician response?

A 54-year-old woman comes to the office because of a 2-month history of progressive shortness of breath with exertion and swelling of her legs. Her daily activities are limited because of the symptoms. She has not had chest pain or palpitations. She initially attributed the symptoms to the heat because they first appeared when she was vacationing in the coastal northeastern United States during the summer. Eight years ago, she had breast cancer treated with mastectomy, chest radiation, and chemotherapy with cisplatin, docetaxel, and doxorubicin. She now is in remission. She currently takes no medications. Vital signs today are temperature 37.2°C (99.0°F), pulse 105/min, respirations 20/min, and blood pressure 134/78 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Physical examination shows well-healed surgical scars on the chest and bilateral mild pitting edema to the knees. Jugular venous pulse is present 9 cm above the sternal angle and increases with hepatic pressure. Crackles are heard in both lung bases. The point of maximal impulse is not displaced. Echocardiography shows a normal ejection fraction and no focal wall motion abnormalities. Which of the following is the most likely cause of this patient’s current condition?

A 49-year-old man comes to the office because of a 1-week history of fever, increasing abdominal girth, and feeling generally unwell. The patient underwent liver transplantation 5 weeks ago for end-stage liver disease secondary to hepatitis C. Medications are tacrolimus, mycophenolate, and spironolactone. The patient reports taking his medications as prescribed. He does not drink alcoholic beverages. Vital signs are temperature 38.7°C (101.6°F), pulse 105/min, respirations 22/min, and blood pressure 110/68 mm Hg. The liver edge is palpated 3 cm below the right costal margin. There is mild diffuse tenderness to palpation of the abdomen and a positive fluid wave. Results of laboratory studies are shown:

Ultrasonography of the right upper quadrant of the abdomen shows diffuse enlargement of the liver but no focal findings and confirms the presence of ascites. Which of the following is the most likely diagnosis?

A 42-year-old woman comes to the office because of a 3-day history of burning, tingling pain over the right side of her face, right side of her body, and right arm and leg. She says it feels as though microscopic worms have infected her skin. This is her sixth office visit for similar symptoms during the past 6 months; previous visits resulted in no physical diagnosis. Medical history otherwise is unremarkable and she takes no medications. She does not drink alcoholic beverages or use illicit drugs. Vital signs are normal. The patient appears worried and fidgets in her seat. Sensation to pinprick, light touch, and vibration is markedly decreased over the right side of the face and body. Sensation is intact on the left. Proprioception is intact. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?

A 66-year-old Hispanic woman is admitted to the hospital because of a 1-week history of increasing dyspnea on exertion and pedal edema. Medical history is significant for congestive heart failure, type 2 diabetes mellitus, and hypertension. The patient underwent placement of an implantable cardioverter-defibrillator 1 year ago. Echocardiography done 2 months ago showed a left ventricular ejection fraction of 0.25 and moderate mitral regurgitation but no pulmonary hypertension. Current medications are lisinopril, furosemide 40 mg twice daily, metoprolol, spironolactone 25 mg daily, and insulin glargine and aspart. She ran out of her lisinopril 1 week ago while visiting a relative and has not yet refilled the prescription. BMI is 26 kg/m2. Vital signs are temperature 36.6°C (97.8°F), pulse 84/min, respirations 22/min, and blood pressure 114/71 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 88%. There is jugular venous distention to the angle of the jaw. Auscultation of the lungs discloses bilateral basilar crackles and an occasional wheeze. Cardiac examination discloses a displaced and enlarged apical impulse, a paradoxically split S2, and a grade 3/6 holosystolic murmur audible at the apex with radiation to the axilla. ECG is shown. Chest x-ray shows cardiomegaly and pulmonary vascular congestion. Results of laboratory studies are shown:

The patient’s condition responds well to intravenous furosemide therapy, resumption of lisinopril therapy, and continuation of her other medications. Which of the following is the most appropriate next step in management to decrease the number of future hospitalizations and improve mortality in this patient?

A 46-year-old man comes to the emergency department because of a 1-week history of increasingly severe, excruciating low back pain. He says the pain is worst at night, improves slightly with movement, and occasionally radiates down his legs. He has had no muscle weakness, numbness, or tingling. Treatment with ibuprofen has provided only mild relief. Medical history is remarkable for type 2 diabetes mellitus and hypertension. Current medications are lisinopril and metformin. He has smoked two packs of cigarettes daily for the past 20 years and drinks two 12-oz bottles of beer weekly. BMI is 27 kg/m2. He appears to be in severe pain. Vital signs are temperature 37.0°C (98.6°F), pulse 96/min, respirations 16/min, and blood pressure 110/70 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Physical examination shows limited range of motion of the lumbar spine. Pain radiates down the patient’s lower extremities when they are raised off the examination table at a 30-degree angle. Patellar and Achilles deep tendon reflexes are 2+ and equal bilaterally. Babinski sign is absent. Results of serum studies are shown:

An x-ray of the lumbar spine shows multiple blastic lesions. Which of the following is the most likely site of the primary neoplasm in this patient?

An investigator at a state health department is alerted to a potential outbreak of Escherichia coli infection. During the past 6 days, 10 members of a high school swim team have been treated in the emergency department because of diarrhea that developed 3 to 4 days after they ate at a local restaurant. A total of 25 members of the team ate at the restaurant on the same day. The restaurant had received a health code citation 5 years ago because of improper food storage. Which of the following factors most increases the likelihood that this scenario is indicative of a point source outbreak?

A 65-year-old man demands to be discharged from the hospital 3 days after admission for management of atrial fibrillation. The patient say that he is “fine” and that “You people are just trying to kill me.” He accuses the physician and nursing staff of trying to “lock me up for crimes I didn’t commit.” He is observed speaking with unseen persons. On admission, rivaroxaban and metoprolol were initiated; yesterday, the patient had hematemesis and was diagnosed with bleeding gastric ulcers. Intravenous administration of omeprazole was begun. Today, his pulse is 90/min and irregularly irregular, and blood pressure is 100/60 mm Hg. Physical examination shows no other abnormalities. Neurologic examination shows no focal findings. On mental status examination, he is alert and oriented to person but not to place or year. He refuses to answer further questions. Which of the following is the most appropriate next step in management?

A 57-year-old man comes to the clinic for a follow-up examination. He has a 1-month history of intermittent mild headaches, for which he began pharmacotherapy 2 weeks ago. Today, he says the medication relieved his headaches and enabled him to function better, but it also made him dizzy, so he stopped taking it as prescribed. He reports no warning symptoms before the onset of a headache. He says he wants a CT scan of the head because his wife is concerned that his headaches are a sign of a serious condition. Which of the following is the most appropriate physician response to this patient regarding his request for a CT scan?

A 27-year-old woman at 28 weeks’ gestation comes to the emergency department because of severe, sharp, left-sided abdominal pain that began yesterday. Her pregnancy has been normal and she has received regular prenatal care. The pain begins in her left flank and radiates to her groin. She has had no nausea or vomiting. There has been no recent change in bowel habits. The patient has had no previous similar episodes of pain. She had a urinary tract infection 1 year ago. Vital signs now are normal. There is some tenderness of the left costovertebral angle. Results of urinalysis are shown:

Which of the following is the most appropriate approach to treating the patient’s pain?

A 59-year-old man is brought to the emergency department by his wife 40 minutes after the sudden onset of increasing left-sided weakness and 30 minutes after the onset of moderate right-sided headache. Medical history is remarkable for a 5-year history of hypertension and a 10-year history of hypercholesterolemia. Medications are lisinopril and atorvastatin. Vital signs are temperature 37.2°C (99.0°F), pulse 82/min and irregularly irregular, respirations 12/min, and blood pressure 194/106 mm Hg. Pulse oximetry on oxygen at 2 L/min via nasal cannula shows an oxygen saturation of 99%. The patient is drowsy. Physical examination discloses a grade 2/6, right carotid bruit and severe weakness of the left lower aspect of the face. Muscle strength is 3/5 in the left upper and lower extremities. Muscle tone is decreased and deep tendon reflexes are 1+ in the left upper and lower extremities. Babinski sign is present on the left. Sensation to light touch is severely decreased over the left side of the face and body. CT scan of the head without contrast is shown. Which of the following is the most appropriate next step in the management of this patient’s weakness?

A 72-year-old woman comes to the emergency department because of a 1-day history of vomiting that began after she ate at a fast-food restaurant. She has not had abdominal pain, diarrhea, or bleeding. Medical history is remarkable for hypercholesterolemia treated with atorvastatin. BMI is 36 kg/m2. Her temperature is 37.5°C (99.5°F), pulse is 110/min, respirations are 12/min, and blood pressure is 90/65 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Physical examination shows dry axillae. The abdomen is soft and nontender. Arterial blood gas analysis is most likely to show which of the following sets of findings in this patient?

A 72-year-old woman comes to the office because of a 1-week history of generalized weakness and fatigue. She says, “It’s so tiring to feel weak all the time, and I take too many medications.” Medical history is remarkable for chronic kidney disease, systolic heart failure, and coronary artery disease. Current medications are 81-mg aspirin, atorvastatin, carvedilol, furosemide, lisinopril, omeprazole, warfarin and eplerenone, which was added to her medication regimen 2 weeks ago. BMI is 20 kg/m2. Her temperature is 37.1°C (98.8°F), pulse is 100/min, respirations are 20/min, and blood pressure is 106/82 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Physical examination shows diminished deep tendon reflexes. Muscle strength is 4/5 in the upper and lower extremities. ECG is shown. Which of the following is the most likely mechanism of fatigue in this patient?

An institutional review board (IRB) receives a proposal for a study of sexually active young women to evaluate whether regular consumption of a mixed fruit juice beverage can decrease the frequency of urinary tract infections. A total of 300 nonpregnant women aged 18 to 25 years who have been examined at a local gynecology clinic for a confirmed urinary tract infection are targeted for enrollment. Participants will be randomized to consume 12 ounces of mixed fruit juices or an equal amount of bottled water daily with their evening meals for a total of 3 months. Each participant will complete a symptom score log daily and will be asked to record the frequency of sexual contact and weekly number of sexual partners. Participants will be asked to obtain a clean-catch urine sample for delivery to the clinic if their symptom score exceeds a prespecified threshold. Each participant will receive $30 upon completion of the study. The investigators would like to request a waiver of informed consent for the study. Which of the following is the most valid justification for the IRB’s denial of this request?

A 68-year-old white man returns to the office for follow-up of an elevated serum cholesterol concentration that was detected on a screening test. He reports recurrent retrosternal chest pain that is associated with exertion and relieved by rest. The patient has no known history of coronary artery disease. He does not smoke cigarettes. Physical examination shows no abnormalities, and a 12-lead resting ECG shows no evidence of myocardial ischemia or infarction. The physician considers ordering exercise stress testing to screen for coronary artery disease. She recalls a recent report related to the accuracy of exercise stress testing when done for this purpose. In the report, the researchers examined whether ECG during graded treadmill exercise stress testing can predict clinically important (75% or more) coronary artery stenosis as shown by arteriography (the gold standard) in a group of men ages 55 to 75 years with chest pain who were referred to a cardiac center. The prevalence of greater than 75% stenosis in the study group was 53%. In this patient population, the results of exercise stress testing were as follows:

Based on these data, which of the following is the most appropriate conclusion to draw regarding patients with greater than 75% stenosis of a coronary artery?

A 3-year-old girl is admitted to the hospital for evaluation of an abdominal mass discovered by her primary care physician during a surveillance ultrasonography obtained earlier today. Medical history is remarkable for congenital absence of the iris and delayed speech. She receives no medications. The patient is at the 20th percentile for height and 30th percentile for weight; BMI is at the 50th percentile. Temperature is 37.0°C (98.6°F), pulse is 106/min, respirations are 22/min, and blood pressure is 102/72 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 100%. The patient appears healthy. Skin examination discloses no rash. Ophthalmoscopic examination discloses nystagmus and abnormal pupils bilaterally. Lungs are clear to auscultation. Bowel sounds are normoactive; palpation of the abdomen discloses a firm mass in the right flank. Examination of the genitalia discloses no abnormalities. Which of the following is the most likely preliminary diagnosis?

A 2-month-old female infant is brought to the office by her parents because of a lesion on her right upper eyelid that was noticed at birth and has increased in size since that time. The infant was born at term following an uncomplicated pregnancy and spontaneous vaginal delivery. Since birth, she has been exclusively breast-fed and has been gaining weight appropriately. Medical history is unremarkable and the infant receives no medications. She is 57 cm (22.4 in; 50th percentile) long and weighs 5 kg (11 lb; 50th percentile); head circumference is 38 cm (15 in; 50th percentile). Temperature is 37.0°C (98.6°F), pulse is 140/min, respirations are 40/min, and blood pressure is 80/50 mm Hg. Physical examination discloses a well-demarcated erythematous non-blanching nodule that is 1 cm in diameter on the right upper eyelid. There is a tiny area of ulceration and bleeding in the center. A second similar lesion that is 0.5 cm in diameter is noted on the infant’s abdomen. Which of the following factors in this patient’s history or physical examination is most indicative of the need for further evaluation?

A 62-year-old man comes to the clinic with his wife because of a 1-year history of restlessness during sleep. His wife says she first noticed him kicking during sleep; he now has episodes of swinging his arms wildly. She sustained a facial contusion from his arm swinging 3 weeks ago and has been sleeping in a separate room since then. The patient reports a 1-year history of decreased sense of smell. He has inflammatory bowel disease treated with mesalamine. His mother has pernicious anemia, and his father died of cirrhosis. The patient’s vital signs are within normal limits. Examination shows slowness of movement. Which of the following components of the neurologic examination is most likely to confirm the suspected diagnosis in this patient?

A 5-year-old boy is brought to the office by his parents for a physical examination required prior to starting kindergarten. The patient was born at 30 weeks’ gestation via uncomplicated spontaneous vaginal delivery and spent 8 weeks in the neonatal intensive care unit with an uncomplicated course. Medical history is otherwise unremarkable and the patient takes no medications. Vaccinations are up-to-date and required vaccinations for school entry will be administered today. Family history is unremarkable. The child is at the 25th percentile for height and above the 50th percentile for weight. Temperature is 37.3°C (99.1°F), pulse is 86/min, respirations are 24/min, and blood pressure is 115/78 mm Hg (95th percentile for age and height). Ophthalmoscopic examination cannot be done because the patient is uncooperative. Lungs are clear to auscultation. Cardiovascular examination discloses a regular rate and rhythm with no murmur. Brachial and femoral pulses are 2+ and equal. Bowel sounds are active. Abdomen is soft with no masses or organomegaly. Examination of the skin shows no rashes. Which of the following is the most appropriate next step in management?

A 74-year-old man is prepared for discharge from the hospital following treatment for deep venous thrombosis of the left popliteal vein diagnosed on admission 2 days ago. The thrombosis occurred following a long car ride and prolonged inactivity. His condition has been treated with intravenous heparin and his recovery has been uncomplicated. Medical history is remarkable for hypertension, hypercholesterolemia, congestive heart failure, stage 4 chronic kidney disease, and osteoarthritis. Routine medications are metoprolol, atorvastatin, furosemide, acetaminophen, and daily aspirin. BMI is 26 kg/m2. Temperature is 36.9°C (98.4°F), pulse is 70/min, respirations are 16/min, and blood pressure is 138/72 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Physical examination shows edema of the left lower extremity that is markedly decreased from admission. The remainder of the examination discloses no abnormalities. The patient resides in a rural community and must travel approximately 2½ hours to reach his primary care physician’s office for follow-up visits. In addition to fitting the patient’s lower extremities with graduated compression stockings, which of the following is the most appropriate pharmacotherapy to prescribe at this time?

A 50-year-old woman comes to the clinic because of a 6-month history of fatigue, nausea, and increased thirst. She also has had a 23-kg (50-lb) weight gain since being laid off from her job 1 year ago. The physician would like the patient to have blood drawn for laboratory studies. There is a laboratory across the street associated with the physician’s practice, in which the physician became the majority shareholder last week. Which of the following is the most appropriate physician next step regarding this potential conflict of interest?

A 55-year-old woman comes to the emergency department because of a 4-hour history of severe, crampy, nonradiating pain in the right upper quadrant of her abdomen. The pain is associated with mild nausea and chills, but she has not vomited. Antacids and over-the-counter omeprazole have provided no relief of the pain. She has not had similar symptoms previously. Medical history is remarkable for obesity and a hysterectomy. She takes no medications. She has been following a diet and exercise program that has resulted in a 14-kg (30-lb) weight loss during the past 3 months. BMI is 38 kg/m2. Temperature is 39.1°C (102.3°F), pulse is 105/min, respirations are 18/min, and blood pressure is 105/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 95%. The patient appears to be in pain, holding her hands over her upper abdomen. She is alert and fully oriented. Physical examination discloses conjunctival icterus. Abdomen is soft and moderately tender to palpation in the right upper quadrant, with no guarding, rebound tenderness, or masses. Liver edge is not palpable. The remainder of the physical examination discloses no abnormalities. Results of laboratory studies are shown:

Ultrasonography of the abdomen shows a calculus impacted in the gallbladder neck with dilated intrahepatic bile ducts and a normal caliber common bile duct. After initiation of intravenous fluids and piperacillin-tazobactam, which of the following is the most appropriate next step in management?

A 2-month-old male infant is brought to the emergency department by his mother because of 1-day history of blue skin discoloration first noticed by a family friend. The patient’s mother had not noticed the skin discoloration and reports that the infant has been acting normally. He was born at 39 weeks’ gestation via spontaneous vaginal delivery. Postnatal course was uncomplicated. Medical history is unremarkable and his only medication is vitamin D supplementation. His diet consists of powdered formula prepared with water from a private well. The infant is 58 cm (23 in; 50th percentile) long and weighs 5.2 kg (11 lb 8 oz; 40th percentile); head circumference is 39 cm (15 in; 50th percentile). Temperature is 37.1°C (98.8°F), pulse is 110/min, respirations are 24/min, and blood pressure is 82/48 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 88%. The patient appears comfortable. Physical examination shows gray-blue discoloration of the nose, oral mucosa, fingers, and toes. Lungs are clear to auscultation. Cardiac examination discloses no murmur; femoral pulses are normal. Abdomen is soft without organomegaly. Results of laboratory studies are shown:

ECG discloses no abnormalities. Which of the following medications is most appropriate to administer at this time?