Free USMLE Step 2 CK: Clinical Knowledge Exam Questions and Answers

A 78-year-old woman comes to the physician for a routine health maintenance examination. She feels well, walks 2 miles daily, and has never smoked. She takes no medications. Vital signs are within normal limits. Cardiopulmonary examination shows no abnormalities. Spirometry and lung volume measurements are obtained. Compared with the values expected in a healthy 30-year-old, which of the following sets of changes is most likely in this patient?

• AA. Decreased FEV1 and decreased residual volume
• BB. Decreased FEV1 and increased residual volume
• CC. Unchanged FEV1 and decreased total lung capacity
• DD. Increased FEV1/FVC ratio and increased total lung capacity
• EE. Increased FVC and decreased functional residual capacity

A 72-year-old man is evaluated on the eighth hospital day because of decreased urine output. He was admitted with pneumonia and has been receiving intravenous gentamicin and ceftriaxone. Medical history includes hypertension treated with lisinopril. Temperature is 37.2°C (99°F), pulse is 84/min, and blood pressure is 128/76 mm Hg. Examination shows no edema and moist mucous membranes. Laboratory studies show: Serum creatinine on admission: 1.0 mg/dL Serum creatinine today: 2.8 mg/dL Urine sodium: 62 mEq/L Urine osmolality: 310 mOsm/kg H2O Fractional excretion of sodium: 3.2% Urinalysis shows brown granular casts. Which of the following is the most likely diagnosis?

• AA. Acute tubular necrosis
• BB. Acute interstitial nephritis
• CC. Rapidly progressive glomerulonephritis
• DD. Prerenal azotemia
• EE. Obstructive uropathy

A 72-year-old man comes to the physician because of a 3-week history of bleeding gums and easy bruising. He is a widower who lives alone and eats mainly tea, bread, and canned soup. He says he has not eaten fresh fruit or vegetables for several months. A 2-cm surgical scar from a hernia repair 2 months ago reopened last week. Examination shows swollen, friable gingiva, perifollicular hemorrhages with coiled hairs on both legs, and scattered ecchymoses. Hemoglobin concentration is 10.2 g/dL, platelet count is 260,000/mm³, and prothrombin time and partial thromboplastin time are within the reference ranges. Supplementation with which of the following is most appropriate?

• AA. Vitamin K
• BB. Vitamin C
• CC. Folate
• DD. Vitamin B12
• EE. Niacin

A 72-year-old woman who speaks only Vietnamese is admitted to the hospital for newly diagnosed atrial fibrillation. The physician plans to discuss starting anticoagulation, including bleeding risks and monitoring. The patient's 19-year-old grandson, who is at the bedside, says he speaks both languages and offers to interpret. The hospital's telephone and video interpreter services are available. Which of the following is the most appropriate action by the physician?

• AA. Use a qualified medical interpreter for the discussion
• BB. Use a machine translation application on the physician's smartphone
• CC. Use a hospital staff member who speaks some Vietnamese and is on the unit
• DD. Provide written instructions in English for the grandson to review with the patient
• EE. Ask the grandson to interpret and have the patient repeat back the key points

A new screening test for a disease has a sensitivity of 90% and a specificity of 95%. The test is used to screen 1000 asymptomatic adults from a population in which the prevalence of the disease is 2%. A woman from this population has a positive test result. Which of the following is the approximate probability that she has the disease?

• AA. 9%
• BB. 18%
• CC. 27%
• DD. 49%
• EE. 90%

A new blood test for pancreatic cancer is introduced into a screening program. After 10 years, the 5-year survival from the time of diagnosis is longer among screened patients than among unscreened patients, but the age at death and the overall mortality rate are the same in both groups. Which of the following biases best explains the apparent survival benefit?

• AA. Length-time bias
• BB. Lead-time bias
• CC. Recall bias
• DD. Selection bias
• EE. Confounding

A 72-year-old man with metastatic pancreatic cancer is admitted with pneumonia and progressive hypoxemia. He is now somnolent and cannot participate in decisions. Three months ago he completed a written advance directive stating that he does not want intubation or mechanical ventilation under any circumstances. His wife is his designated health care proxy. She says, "I can't lose him. Do everything, including the breathing machine." His two adult children say they support their mother. Which of the following is the most appropriate action?

• AA. Follow the majority view of the wife and adult children
• BB. Honor the advance directive and withhold intubation
• CC. Intubate now and withdraw ventilation if there is no improvement
• DD. Intubate according to the wife's wishes as health care proxy
• EE. Obtain a court order appointing a legal guardian

A 68-year-old man is evaluated in the intensive care unit because of decreasing urine output on the third day of hospitalization for septic shock from a perforated diverticulum. He required norepinephrine for 36 hours with a lowest mean arterial pressure of 52 mm Hg and has received piperacillin-tazobactam since admission. His serum creatinine was 1.0 mg/dL on admission and is now 3.4 mg/dL. He has no rash or fever beyond the septic episode. Bladder scan shows 40 mL of urine. Renal ultrasonography shows normal-sized kidneys without hydronephrosis. Urine studies show a sodium of 62 mEq/L, osmolality of 305 mOsm/kg, and fractional excretion of sodium of 3.2%. Urinalysis shows many muddy brown granular casts and no white blood cell casts or eosinophils. Which of the following is the most likely cause of this patient's kidney injury?

• AA. Prerenal azotemia
• BB. Rapidly progressive glomerulonephritis
• CC. Obstructive uropathy
• DD. Acute tubular necrosis
• EE. Acute interstitial nephritis

A 19-year-old man is undergoing an emergency appendectomy under general anesthesia with sevoflurane. Succinylcholine was used for intubation. Twenty minutes into the procedure, the anesthesiologist notes that end-tidal carbon dioxide has risen to 78 mm Hg despite increased minute ventilation. Temperature is 39.6°C (103.3°F), pulse is 142/min, and blood pressure is 150/90 mm Hg. The jaw and limbs are rigid. The urine in the collection bag is dark brown. Volatile anesthetic delivery is stopped and 100% oxygen is administered. Which of the following is the most appropriate pharmacotherapy?

• AA. Dantrolene
• BB. Cyproheptadine
• CC. Acetaminophen
• DD. Lorazepam
• EE. Bromocriptine

A 77-year-old woman is admitted to the hospital with a massive intracerebral hemorrhage and is unresponsive. The treatment team recommends transition to comfort-focused care. Her husband of 50 years and two adult daughters insist that all life-sustaining measures continue. A review of her chart shows a notarized durable power of attorney for health care signed 3 years ago naming her longtime friend, Ms. Alvarez, as her agent. The document states that she would not want prolonged mechanical ventilation if she had no reasonable chance of recovering independence. Ms. Alvarez is at the bedside and agrees with the team's recommendation. Which of the following is the most appropriate decision maker for the patient's care?

• AA. Ms. Alvarez
• BB. Her older daughter
• CC. Her husband
• DD. A court-appointed guardian
• EE. The hospital ethics committee