USMLE Step 2 Quiz
Practice Renal Replacement Therapy And Urologic Complications in USMLE Step 2 with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.
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A 34-year-old man presents to the emergency department with a 4-hour history of severe, colicky left flank pain that radiates to his groin. He is nauseated and pacing around the room. Urinalysis reveals 3+ blood and 0-2 WBCs per high-power field. His temperature is 37.1°C (98.8°F).
Which of the following is the most appropriate imaging study to confirm the diagnosis?
This quiz focuses on Renal Replacement Therapy And Urologic Complications, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.
Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.
A 34-year-old man presents to the emergency department with a 4-hour history of severe, colicky left flank pain that radiates to his groin. He is nauseated and pacing around the room. Urinalysis reveals 3+ blood and 0-2 WBCs per high-power field. His temperature is 37.1°C (98.8°F).
Which of the following is the most appropriate imaging study to confirm the diagnosis?
Explanation: The patient's presentation is classic for nephrolithiasis. A non-contrast helical CT scan of the abdomen and pelvis is the gold standard for diagnosing kidney stones. It is highly sensitive and specific for detecting stones of all types and sizes, and can also identify signs of obstruction like hydronephrosis. A KUB can miss radiolucent stones (e.g., uric acid stones). Renal ultrasound is good for detecting hydronephrosis but is less sensitive for identifying ureteral stones. Intravenous pyelogram has been largely replaced by CT due to risks of contrast nephropathy and lower diagnostic accuracy.
A 58-year-old man is two hours into a hemodialysis session when he complains of sudden lightheadedness and nausea. His blood pressure, which was 150/90 mmHg at the start of the session, is now 85/50 mmHg. His heart rate is 110/min.
Which of the following is the most appropriate immediate action?
Explanation: Intradialytic hypotension is the most common complication of hemodialysis, typically caused by rapid removal of fluid (ultrafiltration) exceeding the plasma refilling rate. The immediate management is to decrease or temporarily stop ultrafiltration and administer an intravenous bolus of isotonic saline to restore intravascular volume. Increasing the ultrafiltration rate would worsen the hypotension. Midodrine is used for prevention, not acute treatment. Stopping the session is a last resort if the patient does not respond to initial measures.
A 42-year-old woman with a history of recurrent kidney stones undergoes a non-contrast CT scan for acute flank pain. The scan reveals a 4-mm stone in the distal left ureter without evidence of significant hydronephrosis. She is afebrile and her pain is controlled with oral analgesics.
Which of the following is the most appropriate management for this patient?
Explanation: For small (<10 mm), uncomplicated ureteral stones, medical expulsive therapy is the first-line treatment. This typically includes adequate hydration, pain control with NSAIDs, and an alpha-blocker like tamsulosin to relax the ureteral smooth muscle and facilitate stone passage. Invasive procedures like ESWL or ureteroscopy are reserved for larger stones, uncontrolled pain, or signs of obstruction or infection. A nephrostomy tube is an intervention for severe obstruction and is not indicated here.
A 70-year-old woman with a history of metastatic breast cancer presents with nausea, weakness, and anuria for the past 36 hours. Her serum creatinine is 6.2 mg/dL and potassium is 6.8 mEq/L. A Foley catheter is placed and drains only 50 mL of urine. A renal ultrasound shows bilateral severe hydronephrosis.
Which of the following is the most appropriate next step in management?
Explanation: This patient has anuric acute kidney injury due to bilateral ureteral obstruction, likely from her metastatic cancer. Since a Foley catheter did not relieve the obstruction, the blockage is located in the upper urinary tract (ureters). The definitive and urgent treatment is to bypass the obstruction and decompress the collecting systems. This is achieved with bilateral percutaneous nephrostomy tubes or ureteral stents. While she has hyperkalemia that needs treatment (calcium gluconate, insulin), the underlying cause must be addressed. Hemodialysis may be required, but relieving the obstruction is the primary intervention.
A 68-year-old woman has been on hemodialysis for 16 years. She presents with a chief complaint of chronic, progressive pain and stiffness in both of her shoulders. She also has a history of bilateral carpal tunnel syndrome requiring surgical release. Physical examination reveals limited range of motion of the shoulders.
This patient's condition is most likely due to the deposition of which of the following substances?
Explanation: This clinical picture is characteristic of dialysis-related amyloidosis, a long-term complication of hemodialysis. It is caused by the accumulation and deposition of beta-2 microglobulin, a protein that is poorly cleared by conventional dialysis membranes. Deposition in osteoarticular structures leads to scapulohumeral periarthritis (shoulder pain), carpal tunnel syndrome, and destructive spondyloarthropathy. The risk increases significantly with the duration of dialysis.
A 38-year-old woman presents to the emergency department with a fever of 39.2°C (102.6°F), chills, and severe right flank pain. Urinalysis is positive for leukocyte esterase, nitrites, and numerous WBCs. A non-contrast CT scan shows a 9-mm calculus at the right ureteropelvic junction with moderate hydronephrosis.
In addition to intravenous fluid resuscitation and broad-spectrum antibiotics, which of the following is the most urgent intervention?
Explanation: This patient has an obstructing kidney stone complicated by infection (obstructive pyelonephritis), which is a urologic emergency. The infection cannot be cleared effectively in the presence of an obstruction. Therefore, urgent decompression of the urinary tract is required. This is accomplished by either placing a ureteral stent via cystoscopy or a percutaneous nephrostomy tube. Definitive stone treatment like ESWL is contraindicated in the setting of an active infection and is performed after the infection has been controlled.
A 72-year-old man with a history of BPH had a Foley catheter placed for acute urinary retention with a post-void residual of 900 mL. His initial creatinine was 4.1 mg/dL. Over the subsequent 6 hours, his urine output has been 2.4 liters. He now complains of dizziness when standing. His blood pressure is 100/65 mmHg, down from 140/80 mmHg on admission. Laboratory studies show a serum sodium of 132 mEq/L.
Which of the following is the most appropriate management for this patient's high urine output?
Explanation: This patient is experiencing post-obstructive diuresis, a polyuric phase that follows the relief of a prolonged bilateral urinary tract obstruction. It is driven by an osmotic diuresis from retained urea and other solutes, as well as impaired tubular concentrating ability. The massive fluid and electrolyte loss can lead to severe volume depletion, hypotension, and electrolyte abnormalities. Management involves careful monitoring and replacement of a portion (e.g., 50-75%) of the urinary losses with intravenous fluids, typically hypotonic saline (0.45% saline) to avoid hypernatremia.
A 56-year-old man with acute kidney injury has a serum potassium of 7.2 mEq/L with peaked T waves on ECG, a pH of 7.15 with a bicarbonate of 10 mEq/L, and marked fluid overload with pulmonary edema unresponsive to diuretics. On examination, a pericardial friction rub is auscultated.
Which of the following findings is the most absolute and urgent indication for initiating renal replacement therapy?
Explanation: All the listed options are indications for urgent renal replacement therapy (the 'AEIOU' mnemonic: Acidosis, Electrolytes, Intoxication, Overload, Uremia). However, uremic pericarditis, manifested by a pericardial friction rub, is considered an absolute and life-threatening indication that requires immediate dialysis to prevent progression to cardiac tamponade. While severe hyperkalemia with ECG changes is also a medical emergency requiring immediate treatment (including dialysis), the development of pericarditis signifies a severe systemic uremic state that must be addressed without delay.
A 25-year-old construction worker presents to the emergency department after a syncopal episode at work on a hot day. He has severe right flank pain. His temperature is 37.0°C (98.6°F), blood pressure is 100/60 mmHg, and heart rate is 115/min. A non-contrast CT scan shows a 12-mm stone in the right proximal ureter with severe hydronephrosis. His creatinine is 2.5 mg/dL.
Which of the following is the most appropriate next step in management?
Explanation: This patient has an obstructing kidney stone that is large (>10 mm) and is associated with signs of severe obstruction (severe hydronephrosis), acute kidney injury, and hemodynamic instability (hypotension, tachycardia likely due to dehydration and pain/vasovagal response). These are indications for urgent urologic intervention to relieve the obstruction. Ureteroscopy allows for direct visualization of the stone, its removal (e.g., with a laser), and placement of a stent to ensure drainage. Medical expulsive therapy is not appropriate for large stones or complicated presentations. ESWL is less effective for proximal ureteral stones and is not typically performed emergently.
A 30-year-old man presents with intermittent, severe left flank pain. A CT scan reveals a 2.5-cm staghorn calculus in the left renal pelvis. His urine culture is negative, and his renal function is normal.
Which of the following is the most appropriate treatment for this patient's kidney stone?
Explanation: Large, complex stones, such as staghorn calculi (>2 cm) filling the renal pelvis and calyces, require surgical removal. Percutaneous nephrolithotomy (PCNL) is the treatment of choice for these stones. This procedure involves creating a tract from the skin directly into the kidney to allow for fragmentation and removal of the stone. ESWL and ureteroscopy are less effective for such a large stone burden and are associated with lower stone-free rates and the need for multiple procedures. Medical therapy is not effective for stones of this size.
A 60-year-old diabetic patient on peritoneal dialysis develops peritonitis that is refractory to 5 days of appropriate intraperitoneal antibiotic therapy. His peritoneal fluid cell count remains elevated, and he continues to have abdominal pain and fever.
Which of the following is the most appropriate next step in management?
Explanation: Refractory peritonitis, defined as failure to improve after 5 days of appropriate antibiotic therapy, is a key indication for removal of the peritoneal dialysis catheter. Continuing PD in this setting can lead to severe complications, including abscess formation and encapsulating peritoneal sclerosis. The source of the infection (the catheter) must be removed. The patient will need to be transitioned to hemodialysis, usually via a temporary central venous catheter, until the infection resolves and a decision can be made about future RRT.
A 45-year-old woman on continuous ambulatory peritoneal dialysis (CAPD) for the past three years presents with a two-day history of diffuse abdominal pain, fever, and nausea. She notes that the dialysis fluid she drained this morning was cloudy. On examination, she has a temperature of 38.5°C (101.3°F) and diffuse abdominal tenderness with rebound.
After sending a sample of the peritoneal fluid for analysis, which of the following is the most appropriate next step?
Explanation: The clinical presentation is highly suggestive of PD-associated peritonitis. The standard of care is to promptly initiate empiric intraperitoneal antibiotics after obtaining a fluid sample for cell count, Gram stain, and culture. Intraperitoneal administration achieves high local concentrations and is more effective than intravenous administration for this condition. Catheter removal is reserved for refractory or fungal peritonitis. A CT scan is not necessary for the initial diagnosis.
A 65-year-old man who has been receiving hemodialysis for 8 years through a left arm arteriovenous fistula presents with progressive pain, swelling, and tingling in his left hand that worsens during dialysis sessions. On examination, the fingers of his left hand are cool and pale with delayed capillary refill compared to the right hand. A bruit and thrill are present over the fistula.
Which of the following is the most likely diagnosis?
Explanation: This patient's symptoms are classic for dialysis access-associated steal syndrome. The high flow through the arteriovenous fistula shunts an excessive amount of blood away from the distal extremity, causing ischemia, particularly when the fistula flow is at its maximum during dialysis. Symptoms include pain, coolness, pallor, and paresthesias. Fistula thrombosis would present with loss of the thrill and bruit. Central venous stenosis typically causes swelling of the entire arm. Carpal tunnel syndrome would not typically cause coolness and pallor.
A physician is explaining the differences between hemodialysis and peritoneal dialysis to a 50-year-old patient with type 2 diabetes and end-stage renal disease. The patient is particularly concerned about metabolic control.
Compared to a patient on standard in-center hemodialysis, a patient on continuous ambulatory peritoneal dialysis is at a significantly higher risk for which of the following metabolic disturbances?
Explanation: Peritoneal dialysis utilizes a dialysate solution containing high concentrations of dextrose to create an osmotic gradient for fluid removal (ultrafiltration). The continuous absorption of this glucose load across the peritoneal membrane can lead to significant hyperglycemia, weight gain, and hypertriglyceridemia. In contrast, hemodialysis is intermittent, and problems like hyperkalemia and metabolic acidosis are more likely to build up between sessions. Both modalities manage calcium and phosphate levels, but the glucose load is a unique and prominent feature of PD.
A 59-year-old man on peritoneal dialysis for 9 years presents with a 4-month history of progressive anorexia, early satiety, and intermittent, crampy abdominal pain. He has had a 10-kg weight loss. He has not had a fever or cloudy dialysate. An abdominal X-ray shows dilated loops of small bowel.
Which of the following is the most likely diagnosis?
Explanation: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of long-term peritoneal dialysis. It involves the formation of a dense fibrocollagenous membrane that encases the small bowel, leading to chronic inflammation and symptoms of bowel obstruction, including nausea, vomiting, pain, and malnutrition. The greatest risk factor is the duration of peritoneal dialysis. His presentation is subacute/chronic, making acute issues like volvulus or ischemic colitis less likely, and the absence of fever or cloudy fluid argues against typical peritonitis.
A 62-year-old woman with end-stage renal disease secondary to diabetes is starting renal replacement therapy. She is highly motivated, wishes to maintain her independence and current employment, and has no history of abdominal surgeries. She expresses a desire to minimize visits to a medical facility.
Which of the following is the most suitable long-term renal replacement therapy for this patient?
Explanation: Peritoneal dialysis (PD) is an excellent option for motivated patients who want to manage their own care and maintain a flexible lifestyle. It can be performed at home, which aligns with her desire to minimize facility visits. Her lack of prior abdominal surgeries makes her a good candidate. In-center hemodialysis requires travel to a dialysis unit three times a week. While transplantation is the ultimate goal, it is not an immediate option and requires a suitable donor and extensive workup. Nocturnal HD is less common and still requires travel to a center.
A 55-year-old man with a tunneled hemodialysis catheter develops a fever of 39.0°C (102.2°F) and rigors during his dialysis session. He is hemodynamically stable. Blood cultures are drawn from the catheter and a peripheral vein. Empiric intravenous vancomycin and cefepime are started.
Which of the following is the most appropriate next step in managing this patient's catheter?
Explanation: The patient has a suspected catheter-related bloodstream infection (CRBSI). In patients with a tunneled dialysis catheter and signs of sepsis, prompt removal of the catheter is indicated in addition to systemic antibiotics. Waiting for culture results can lead to delays in source control and worse outcomes. Guidewire exchange is not recommended for CRBSI because it does not eradicate the infection along the subcutaneous tract. A new temporary catheter should be placed at a different site until the infection is cleared.
A 48-year-old woman with end-stage renal disease receives a living-related kidney transplant. On postoperative day 5, her urine output decreases, and her serum creatinine rises from 1.5 mg/dL to 2.5 mg/dL. A renal ultrasound with Doppler is performed.
The primary purpose of the ultrasound with Doppler in this setting is to rule out which of the following complications?
Explanation: In the immediate post-transplant period, a sudden rise in creatinine and decrease in urine output should prompt evaluation for surgical or technical complications. A renal ultrasound with Doppler is the initial imaging test of choice to assess for urologic complications like ureteral obstruction (which would show hydronephrosis) and vascular complications like renal artery or vein thrombosis (which would show abnormal blood flow). While acute rejection, drug toxicity, and viral nephropathy are on the differential for allograft dysfunction, they are diagnoses of exclusion after ruling out these urgent mechanical and vascular problems.
A 78-year-old man with a history of benign prostatic hyperplasia presents to the emergency department with a 24-hour history of inability to urinate and lower abdominal discomfort. His vital signs are stable. On examination, he has a distended, tender suprapubic mass. Laboratory studies show a serum creatinine of 2.8 mg/dL, which was 1.1 mg/dL six months ago. His prostate is enlarged and smooth on digital rectal examination.
Which of the following is the most appropriate initial step in management?
Explanation: This patient presents with acute urinary retention secondary to benign prostatic hyperplasia, leading to postrenal acute kidney injury. The most appropriate initial step is to relieve the obstruction, which is both diagnostic and therapeutic. Insertion of a Foley catheter will decompress the bladder, alleviate the patient's symptoms, and allow for recovery of renal function. Ultrasound would be the next step if catheterization is unsuccessful or if an upper tract obstruction is suspected. Tamsulosin is used for chronic management but is not the initial treatment for acute retention. Hemodialysis is not indicated unless there are life-threatening complications of renal failure that persist after the obstruction is relieved.
A 67-year-old man with end-stage renal disease is undergoing his first hemodialysis treatment. His pre-dialysis BUN was 150 mg/dL. Near the end of the session, he becomes disoriented and complains of a severe headache and nausea. He then has a generalized tonic-clonic seizure.
This patient's condition is most likely caused by which of the following mechanisms?
Explanation: This patient is experiencing dialysis disequilibrium syndrome (DDS), a neurologic complication that occurs most often in patients undergoing their first few dialysis treatments, especially when the pre-dialysis BUN is very high. Hemodialysis removes urea from the blood much faster than it can be cleared from the brain. This creates an osmotic gradient that pulls water into the brain, causing cerebral edema, increased intracranial pressure, and the resulting neurologic symptoms. It is prevented by using shorter, less efficient dialysis sessions initially.