Renal
Renal
Renal
Renal
Renal
100
Which of the following is the leading cause of chronic kidney disease in North America?
A. Autosomal dominant polycystic kidney disease
B. Contrast nephropathy
C. Diabetic nephropathy
D. Focal segmental glomerulosclerosis
E. Recurrent renal calculi
The answer is C. It has been estimated from population data that at least 6% of the adult population in the United States has chronic kidney disease (CKD) at stages 1 and 2. An additional 4.5% of the U.S. population is estimated to have stages 3 and 4 CKD. Table VI-10 lists the five most frequent categories of causes of CKD, cumulatively accounting for >90% of the CKD disease burden worldwide. The relative contribution of each category varies among different geographic regions. The most frequent cause of CKD in North America and Europe is diabetic nephropathy, most often secondary to type 2 diabetes mellitus. Patients with newly diagnosed CKD often have hypertension. When no overt evidence for a primary glomerular or tubulointerstitial kidney disease process is present, CKD is frequently attributed to hypertension. However, it is now appreciated that such individuals can be considered in two categories. The first includes patients with a subclinical primary glomerulopathy, such as focal segmental or global glomerulosclerosis. The second includes patients in whom progressive nephrosclerosis and hypertension is the renal correlate of a systemic vascular disease, often also involving large- and small-vessel cardiac and cerebral pathology.
100
All of the following medications can cause acute interstitial nephritis EXCEPT:
A. Celecoxib
B. Hydromorphone
C. Pantoprazole
D. Penicillin
E. Valproate
The answer is B.(Chap. 310) Although biopsy-proven acute interstitial nephritis (AIN) accounts for no more than ~15% of cases of unexplained acute renal failure, this is likely a substantial underestimate of the true incidence (Table VI-33). This is because potentially offending medications are more often identified and empirically discontinued in a patient noted to have a rising serum creatinine, without the benefit of a renal biopsy to establish the diagnosis of AIN. The classic presentation of AIN, namely, fever, rash, peripheral eosinophilia, and oliguric renal failure occurring after 7–10 days of treatment with methicillin or another β-lactam antibiotic, is the exception rather than the rule. More often, patients are found incidentally to have a rising serum creatinine or present with symptoms attributable to acute renal failure. All of the listed drugs except hydromorphone have been associated with AIN. Opiates are not known to cause AIN.
100
Which of the following clinical features is characteristic of patients with nephropathy due to type 1 diabetes?
A. Kidney size is reduced
B. Most patients also have diabetic retinopathy
C. Proteinuria is uncommon
D. Renal failure occurs within 1–2 years after the onset of proteinuria
E. Urinalysis shows red blood cell casts
The answer is B.(Chap. 308) Proteinuria in frank diabetic nephropathy can be variable, ranging from 500 mg to 25 g per 24 hours, and it is often associated with nephrotic syndrome. The proteinuria is not typically associated with red blood cell casts. More than 90% of patients with type 1 diabetes and nephropathy have diabetic retinopathy, so the absence of retinopathy in type 1 patients with proteinuria should prompt consideration of a diagnosis other than diabetic nephropathy; only 60% of patients with type 2 diabetes with nephropathy have diabetic retinopathy. Also, characteristically, patients with advanced diabetic nephropathy have normal to enlarged kidneys, in contrast to many other glomerular diseases where kidney size is usually decreased. After the onset of proteinuria, renal function inexorably declines, with 50% of patients reaching renal failure over another 5–10 years; thus, from the earliest stages of microalbuminuria, it usually takes 10–20 years to reach end-stage renal disease.
100
The use of which of the following medications can precipitate AKI in a patient with renal artery stenosis:
A. corticosteroids
b. angiotensin II receptor antagonist
c. beta adrenergic antagonist
d. cephalosporins
b. angiotensin II receptor antagonist
100
The most likely causative organism in community acquired UTI in women during reproductive years is:
A. Klebsilla species
b. Proteus mirabilis
c. E coli
d. Staphylococcus saprophyticus
c. E coli
200
Which of the following is the most common acute complication of hemodialysis?
A. Anaphylactoid reactions to dialyzer
B. Bleeding from access site
C. Hypertension
D. Hypotension
E. Muscle cramps
The answer is D. Hypotension is the most common acute complication of hemodialysis, particularly among patients with diabetes mellitus. Numerous factors appear to increase the risk of hypotension, including excessive ultrafiltration with inadequate compensatory vascular filling, impaired vasoactive or autonomic responses, osmolar shifts, overzealous use of antihypertensive agents, and reduced cardiac reserve. Hypotension during dialysis can frequently be prevented by careful evaluation of the dry weight and by ultrafiltration modeling, such that more fluid is removed at the beginning rather than the end of the dialysis procedure. Excessively rapid fluid removal (>13 mL/kg per hour) should be avoided, as rapid fluid removal has been associated with adverse outcomes, including cardiovascular deaths. Additional maneuvers to prevent intradialytic hypotension include the performance of sequential ultrafiltration followed by dialysis, cooling of the dialysate during dialysis treatment, and avoiding heavy meals during dialysis. Muscle cramps during dialysis are also a common complication. The etiology of dialysis-associated cramps remains obscure. Changes in muscle perfusion because of excessively rapid volume removal or targeted removal below the patient’s estimated dry weight often precipitate dialysis-associated cramps. Strategies that may be used to prevent cramps include reducing volume removal during dialysis, ultrafiltration profiling, and the use of sodium modeling. Anaphylactoid reactions to the dialyzer, particularly on its first use, have been reported most frequently with the bioincompatible cellulosic-containing membranes. Dialyzer reactions can be divided into two types, A and B. Type A reactions are attributed to an IgE-mediated intermediate hypersensitivity reaction to ethylene oxide used in the sterilization of new dialyzers. This reaction typically occurs soon after the initiation of a treatment (within the first few minutes) and can progress to full-blown anaphylaxis if the therapy is not promptly discontinued. The type B reaction consists of a symptom complex of nonspecific chest and back pain, which appears to result from complement activation and cytokine release. These symptoms typically occur several minutes into the dialysis run and typically resolve over time with continued dialysis.
200
A 48-year-old man with diabetes mellitus, hyperlipidemia, and atrial fibrillation presents to the emergency department for evaluation of left flank pain and groin pain that has been severe and present for approximately 3 hours. His medications include metformin, atorvastatin, and warfarin. He is uncomfortable and has a temperature of 37°C (98.6°F), heart rate of 105 beats/min, blood pressure of 145/95, respiratory rate of 21 breaths/min, and room air oxygen saturation of 98%. His physical examination is notable for left flank pain but no abdominal organomegaly or focal tenderness. An electrocardiogram shows sinus tachycardia with nonspecific ST-T wave changes. International normalized ratio is 2.0. His renal function is normal, and urine analysis shows many red blood cells, few white blood cells, no bacteria, and no crystals. Which of the following is the preferred diagnostic study?
A. 24-Hour urine collection
B. Cystoscopy
C. MRI
D. Noncontrast CT scan
E. Ultrasound
The answer is D.(Chap. 312) This patient has a typical clinical, laboratory, and radiologic presentation of nephrolithiasis. The CT shows a 10-mm obstructing calculus in the distal left ureter at the level of S1 and another 6-mm stone in the interpolar region of the left kidney. There is also left hydronephrosis and perinephric fat stranding. At present, there are no widely accepted, evidence-based guidelines for the evaluation and treatment of nephrolithiasis. The diagnosis is often made based on the history, physical examination, and urinalysis. Thus, it may not be necessary to wait for radiographic confirmation before treating the symptoms. The diagnosis is confirmed by an appropriate imaging study, preferably helical CT, which is highly sensitive, allows visualization of uric acid stones (traditionally considered “radiolucent”), and is able to avoid radiocontrast. Helical CT detects stones as small as 1 mm that may be missed by other imaging modalities. Typically, helical CT reveals a ureteral stone or evidence of recent passage (e.g., perinephric stranding or hydronephrosis), whereas a plain abdominal radiograph (kidney/ureter/bladder) can miss a stone in the ureter or kidney, even if it is radiopaque, and does not provide information on obstruction. Abdominal ultrasound offers the advantage of avoiding radiation and provides information on hydronephrosis, but it is not as sensitive as CT and images only the kidney and possibly the proximal segment of the ureter; thus, most ureteral stones are not detectable by ultrasound. Urologic intervention, such as cystoscopy, should be postponed unless there is evidence of a urinary tract infection (UTI), a low probability of spontaneous stone passage (e.g., a stone measuring ≥6 mm or an anatomic abnormality), or intractable pain. A ureteral stent may be placed cystoscopically, but this procedure typically requires general anesthesia, and the stent can be quite uncomfortable, may cause gross hematuria, and may increase the risk of UTI. Many patients who experience their first episode of colic seek emergent medical care. Randomized trials have demonstrated that parenterally administered nonsteroidal anti-inflammatory drugs (such as ketorolac) are just as effective as opioids in relieving symptoms and have fewer side effects. Excessive fluid administration has not been shown to be beneficial; therefore, the goal should be to maintain euvolemia. Use of an alpha blocker may increase the rate of spontaneous stone passage.
200
Which segment of the kidney reabsorbs the highest percentage of filtered sodium chloride?
A. Collecting duct
B. Distal convoluted tubule
C. Loop of Henle
D. Proximal convoluted tubule
The answer is D.(Chap. 303) The proximal tubule is responsible for reabsorbing ~60% of filtered sodium chloride (NaCl) and water, as well as ~90% of filtered bicarbonate and most critical nutrients such as glucose and amino acids. The proximal tubule uses both cellular and paracellular transport mechanisms. The apical membrane of proximal tubular cells has an expanded surface area available for reabsorptive work created by a dense array of microvilli called the brush border, and leaky tight junctions enable high-capacity fluid reabsorption. Approximately 15–25% of filtered NaCl is reabsorbed in the loop of Henle, mainly by the thick ascending limb. The distal convoluted tubule reabsorbs ~5% of the filtered NaCl. This segment is composed of a tight epithelium with little water permeability. The collecting duct modulates the final composition of urine. The two major divisions, the cortical collecting duct and inner medullary collecting duct, contribute to reabsorbing ~4–5% of filtered Na+ and are important for hormonal regulation of salt and water balance.
200
Creatinine clearance usually:
A. approximates GFR
b. does not change as part of normative aging
c. in greater in women compared to men
d. increases w/ hypotension
A. approximates GFR
200
You see a 35 year old female with an uncomplicated UTI. She is otherwise healthy and reports allergy to sulfa. appropriate therapy would include:
A. TMP-SMX
B. AMOXICILLIN
C. AZITHROMYCIN
D. NITROFURANTOIN
D. NITROFURANTOIN
300
Which of the following interventions has been shown to decrease the recurrence of calcium oxalate renal stones?
A. A diet with abundant spinach and rhubarb
B. Aspirin
C. Low-calcium diet (400 mg/day)
D. Thiazide diuretics
E. Vitamin C supplements
The answer is D.(Chap. 312) Risk factors for calcium oxalate stones include higher urine calcium, higher urine oxalate, and lower urine citrate. Individuals with higher urine calcium excretion tend to absorb a higher percentage of ingested calcium. Nevertheless, dietary calcium restriction is not beneficial and, in fact, is likely to be harmful. In a randomized trial in men with high urine calcium and recurrent calcium oxalate stones, a diet containing 1200 mg of calcium and a low intake of sodium and animal protein significantly reduced subsequent stone formation from that with a low-calcium diet (400 mg/d). A thiazide diuretic, in doses higher than those used to treat hypertension, can substantially lower urine calcium excretion. Several randomized controlled trials have demonstrated that thiazide diuretics, most commonly chlorthalidone, can reduce calcium oxalate stone recurrence by ~50%. A reduction in urine oxalate will in turn reduce the supersaturation of calcium oxalate. In patients with the common form of nephrolithiasis, avoiding high-dose vitamin C supplements is the only known strategy that reduces endogenous oxalate production. Oxalate is a metabolic end product; therefore, any dietary oxalate that is absorbed will be excreted in the urine. Spinach, rhubarb, beer, and chocolate are all rich in oxalate. Aspirin has no known effect on nephrolithiasis.
300
A 33-year-old woman with recently treated acute myelogenous leukemia now in remission is admitted to the hospital with lethargy, fever, and tachycardia. Blood cultures grow Pseudomonas that is resistant to cefepime. She is started on IV gentamicin. Five days after starting gentamicin, her serum creatinine rises from her baseline of 1.0 mg/dL to 2.4 mg/dL. No red or white cell casts are seen on her urinalysis. Her magnesium level is decreased at 1.5 mg/dL. Renal ultrasound is unremarkable with no hydronephrosis. Which of the following is the most likely mechanism of her acute kidney injury?
A. Acute interstitial nephritis
B. Acute tubular necrosis
C. Glomerulonephritis
D. Ischemic injury
E. Obstruction
The answer is B.(Chap. 304) Several antimicrobial agents are commonly associated with acute kidney injury (AKI). Aminoglycosides (e.g., gentamicin) and amphotericin B both cause tubular necrosis. Nonoliguric AKI (i.e., with a urine volume >400 mL/day) accompanies 10–30% of courses of aminoglycoside antibiotics, even when plasma levels are in the therapeutic range. Aminoglycosides are freely filtered across the glomerulus and then accumulate within the renal cortex, where concentrations can greatly exceed those of the plasma. AKI typically manifests after 5–7 days of therapy and can present even after the drug has been discontinued. Hypomagnesemia is a common finding. AKI secondary to acute interstitial nephritis can occur as a consequence of exposure to many antibiotics, including penicillins, cephalosporins, quinolones, sulfonamides, and rifampin. There is no reason for obstructive nephropathy or ischemic injury by history. Renal ultrasound shows no evidence of obstruction. There are no red or white cell casts or anything in the history to suggest glomerulonephritis.
300
The pain associated with acute urinary tract obstruction is a result of which of the following?
A. Compensatory natriuresis
B. Decreased medullary blood flow
C. Increased renal blood flow
D. Vasodilatory prostaglandins
The answer is C.(Chap. 313) In acute urinary tract obstruction, pain is due to distention of the collecting system or renal capsule. Acutely, there is a compensatory increase in renal blood flow when kidney function is impaired by obstruction, which further exacerbates capsular stretch. Eventually, vasodilatory prostaglandins act to preserve renal function when glomerular filtration rate has decreased. Medullary blood flow decreases as the pressure of the obstruction further inhibits the renal parenchyma from perfusing; however, the ensuing chronic renal destruction may occur without substantial pain. When an obstruction has been relieved, there is a postobstructive diuresis that is mediated by relief of tubular pressure, increased solute load (per nephron), and natriuretic factors. There can be an extreme amount of diuresis, but this is not painful.
300
Creatinine is best describes as:
A. a substance produced by the kidney
b. a product related to skeletal muscle metabolism
c. produced by the liver and filtered by the kidney
d. a by product of protein metabolism
b. a product related to skeletal muscle metabolism
300
An example of a first-line therapeutic agent for treatment of pyelonephritis:
A. amoxicillin with calavulanate
B. trimethoprim-sulfamethoxazole
c. Ciprofloxacin
d. nitrofurantoin
c. Ciprofloxacin
400
A 21-year-old man is diagnosed with poststreptococcal glomerulonephritis. Which of the following is likely to be found in his urine?
A. >3 g per 24-hour proteinuria without hematuria
B. Macroscopic hematuria and 24-hour urinary albumin of 227 mg
C. Microscopic hematuria with leukocytes and 24-hour urinary albumin of 227 mg
D. Positive urine culture for Streptococcus
E. Sterile pyuria without proteinuria
The answer is C.(Chap. 308) The hallmark of glomerular renal disease is microscopic hematuria and proteinuria (Table VI-27). IgA nephropathy and sickle cell disease are the exception to this, when gross hematuria may be present. Proteinuria may be heavy (>3 g per 24 hours) or lighter with microalbuminuria (30–300 mg per 24 hours) depending on the underlying disease or site of the immune lesion. Patients with post-streptococcal glomerulonephritis often have pyuria, but cultures are not expected to be positive because the infection is usually a skin or mucosal infection, and it is the immune reaction that drives the renal lesion.
400
A 65-year-old man with a history of hypertension, diabetes, and chronic low back pain presents to the clinic for follow-up. His physical examination is unremarkable with no edema or jugular venous distension. Recent laboratory testing shows a decreased glomerular filtration rate of 55 mL/min/1.73 m2. His hemoglobin A1c is 5.4%. He is currently on metformin, naproxen, and hydrochlorothiazide. What medication change could help slow his progression of chronic kidney disease?
A. Add furosemide
B. Discontinue metformin
C. Discontinue naproxen
D. Substitute lisinopril for hydrochlorothiazide
E. C and D
The answer is E.(Chap. 305) It is important to limit exposure to nephrotoxic agents to prevent progression of chronic kidney disease. These include nonsteroidal anti-inflammatory drugs like naproxen and radiographic dye. Avoiding volume depletion is also helpful. This patient had no indication for a diuretic so adding furosemide is not indicated and may lead to volume depletion. Several controlled studies have shown that angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers are effective in slowing the progression of renal failure in patients with advanced stages of both diabetic and nondiabetic chronic kidney disease, in large part through effects on efferent vasodilatation and the subsequent decline in glomerular hypertension. Controlling diabetes is important in managing diabetic nephropathy. His diabetes is well managed with metformin currently, so it should not be discontinued.
400
All of the following electrolyte disorders are commonly found in a person with chronic renal failure EXCEPT:
a. hypernatremia
b. hypercalcemia
c. hyperkalemia
d. hypophosphatemia
d. hypophosphatemia
400
Poststreptococcal glomerulonephritis typically occurs how long after a bacterial pharyngitis infection:
A. 4-6 weeks
b. 1-2 weeks
c. 3-4 weeks
d. 2 months
b. 1-2 weeks
400
a 68 year old man presents w/ suspected bladder cancer. you consider that it's common presenting sign or symptom is:
A. painful urination
b. fever and flank pain
c. painless gross hematuria
d. palpable abdominal mass
c. painless gross hematuria
500
In stage V chronic kidney disease, glomerular filtration rate is below which of the following levels?
A. 90 mL/min/1.73 m2
B. 60 mL/min/1.73 m2
C. 25 mL/min/1.73 m2
D. 15 mL/min/1.73 m2
E. 0 mL/min/1.73 m2 (anuria)
The answer is D.(Chap. 305) Chronic kidney disease (CKD) encompasses a spectrum of different pathophysiologic processes associated with abnormal kidney function and a progressive decline in glomerular filtration rate (GFR). Stages of CKD are stratified by both estimated GFR and the degree of albuminuria to predict risk of progression of CKD. Previously, CKD had been staged solely by the GFR. However, the risk of worsening of kidney function is closely linked to the amount of albuminuria, so it has been incorporated into the classification (Figure VI-13). Note that although age impacts GFR, it is not an independent criterion for risk of progression to CKD. CKD is still staged by GFR. GFR is ≥90 mL/min/1.73 m2 in stage I, 60–89 mL/min/1.73 m2 in stage II, 30–59 mL/min/1.73 m2 in stage III, 15–29 mL/min/1.73 m2 in stage IV, and <15 mL/min/1.73 m2 in stage V.
500
Which of the following patients has the greatest risk of progression to chronic kidney disease?
A. A 30-year-old man with an estimated glomerular filtration rate (GFR) of 50 mL/min/1.73 m2 and 350 mg/g of persistent albuminuria
B. A 45-year-old man with an estimated GFR of 90 mL/ min/1.73 m2 and <30 mg/g of persistent albuminuria
C. A 55-year-old man with an estimated GFR of 70 mL/ min/1.73 m2 and 100 mg/g of persistent albuminuria
D. A 65-year-old woman with an estimated GFR of 65 mL/ min/1.73 m2 and <30 mg/g of persistent albuminuria
E. A 75-year-old man with an estimated GFR of 35 mL/ min/1.73 m2 and <30 mg/g of persistent albuminuria
The answer is A.(Chap. 305) Chronic kidney disease (CKD) encompasses a spectrum of different pathophysiologic processes associated with abnormal kidney function and a progressive decline in glomerular filtration rate (GFR). Stages of CKD are stratified by both estimated GFR and the degree of albuminuria to predict risk of progression of CKD. Previously, CKD had been staged solely by the GFR. However, the risk of worsening of kidney function is closely linked to the amount of albuminuria, so it has been incorporated into the classification (Figure VI-13). Note that although age impacts GFR, it is not an independent criterion for risk of progression to CKD. CKD is still staged by GFR. GFR is ≥90 mL/min/1.73 m2 in stage I, 60–89 mL/min/1.73 m2 in stage II, 30–59 mL/min/1.73 m2 in stage III, 15–29 mL/min/1.73 m2 in stage IV, and <15 mL/min/1.73 m2 in stage V.
500
All of the following a common precipitating factors in AKI except:
A. anaphylaxis
b. infection
c. MI
d. type 1 DM
d. type 1 DM
500
Diagnostic confirmation of glomerulonephritis typically requires:
A. urinalysis plus CBC with diff
b. abdominal CT scan
c. kidney ultrasound
d. kidney biopsy
d. kidney biopsy
500
The following behavioral intervention is most appropriate for which type of incontinence:
establishing a voiding schedule and gentle bladder stretching
urge incontinence