Campbell-Walsh Urology, 11th Edition

PART III

Infections and Inflammation

12

Infections of the Urinary Tract

Anthony J. Schaeffer; Richard S. Matulewicz; David James Klumpp

Questions

  1. Acute pyelonephritis is the most likely diagnosis in a patient with:
  2. chills, fever, and flank pain.
  3. bacteria and pyuria.
  4. focal scar in renal cortex.
  5. delayed renal function.
  6. vesicoureteral reflux.
  7. Bacteriuria without pyuria is indicative of:
  8. infection.
  9. colonization.
  10. tuberculosis.
  11. contamination.
  12. stones.
  13. Nosocomial urinary tract infections (UTIs):
  14. occur in patients who are hospitalized or institutionalized.
  15. are caused by common bowel bacteria.
  16. can be suppressed by low-dose antimicrobial therapy.
  17. are due to reinfection.
  18. are due to bacterial persistence.
  19. Most recurrent infections in female patients are:
  20. complicated.
  21. reinfections.
  22. due to bacterial resistance.
  23. due to hereditary susceptibility factors.
  24. composed of multiple organisms.
  25. Rates of reinfection (i.e., time to recurrence) are influenced by:
  26. bladder dysfunction.
  27. renal scarring.
  28. vesicoureteral reflux.
  29. antimicrobial treatment.
  30. age.
  31. The long-term effect of uncomplicated recurrent UTIs is:
  32. renal scarring.
  33. hypertension.
  34. azotemia.
  35. ureteral vesical reflux.
  36. minimal.
  37. The ascending route of infection is least enhanced by:
  38. catheterization.
  39. spermicidal agents.
  40. indwelling catheter.
  41. fecal soilage of perineum.
  42. frequent voiding.
  43. Approximately 10% of symptomatic lower UTIs in young, sexually active female patients are caused by:
  44. Escherichia coli.
  45. Staphylococcus saprophyticus.
  46. Pseudomonas.
  47. Proteus mirabilis.
  48. Staphylococcus epidermidis.
  49. The virulence factor that is most important for adherence is:
  50. hemolysin.
  51. K antigen.
  52. pili.
  53. colicin production.
  54. O serogroup.
  55. Phase variation of bacterial pili:
  56. occurs only in vitro.
  57. affects bacterial virulence.
  58. is characteristic of pyelonephritic E. coli.
  59. is irreversible.
  60. refers to change in pilus length.
  61. The finding that first suggested a biologic difference in women susceptible to UTIs is:
  62. increased adherence of bacteria to vaginal cells.
  63. decreased estrogen concentration in vaginal cells.
  64. elevated vaginal pH.
  65. nonsecretor status.
  66. postmenopausal status.
  67. Increased bacterial adherence resulting in increased susceptibility of women to recurrent UTIs has not been demonstrated in:
  68. introital mucosa.
  69. urethral mucosa.
  70. buccal mucosa.
  71. vaginal fluid.
  72. bladder mucosa.
  73. The primary bladder defense is:
  74. low urine pH.
  75. low urine osmolarity.
  76. voiding.
  77. Tamm-Horsfall protein (uromucoid).
  78. vaginal mucus.
  79. The most significant sequela of renal papillary necrosis is renal:
  80. failure.
  81. abscess.
  82. obstruction.
  83. stone.
  84. cancer.
  85. Severity and morbidity of bacteriuria is most morbid in patients with:
  86. spinal cord injuries.
  87. pregnancy.
  88. reflux.
  89. diabetes mellitus.
  90. human immunodeficiency virus (HIV) infection.
  91. The most reliable urine specimen is obtained by:
  92. urethral catheterization.
  93. catheter aspiration.
  94. midstream voiding.
  95. suprapubic aspiration.
  96. antiseptic periurethral preparation.
  97. The validity of a midstream urine specimen should be questioned if microscopy reveals:
  98. squamous epithelial cells.
  99. red blood cells.
  100. bacteria.
  101. white blood cells.
  102. casts.
  103. Rapid screening methods for detecting UTIs should be used primarily for:
  104. low-risk asymptomatic patients.
  105. pregnant women.
  106. children.
  107. catheterized patients.
  108. elderly patients.
  109. The most accurate test for evaluation of infection in the kidney is:
  110. the Fairley bladder washout test.
  111. ureteral catheterization.
  112. gallium scanning.
  113. computed tomography (CT).
  114. the antibody-coated bacteria test.
  115. Urinary tract imaging is NOT usually indicated for recurrent UTIs in:
  116. women.
  117. girls.
  118. men.
  119. boys.
  120. spinal cord-injured patients.
  121. The most sensitive imaging modality for diagnosing renal abscess is:
  122. ultrasonography.
  123. indium scanning.
  124. gallium scanning.
  125. excretory urography.
  126. CT.
  127. Cure of UTIs depends most on an antimicrobial agent's:
  128. serum half-life.
  129. serum level.
  130. urine level.
  131. duration of therapy.
  132. frequency of therapy.
  133. During the past 5 years, the least development of antimicrobial resistance has been observed for:
  134. ampicillin.
  135. cephalosporins.
  136. nitrofurantoin.
  137. fluoroquinolones.
  138. trimethoprim-sulfamethoxazole (TMP-SMX).
  139. The ideal class of drugs for empirical treatment of uncomplicated UTIs is:
  140. aminopenicillins.
  141. aminoglycosides.
  142. fluoroquinolones.
  143. cephalosporins.
  144. nitrofurantoins.
  145. Antimicrobial prophylaxis is characterized as:
  146. administration of an antimicrobial agent within 4 to 6 hours of the procedure.
  147. administration of an antimicrobial agent for a period of time covering the first 48 hours after the procedure.
  148. administration of an antimicrobial agent within 30 minutes of the initiation of a procedure and for a period of time covering the first 48 hours after the procedure.
  149. administration of an antimicrobial agent within 30 minutes of the initiation of a procedure and for a period of time that covers the duration of the procedure.
  150. administration of an antimicrobial agent the night before the initiation of a procedure and for a period of time that covers the duration of the procedure.
  151. Antimicrobial prophylaxis for transurethral resection of the prostate is not indicated for patients with:
  152. valvular heart disease.
  153. prosthetic valves.
  154. unknown urine culture.
  155. sterile urine.
  156. indwelling catheter.
  157. Prophylaxis for endocarditis should not be administered in patients with:
  158. a history of childhood heart murmurs.
  159. heart valves inserted more than 5 years ago.
  160. calcified heart valves associated with a murmur.
  161. all synthetic heart valves.
  162. cadaveric heart valves.
  163. The host factor least likely to be associated with an increased risk of infection is:
  164. advanced age.
  165. a history of previous infection in the site/organ of interest.
  166. residence in a chronic care facility.
  167. indwelling orthopedic pins.
  168. coexistent infection.
  169. Urine culture is not routinely recommended for the clinical diagnosis of acute cystitis in:
  170. young women.
  171. elderly women.
  172. children.
  173. men.
  174. patients with hematuria.
  175. The drug of choice for uncomplicated cystitis in most young women is:
  176. TMP-SMX.
  177. fluoroquinolone.
  178. penicillin.
  179. cephalosporin.
  180. nitrofurantoin.
  181. The optimal duration of antimicrobial therapy for symptomatic acute uncomplicated cystitis in women is:
  182. 1 day.
  183. 3 days.
  184. 7 days.
  185. 14 days.
  186. 21 days.
  187. Treatment of asymptomatic bacteriuria is most indicated in patients who are:
  188. elderly.
  189. catheterized.
  190. pregnant.
  191. confused.
  192. incontinent.
  193. Screening for bacteriuria is beneficial in:
  194. pregnant women.
  195. elderly patients.
  196. men.
  197. children.
  198. spinal cord-injured patients.
  199. The most common cause of unresolved bacteriuria during antimicrobial therapy is:
  200. development of bacterial resistance.
  201. rapid reinfections.
  202. azotemia.
  203. staghorn calculi.
  204. initial bacterial resistance.
  205. Nitrofurantoin prophylaxis is effective because of the concentration of the drug in the:
  206. urine.
  207. vaginal mucus.
  208. bowel.
  209. serum.
  210. bladder.
  211. The ideal antimicrobial agent for self-start therapy for a UTI is:
  212. a fluoroquinolone.
  213. a cephalosporin.
  214. nitrofurantoin.
  215. TMP-SMX.
  216. tetracycline.
  217. The most common cause of acute pyelonephritis in young women is:
  218. vesicoureteral reflux.
  219. P-piliated bacteria.
  220. type 1 piliated bacteria.
  221. recurrent UTIs.
  222. bacterial endotoxin.
  223. The optimal antimicrobial agent for treatment of acute uncomplicated pyelonephritis in women is:
  224. TMP-SMX.
  225. a cephalosporin.
  226. an aminoglycoside.
  227. a fluoroquinolone.
  228. nitrofurantoin.
  229. A patient with acute pyelonephritis, persistent fever, and flank pain for 24 hours warrants:
  230. observation.
  231. CT.
  232. change in antimicrobial therapy.
  233. ultrasonography.
  234. blood cultures.
  235. The overall mortality rate in emphysematous pyelonephritis is approximately:
  236. 5%.
  237. 10%.
  238. 20%.
  239. 40%.
  240. 60%.
  241. In chronic renal abscess the predominant urographic abnormality is:
  242. calyceal distortion.
  243. renal mass.
  244. calculi.
  245. hydronephrosis.
  246. calyceal amputation.
  247. The high mortality rate associated with perinephric abscess is primarily attributed to:
  248. bacterial hemolysis.
  249. diabetes mellitus.
  250. delay in diagnosis.
  251. inappropriate antimicrobial therapy.
  252. inadequate drainage.
  253. The primary treatment for a small perirenal abscess in a functioning kidney is:
  254. nephrectomy.
  255. partial nephrectomy.
  256. open surgical drainage.
  257. percutaneous drainage.
  258. retrograde ureteral drainage.
  259. Most patients with chronic pyelonephritis present with:
  260. hypertension.
  261. renal failure.
  262. chronic infection.
  263. flank pain.
  264. no symptoms.
  265. The most common bacterial cause of xanthogranulomatous pyelonephritis is:
  266. Escherichia coli.
  267. Pseudomonas.
  268. Klebsiella.
  269. Proteus mirabilis.
  270. Staphylococcus.
  271. It is hypothesized that the nidus for the Michaelis-Gutmann body is:
  272. renal papillae.
  273. bacterial fragments.
  274. calcium crystals.
  275. macrophages.
  276. uric acid stones.
  277. Echinococcosis is rare in/among:
  278. the former Soviet Union.
  279. Eskimos.
  280. Native Americans.
  281. the United States.
  282. Eastern Europe.
  283. The most reliable early clinical indicator of septicemia is:
  284. chills.
  285. fever.
  286. hyperventilation.
  287. lethargy.
  288. change in mental status.
  289. Compared with nonpregnant women, pregnant women have a higher prevalence of:
  290. asymptomatic bacteriuria.
  291. acute cystitis.
  292. acute pyelonephritis.
  293. recurrent cystitis.
  294. bacterial persistence.
  295. Clinical pyelonephritis during pregnancy is most commonly linked to:
  296. maternal sepsis.
  297. maternal anemia.
  298. maternal hypertension.
  299. eclampsia.
  300. congenital malformations.
  301. The drug thought to be safe in any phase of pregnancy is:
  302. a fluoroquinolone.
  303. nitrofurantoin.
  304. a sulfonamide.
  305. penicillin.
  306. tetracycline.
  307. The majority of elderly patients with bacteriuria are:
  308. asymptomatic.
  309. febrile.
  310. incontinent.
  311. confused.
  312. dysuric.
  313. In the absence of obstruction, treatment of asymptomatic bacteriuria in the elderly:
  314. is cost effective.
  315. prevents renal failure.
  316. reduces mortality.
  317. reduces morbidity.
  318. is unnecessary.
  319. The most common predisposing factor for hospital-acquired UTIs is:
  320. surgery.
  321. antimicrobial therapy.
  322. age.
  323. catheterization.
  324. diabetes mellitus.
  325. The most effective measure for reducing catheter-associated UTI is:
  326. closed drainage.
  327. antimicrobial prophylaxis.
  328. catheter irrigation.
  329. intermittent catheterization.
  330. daily meatal care.
  331. In spinal cord-injured patients the bladder drainage technique with the lowest complication rate is:
  332. clean intermittent catheterization (CIC).
  333. suprapubic drainage.
  334. indwelling catheter.
  335. condom catheter.
  336. suprapubic pressure.
  337. Fournier gangrene in the early stage is least likely to be associated with scrotal:
  338. pain.
  339. discharge.
  340. crepitation.
  341. erythema.
  342. swelling.

Pathology

  1. See Figure 12-1.
    A 65-year-old woman has the acute onset of right flank pain, fever, and an enlarged kidney on imaging. Blood cultures and urine cultures are obtained and broad-spectrum antibiotics administered. The patient improves, but the kidney on imaging remains enlarged. A needle biopsy of the kidney is obtained. The pathology report is acute pyelonephritis with numerous neutrophils within the interstitium and the renal tubules. The biopsy:

FIGURE 12-1 (From Bostwick DG, Qian J, Hossain D. Non-neoplastic diseases of the prostate. In: Bostwick DG, Cheng L, editors. Urologic surgical pathology. 2nd ed. Edinburgh: Mosby; 2008.)

  1. provides information as to the length of time antibiotics should be administered.
  2. suggests that the antibiotics should be changed.
  3. is unnecessary.
  4. suggests the need for a percutaneous drain.
  5. suggests that an abscess is likely to develop.
  6. A 65-year-old man has fever and malaise. A CT scan reveals an 8-cm solid mass in his left kidney with marked thickening of the retroperitoneum around the kidney and pancreas. The kidney is poorly functioning and there is a 1 cm stone in the renal pelvis. A biopsy is done and reveals xanthogranulomatous pyelonephritis, which is depicted in Figure 12-2. The next step in management is:

FIGURE 12-2 (From Bostwick DG, Cheng L, editors. Urologic surgical pathology. 2nd ed. Edinburgh: Mosby; 2008.)

  1. extracorporeal shockwave lithotripsy.
  2. biopsy of the retroperitoneum.
  3. left nephrectomy.
  4. urine culture and treatment according to sensitivities.
  5. partial left nephrectomy
  6. A 45-year-old woman is found to have a raised bladder lesion on cystoscopy. The biopsy shown in Figure 12-3reveals malakoplakia. The nest step in management is:

FIGURE 12-3A AND B (From Bostwick DG, Cheng L, editors. Urologic surgical pathology. 2nd ed. Edinburgh: Mosby; 2008.)

  1. intravesical bacille Calmette-Guérin.
  2. fulguration of the lesions.
  3. intravesical mitomycin C.
  4. treat with a sulfonamide for several months.
  5. a 3-day course of ciprofloxacin.

Imaging

  1. A 72-year-old man presents with right flank pain and fever. A contrast-enhanced CT scan is shown in Figure 12-4. The most likely diagnosis is:

FIGURE 12-4

  1. acute right renal obstruction.
  2. delayed excretion in left kidney.
  3. cellulitis in right flank.
  4. right perinephric abscess.
  5. xanthogranulomatous pyelonephritis.
  6. A 40-year-old woman presents with pelvic pain and fever. A contrast-enhanced CT scan is shown in Figure 12-5. The most likely diagnosis is:

FIGURE 12-5

  1. renal infarct.
  2. renal artery occlusion.
  3. chronic pyelonephritis.
  4. acute urinary obstruction.
  5. acute pyelonephritis.
  6. A 22-year-old woman presents with shaking chills and fever. An enhanced CT image is shown in Figure 12-6. The next step in management is:

FIGURE 12-6

  1. percutaneous drainage.
  2. nephrectomy.
  3. partial nephrectomy.
  4. open surgical drainage.
  5. cystoscopy and retrograde urography.

Answers

  1. a. Chills, fever, and flank pain.Acute pyelonephritis is a clinical syndrome of chills, fever, and flank pain that is accompanied by bacteriuria and pyuria, a combination that is reasonably specific for an acute bacterial infection of the kidney.
  2. b. Colonization.Bacteriuria without pyuria is generally indicative of bacterial colonization without infection of the urinary tract.
  3. a. Occur in patients who are hospitalized or institutionalized.Nosocomial or health care–associated UTIs occur in patients who are hospitalized or institutionalized and may be caused by Pseudomonas and other more antimicrobial-resistant strains.
  4. b. Reinfections.Of these recurrent infections, 71% to 73% are caused by reinfection with different organisms, rather than recurrence with the same organism.
  5. d. Antimicrobial treatment.Whether a patient receives no treatment or short-term, long-term, or prophylactic antimicrobial treatment, the risk of recurrent bacteriuria remains the same; antimicrobial treatment appears to alter only the time until recurrence.
  6. e. Minimal.The long-term effects of uncomplicated recurrent UTIs are not completely known, but, so far, no association between recurrent infections and renal scarring, hypertension, or progressive renal azotemia has been established.
  7. e. Frequent voiding.This route is further enhanced in individuals with significant soilage of the perineum with feces, women using spermicidal agents, and patients with intermittent or indwelling catheters.
  8. b.Staphylococcus saprophyticus. S. saprophyticus is now recognized as causing approximately 10% of symptomatic lower UTIs in young, sexually active females, whereas it rarely causes infection in males and elderly individuals.
  9. c. Pili.Studies have demonstrated that interactions between FimH and receptors expressed on the luminal surface of the bladder epithelium are critical to the ability of many uropathogenic E. coli strains to colonize the bladder and cause disease.
  10. b. Affects bacterial virulence.This process is called phase variation and has obvious biologic and clinical implications. For example, the presence of type 1 pili may be advantageous to the bacteria for adhering to and colonizing the bladder mucosa but disadvantageous because the pili enhance phagocytosis and killing by neutrophils.
  11. a. Increased adherence of bacteria to vaginal cells.These studies established increased adherence of pathogenic bacteria to vaginal epithelial cells as the first demonstrable biologic difference that could be shown in women susceptible to UTI.
  12. e. Bladder mucosa.These studies individually and collectively support the concept that there is an increased epithelial receptivity for E. coli on the introital, urethral, and buccal mucosa that is characteristic of women susceptible to recurrent UTIs and may be a genotypic trait. Thus the vaginal fluid appears to influence adherence to cells and presumably vaginal mucosal colonization.
  13. c. Voiding.Bacteria presumably make their way into the bladder fairly often. Whether small inocula of bacteria persist, multiply, and infect the host depends in part on the ability of the bladder to empty.
  14. c. Obstruction.A patient who suffers from an acute ureteral obstruction caused by a sloughed papilla and who has a concomitant UTI should have the condition treated as a urologic emergency.
  15. a. Spinal cord injuries.Of all patients with bacteriuria, no group compares in severity and morbidity with those who have spinal cord injury.
  16. d. Suprapubic aspiration.A single aspirated specimen reveals the bacteriologic status of the bladder urine without introducing urethral bacteria, which can start a new infection.
  17. a. Squamous epithelial cells.The validation of the midstream urine specimen can be questioned if numerous squamous epithelial cells (indicative of preputial, vaginal, or urethral contaminants) are present.
  18. a. Low-risk asymptomatic patients.The main role of rapid screening methods for UTIs is in screening asymptomatic patients.
  19. b. Ureteral catheterization.Ureteral catheterization allows not only separation of bacterial persistence into upper and lower urinary tracts but also separation of the infection between one kidney and the other.
  20. a. Women.Several reports of women patients with recurrent UTIs show that excretory urograms are unnecessary for routine evaluation in women. Those who have special risk factors are excluded.
  21. e. CT.CT and magnetic resonance imaging are more sensitive than excretory urography or ultrasonography in the diagnosis of acute focal bacterial nephritis, renal and perirenal abscesses, and radiolucent calculi.
  22. c. Urine level.Efficacy of the antimicrobial therapy is critically dependent on the antimicrobial levels in the urine and the length of time that this level remains above the minimum inhibitory concentration of the infecting organism. Thus resolution of infection is closely associated with the susceptibility of the bacteria to the concentration of the antimicrobial agent achieved in the urine.
  23. c. Nitrofurantoin.Over a 5-year period the prevalence of resistance to trimethoprim-sulfamethoxazole, ampicillin, and cephalothin increased significantly, whereas resistance to nitrofurantoin and ciprofloxacin remained uncommon.
  24. c. Fluoroquinolones.The fluoroquinolones have a broad spectrum of activity that makes them ideal for the empirical treatment of UTIs.
  25. d. Administration of an antimicrobial agent within 30 minutes of the initiation of a procedure and for a period of time that covers the duration of the procedure.Surgical antimicrobial prophylaxis entails treatment with an antimicrobial agent before and for a limited time after a procedure to prevent local or systemic postprocedural infections.
  26. d. Sterile urine.Prolonged use of an indwelling urethral catheter is common in hospitalized patients and is associated with an increased risk of bacterial colonization, with a 3% to 10% incidence of bacteriuria per catheter day in one study and 100% incidence of bacteriuria with long-term catheterization (> 30 days). Prophylactic antimicrobial therapy during catheterization is not generally recommended because bacterial resistance can develop rapidly. Chronically catheterized patients have bacteriuria and should be treated therapeutically, not with prophylaxis.
  27. a. A history of childhood heart murmurs.The American Heart Association's recommendations on the prevention of bacterial endocarditis are based on the patient's risk of developing endocarditis and the likelihood that a procedure will cause bacteremia with an organism that can cause endocarditis. Prophylaxis is recommended for both high- and moderate-risk patients. High-risk patients include individuals with prosthetic heart valves, previous bacterial endocarditis, cyanotic congenital heart disease, and systemic-pulmonary shunts or conduits. Moderate-risk patients include other congenital malformations (excluding isolated secundum atrial septal defects, surgically repaired atrial septal defect, ventricular septal defects, or patent ductus arteriosus), acquired valvular dysfunction, hypertrophic cardiomyopathy, and mitral valve prolapse with valvular regurgitation and/or thickened leaflets. Antimicrobial prophylaxis is not recommended for patients with congenital malformations including isolated secundum atrial septal defects, surgically repaired atrial septal defect, ventricular septal defects, or patent ductus arteriosus; previous coronary artery bypass graft surgery; benign heart murmurs; previous Kawasaki disease or rheumatic fever without valvular dysfunction; or implanted pacemakers or defibrillators.
  28. d. Indwelling orthopedic pins.Bacterial seeding of implanted orthopedic hardware is a rare but morbid event. A joint commission of the American Urological Association, the American Academy of Orthopaedic Surgeons, and infectious disease specialists convened in 2003 and released an advisory statement on antibiotic prophylaxis for urologic patients with total joint replacement. In general, antimicrobial prophylaxis for urologic patients with total joint replacements, pins, plates, or screws is not indicated. Prophylaxis is advised for individuals at higher risk of seeding a prosthetic joint and include those with recently inserted implants (within 2 years).
  29. a. Young women.In women with recent onset of symptoms and signs suggesting acute cystitis and in whom factors associated with upper tract or complicated infection are absent, a urinalysis that is positive for pyuria, hematuria, or bacteriuria or a combination should provide sufficient documentation of UTI and a urine culture may be omitted.
  30. a. TMP-SMX.TMP and TMP-SMX are recommended in areas where the prevalence of resistance to these drugs among E. coli strains causing cystitis is less than 20%.
  31. b. 3 days.Three-day therapy is the preferred regimen for uncomplicated cystitis in women.
  32. c. Pregnant.In populations other than those for whom treatment has been documented to be beneficial (e.g., pregnant women and patients undergoing urologic interventions), screening for or treatment of asymptomatic bacteriuria is not appropriate and should be discouraged.
  33. a. Pregnant women.In populations other than those for whom treatment has been documented to be beneficial (e.g., pregnant women and patients undergoing urologic interventions), screening for or treatment of asymptomatic bacteriuria is not appropriate and should be discouraged.
  34. e. Initial bacterial resistance.Most commonly, the bacteria are resistant to the antimicrobial agent selected to treat the infection.
  35. a. Urine. Nitrofurantoin, which does not alter the bowel flora, is present for brief periods at high concentrations in the urineand leads to repeated elimination of bacteria from the urine, presumably by interfering with bacterial initiation of infection.
  36. a. A fluoroquinolone.Fluoroquinolones are ideal for self-start therapy because they have a spectrum of activity broader than that of any of the other oral agents and are superior to many parenteral antimicrobial agents, including aminoglycosides.
  37. b. P-piliated bacteria.If vesicourethral reflux is absent, a patient bearing the P blood group phenotype may have special susceptibility to recurrent pyelonephritis caused by E. coli that have P pili and bind to the P blood group antigen receptors.
  38. d. A fluoroquinolone.For patients who will be managed as outpatients, single-drug oral therapy with a fluoroquinolone is more effective than TMP-SMX for patients with domiciliary infections.
  39. a. Observation.Even though the urine usually becomes sterile within a few hours of starting antimicrobial therapy, patients with acute uncomplicated pyelonephritis may continue to have fever, chills, and flank pain for several more days after initiation of successful antimicrobial therapy. They should be observed.
  40. d. 40%.Emphysematous pyelonephritis should be considered a complication of severe pyelonephritis rather than a distinct entity. The overall mortality rate is 43%.
  41. b. Renal mass.In a more chronic abscess, the predominant urographic abnormalities are those of a renal mass lesion.
  42. c. Delay in diagnosis.Although 71% of all the patients had eventual surgical treatment of their perinephric abscesses, the diagnostic delay of those patients admitted to medical services postponed definitive treatment and consequently caused higher mortality.
  43. d. Percutaneous drainage.Although surgical drainage, or nephrectomy if the kidney is nonfunctioning or severely infected, is the classic treatment for perinephric abscesses, renal ultrasonography and CT make percutaneous aspiration and drainage of small perirenal collections possible.
  44. e. No symptoms.There are no symptoms of chronic pyelonephritis until it produces renal insufficiency, and then the symptoms are similar to those of any other form of chronic renal failure.
  45. d.Proteus mirabilis. Although review of the literature shows Proteus to be the most common organism involved with xanthogranulomatous pyelonephritis, E. coli is also common.
  46. b. Bacterial fragments.It is hypothesized that bacteria or bacterial fragments form the nidus for the calcium phosphate crystals that laminate the Michaelis-Gutmann bodies.
  47. d. The United States.In the United States the disease is rare, but it is found in immigrants from Eastern Europe or other foreign endemic areas or as an indigenous infection among Native Americans in the Southwest United States and in Eskimos.
  48. c. Hyperventilation.Even before temperature extremes and the onset of chills, bacteremic patients often begin to hyperventilate. Thus the earliest metabolic change in septicemia is a resultant respiratory alkalosis.
  49. c. Acute pyelonephritis.Pyelonephritis develops in 1% to 4% of all pregnant women and in 20% to 40% of pregnant women with untreated bacteriuria.
  50. a. Maternal sepsis. Pregnant women with asymptomatic bacteriuria are at higher risk for developing a symptomatic UTI that results in adverse fetal sequelae, complications associated with bacteriuria during pregnancy, and pyelonephritis and its possible sequelae, such as sepsis in the mother. Therefore all women with asymptomatic bacteriuria should be treated.
  51. d. Penicillin.The aminopenicillins and cephalosporins are considered safe and generally effective throughout pregnancy. In patients with penicillin allergy, nitrofurantoin is a reasonable alternative.
  52. a. Asymptomatic.Most elderly patients with bacteriuria are asymptomatic; estimates among women living in nursing homes range from 17% to 55%, as compared with 15% to 31% for their male cohorts.
  53. e. Is unnecessary. Prospective randomized comparative trials of antimicrobial or no therapy in elderly male and female nursing home residents with asymptomatic bacteriuria consistently document no benefit of antimicrobial therapy.There was no decrease in symptomatic episodes and no improvement in survival. In fact, treatment with antimicrobial therapy increases the occurrence of adverse drug effects and reinfection with resistant organisms and increases the cost of treatment. Therefore asymptomatic bacteriuria in elderly residents of long-term care facilities should not be treated with antimicrobial agents.
  54. d. Catheterization.Catheter-associated bacteriuria is the most common hospital-acquired infection, accounting for up to 40% of such infections.
  55. a. Closed drainage.Careful aseptic insertion of the catheter and maintenance of a closed dependent drainage system are essential to minimize development of bacteriuria.
  56. a. Clean intermittent catheterization.Although never rigorously compared with indwelling urethral catheterization, CIC has been shown to decrease lower urinary tract complications by maintaining low intravesical pressure and reducing the incidence of stones.
  57. b. Discharge.Early on, the involved area is swollen, erythematous, and tender as the infection begins to involve the deep subcutaneous tissue. Pain is prominent, and fever and systemic toxicity are marked. The swelling and crepitus of the scrotum quickly increase, and dark purple areas develop and progress to extensive gangrene.

Pathology

  1. c. Is unnecessary.The figure shows numerous neutrophils within the interstitium and the renal tubules. The neutrophils in the tubules become white blood cell casts. The pathologic findings including an enlarged kidney may persist for several weeks despite appropriate treatment. There is no indication for a biopsy in this patient.
  2. c. Left nephrectomy.The figure shows the foamy macrophages with neutrophils and cellular debris characteristic of xanthogranulomatous pyelonephritis. It may be associated with renal calculi and Proteusinfection. E. coli is also a common organism found in this disease. Although partial nephrectomy has been performed for a small localized mass in a functioning kidney, a left nephrectomy in this situation is likely required and is necessary to rid the patient of the infection. An associated retroperitoneal inflammatory process with thickening is not uncommon.
  3. d. Treat with a sulfonamide for several months.Figure 12-3A shows von Hansemann histiocytes, and Figure 12-3B demonstrates the Michaelis-Gutmann bodies, both of which are characteristic of malakoplakia. It is thought to be infectious in origin, and therefore the treatment is an extended course of an antibiotic that achieves a high intracellular concentration.

Imaging

  1. d. Right perinephric abscess.The CT scan is obtained in the late arterial to nephrographic phase of the examination (the aorta is still opacified with contrast agent), before the excretion of the contrast agent. Thus option b is incorrect. There are multiple calculi in the right kidney, which is small and atrophic, indicating a chronic process (thus option a is incorrect). There is thickening of the perinephric fascia, and gas bubbles are seen in the posterior paranephric space, extending to the right flank. In addition, there are fluid collections in the posterior paranephric space and in the soft tissues of the right flank, making option d the most likely diagnosis. Xanthogranulomatous pyelonephritis is a chronic inflammatory condition associated with staghorn calculi. The affected kidney is usually enlarged rather than shrunken, as is the case here (making option e unlikely).
  2. e. Acute pyelonephritis.The image demonstrates a pelvic kidney with wedge-shaped area of decreased enhancement, characteristic of acute pyelonephritis. Renal infarcts cause areas of poor perfusion that are more sharply defined and more poorly enhancing than in the present case (making option a unlikely). The clinical history of fever also supports an infection. With renal artery occlusion (option b) the kidney would demonstrate no enhancement. Chronic pyelonephritis causes scarring in the kidney, and the nephrogram is usually normal. The renal contour in the present case is smooth, making option c unlikely. Acute urinary obstruction (option d) is ruled out because the visualized collecting system does not appear dilated.
  3. a. Percutaneous drainage.The image demonstrates a low-attenuation area in the posterior interpolar region of the left kidney, with perinephric fascial thickening, consistent with a renal abscess. Intravenous antimicrobial therapy with percutaneous drainage of renal abscesses is highly effective and is the treatment of choice. Antimicrobial therapy alone is unlikely to be effective, given the size of the abscess. Nephrectomy, partial nephrectomy, and surgical drainage are rarely indicated in young patients with normally functioning kidneys. Cystoscopy is not warranted.

Chapter review

  1. UTIs cause significant morbidity; they do not cause progressive renal failure unless significant comorbidities are present.
  2. Increased receptors for uropathogenic E. colion vaginal epithelial cells and buccal mucosal cells in women with recurrent UTIs imply a genetic etiology; moreover, hormonal changes may alter adherence of bacteria to the receptors in the vaginal epithelial cells, explaining the cyclic nature of UTIs in women.
  3. If appropriate antimicrobial therapy fails to eradicate bacteria and there is a rapid recurrence, imaging is indicated to determine abnormalities that may cause persistence.
  4. When a patient has a symptomatic UTI and gram-negative rods are seen on the urine analysis but the routine culture is negative, an anaerobic infection should be suspected.
  5. 102cfu/mL in a symptomatic patient confirms a UTI.
  6. Patients with indwelling catheters should be treated only when symptomatic.
  7. Whether a patient receives no treatment or short-term, long-term, or prophylactic antimicrobial treatment, the risk of recurrent bacteriuria remains the same; antimicrobial treatment appears to alter only the time until recurrence.
  8. There is no association between recurrent infections and renal scarring, hypertension, or progressive renal azotemia
  9. Staphylococcus saprophyticusis now recognized as causing approximately 10% of symptomatic lower UTIs in young, sexually active females, whereas it rarely causes infection in males and elderly individuals.
  10. The validation of the midstream urine specimen can be questioned if numerous squamous epithelial cells (indicative of preputial, vaginal, or urethral contaminants) are present.
  11. The fluoroquinolones have a broad spectrum of activity that makes them ideal for the empirical treatment of UTIs.
  12. Prophylaxis is recommended for both high- and moderate-risk patients. High-risk patients include individuals with prosthetic heart valves, previous bacterial endocarditis, cyanotic congenital heart disease, and systemic-pulmonary shunts or conduits. Moderate-risk patients include other congenital malformations (excluding isolated secundum atrial septal defects, surgically repaired atrial septal defect, ventricular septal defects, or patent ductus arteriosus), acquired valvular dysfunction, hypertrophic cardiomyopathy, and mitral valve prolapse with valvular regurgitation and/or thickened leaflets. Antimicrobial prophylaxis is not recommended for patients with congenital malformations including isolated secundum atrial septal defects, surgically repaired atrial septal defect, ventricular septal defects, or patent ductus arteriosus; previous coronary artery bypass graft surgery; benign heart murmurs; previous Kawasaki disease or rheumatic fever without valvular dysfunction; or implanted pacemakers or defibrillators.
  13. In general, antimicrobial prophylaxis for urologic patients with total joint replacements, pins, plates, or screws is not indicated. Prophylaxis is advised for individuals at higher risk of seeding a prosthetic joint and include those with recently inserted implants (within 2 years).
  14. Three-day therapy is the preferred regimen for uncomplicated cystitis in women.
  15. If vesicourethral reflux is absent, a patient bearing the P blood group phenotype may have special susceptibility to recurrent pyelonephritis caused by E. colithat have P pili and bind to the P blood group antigen receptors.
  16. Emphysematous pyelonephritis should be considered a complication of severe pyelonephritis rather than a distinct entity. The overall mortality rate is 43%.
  17. Although surgical drainage, or nephrectomy if the kidney is nonfunctioning or severely infected, is the classic treatment for perinephric abscesses, renal ultrasonography and CT make percutaneous aspiration and drainage of small perirenal collections possible.
  18. Proteusis the most common organism involved with xanthogranulomatous pyelonephritis; E. coli is also common.
  19. Even before temperature extremes and the onset of chills, bacteremic patients often begin to hyperventilate. Thus the earliest metabolic change in septicemia is a resultant respiratory alkalosis.
  20. Pregnant women with asymptomatic bacteriuria are at higher risk for developing a symptomatic UTI that results in adverse fetal sequelae, complications associated with bacteriuria during pregnancy, and pyelonephritis and its possible sequelae, such as sepsis in the mother. Therefore all pregnant women with asymptomatic bacteriuria should be treated.
  21. The aminopenicillins and cephalosporins are considered safe and generally effective throughout pregnancy.
  22. In elderly male and female nursing home residents with asymptomatic bacteriuria there is no benefit to administering antimicrobial therapy.
  23. In the early stages of Fournier gangrene, the involved area is swollen, erythematous, and tender as the infection begins to involve the deep subcutaneous tissue. Pain is prominent, and fever and systemic toxicity are marked. The swelling and crepitus of the scrotum quickly increase, and dark purple areas develop and progress to extensive gangrene.