Jump to content

Pyelonephritis

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 195.113.195.250 (talk) at 13:21, 20 August 2012. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Pyelonephritis
SpecialtyUrology Edit this on Wikidata

Pyelonephritis (from Greek πήληξ – pyelum, meaning "renal pelvis", νεφρός – nephros, meaning "kidney", and -itis, meaning "inflammation") is an ascending urinary tract infection that has reached the pyelum or pelvis of the kidney. It is a form of nephritis that is also referred to as pyelitis. Severe cases of pyelonephritis can lead to pyonephrosis (pus accumulation around the kidney), urosepsis (a systemic inflammatory response of the body to infection), kidney failure and even death.

Pyelonephritis presents with fever, accelerated heart rate, painful urination, abdominal pain radiating to the back, nausea, and tenderness at the costovertebral angle on the affected side. Pyelonephritis that has progressed to urosepsis may be accompanied by signs of septic shock, including rapid breathing, decreased blood pressure, violent shivering, and occasionally delirium. Pyelonephritis requires antibiotic therapy, and sometimes surgical intervention such as ureteroscopy, percutaneous nephrostomy or percutaneous nephrolithotomy, as well as treatment of any underlying causes to prevent its recurrence. Xanthogranulomatous pyelonephritis is a rare form of chronic pyelonephritis in which nephrectomy (removal of the kidney) is usually necessary for definitive treatment.

Signs and symptoms

Symptoms of acute pyelonephritis generally develop rapidly over a few hours or a day. It can cause high fever, pain on passing urine, and abdominal pain that radiates along the flank towards the back. There is often associated vomiting.[1]

Chronic pyelonephritis causes persistent flank or abdominal pain, signs of infection (fever, unintentional weight loss, malaise, decreased appetite), lower urinary tract symptoms and blood in the urine.[2] Chronic pyelonephritis can in addition cause fever of unknown origin. Furthermore, inflammation-related proteins can accumulate in organs and cause the condition AA amyloidosis.[3]

Physical examination may reveal fever and tenderness at the costovertebral angle on the affected side.[4]

Causes

Most cases of "community-acquired" pyelonephritis are due to bowel organisms that enter the urinary tract. Common organisms are E. coli (70–80%) and Enterococcus faecalis. Hospital-acquired infections may be due to coliform bacteria and enterococci, as well as other organisms uncommon in the community (e.g. Pseudomonas aeruginosa and various species of Klebsiella). Most cases of pyelonephritis start off as lower urinary tract infections, mainly cystitis and prostatitis.[1] E. coli can invade the superficial umbrella cells of the bladder to form intracellular bacterial communities (IBCs), which can mature into biofilms. These biofilm-producing E. coli are resistant to antibiotic therapy and immune system responses, and present a possible explanation for recurrent urinary tract infections, including pyelonephritis.[5] Risk is increased in the following situations:[1][6]

Diagnosis

Laboratory examination

Urinalysis may show signs of urinary tract infection. Specifically, the presence of nitrite and white blood cells on a urine test strip in patients with typical symptoms are sufficient for the diagnosis of pyelonephritis, and are an indication for empirical treatment. Blood tests such as a complete blood count may show neutrophilia. Microbiological culture of the urine, with or without blood cultures and antibiotic sensitivity testing are useful for establishing a formal diagnosis.[1]

Imaging studies

If a kidney stone is suspected (e.g. on the basis of characteristic colicky pain or the presence of a disproportionate amount of blood in the urine), a kidneys, ureters, and bladder x-ray (KUB film) may assist in identifying radioopaque stones.[1] Where available, a noncontrast helical CT scan with 5 millimeter sections is the diagnostic modality of choice in the radiographic evaluation of suspected nephrolithiasis.[7][8][9] All stones are detectable on CT scans except very rare stones composed of certain drug residues in the urine.[10] In patients with recurrent ascending urinary tract infections, it may be necessary to exclude an anatomical abnormality, such as vesicoureteral reflux or polycystic kidney disease. Investigations used in this setting include ultrasonography of the kidneys or voiding cystourethrography.[1] CT scan or abdominal ultrasonography is useful in the diagnosis of xanthogranulomatous pyelonephritis; serial imaging may be useful for differentiating this condition from kidney cancer.[2]

Classification

Acute pyelonephritis

Acute pyelonephritis is an exudative purulent localized inflammation of the renal pelvis (collecting system) and kidney. The renal parenchyma presents in the interstitium abscesses (suppurative necrosis), consisting in purulent exudate (pus): neutrophils, fibrin, cell debris and central germ colonies (hematoxylinophils). Tubules are damaged by exudate and may contain neutrophil casts. In the early stages, the glomerulus and vessels are normal. Gross pathology often reveals pathognomonic radiations of bleeding and suppuration through the renal pelvis to the renal cortex.[citation needed]

Chronic pyelonephritis

Chronic pyelonephritis implies recurrent kidney infections, and can result in scarring of the renal parenchyma and impaired function, especially in the setting of obstruction. A perinephric abscess (infection around the kidney) and/or pyonephrosis may develop in severe cases of pyelonephritis.[11]

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis is an unusual form of chronic pyelonephritis characterized by granulomatous abscess formation, severe kidney destruction, and a clinical picture that may resemble renal cell carcinoma and other inflammatory renal parenchymal diseases. Most patients present with recurrent fevers and urosepsis, anemia, and a painful renal mass. Other common manifestations include kidney stones and loss of function of the affected kidney. Bacterial cultures of renal tissue are almost always positive.[12] Microscopically, there are granulomas and lipid-laden macrophages (hence the term xantho-, which means yellow in ancient Greek). It is found in roughly 20% of specimens from surgically managed cases of pyelonephritis.[2]

Management

In patients suspected of having pyelonephritis, a urine culture and antibiotic sensitivity test is performed, and initial therapy is tailored on the basis of the infecting organism. As most cases of pyelonephritis are due to bacterial infections, antibiotics are the mainstay of treatment. The choice of antibiotic depends on the species and antibiotic sensitivity profile of the infecting organism, and may include fluoroquinolones, cephalosporins, aminoglycosides, or trimethoprim/sulfamethoxazole, either alone or in combination.[13]

In patients not requiring hospitalization where there is a low prevalence of antibiotic-resistant bacteria, an oral fluoroquinolone such as ciprofloxacin or levofloxacin is an appropriate initial choice for therapy. In areas where there is a higher prevalence of fluoroquinolone resistance, it is useful to initiate treatment with a single intravenous dose of a long-acting antibiotic such as ceftriaxone or an aminoglycoside, and then continuing treatment with an oral fluoroquinolone. Oral trimethoprim/sulfamethoxazole is an appropriate choice for therapy if the uropathogen is known to be susceptible. If trimethoprim/sulfamethoxazole is used when the susceptibility is not known, it is useful to initiate treatment with a single intravenous dose of a long-acting antibiotic such as ceftriaxone or an aminoglycoside. Oral beta-lactam antibiotics are less effective than other available agents for treatment of pyelonephritis.[13]

People with acute pyelonephritis that is accompanied by high fever and leukocytosis are typically admitted to the hospital for intravenous hydration and intravenous antibiotic treatment. Treatment is typically initiated with an intravenous fluoroquinolone, an aminoglycoside, an extended-spectrum penicillin or cephalosporin, or a carbapenem. Combination antibiotic therapy is often used in such situations. The treatment regimen is selected based on local resistance data and the susceptibility profile of the specific infecting organism(s).[13]

During the course of antibiotic treatment, serial white blood cell count and temperature are closely monitored. Typically, the intravenous antibiotics are continued until the patient is afebrile for at least 24 to 48 hours, then equivalent oral antibiotic agents can be given for a total of 2–week duration of treatment.[14] Intravenous fluids may be administered to compensate for the reduced oral intake, insensible losses (due to the raised temperature) and vasodilation and to optimize urine output. Percutaneous nephrostomy or ureteral stent placement may be indicated to relieve obstruction caused by a stone. Children with acute pyelonephritis can be treated effectively with oral antibiotics (cefixime, ceftibuten and amoxycillin/clavulanic acid) or with short courses (2 to 4 days) of intravenous therapy followed by oral therapy. If intravenous therapy is chosen, single daily dosing with aminoglycosides is safe and effective.[citation needed]

Treatment of xanthogranulomatous pyelonephritis involves antibiotics as well as surgery. Nephrectomy is the best surgical treatment in the overwhelming majority of cases, although polar resection (partial nephrectomy) has been effective for some people with localized disease.[2][15] Watchful waiting with serial imaging may be appropriate in rare circumstances.[16]

Prevention

In people who experience recurrent urinary tract infections, additional investigations may identify an underlying abnormality. Occasionally, surgical intervention is necessary to reduce the likelihood of recurrence. If no abnormality is identified, some studies suggest long-term preventive (prophylactic) treatment with antibiotics, either daily or after sexual activity.[17] In children at risk for recurrent urinary tract infections, meta-analysis of the existing literature indicates that not enough studies have been performed to conclude prescription of long-term antibiotics have a net positive benefit.[18] Ingestion of cranberry juice has been studied as a prophylactic measure; many studies suggest a benefit.[19][20][21] Increasing fluid intake, consuming cranberry juice, blueberry juice, and fermented milk products containing probiotic bacteria have all been shown to inhibit adherence of bacteria to the epithelial cells of the urinary tract, and may reduce the recurrence rate of urinary tract infections.[19]

Epidemiology

The incidence of pyelonephritis is roughly 12–13 cases annually per 10,000 population in women receiving outpatient treatment and 3–4 requiring admission. In men, 2–3 per 10,000 are treated as outpatients and 1–2/10,000 require admission.[22] Young women are most often affected, probably reflecting sexual activity in that age group. Infants and the elderly are also at increased risk, reflecting anatomical changes and hormonal status.[22] Xanthogranulomatous pyelonephritis is most common in middle-aged women.[12] It can present somewhat differently in children, in whom it may be mistaken for Wilms' tumor.[23]

See also

References

  1. ^ a b c d e f Ramakrishnan, K; Scheid, DC (2005). "Diagnosis and management of acute pyelonephritis in adults" (PDF). American Family Physician. 71 (5): 933–42. PMID 15768623.
  2. ^ a b c d Korkes, F (2008). "Xanthogranulomatous pyelonephritis: clinical experience with 41 cases". Urology. 71 (2): 178–80. doi:10.1016/j.urology.2007.09.026. PMID 18308077. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ Herrera, GA; Picken, MM (2007). "Chapter 19: Renal Diseases". In Jennette, JC; Olson, JL; Schwartz, MM; Silva, FG (eds.). Heptinstall's Pathology of the Kidney. Vol. 2 (6th ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 853–910. ISBN 978-0-7817-4750-9.
  4. ^ Weiss, M; Liapis, H; Tomaszewski, JE; Arend, LJ (2007). "Chapter 22: Pyelonephritis and other infections, reflux nephropathy, hydronephrosis, and nephrolithiasis". In Jennette, JC; Olson, JL; Schwartz, MM; Silva, FG (eds.). Heptinstall's Pathology of the Kidney. Vol. 2 (6th ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 991–1082. ISBN 978-0-7817-4750-9.
  5. ^ Hultgren, SJ (2011). "Pathogenic Cascade of E. coli UTI". UTI Pathogenesis. St. Louis, Missouri: Molecular Microbiology and Microbial Pathogenesis Program, Washington University. Retrieved 2011-06-05.
  6. ^ Scholes, D (2005). "Risk factors associated with acute pyelonephritis in healthy women" (PDF). Annals of Internal Medicine. 142 (1): 20–7. PMID 15630106. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  7. ^ Pearle, MS; Calhoun, EA; Curhan, GC (2007). "Chapter 8: Urolithiasis". In Litwin, MS; Saigal, CS (eds.). Urologic Diseases in America (NIH Publication No. 07–5512) (PDF). Bethesda, Maryland: US Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. pp. 283–319.
  8. ^ Smith, RC; Varanelli, M (2000). "Diagnosis and Management of Acute Ureterolithiasis: CT Is Truth" (PDF). American Journal of Roentgenology. 175 (1): 3–6. PMID 10882237.
  9. ^ Fang, LST (2009). "Chapter 135: Approach to the Paient with Nephrolithiasis". In Goroll, AH; Mulley, AG (eds.). Primary care medicine: office evaluation and management of the adult patient (6th ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 962–7. ISBN [[Special:BookSources/978071775137 |978071775137 [[Category:Articles with invalid ISBNs]]]]. {{cite book}}: Check |isbn= value: invalid character (help)
  10. ^ Pietrow, PK (2006). "Medical Management of Common Urinary Calculi" (PDF). American Family Physician. 74 (1): 86–94. PMID 16848382. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  11. ^ Griebling, TL (2007). "Chapter 18: Urinary Tract Infection in Women". In Litwin, MS; Saigal, CS (eds.). Urologic Diseases in America (NIH Publication No. 07–5512) (PDF). Bethesda, Maryland: US Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. pp. 589–619.
  12. ^ a b Malek, RS; Elder, JS (1978). "Xanthogranulomatous pyelonephritis: a critical analysis of 26 cases and of the literature". Journal of Urology. 119 (5): 589–93. PMID 660725.
  13. ^ a b c Gupta, K (2011). "International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases" (PDF). Clinical Infectious Diseases. 52 (5): e103–20. doi:10.1093/cid/ciq257. PMID 21292654. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ Cabellon, MCL (2005). "Chapter 8: Urinary Tract Infections". In Starlin, R (ed.). The Washington Manual: Infectious Diseases Subspecialty Consult (1st ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 95–108. ISBN 978-0-7817-4373-0.
  15. ^ Rosi, P (1986). "Xanthogranulomatous pyelonephritis: clinical experience with 62 cases". European Urology. 12 (2): 96–100. PMID 3956552. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ Lebret, T (2007). "Percutaneous core biopsy for renal masses: indications, accuracy and results". The Journal of Urology. 178 (4 Pt 1): 1184–8. doi:10.1016/j.juro.2007.05.155. PMID 17698122. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  17. ^ Schooff, M; Hill, K (2005). "Antibiotics for recurrent urinary tract infections". American Family Physician. 71 (7): 1301–2. PMID 15832532.
  18. ^ Williams, GJ; Craig, JC (2011). Williams, Gabrielle (ed.). "Long-term antibiotics for preventing recurrent urinary tract infection in children". Cochrane Database of Systematic Reviews. 2011 (3): CD001534. doi:10.1002/14651858.CD001534.pub3. PMID 21412872.
  19. ^ a b Wilkens, KG; Juneja, V (2007). "Chapter 39: Medical Nutrition Therapy for Renal Disorders". In Mahan, LK; Escott-Stump (eds.). Krause's food & nutrition therapy (12th ed.). Philadelphia: W.B. Saunders. pp. 921–58. ISBN 978-1-4160-3401-8.
  20. ^ Raz, R (2004). "Cranberry juice and urinary tract infection" (PDF). Clinical Infectious Diseases. 38 (10): 1413–9. doi:10.1086/386328. PMID 15156480. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  21. ^ Wang CH, Fang CC, Chen NC; et al. (2012). "Cranberry-containing products for prevention of urinary tract infections in susceptible populations". Arch Intern Med. 172 (13): 988–96. doi:10.1001/archinternmed.2012.3004. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  22. ^ a b Czaja, CA (2007). "Population-based epidemiologic analysis of acute pyelonephritis" (PDF). Clin Infect Dis. 45 (3): 273–80. doi:10.1086/519268. PMID 17599303. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  23. ^ Goodman, TR (1998). "Paediatric xanthogranulomatous pyelonephritis". International Journal of Clinical Practice. 52 (1): 43–5. PMID 9536568. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
Retrieved from "https://en.wikipedia.org/w/index.php?title=Pyelonephritis&oldid=508287904"