View source for Urinalysis in urinary tract infection

__noTOC__
[[File:Test prouzky.png| thumb | 400px | Diagnostic strips for urinalysis]]
<!----------------------------------------------------------------------------------------------------------------
*  VLOŽENÝ ČLÁNEK
*  Pozor – tento článek je využíván dalšími články, do kterých je vložen. Buďte prosím opatrní při jeho editaci:
*    1. Nemažte příkazy <noinclude> </noinclude>. Označují části článku, které se při vkládání nepřenášejí.
*    2. Neměňte úrovně použitých nadpisů. Neuvážené použití nadpisů vyšší úrovně by mohlo znepřehlednit jiné články.
*    3. Rozsáhlejší editace, rozšíření či zkrácení článku by mohly narušit koncept dalších článků. Změny projednejte v diskusi.
* Seznam článků, do kterých je tento článek vložen, naleznete v seznamu odkazujících článků pod odkazem „Odkazuje sem“. 
*
* Neodstraňujte, prosím, tento komentář. V případě nejasností kontaktujte redakci (redakce@wikiskripta.eu)
*
* Toto upozornění se vkládá šablonou {{subst:Vložený článek}}
-------------------------------------------------------------------------------------------------------------->
When a urinary tract infection is suspected, we examine the urine chemically and evaluate the urinary sediment. In indicated cases, we also use urine culture with antibiotic susceptibility testing.
== Chemical examination of urine ==
A number of abnormalities can be found in urinary tract infections during '''chemical urinalysis''':
=== Alkaliuria ===
Some bacteria (e.g. ''[[Pseudomonas]]'', ''[[Klebsiella]]'''<ref name=Pecková>{{Cite
| type = web
| surname1 = Pecková
| name1 = Marie
| url = http://www.propedeutika.cz/met_lab_moc.html
| source_name = Základní soubory laboratorních vyšetření
| subtitle= Chemické, mikroskopické a bakteriologické vyšetření moče
| year = 2011
| cited = 2014-05-27
}}
</ref>) decompose [[Urea|urea]] by the enzyme urease into ammonia. This alkalinizes the urine. Infection of the [[urinary tract]] should therefore always be considered if the urine pH is higher than 6.5. However, more acidic urine does not exclude a urinary infection.
Other causes of alkaline urine are more rare. Higher urine pH tends to be found in people with a diet rich in plant components.
=== Nitrites ===
In particular, Gram-negative bacteria (mainly ''[[E. coli]]''', ''[[Proteus mirabilis|Proteus]]'', ''[[Klebsiella]]'', ''[[Aerobacter]]''') can reduce nitrate to nitrite. The presence of nitrite is thus an indirect sign of bacteriuria. This test is very specific, but its sensitivity is only around 50%. <ref>{{Cite
  | type = article
  | surname1 = Fox
  | name1 = Gary N
  | article = Sensitivity and specificity of urinary nitrite for UTIs
  | journal = Am Fam Physician
  | year = 2005
  | number = 11
  | volume = 72
  | pages = 2180; author reply 2180, 2182
  | url = https://www.ncbi.nlm.nih.gov/pubmed/16342841
  | issn = 0002-838X
}}</ref>

=== Hematuria ===
It is demonstrable in most urinary infections. Positivity of urine chemistry for blood can also be caused by the presence of peroxidases in bacteriuria. Unfortunately, the test is not very specific.

=== Leukocyturia ===
It also accompanies a large proportion of urinary tract infections. Quantitative urine sediment testing is more sensitive than chemical urinalysis.

=== Proteinuria ===
The amount of protein in the urine in urinary tract infections varies from concentrations that are not detectable by basic techniques to values around 2 g/l.

=== Other findings in urine chemistry ===
In urinary tract infections, [[bilirubin]], [[Urobilinogen|urobilinogen]] and [[ketone bodies]] are often false positives.


<div class="note">
It follows that the result of urine chemistry can be very rich in urinary tract infection. On the other hand, we also encounter bacteriuria with completely normal chemical findings. Any combination of results between these two extremes is therefore compatible with the diagnosis of urinary tract infection. However:
* If nitrites are positive, urinary infection is almost certain (specificity > 95%). However, quite often nitrites remain negative in urinary infection (sensitivity around 50%).
* 98% of urinary infections are positive for at least one of the parameters hematuria, leukocyturia, nitrites, proteinuria <ref>{{Cite
  | type = article
  | surname1 = Patel
  | name1 = H D
  | surname2 = Livsey
  | name2 = S A
  | surname3 = Swann
  | name3 = R A
  | Collective = ano
  | article= Can urine dipstick testing for urinary tract infection at point of care reduce laboratory workload?
  | journal = J  Clin  Pathol
  | year = 2005
  | number = 9
  | volume = 58
  | pages  = 951-4
  | url = https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770822/?tool=pubmed
  | issn = 0021-9746
}}</ref>. 
However, with the exception of nitrites, the finding is often due to another cause and urinary tract infection must therefore be confirmed by further examination (microscopic and culture).
</div>

== Sediment examination ==

In urinary '''sediment''' in urinary tract infections we usually find higher numbers of '''[[Erythrocytes|erythrocytes]] and [[Leukocytes|leukocytes]]'''; in these parameters sediment examination is usually more sensitive than chemical examination. There are also higher numbers of '''epithelial cells''' corresponding to the site of inflammation and, of course, more '''bacteria''' are found.

<noinclude>

== Links ==
=== References ===
<references/>
</noinclude>

[[Category:Biochemistry]]
[[Category:Clinical biochemistry]]