Oliguria
{{Short description|Medical condition of low urine output}}
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| name = Oliguria
| synonyms = Hypouresis
| field = Urology
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Oliguria or hypouresis is the low output of urine specifically more than 80 ml/day but less than 400ml/day.{{cite book |last=Boon |first=Nicholas A. |first2=Nicki R. |last2=Colledge |first3=Brian R. |last3=Walker |display-authors=1 |title=Davidson's Principles & Practice of Medicine |edition=20th |publisher=Elsevier/Churchill Livingstone |location=Edinburgh |year=2006 |page=475 |isbn=978-0-443-10057-4 }} The decreased output of urine may be a sign of dehydration, kidney failure, hypovolemic shock, hyperosmolar hyperglycemic nonketotic syndrome (HHNS), multiple organ dysfunction syndrome, urinary obstruction/urinary retention, diabetic ketoacidosis (DKA), pre-eclampsia, and urinary tract infections, among other conditions.
Beyond oliguria is anuria, which represents an absence of urine, clinically classified as below 80 or 100 ml/day.
The term oliguria is derived from oligo-meaning "small, little," + -uria, from the Greek word ouron, meaning "urine".{{Cite web|url=https://www.etymonline.com/word/oliguria|title=Oliguria {{!}} Origin and meaning of oliguria by Online Etymology Dictionary|last=|first=|date=|website=www.etymonline.com|language=en|archive-url=|archive-date=|access-date=2020-03-02}}
Definition
Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants,{{cite journal | vauthors = Klahr S, Miller S | title = Acute oliguria | journal = N Engl J Med | volume = 338 | issue = 10 | pages = 671–5 | year = 1998 | pmid = 9486997 | doi = 10.1056/NEJM199803053381007}} [http://content.nejm.org/cgi/content/full/338/10/671 Free Full Text]. less than 0.5 mL/kg/h in children, and less than 400 mL or 500 mL[http://www.merck.com/mmpe/sec06/ch063/ch063f.html Merck manuals > Oliguria] Last full review/revision March 2009 by Soumitra R. Eachempati per 24h in adults - this equals 17 or 21 mL/hour. For example, in an adult weighing 70 kg it equals 0.24 or 0.3 mL/kg/h. Alternatively, however, the value of 0.5 mL/kg/h is commonly used to define oliguria in adults as well.
Diagnostic approach
Perform ultrasound examination of the kidney to rule out obstructive processes.{{cn|date=April 2021}}
The mechanisms causing oliguria can be categorized globally in three different categories:{{cn|date=April 2021}}
- Prerenal: in response to hypoperfusion of the kidney (e.g. as a result of dehydration by poor oral intake, cardiogenic shock, diarrhea, G6PD deficiency, massive bleeding or sepsis)
- Renal: due to kidney damage (severe hypoperfusion, rhabdomyolysis, medication)
- Postrenal: as a consequence of obstruction of the urine flow (e.g. enlarged prostate, tumour compression urinary outflow, expanding hematoma or fluid collection)
=Postoperative oliguria=
Patients usually have a decrease in urine output after a major operation that may be a normal physiological response to:{{cn|date=April 2021}}
- fluid/ blood loss – decreased glomerular filtration rate secondary to hypovolemia and/or hypotension
- response of adrenal cortex to stress-increase in aldosterone (Na and water retention) and antidiuretic hormone (ADH) release
Babies
Oliguria, when defined as less than 1 mL/kg/h, in infants is not attributed to kidney failure.{{cite journal | author = Arant B | title = Postnatal development of renal function during the first year of life | journal = Pediatr Nephrol | volume = 1 | issue = 3 | pages = 308–13 | year = 1987 | pmid = 3153294 | doi = 10.1007/BF00849229| s2cid = 9166918 }}
See also
- Polyuria (excessive urine production)
- Anuria (absolute lack of urine output)
- Intra-abdominal hypertension (IAH) and Abdominal Compartment Syndrome (ACS)
References
{{Reflist}}
External links
{{Medical resources
| ICD10 = {{ICD10|R|34||r|30}}
| ICD9 = {{ICD9|788.5}}
| MeshID = D009846
| MedlinePlus = 003147
| DiseasesDB=23641
}}
{{Urinary system symptoms and signs}}