Oliguria or hypouresis is the low output of

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra. Cel ...

specifically more than 80 ml/day but less than 400ml/day.Boon et al, Davidson's Principles & Practice of Medicine (20th Ed), p475 The decreased output of urine may be a sign of

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

, hypovolemic shock, hyperosmolar hyperglycemic nonketotic syndrome (HHNS),

multiple organ dysfunction syndrome Multiple organ dysfunction syndrome (MODS) is altered organ (anatomy), organ function in an acutely ill patient requiring medicine, medical intervention to achieve homeostasis. Although Irwin and Rippe cautioned in 2005 that the use of "multiple ...

urinary obstruction Urinary retention is an inability to completely empty the bladder. Onset can be sudden or gradual. When of sudden onset, symptoms include an inability to urinate and lower abdominal pain. When of gradual onset, symptoms may include urinary incont ...

urinary retention Urinary retention is an inability to completely empty the bladder. Onset can be sudden or gradual. When of sudden onset, symptoms include an inability to urinate and lower abdominal pain. When of gradual onset, symptoms may include loss of bladd ...

, diabetic ketoacidosis (DKA),

pre-eclampsia Pre-eclampsia is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease ...

, and

urinary tract infection A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidney ...

s, among other conditions. Beyond oliguria is

anuria Anuria is nonpassage of urine, in practice is defined as passage of less than 100Harrison's Principles of Internal Medicine, 19E PAGE 292 milliliters of urine in a day. Anuria is often caused by failure in the function of kidneys. It may also occu ...

, 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".

Definition

Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants,Free Full Text
less than 0.5 mL/kg/h in children, and less than 400 mL or 500 mL
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/hour/kg. 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. The mechanisms causing oliguria can be categorized globally in three different categories: * Prerenal: in response to

hypoperfusion Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion is measured as the rate at which blood is deliver ...

of the kidney (e.g. as a result of

by poor oral intake,

cardiogenic shock Cardiogenic shock (CS) is a medical emergency resulting from inadequate blood flow due to the dysfunction of the ventricles of the heart.Textbooks of Internal MedicinHarrison's Principles of Internal Medicine 16th Edition, The McGraw-Hill Compan ...

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

G6PD deficiency Glucose-6-phosphate dehydrogenase deficiency (G6PDD), which is the most common enzyme deficiency worldwide, is an inborn error of metabolism that predisposes to red blood cell breakdown. Most of the time, those who are affected have no symptoms. ...

, massive

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

sepsis Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

) * Renal: due to kidney damage (severe

rhabdomyolysis Rhabdomyolysis (also called rhabdo) is a condition in which damaged skeletal muscle breaks down rapidly. Symptoms may include muscle pains, weakness, vomiting, and confusion. There may be tea-colored urine or an irregular heartbeat. Some of th ...

medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

) * Postrenal: as a consequence of obstruction of the urine flow (e.g.

enlarged prostate Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, inability to urinate, or loss o ...

, tumour compression urinary outflow, expanding

hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...

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: * fluid/ blood loss – decreased glomerular filtration rate secondary to hypovolemia and/or hypotension * response of adrenal cortex to stress -increase in

aldosterone Aldosterone is the main mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon. It plays a c ...

(Na and water retention) and

antidiuretic hormone Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travel ...

(ADH) release

Babies

Oliguria, when defined as less than 1 mL/kg/h, in

infant An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...

s is not attributed to kidney failure.

References

External links