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oliguria
Urine output < 400 mL/day or < 20 mL/hour in adults, < 240 mL/day in children, & < 15-20 mL/kg/day in neonates. Urine flows less than this are insufficient to excrete the daily osmolar load.
Etiology:
1) pre-renal
a) hypovolemia
- hemorrhage
- dehydration
- gastrointestinal losses
- renal losses (diuretics)
b) decreased effective blood volume
- vasodilation
- pharmacologic agents
- sepsis
- anaphylaxis
- sequestration of extracellular fluid (3rd spacing)
- burns
- abdominal surgery
- peritonitis
- pancreatitis
- congestive heart failure (CHF)
- cardiogenic shock
- hepatorenal syndrome
- hypoalbuminemia
2) renal
a) acute tubular necrosis (ATN)
- ischemia
- hypotension
- sepsis
- nephrotoxin
- aminoglycosides radiographic contrast agent
- rhabdomyolysis
- eclampsia
b) vascular disease
- renal vein thrombosis
- renal vasculitis
- malignant hypertension
c) bilateral renal cortical necrosis
d) end-stage renal disease (ESRD)
e) acute glomerulonephritis
f) hemolytic-uremic syndrome (HUS)
g) acute interstitial nephritis (AIN)
h) hypercalcemia
i) urine paraproteins
- multiple myeloma
- Waldenstrom's macroglobulinemia
- amyloidosis
j) urinary crystals
3) post-renal (rare in children)
a) bilateral ureteral obstruction
- external compression
- retroperitoneal fibrosis
- tumor
- lymph nodes
- intrinsic occlusion
- urinary calculus
- tumor
b) bladder outlet obstruction
- neurogenic bladder
- urinary calculus
- tumor
- posterior urethral valves - newborn males
c) urethral obstruction
- prostatic enlargement
- stricture
- trauma
d) congenital malformation of kidney
- children
Laboratory:
1) urine output
2) urinalysis
a) protein by dipstick
b) microscopy
- tubular epithelial cells
- RBC
- RBC casts
- WBC casts
3) urinary indices*
4) serum chemistries
a) urea nitrogen
b) creatinine
5) complete blood count (CBC)
6) renal ultrasound
7) cystoscopy & retrograde pyelogram
8) renal flow scan *Indices of oliguria
index prerenal ATN*
urine osmolality (mOsm/L) > 500 < 350
urine/plasma creatinine > 40 < 20
BUN/creatinine (plasma) > 20 < 15
FENA# < 1% > 3%
* acute tubular necrosis
# fractional excretion of sodium
Management:
1) catheterize bladder - relieve obstruction
2) optimize arterial blood volume & cardiac status
a) fluid challenge with saline unless in CHF
b) restrict salt & water intake if in CHF
3) discontinue nephrotoxic agents
4) maintain electrolyte balance
5) maintain acid-base status
6) treat hypertension
7) treat hypotension
7) monitor input & output
8) maintain urine output after hemodynamics & arterial blood volume is maximized
a) loop diuretics
b) low-dose dopamine
9) hemodialysis
Related
acute renal failure (ARF)
Specific
anuria
General
sign/symptom
References
- Saunders Manual of Medical Practice, Rakel (ed),
WB Saunders, Philadelphia, 1996, pg 523-525
- Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed)
Lippincott-Raven, Philadelphia, 1998, pg 596