Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Definition ++ Oliguric: Anuria or oliguria (<0.5 mL/kg/h in children; <1 mL/kg/h in infants) with an associated increase in serum creatinineNon-oliguric: Increased serum creatinine with normal or increased urine output (usually seen with nephrotoxic medications) +++ Etiology ++ It should be understood that the following classifications of etiology are somewhat artificial because there can be a great deal of overlap (eg, sepsis can cause both prerenal and intrinsic renal disease; obstructive uropathy, if severe enough, can also cause intrinsic renal disease). ++Table Graphic Jump Location|Download (.pdf)|PrintPrerenalIntrinsic RenalPostrenalReduced intravascular volumeHemorrhageDehydrationCHDPolycythemiaIndomethacin useAdrenergic drugsBirth asphyxiaSepsisATNCongenital abnormalities Renal agenesisRenal dysplasiaPolycystic diseaseThromboembolic diseaseNephrotoxins MedicationsRadiographic contrastMaternal ACE inhibitor or indomethacin useUrethral obstruction (eg, posterior urethral valves)UreteroceleUreteropelvic obstructionUreterovesicular obstructionExtrinsic compression of uretersNeurogenic bladderMegacystis or megaureter syndrome +++ Diagnosis ++ Perform history to elicit predisposing factors listed above and physical exam to palpate for abdominal masses and other congenital urogenital abnormalities.Bladder catheterization to confirm inadequate urine output and r/o obstruction.If prerenal failure is suspected on the basis of history or physical exam and there is no evidence of heart failure or volume overload, a fluid challenge of 10–20 mL/kg of normal saline can be administered over 30–60 min. Lack of response suggests intrinsic renal or postrenal failure.Laboratory studies Serum electrolytes, BUN, creatinineCBC, platelet countUrinalysis with microscopic analysisUrinary sodium and creatinine with simultaneous serum sodium and creatinine to calculate FENa (these studies are not valid if diuretic is used) + ++ Imaging: US examination of kidneys and urinary system ++Table Graphic Jump Location|Download (.pdf)|PrintPrerenalIntrinsic RenalUrine osmolality (mOsm)>400<400Urine sodium (mEq/L)31 ± 1963 ± 35Urine/plasma creatinine29 ± 1610 ± 4Fractional excretion of sodium (%)<1.5>2.5 +++ Management +++ Oliguric Acute Kidney Injury ++ Discontinue or minimize all fluids that contain potassium and phosphorus.Please see chapter 34 for management of hyperkalemia in neonates.Fluid management should be strict, with administration of fluids equal to insensible fluid losses plus urine and other fluid output (eg, chest tubes).Monitor serum sodium, potassium, calcium, and phosphorus levels.Treat hypocalcemia as required (see Chapter 34 [Endocrinology] for treatment of hypocalcemia in neonates).Protein intake may need to be restricted.Monitor for metabolic acidosis and correct as appropriate with intermittent administration of sodium bicarbonate or sodium acetate infusions.Monitor BP and treat hypertension as indicated (See “Hypertension” section in this chapter).Serum levels of all medications that are excreted by the kidney must be monitored carefully to avoid further nephrotoxic injury. Limit all nephrotoxic agents when clinically feasible.Dialysis is indicated when conservative measures ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.