Oliguria

Decreased urine output less than 400 mL/day

Definition

Oliguria is a urine output of less than 400 mL per day in adults (or less than 0.5 mL/kg/hour). It is an early warning sign of acute kidney injury or fluid volume deficit.

Causes

  • Pre-renal: Hypovolemia, hypotension, heart failure.
  • Intrarenal: Acute tubular necrosis, nephrotoxic drugs.
  • Post-renal: Obstruction (stones, BPH, blocked catheter).

Nursing Interventions

  • Assess for underlying cause
  • Check Foley catheter patency and bladder distention
  • Monitor vital signs, I&O, daily weights
  • Labs: BUN, creatinine, electrolytes, urinalysis
  • IV fluids for hypovolemia
  • Avoid nephrotoxic agents
  • Prepare for dialysis if severe

NCLEX Relevance

Oliguria + rising creatinine = AKI. Check catheter patency first.