What can we give a patient with no urine output?

Management of Anuria (No Urine Output)

For patients with no urine output, furosemide should be administered, but only after confirming there is no mechanical obstruction such as a blocked urinary catheter or urinary retention. 1

Initial Assessment

When faced with a patient with no urine output (anuria), follow this algorithmic approach:

1. Rule out mechanical obstruction:

   • Check for kinked or blocked urinary catheter
   • Perform bladder scan to rule out urinary retention
   • If catheter is present, flush gently or replace 1

2. Assess volume status:

   • Clinical examination (peripheral perfusion, capillary refill, pulse rate, blood pressure, jugular venous pressure)
   • Fluid balance (intake, output, weight) 1

Management Based on Volume Status

For Hypovolemic Patients:

• Administer fluid resuscitation with crystalloids (avoid potassium-containing solutions)
• Initial fluid bolus of 20 mL/kg for patients with tachycardia or signs of sepsis 1
• Continue rapid fluid administration until clinical signs of hypovolemia improve
• Target adequate central venous pressure and urine output >0.5 mL/kg/h 1

For Euvolemic/Hypervolemic Patients:

• Administer IV furosemide:

  • Initial dose: 40-80 mg IV bolus 1, 2
  • If no response, increase to 100-200 mg IV bolus
  • For persistent anuria, consider continuous infusion at 5-10 mg/hour 2
  • Maximum daily dose should remain <240 mg during first 24 hours 3

• For diuretic resistance:

  • Add thiazide diuretic (metolazone 2.5-10 mg PO) 4
  • Metolazone and furosemide administered concurrently have produced marked diuresis in patients with edema or ascites refractory to treatment with maximum doses of either drug alone 4

Monitoring and Follow-up

• Monitor fluid status, electrolytes, and renal function closely
• Assess urine output hourly
• Target urine output >0.5 mL/kg/h 1
• If oliguria persists despite adequate volume resuscitation, seek urgent nephrology consultation 1

Special Considerations

1. In crush injury or rhabdomyolysis:

   • Early intensive fluid resuscitation is critical
   • Initial fluid infusion rate should be 1000 mL/h, tapered by at least 50% after 2 hours 1
   • Avoid potassium-containing balanced salt solutions 1

2. In acute kidney injury:

   • Do not use furosemide unless hypervolemia, hyperkalemia, or renal acidosis is present 1
   • Do not use dopamine in an attempt to improve renal function 1

3. In heart failure patients:

   • Low-dose continuous infusion of furosemide (5-6 mg/h) can be effective in achieving diuresis 2
   • Insufficient natriuretic response (urine sodium <50 mmol/L) is associated with poor outcomes 5

Pitfalls to Avoid

1. Don't treat the numbers, treat the patient: Furosemide cannot improve kidney function but may even be harmful to the kidney. Treat the patient, not just the urine output! 1

2. Don't forget to check for mechanical obstruction: As illustrated in a case report, a distended bladder due to urinary retention can mimic renal failure. Always verify there is truly no urine production before assuming renal failure 1

3. Don't delay renal replacement therapy consultation: If anuria persists despite appropriate interventions, early nephrology consultation for possible renal replacement therapy is essential 1

4. Don't miss the opportunity to use diuretics in patients with residual renal function: Even small doses of furosemide (40 mg) can double urine output in patients with chronic kidney disease who have residual renal function 6

By following this structured approach, you can systematically address anuria while avoiding common pitfalls in management.