What is the most appropriate treatment for a patient with acute decompensated heart failure (ADHF) experiencing diuretic resistance on furosemide (Lasix) 40 milligrams intravenous (IV) twice daily?

Management of Diuretic Resistance in Acute Decompensated Heart Failure

For a patient with acute decompensated heart failure experiencing diuretic resistance on furosemide 40 mg IV twice daily, the most appropriate treatment option is to re-bolus with furosemide 40 mg IV × one dose and start furosemide IV infusion.

Understanding Diuretic Resistance in ADHF

Diuretic resistance is a common challenge in acute decompensated heart failure (ADHF) management that requires prompt intervention to achieve adequate decongestion:

• Diuretic resistance is characterized by inadequate diuretic response despite standard dosing of loop diuretics 1
• Patients with hypotension (SBP < 90 mmHg), severe hyponatremia, or acidosis are particularly likely to experience diuretic resistance 1
• Continuous infusion of loop diuretics may overcome diuretic resistance by maintaining more consistent drug levels 2

Evidence-Based Management Strategy

First-Line Approach: Continuous Infusion

• When diuresis is inadequate with intermittent boluses, guidelines recommend intensifying the diuretic regimen by using continuous infusion of loop diuretics 1
• A randomized controlled trial in high-risk ADHF patients showed that continuous infusion of furosemide achieved:
  • Greater total urinary output (10,020 ml vs. 8,612 ml, p=0.04)
  • Higher rate of freedom from congestion (48% vs. 25%, p=0.04)
  • Lower treatment failure rate (15% vs. 38%, p=0.02) 2

Implementation of Continuous Infusion

• Initial approach: Administer a loading dose (re-bolus with furosemide 40 mg IV) followed by continuous infusion 1, 3
• The total furosemide dose should remain < 100 mg in the first 6 hours and < 240 mg during the first 24 hours 1
• Close monitoring is essential:
  • Frequent assessment of urine output
  • Daily monitoring of electrolytes, renal function
  • Assessment of clinical signs of congestion 1

Alternative Strategies for Diuretic Resistance

If continuous infusion alone is insufficient, consider these additional options:

Combination Diuretic Therapy

• Adding a thiazide diuretic or aldosterone antagonist can be effective for diuretic resistance 1
• Thiazides (hydrochlorothiazide 25 mg PO) or aldosterone antagonists (spironolactone 25-50 mg PO) can be used in combination with loop diuretics 1
• Combination therapy in lower doses is often more effective with fewer side effects than higher doses of a single agent 1

High-Dose Strategy

• Increasing the dose of furosemide may be considered if the initial approach fails 1
• However, high doses of diuretics may lead to:
  • Hypovolemia and hyponatremia
  • Increased risk of hypotension with ACEIs/ARBs
  • Potential for worsening renal function 1, 4

Monitoring and Safety Considerations

• Regular monitoring is essential during diuretic therapy 1:

  • Symptoms and clinical status
  • Urine output (consider bladder catheterization for accurate measurement)
  • Renal function and electrolytes
  • Body weight

• Potential adverse effects to monitor 1:

  • Electrolyte abnormalities (hypokalemia, hyponatremia)
  • Hypovolemia and dehydration
  • Worsening renal function
  • Neurohormonal activation

Why Other Options Are Less Appropriate

• Decreasing furosemide dose to 20 mg IV twice daily: This would likely worsen congestion in a patient already experiencing diuretic resistance 1, 3

• Adding bumetanide 2 mg IV twice daily: Using two loop diuretics simultaneously is not recommended as they compete for the same receptor site; changing administration method (to continuous infusion) is preferred 1

• Discontinuing furosemide and starting spironolactone alone: Aldosterone antagonists have weaker diuretic effects than loop diuretics and are recommended as adjuncts, not replacements 1