What is the role of albumin and furosemide (Lasix) in managing pulmonary congestion in patients with heart failure and Acute Kidney Injury (AKI)?

Albumin Plus Furosemide in Pulmonary Congestion with Heart Failure and AKI

Furosemide remains the cornerstone treatment for pulmonary congestion in heart failure patients with AKI, but adding albumin does NOT improve outcomes and is not recommended based on the highest quality evidence.

Primary Treatment Approach

Intravenous furosemide should be administered immediately for pulmonary congestion, even in the presence of AKI, provided systolic blood pressure is ≥90 mmHg and the patient has adequate tissue perfusion. 1, 2 The goal is to eliminate fluid overload using the lowest effective dose, as persistent congestion drives mortality more than transient worsening of renal function. 2

Initial Furosemide Dosing Algorithm

• For patients NOT on chronic diuretics: Start with 20-40 mg IV bolus given slowly over 1-2 minutes 1, 3
• For patients already on oral furosemide: Use IV dose at least equal to their home oral dose 1, 3
• For patients on >40 mg daily at home: Consider starting with 80 mg IV 4
• Maximum initial limits: <100 mg in first 6 hours, <240 mg in first 24 hours 2, 4

Critical Pre-Administration Requirements

Absolute contraindications to furosemide include: 1, 2

• Systolic BP <90 mmHg with signs of hypoperfusion
• Marked hypovolemia or anuria
• Severe hyponatremia (<120-125 mmol/L)
• Cardiogenic shock without circulatory support

If hypotension is present, provide circulatory support FIRST (inotropes, vasopressors) before administering diuretics. 1, 2 Giving furosemide to hypotensive patients expecting hemodynamic improvement will worsen hypoperfusion and precipitate shock. 4

The Albumin Question: Evidence-Based Answer

Adding albumin to furosemide does NOT improve diuresis, oxygenation, or clinical outcomes in critically ill patients with hypoalbuminemia and should not be routinely used. 5

The most recent and highest quality study directly addressing this question found:

• No significant difference in urinary furosemide excretion between furosemide alone versus furosemide plus albumin 5
• No significant difference in sodium excretion or urine output between groups 5
• Only a marginally higher furosemide excretion in the first 2 hours with albumin (not sustained) 5

This contradicts older theoretical rationales and demonstrates that albumin co-administration is not an effective intervention for enhancing furosemide efficacy in critically ill hypoalbuminemic patients. 5

Managing Furosemide in the Context of AKI

Accept Transient Worsening of Renal Function

Mild-to-moderate decreases in renal function should be accepted if the patient remains asymptomatic with adequate urine output and perfusion. 2 Excessive concern about rising creatinine leads to underutilization of diuretics and refractory edema, which worsens outcomes more than mild renal dysfunction. 2

Transient worsening of renal function (WRF) associated with aggressive decongestion does not necessarily portend poor prognosis. 6 The DOSE trial showed that higher furosemide doses (2.5 times previous oral dose) resulted in greater dyspnea improvement and fluid loss at the cost of transient WRF, but without long-term harm. 1

Monitoring Requirements

Place a bladder catheter to track hourly urine output and rapidly assess response. 2, 4 Monitor:

• Blood pressure every 15-30 minutes in first 2 hours 4
• Urine output hourly (target >0.5 mL/kg/h) 2, 4
• Electrolytes (sodium, potassium) within 6-24 hours 4
• Renal function (creatinine) within 24 hours 4

When to Stop or Reduce Furosemide

Absolute indications to discontinue furosemide: 2, 4

• Progressive renal failure with anuria
• Severe hyponatremia (<120 mmol/L)
• Severe hypokalemia (<3 mmol/L)
• Marked hypotension with hypoperfusion despite circulatory support

Managing Diuretic Resistance in AKI

If inadequate response after 24-48 hours, use combination therapy rather than escalating furosemide alone: 1

1. Add thiazide diuretic: Hydrochlorothiazide 25 mg PO or metolazone 2.5 mg PO for sequential nephron blockade 1, 2
2. Add aldosterone antagonist: Spironolactone 25-50 mg PO 1
3. Consider continuous infusion: 5-10 mg/hour (maximum 4 mg/min) may be superior to bolus dosing 1, 7
4. Combine with inotropes if low output: Dobutamine or dopamine 2.5 μg/kg/min may enhance renal perfusion 1, 4

Monitor electrolytes closely with combination therapy to avoid severe hypokalemia and further renal dysfunction. 1, 2

Concurrent Vasodilator Therapy

For pulmonary congestion with preserved blood pressure (SBP >110 mmHg), IV nitroglycerin is superior to high-dose furosemide alone and should be started concurrently. 1, 4

• Start IV nitroglycerin 10-20 μg/min, increase by 5-10 μg/min every 3-5 minutes 1
• Combination of high-dose nitrates with low-dose furosemide is more effective than high-dose diuretic alone 4
• This reduces need for aggressive diuresis and minimizes AKI risk 2

Common Pitfalls to Avoid

1. Withholding diuretics due to mild creatinine elevation: Persistent congestion is more harmful than transient WRF 2
2. Using furosemide as monotherapy in acute pulmonary edema: Vasodilators should be started concurrently if BP allows 4
3. Giving furosemide to hypotensive patients without circulatory support first: This worsens shock 2, 4
4. Adding albumin expecting enhanced diuresis: Recent evidence shows no benefit 5
5. Stopping diuretics prematurely: Continue until all clinical evidence of fluid retention is eliminated 2

Maximum Dosing Considerations

Furosemide can be safely escalated up to 500 mg per dose in refractory cases, but doses ≥250 mg must be given as infusion over 4 hours to prevent ototoxicity. 4 If no response at 500 mg with adequate filling pressures, consider:

• Ultrafiltration or dialysis 1, 4
• Continuous venovenous hemofiltration (CVVH) in severe renal dysfunction 1