In a 70‑year‑old patient with chronic heart failure admitted for acute‑on‑chronic dyspnea and peripheral edema who also has stage IV chronic kidney disease (eGFR ≈15‑29 mL/min), how should diuresis be managed?

Management of Acute Decompensated Heart Failure with Stage IV CKD

In a 70-year-old patient with acute-on-chronic heart failure and stage IV CKD (eGFR 15-29 mL/min), proceed with aggressive intravenous loop diuretic therapy, accepting moderate rises in creatinine (up to 25-30% or <2.5 mg/dL) as long as clinical decongestion is achieved, and add sequential nephron blockade with metolazone if diuretic resistance develops. 1, 2

Initial Assessment and Stabilization

Confirm volume overload status by examining for pulmonary congestion (rales, orthopnea, dyspnea at rest), peripheral edema, elevated jugular venous pressure, and consider point-of-care ultrasound to assess inferior vena cava diameter and lung B-lines. 1

Check baseline labs immediately: serum creatinine, blood urea nitrogen, electrolytes (especially potassium), and natriuretic peptides if diagnosis uncertain. 1

Monitor vital signs closely: systolic blood pressure, heart rate, oxygen saturation, and urine output every 2-4 hours until stabilized. 1

Diuretic Strategy in Stage IV CKD

Step 1: High-Dose Intravenous Loop Diuretics

Start with intravenous furosemide at 2.5 times the patient's usual oral daily dose (or 80-160 mg IV if diuretic-naïve), given either as bolus every 12 hours or continuous infusion. 1 The 2012 ESC guidelines note that high-dose strategies produce greater dyspnea improvement despite transient creatinine rises. 1

Assess diuretic response at 2 hours: measure spot urine sodium concentration. A value <50-70 mEq/L indicates inadequate response and diuretic resistance. 1 Alternatively, urine output <100-150 mL/hour during the first 6 hours signals insufficient response. 1

Step 2: Sequential Nephron Blockade for Diuretic Resistance

If loop diuretics alone fail to achieve adequate diuresis, add metolazone 2.5-5 mg orally once daily to create synergistic blockade at both the loop of Henle and distal tubule. 1, 3 This combination is particularly effective in stage IV CKD where thiazides alone are ineffective (eGFR <30 mL/min). 1, 2

Monitor electrolytes and renal function every 1-2 days when using combination diuretics, as metolazone can cause profound fluid and electrolyte losses. 3

Step 3: Consider Ultrafiltration for Refractory Cases

If persistent congestion remains despite maximized diuretic therapy (high-dose loop diuretic plus metolazone), consider ultrafiltration as a mechanical method of fluid removal. 1 The 2009 ACC/AHA guidelines note this can restore responsiveness to conventional diuretic doses in diuretic-resistant patients. 1

Managing Worsening Renal Function During Diuresis

Accept creatinine rises up to 25-30% or absolute values <2.5 mg/dL without stopping therapy, provided the patient is achieving clinical decongestion (reduced dyspnea, decreased edema, weight loss). 1, 2 The ACC/AHA guidelines explicitly state that small-to-moderate BUN and creatinine elevations should not lead to minimizing therapy intensity. 1

Distinguish true worsening renal function from hemoconcentration: rising creatinine with clinical improvement and hemoconcentration (rising hemoglobin/hematocrit) often reflects successful decongestion rather than kidney injury. 1

Stop diuretics only if: 1, 2

• Creatinine rises >30% or exceeds 2.5 mg/dL
• Severe oliguria develops (<15 mL/hour) despite adequate filling pressures
• Hemodynamic instability occurs (systolic BP <85 mmHg with signs of hypoperfusion)

Guideline-Directed Medical Therapy Optimization

ACE Inhibitors/ARBs

Continue or cautiously initiate ACE inhibitors at low doses even in stage IV CKD, as they improve mortality in heart failure. 1, 2, 4, 5, 6 Start with low doses (e.g., enalapril 2.5 mg twice daily, lisinopril 2.5 mg daily) and titrate slowly. 1, 2

Check potassium and creatinine 1-2 weeks after starting or uptitrating ACE inhibitors. 1, 2 Accept creatinine rises up to 25-30% without discontinuation. 2

Avoid starting ACE inhibitors during acute decompensation if systolic BP <80 mmHg or signs of hypoperfusion exist. 1

Beta-Blockers

Do NOT initiate beta-blockers during acute decompensation with significant fluid overload or need for IV inotropes. 1, 2 Beta-blockers should only be started after clinical stability is achieved. 1, 2

Continue home beta-blockers at reduced doses if patient is already taking them, unless severe hypotension or bradycardia develops. 4, 5

Mineralocorticoid Receptor Antagonists

Use spironolactone or eplerenone with extreme caution in stage IV CKD due to high hyperkalemia risk. 1, 2 Only consider if potassium <5.0 mmol/L and creatinine <2.5 mg/dL. 2

If used, start spironolactone 12.5 mg daily and recheck potassium and creatinine after 4-6 days. 2 Discontinue if potassium rises >5.5 mmol/L. 2

SGLT2 Inhibitors

Consider adding an SGLT2 inhibitor (dapagliflozin, empagliflozin) as these improve cardiovascular and renal outcomes even in stage IV CKD (eGFR >20 mL/min). 2, 4, 5, 6 They also reduce hyperkalemia risk, facilitating safer use of RAAS inhibitors. 2

Critical Medications to Avoid

Absolutely avoid NSAIDs as they promote sodium retention, worsen renal function, and blunt diuretic efficacy. 1, 2

Do not use thiazide diuretics as monotherapy when eGFR <30 mL/min—they are ineffective. 1, 2 Use only in combination with loop diuretics for synergistic effect. 1, 2

Avoid routine intermittent inotrope infusions (dobutamine, milrinone) as they increase mortality. 1 Use only for cardiogenic shock or severe hypoperfusion. 1

Discharge Planning and Follow-Up

Do not discharge until euvolemia is achieved and a stable diuretic regimen is established. 1 Patients discharged with residual congestion have high readmission rates. 1

Establish a target "dry weight" for ongoing diuretic adjustment at home. 1

Restrict dietary sodium to ≤2 grams daily and educate on daily weight monitoring (report gains >2-3 pounds in 1-2 days). 1, 2

Recheck electrolytes and renal function 1-2 weeks post-discharge, then monthly for 3 months, then every 3-6 months. 1, 2

Common Pitfalls to Avoid

Stopping diuretics prematurely due to rising creatinine when the patient still has clinical congestion leads to treatment failure and readmission. 1

Using inadequate loop diuretic doses in stage IV CKD—these patients require higher doses due to reduced renal perfusion and drug delivery to tubules. 1

Withholding ACE inhibitors entirely due to fear of worsening renal function deprives patients of mortality benefit. 2, 4, 5, 6

Initiating multiple RAAS inhibitors simultaneously (ACE inhibitor + MRA) in stage IV CKD dramatically increases hyperkalemia risk. 2