How do you balance fluid administration in a patient with heart failure (HF) and acute kidney injury (AKI)?

From the Guidelines

Balancing fluid management in a patient with heart failure and acute kidney injury requires careful assessment and monitoring, with a focus on restricting fluids in volume-overloaded patients and cautiously administering fluids in those who are hypovolemic, as recommended by the 2016 European Society of Cardiology guidelines 1.

Key Considerations

• Evaluate the patient's volume status through physical examination, hemodynamic parameters, and laboratory values.
• Implement diuretic therapy with loop diuretics like furosemide (starting at 20-40mg IV, titrating as needed) while closely monitoring renal function, as suggested by the 2013 American College of Cardiology Foundation/American Heart Association guidelines 1.
• Consider continuous infusion (5-10mg/hour) if bolus therapy is ineffective.
• For hypovolemic patients, administer small fluid boluses (250-500mL) and reassess frequently.
• Maintain mean arterial pressure above 65mmHg to ensure adequate renal perfusion, using vasopressors if necessary, as recommended by the 2009 American College of Cardiology Foundation/American Heart Association guidelines 1.

Monitoring and Adjustments

• Monitor urine output (target >0.5mL/kg/hour), daily weights, intake/output, electrolytes, and renal function.
• Adjust diuretic dose and fluid administration based on patient's symptoms and clinical status, as recommended by the 2016 European Society of Cardiology guidelines 1.
• Consider invasive hemodynamic monitoring in patients with persistent symptoms despite empiric adjustment of standard therapies, as suggested by the 2009 American College of Cardiology Foundation/American Heart Association guidelines 1.

Recent Recommendations

• The 2020 Kidney Disease: Improving Global Outcomes conference highlights the importance of determining the optimal indications and targets for fluid and vasoactive drugs to improve kidney outcomes in acute medical illness and in the perioperative setting 1.
• The conference also emphasizes the need to investigate new techniques to detect fluid overload in adults and define fluid overload thresholds to guide management decisions.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Adults: Parenteral therapy with Furosemide Injection should be used only in patients unable to take oral medication or in emergency situations and should be replaced with oral therapy as soon as practical. Therapy should be individualized according to patient response to gain maximal therapeutic response and to determine the minimal dose needed to maintain that response. Close medical supervision is necessary

To balance fluid administration in a patient with heart failure (HF) and acute kidney injury (AKI), the key is individualized therapy. The dose of furosemide should be adjusted based on the patient's response to gain maximal therapeutic effect while minimizing the risk of adverse effects.

• Start with a low dose: The usual initial dose of furosemide is 20 to 40 mg given as a single dose, injected intramuscularly or intravenously.
• Monitor patient response: Close medical supervision is necessary to monitor the patient's response to the medication and adjust the dose as needed.
• Adjust dose cautiously: The dose may be raised by 20 mg and given not sooner than 2 hours after the previous dose until the desired diuretic effect has been obtained.
• Consider geriatric and pediatric patients: Dose selection for the elderly patient should be cautious, usually starting at the low end of the dosing range, and pediatric patients require careful consideration of the initial dose and potential for increased dosage 2.

From the Research

Balancing Fluid Administration in HF and AKI Patients

To balance fluid administration in patients with heart failure (HF) and acute kidney injury (AKI), several strategies can be employed:

• Optimization of diuretic intervention to maximize water and sodium excretion is the first therapeutic strategy in HF patients with fluid overload 3.
• When diuretic therapy fails to relieve congestion, renal replacement therapy represents an alternative option for fluid removal and restoring diuretic responsiveness 3.
• Assessing fluid balance is crucial in HF and AKI, as fluid accumulation is a common theme in the pathophysiology and clinical course of both syndromes 4.
• Determining fluid balance in HF may be complex and depend on underlying pathophysiology, but newer biomarkers (e.g., B-type natriuretic peptides) and novel technology (e.g., impedance cardiography) can be useful for detection and risk identification 4.

Treatment Approaches

Different treatment approaches can be considered:

• Ultrafiltration versus diuretics in congestive heart failure: high-dose diuretics along with vasodilators and other medications are the standard first-line therapy, but sometimes ineffective due to diuretic resistance or AKI 5.
• Extracorporeal ultrafiltration should not be used as an initial or alternative to diuretic therapy, but reserved for diuretic-resistant individuals 6.
• Treatment patterns of patients with acute heart failure who develop AKI involve reducing or discontinuing selected medication classes (e.g., ACE-Is/ARBs, beta-blockers, and diuretics) and fluids administration, with higher discontinuation rates in patients with hypotension 7.

Key Considerations

Key considerations in balancing fluid administration include:

• The interplay between the heart, kidney, and lung in volume regulation and management 3.
• The importance of timely identification of AKI and worsening heart failure in patients with acute decompensated heart failure 6.
• The need for randomized clinical trials to address the treatment of AHF patients with AKI 7.
• The potential trade-off between improving renal outcome and less efficient decongestion when discontinuing or reducing diuretics or neurohormonal blockers 7.