What is the effect of diuresis in patients with Impaired Renal Function (IRF)?

From the Guidelines

Diuretics should be used cautiously in renal failure, with loop diuretics like furosemide being the preferred option. For patients with acute kidney injury or chronic kidney disease, furosemide can be started at 40-80mg IV or oral doses, potentially increasing to 160-200mg if needed based on response 1. Thiazide diuretics are generally ineffective when creatinine clearance falls below 30 ml/min. In severe renal failure, continuous furosemide infusions (10-20mg/hour) may be more effective than bolus dosing. Close monitoring of electrolytes, especially potassium, sodium, and magnesium, is essential during diuretic therapy in renal failure. Fluid status should be carefully assessed to avoid over-diuresis, which can worsen kidney function. The mechanism behind loop diuretics' effectiveness in renal failure relates to their action in the thick ascending limb of the loop of Henle, which remains somewhat functional even in compromised kidneys. Combination therapy with a loop diuretic and a thiazide-like diuretic (metolazone 2.5-10mg) may overcome diuretic resistance in severe cases, but requires very careful monitoring due to increased risk of electrolyte abnormalities and volume depletion.

Some key points to consider when using diuretics in renal failure include:

• The dose requirement must be tailored to the individual patient’s needs and requires careful clinical monitoring 1.
• Loop diuretics are generally preferred over thiazide diuretics in patients with moderate or severe heart failure.
• Close monitoring of potassium, sodium, and creatinine levels is essential during diuretic therapy.
• Combination therapy with a loop diuretic and a thiazide-like diuretic may be effective in overcoming diuretic resistance, but requires careful monitoring.

It's also important to note that diuretic resistance can be overcome by the intravenous administration of diuretics, the use of 2 or more diuretics in combination, or the use of diuretics together with drugs that increase renal blood flow 1. However, these strategies require careful monitoring and adjustment to avoid adverse effects.

Overall, the use of diuretics in renal failure requires careful consideration of the patient's individual needs and close monitoring to avoid adverse effects. The goal of diuretic therapy should be to improve symptoms and prevent complications, while minimizing the risk of adverse effects.

From the FDA Drug Label

As with any effective diuretic, electrolyte depletion may occur during furosemide therapy, especially in patients receiving higher doses and a restricted salt intake In patients with severe symptoms of urinary retention (because of bladder emptying disorders, prostatic hyperplasia, urethral narrowing), the administration of furosemide can cause acute urinary retention related to increased production and retention of urine. In patients at high risk for radiocontrast nephropathy, furosemide can lead to a higher incidence of deterioration in renal function after receiving radiocontrast compared to high-risk patients who received only intravenous hydration prior to receiving radiocontrast. Reversible elevations of BUN may occur and are associated with dehydration, which should be avoided, particularly in patients with renal insufficiency

Diuresing in renal failure should be done with caution.

• Furosemide may cause dehydration and electrolyte depletion, especially in patients with renal insufficiency.
• Monitoring of serum electrolytes, CO2, creatinine, and BUN is necessary to avoid complications.
• Spironolactone can cause hyperkalemia, hypotension, and worsening renal function, particularly in patients with impaired renal function 2 3.

From the Research

Diuresing in Renal Failure

• Diuretic drugs are used to induce diuresis in patients with chronic kidney disease (CKD) by acting on electrolyte transporters in the kidney 4.
• The use of diuretics in CKD is based on the restriction of dietary sodium intake and the enhancement of urinary sodium excretion to manage sodium and volume overload 4.
• Different types of diuretics, such as thiazide, loop diuretics, and mineralocorticoid receptor antagonists, are used to manage hypertension, volume overload, and electrolyte imbalances in CKD patients 4, 5.

Management of Fluid Overload

• Diuretics can be used to manage fluid overload in patients with acute decompensated heart failure due to volume overload, with a combination of triple diuretics and an aquaretic-like vasopressin antagonist showing promising results 6.
• Combination therapy with low-dose metolazone and furosemide can be an effective "needleless" approach in managing refractory fluid overload in elderly renal failure patients under palliative care 7.
• Fluid management in CKD requires a multimodal clinical approach, including the assessment of fluid status, determination of fluid distribution, and management of fluid overload to prevent adverse cardiovascular outcomes 8.

Complications and Considerations

• The use of diuretics in CKD patients can be associated with complications such as intravascular volume depletion, azotemia, ototoxicity, hyperlipidemia, and electrolyte disturbances 5.
• The definition of fluid overload in CKD is ambivalent, and its relation to symptom burden has not been well studied, highlighting the need for further research in this area 8.