Should diuretics be withheld in the setting of acute kidney injury (AKI)?

From the Guidelines

Diuretics should be withheld in the setting of acute kidney injury (AKI), except in cases of volume overload, where their use may improve outcomes. This recommendation is based on the most recent and highest quality evidence, which suggests that diuretics do not prevent AKI and may lead to increased mortality 1. The use of diuretics in AKI can worsen kidney function by causing further volume depletion, electrolyte abnormalities, and reduced renal perfusion.

Key Considerations

• The priority in AKI should be identifying and treating the underlying cause while optimizing volume status.
• If the AKI is pre-renal (caused by volume depletion or hypoperfusion), diuretics would exacerbate the problem by further reducing intravascular volume.
• For patients with heart failure or volume overload despite AKI, limited and careful use of diuretics may still be necessary under close monitoring of kidney function, electrolytes, and volume status.
• The decision to hold or continue diuretics should be individualized based on the patient's volume status, the etiology of AKI, and the risk-benefit assessment of diuretic therapy in their specific clinical context.

Evidence Summary

The KDIGO practice guideline on acute kidney injury suggests not using diuretics to treat AKI, except in the management of volume overload (2C) 1. A study using data from the Fluid and Catheter Treatment Trial found that a cumulative positive daily fluid balance in patients who developed AKI was associated with higher mortality, whereas higher furosemide doses had a protective effect on mortality in those patients with AKI 1. Another commentary on the 2012 KDIGO clinical practice guideline for acute kidney injury highlights the need for knowledge translation in the appropriate use of diuretics in AKI, particularly in the management of fluid overload 1.

From the Research

Diuretics in Acute Kidney Injury (AKI)

• The use of diuretics in AKI has been extensively studied, with mixed results 2, 3, 4, 5, 6.
• Loop diuretics, such as furosemide, have been shown to be ineffective in reducing mortality, the need for dialysis, or improving renal function in patients with AKI 2, 3, 5.
• However, diuretics may be beneficial in certain situations, such as preventing fluid overload and pulmonary edema, as long as euvolemia is maintained 3, 4, 6.
• The furosemide stress test may also be useful in identifying patients at higher risk of AKI progression 3.
• It is essential to note that diuretics should only be used short-term and at high doses, while avoiding simultaneous use of nephrotoxins, and that persistent use of diuretics can lead to delayed initiation of dialysis or ultrafiltration and increased risk of negative patient outcomes 4.

Key Findings

• No evidence suggests that loop diuretics reduce mortality, the need for dialysis, or improve renal function in AKI patients 2, 3, 5.
• Diuretics may be effective in preventing AKI when applied in lower doses for a prolonged period in patients with mild to moderate renal insufficiency 2.
• Fluid overload should be avoided, and early initiation of continuous renal replacement therapies may be preferable if fluid overload develops and the patient does not respond to diuretics 4, 6.

Clinical Implications

• The management of AKI remains largely supportive, and the use of diuretics should be guided by careful consideration of the patient's hemodynamic status and fluid balance 2, 5, 6.
• Isotonic crystalloids should be used instead of colloids for initial expansion of intravascular volume in patients at risk for AKI or with AKI 6.
• Aggressive fluid repletion in the early setting may be beneficial, but fluid overload should be avoided, as it has been associated with increased mortality and reduced rate of kidney recovery in observational studies 4, 6.