What is the treatment for acute kidney injury (AKI) on chronic kidney disease (CKD) for a patient on diuretic, without congestive heart failure (CHF)?

From the Guidelines

For a patient with acute kidney injury (AKI) superimposed on chronic kidney disease (CKD) who is on diuretics without congestive heart failure (CHF), the first step is to temporarily discontinue the diuretic medication, as recommended by the most recent guidelines 1. When managing a patient with AKI on CKD who is taking diuretics without CHF, it is crucial to prioritize their volume status and renal function.

• The patient's volume status should be assessed immediately, and if they are dehydrated, cautious intravenous fluid repletion with isotonic saline or balanced crystalloids should be initiated, as suggested by the KDIGO guidelines 1.
• Monitoring of serum creatinine, blood urea nitrogen, electrolytes (particularly potassium), and urine output should be done daily to assess the patient's renal function and guide further management.
• Nephrotoxic medications, including NSAIDs, aminoglycosides, and contrast agents, should be avoided to prevent further renal injury, as recommended by the KDIGO guidelines 1.
• If hyperkalemia is present, it should be treated accordingly with insulin/glucose, calcium gluconate, or sodium polystyrene sulfonate as needed.
• The underlying cause of AKI should be identified and addressed, which may include pre-renal causes (volume depletion possibly from excessive diuresis), intrinsic renal causes, or post-renal obstruction.
• Diuretics can contribute to AKI by causing volume depletion and decreased renal perfusion, particularly in CKD patients who already have compromised kidney function, as noted in the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1.
• Once the AKI resolves and volume status normalizes, diuretic therapy can be cautiously reintroduced at a lower dose if clinically indicated, with close monitoring of kidney function and electrolytes, as suggested by the clinical practice update on the evaluation and management of acute kidney injury in patients with cirrhosis 1.

From the Research

Treatment of Acute Kidney Injury (AKI) in Patients with Chronic Kidney Disease (CKD) on Diuretics without Congestive Heart Failure (CHF)

• The use of diuretics in patients with AKI and CKD is a common practice, but its effectiveness is still debated 2, 3, 4, 5, 6.
• A systematic review of the literature found that loop diuretics do not reduce mortality, the need for dialysis, or length of hospital stay in patients with AKI 2.
• Furosemide, a potent loop diuretic, may be useful in achieving fluid balance and facilitating mechanical ventilation in patients with acute lung injury without hemodynamic instability 5.
• The severity of AKI establishes whether a patient will respond to furosemide, and continuous infusion of furosemide may be superior to bolus doses in achieving diuretic response 3.
• A Cochrane systematic review found that diuretics may reduce the risk of AKI and probably reduce the incidence of kidney replacement therapy (KRT) use when used for prevention, but may make little or no difference when used for treatment 6.

Diuretic Use in AKI Prevention and Treatment

• Diuretics may reduce the risk of AKI (RR 0.75,95% CI 0.61 to 0.92) and probably reduce any use of KRT (RR 0.63,95% CI 0.43 to 0.91) and death (RR 0.73,95% CI 0.59 to 0.92) when used for prevention 6.
• When used for treatment, diuretics may make little or no difference to any use of KRT (RR 0.93,95% CI 0.83 to 1.04) or death (RR 1.08,95% CI 0.96 to 1.22) 6.
• Diuretics may increase hypotension (RR 1.99,95% CI 1.16 to 3.41) and probably increase arrhythmias (RR 1.62,95% CI 1.12 to 2.33) when used for treatment 6.

Clinical Implications

• The use of diuretics in patients with AKI and CKD should be individualized and based on the severity of AKI and the patient's clinical condition 2, 3, 4, 5, 6.
• Continuous infusion of furosemide may be considered in patients with severe AKI, but more studies are needed to support its use 3.
• The benefits and risks of diuretic use in AKI prevention and treatment should be carefully weighed, and more research is needed to explore the role of diuretics in established AKI 6.