What are the treatment options for Acute Kidney Injury (AKI)?

From the Guidelines

The treatment for acute kidney injury (AKI) should prioritize addressing the underlying cause, supporting kidney function, and initiating renal replacement therapy (RRT) when life-threatening changes in fluid, electrolyte, and acid-base balance exist, as recommended by the KDIGO clinical practice guideline 1.

Initial Management

Initial management includes stopping nephrotoxic medications, ensuring adequate hydration, and maintaining proper blood pressure. For volume depletion, intravenous fluids like normal saline or lactated Ringer's solution are administered.

• If the patient is hypervolemic, diuretics such as furosemide may be used, though they don't improve kidney recovery, as suggested by the KDIGO guideline 1.
• Electrolyte imbalances require correction—hyperkalemia might need insulin with glucose, sodium bicarbonate, or calcium gluconate.
• Metabolic acidosis may require sodium bicarbonate if severe, as explored in the context of fluid management and hemodynamic support 1.

Renal Replacement Therapy (RRT)

In severe cases, RRT is indicated for refractory hyperkalemia, severe acidosis, volume overload unresponsive to diuretics, or uremic symptoms.

• The timing of dialysis initiation should be individualized based on clinical status rather than specific laboratory values, considering the broader clinical context and trends of laboratory tests 1.
• The decision to start RRT should consider the presence of conditions that can be modified with RRT, rather than single BUN and creatinine thresholds alone, as recommended by the KDIGO guideline 1.
• The choice of RRT modality, such as continuous renal replacement therapy (CRRT) or intermittent hemodialysis (IHD), should be based on the patient's hemodynamic stability and clinical status, with CRRT suggested for hemodynamically unstable patients or those with acute brain injury 1.

Monitoring and Adjustments

AKI treatment requires close monitoring of kidney function, urine output, and electrolytes to guide therapy adjustments and prevent complications during the recovery phase.

• The dose of RRT should be prescribed before starting each session, with frequent assessment of the actual delivered dose to adjust the prescription, as recommended by the KDIGO guideline 1.
• The goal of RRT should be to achieve electrolyte, acid-base, solute, and fluid balance that meets the patient's needs, with a recommended Kt/V of 3.9 per week for intermittent or extended RRT, and an effluent volume of 20-25 mL/kg/h for CRRT 1.

From the Research

Treatment Approaches for Acute Kidney Injury (AKI)

• The management of AKI is founded on treating the underlying cause, but supportive care via fluid management, vasopressor therapy, and kidney replacement therapy (KRT) is also crucial 2.
• Blood pressure targets are often higher in AKI, and these can be achieved with fluids and vasopressors, some of which may be more kidney-protective than others 2.
• Initiation of KRT is controversial, and studies have not consistently demonstrated any benefit to early start dialysis 2.

General Management Principles

• Accurate diagnosis of the underlying cause is key to successful management and includes a focused history and physical examination, serum and urine electrolyte measurements, and renal ultrasonography when risk factors for a postrenal cause are present 3.
• General management principles for AKI include determination of volume status, fluid resuscitation with isotonic crystalloid, treatment of volume overload with diuretics, discontinuation of nephrotoxic medications, and adjustment of prescribed drugs according to renal function 3.
• Additional supportive care measures may include optimizing nutritional status and glycemic control 3.

Role of Kidney Replacement Therapy

• AKI can be lethal, and kidney replacement therapy is frequently required 4.
• Conservative management should first be attempted for patients with AKI, and if conservative management fails, renal replacement therapy or hemodialysis can be used 5.

Importance of Early Detection and Prevention

• Even one episode of AKI increases the risk of cardiovascular disease, chronic kidney disease, and death, making early determination of etiology, management, and long-term follow-up of AKI essential 6.
• Prevention and early detection of AKI are crucial, as AKI has a poor prognosis in critically ill patients and can lead to long-term consequences such as CKD and cardiovascular morbidity 4.