From the Guidelines
Managing acute kidney injury (AKI) in patients with stage 4 chronic kidney disease (CKD) requires prompt discontinuation of nephrotoxic agents, careful monitoring of fluid status and electrolytes, and consideration of renal replacement therapy when necessary, as outlined in the KDIGO guidelines 1. The immediate priorities are to identify and treat the underlying cause of AKI, adjust medication dosages based on the patient's current estimated glomerular filtration rate, and maintain fluid and electrolyte balance.
- Potentially nephrotoxic medications, such as NSAIDs, aminoglycosides, and contrast agents, should be discontinued when possible, as recommended by the KDIGO guidelines 1.
- Fluid management is critical, with the goal of achieving euvolemia through careful assessment of fluid status, and avoiding both dehydration and volume overload.
- Electrolyte abnormalities, particularly hyperkalemia, should be monitored closely and treated promptly with insulin plus glucose, sodium bicarbonate, or sodium polystyrene sulfonate.
- Blood pressure should be optimized, typically aiming for <130/80 mmHg, using ACE inhibitors or ARBs cautiously due to their potential to worsen kidney function acutely.
- Daily monitoring of kidney function, electrolytes, and urine output is essential, with consideration of alternatives to radiocontrast and noninvasive diagnostic workup as needed 1.
- Nutritional support should include protein restriction and potassium and phosphate restriction as needed.
- Renal replacement therapy should be considered for refractory hyperkalemia, volume overload, uremic symptoms, or severe acidosis, although the decision to initiate KRT for AKI is usually made in the early period or once the patient develops CKD 1. The comprehensive approach to managing AKI in CKD stage 4 patients aims to prevent progression to end-stage renal disease and improve patient outcomes, as emphasized by the importance of checking for change in drug dosing 1 and proactive preparation for renal replacement therapy 1.
From the Research
Management of Acute Kidney Injury (AKI) in Patients with Chronic Kidney Disease (CKD) Stage 4
To manage AKI in patients with CKD stage 4, the following steps can be taken:
- Identify the cause of AKI and address it promptly 2
- Monitor serum creatinine levels and urine output to assess the severity of AKI 3
- Control fluid volume status and achieve euvolemia 2
- Optimize nutrition and control blood glucose levels 2
- Consider pharmacotherapy, such as angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs), to reduce the risk of mortality and recurrent AKI 4
Assessment and Diagnosis
The diagnosis of AKI is based on an increase in serum creatinine levels or a decrease in urine output 3. The Kidney Disease: Improving Global Outcomes (KDIGO) criteria define AKI as an increase in serum creatinine levels of 0.3 mg/dL or more within 48 hours, or a 1.5-fold increase in serum creatinine levels within 7 days, or a decrease in urine output to less than 0.5 mL/kg/hour for 6 hours 3, 2.
Treatment and Management
The treatment of AKI involves addressing the underlying cause, controlling fluid volume status, and optimizing nutrition and blood glucose levels 2. The use of ACEi or ARBs may be beneficial in reducing the risk of mortality and recurrent AKI in patients with AKI 4. However, the prescription rate of these agents is often lower than recommended, particularly in patients with CKD stage G1-G5 aged <75 years 5.
Considerations for CKD Stage 4 Patients
Patients with CKD stage 4 are at higher risk of developing AKI and progressing to end-stage renal disease (ESRD) 6. Therefore, it is essential to closely monitor these patients and address any potential causes of AKI promptly. The use of ACEi or ARBs may be beneficial in reducing the risk of mortality and recurrent AKI in these patients 4. However, the decision to use these agents should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history.