What is the management of kidney injury in chronic kidney disease (CKD)?

Management of Acute Kidney Injury in Chronic Kidney Disease

Patients with CKD are at substantially increased risk for acute kidney injury (AKI) and require heightened vigilance, aggressive prevention strategies, and structured post-AKI follow-up to prevent progression to kidney failure. 1

Recognition of AKI Risk in CKD Patients

• All people with CKD should be considered at increased risk of AKI, even after adjusting for comorbid conditions. 1
• The relationship between CKD and AKI is bidirectional: CKD increases AKI risk, and AKI episodes accelerate CKD progression and increase risk of incident CKD. 1
• This risk increases with age, making older CKD patients particularly vulnerable. 1

Prevention Strategies

Nephrotoxin Avoidance

• Avoid NSAIDs in all CKD patients due to high nephrotoxicity risk and potential for precipitating AKI. 2
• Review and limit over-the-counter medicines and herbal remedies that may be harmful. 1
• When prescribing potentially nephrotoxic medications, always weigh benefits versus harms and monitor closely. 1

Medication Management

• Adjust all medication dosages according to kidney function using validated eGFR equations. 1, 3
• For drugs with narrow therapeutic windows, monitor eGFR, electrolytes, and therapeutic drug levels regularly in both outpatient and hospital settings. 1
• Use therapeutic drug monitoring during aminoglycoside administration. 1

Contrast Media Considerations

• Intravenous iodinated contrast does not carry large risks in CKD patients and imaging studies should be performed based on diagnostic value and impact on management. 1
• Avoid iodinated contrast when possible in patients with eGFR <30 mL/min/1.73m² due to contrast-induced nephropathy risk. 4
• If gadolinium-based MRI contrast is required, use Group II agents at the lowest diagnostic dose. 4

Volume and Hemodynamic Management

• Use isotonic crystalloids rather than colloids for volume expansion in patients at risk of AKI. 1
• Use vasopressors and fluids appropriately to treat patients in shock. 1
• Avoid diuretics, dopamine, and recombinant human IGF-1 to prevent or treat AKI as they lack efficacy. 1

Post-AKI Management and Follow-up

Risk Stratification for Follow-up

• Target follow-up to highest-risk populations: patients with baseline CKD, severe AKI (stage 3), or incomplete recovery of kidney function at hospital discharge. 1
• Patients with mild, readily reversible AKI (e.g., volume depletion without baseline CKD) are at relatively low risk of progressive CKD. 1
• The risk of progressive CKD after AKI is directly related to AKI severity, making stage-based follow-up timing appropriate. 1

Timing of Follow-up

• Patients with stage 3 AKI require far earlier post-discharge follow-up than those with stage 1 AKI. 1
• Patients with AKI in the setting of pre-existing CKD or those who develop worsening CKD as a consequence of AKI represent a particularly high-risk group requiring close monitoring. 1

Comprehensive CKD Management to Prevent AKI

Blood Pressure Control

• Target BP <130/80 mmHg in patients with albuminuria ≥30 mg/24 hours and <140/90 mmHg in those without albuminuria. 3, 2
• Initiate ACE inhibitors or ARBs as first-line therapy, particularly in patients with albuminuria >300 mg/24 hours. 1, 3
• Titrate RAAS inhibitors to maximum tolerated dose in patients with moderately-to-severely increased albuminuria. 2

SGLT2 Inhibitor Therapy

• Initiate SGLT2 inhibitors in patients with eGFR ≥20 mL/min/1.73 m² who have type 2 diabetes, ACR ≥200 mg/g, or heart failure (Grade 1A). 2
• SGLT2 inhibitors reduce risk of kidney failure, kidney function decline, and cardiovascular disease. 1

Lifestyle Modifications

• Limit sodium intake to <2 g per day. 1, 3
• Maintain protein intake at 0.8 g/kg body weight/day in CKD G3-G5. 3
• Encourage 150 minutes weekly of moderate-intensity physical activity adjusted to cardiovascular tolerance. 3
• Achieve smoking cessation and maintain healthy body weight (BMI 20-25 kg/m²). 1

Glycemic Control

• Target hemoglobin A1c of approximately 7% in diabetic patients. 1, 2
• Use metformin as first-line therapy when eGFR ≥30 mL/min/1.73m². 3

Cardiovascular Risk Reduction

• Prescribe statin therapy for all adults ≥50 years with CKD regardless of GFR category. 3, 2
• For adults 18-49 years, initiate statins if they have coronary disease, diabetes, prior stroke, or 10-year coronary event risk >10%. 3

Monitoring and Surveillance

• Monitor eGFR and electrolytes regularly, with frequency increasing based on worsening GFR category and albuminuria level. 2
• Monitor for hyperkalemia, especially in patients on RAAS inhibitors or with eGFR <30 mL/min/1.73m². 4
• Measure blood pressure at every clinical encounter using standardized technique. 4
• Screen for and manage metabolic complications including acidosis (treat when bicarbonate <18 mmol/L), hyperphosphatemia, and anemia. 3

Nephrology Referral

• Refer to nephrology when 5-year kidney failure risk is 3-5% or when eGFR <30 mL/min/1.73m² or albuminuria ≥300 mg per 24 hours. 3
• Use validated risk prediction equations incorporating eGFR and albuminuria to guide referral timing. 3
• A 2-year kidney failure risk >10% triggers multidisciplinary care initiation. 3

Critical Pitfalls to Avoid

• Do not use stage-based AKI management protocols alone; base management on overall clinical status, specific AKI cause, trends in kidney function, comorbidities, volume status, and electrolyte disturbances. 1
• Do not overwhelm the system with 3-month follow-up of all stage 1 AKI patients; prioritize high-risk populations. 1
• Avoid combining ACE inhibitors with ARBs as evidence is insufficient to support this practice for preventing CKD progression. 1
• Do not withhold appropriate diagnostic imaging due to unfounded contrast concerns in patients with moderate CKD. 1