What are the treatment strategies for Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD)?

Treatment Strategies for Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD)

The management of AKI and CKD requires prompt identification of underlying causes, optimization of hemodynamics, avoidance of nephrotoxins, and targeted interventions based on disease stage to prevent progression and reduce mortality.

Acute Kidney Injury (AKI) Management

Initial Assessment and Classification

• Diagnose AKI using KDIGO criteria 1:
  • Stage 1: Increase in serum creatinine ≥0.3 mg/dL within 48h or 1.5-1.9 times baseline; urine output <0.5 mL/kg/h for >6h
  • Stage 2: Serum creatinine 2.0-2.9 times baseline; urine output <0.5 mL/kg/h for >12h
  • Stage 3: Serum creatinine ≥3.0 times baseline or ≥4.0 mg/dL or RRT initiation; urine output <0.3 mL/kg/h for 24h or anuria for ≥12h

Fluid Management

• Maintain optimal fluid status (euvolemia) as this is critical in reducing AKI incidence and progression 2
• Use isotonic crystalloids rather than colloids for initial volume expansion 2
• Avoid 0.9% saline when possible, preferring balanced crystalloid solutions to reduce hyperchloremic acidosis 2
• Implement restrictive fluid management after initial resuscitation to achieve neutral or negative fluid balance 3
• Monitor fluid status daily through clinical examination and fluid balance records 2

Medication Management

• Review and stop medications that can cause or worsen AKI unless essential 2
• Particular caution with:
  • NSAIDs, especially in combination with diuretics and ACE inhibitors/ARBs (the "triple whammy") 2
  • Aminoglycosides and amphotericin B 2
• Consult pharmacists for optimizing medication choices and dosages 2
• Adjust medication dosages according to current kidney function 2

Renal Replacement Therapy (RRT)

• Consider RRT initiation for:
  • Severe hyperkalemia resistant to medical management
  • Severe metabolic acidosis
  • Volume overload unresponsive to diuretics
  • Uremic symptoms (encephalopathy, pericarditis)
  • Certain toxin ingestions 2
• Individualize RRT modality (continuous vs. intermittent) based on hemodynamic stability and clinical context 4

Monitoring and Follow-up

• Measure serum creatinine, urea, and electrolytes at least every 48 hours or more frequently if clinically indicated 2
• Monitor patients for development or progression of CKD after AKI episode 2
• Schedule follow-up for all AKI survivors at 3 months to assess for CKD development, even those with apparent complete recovery 1

Chronic Kidney Disease (CKD) Management

Diagnosis and Classification

• Define CKD as abnormalities in kidney structure or function persisting >3 months 1
• Classify CKD based on:
  • Cause
  • GFR category (G1-G5)
  • Albuminuria category (A1-A3)

Core Management Strategies

• Blood pressure control: Target <130/80 mmHg using ACE inhibitors or ARBs as first-line agents
• Glycemic control in diabetic patients: Target HbA1c ~7%
• Lipid management: Statins for cardiovascular risk reduction
• Dietary modifications:
  • Sodium restriction (<2g/day)
  • Protein restriction (0.8g/kg/day for non-dialysis CKD)
  • Potassium and phosphate restriction as needed

Complications Management

• Anemia: Consider erythropoiesis-stimulating agents when Hb <10 g/dL
• Mineral bone disorder: Phosphate binders, vitamin D analogs, calcimimetics
• Metabolic acidosis: Oral bicarbonate supplementation to maintain serum bicarbonate >22 mEq/L
• Volume overload: Diuretics (loop diuretics often required)

Progression Prevention

• Regular monitoring of GFR and albuminuria
• Avoid nephrotoxins
• Treat urinary tract infections promptly
• Prepare for renal replacement therapy when eGFR <30 mL/min/1.73m²

AKI-CKD Connection

• AKI significantly increases risk for subsequent CKD development and progression 5
• Patients with pre-existing CKD have higher risk of developing AKI 5
• Implement more intensive monitoring for patients who have experienced both conditions

Common Pitfalls to Avoid

1. Overaggressive fluid resuscitation: Fluid overload can worsen kidney function and delay recovery 6, 3
2. Delayed nephrology consultation: Obtain nephrology input for worsening AKI despite initial management, AKI not resolved after 48 hours, need for RRT, complex fluid management, or diagnostic uncertainty 1
3. Failure to monitor AKI survivors: All AKI patients require follow-up to assess for CKD development 2, 1
4. Inadequate medication review: Continuing nephrotoxic medications can worsen kidney injury 2
5. Neglecting electrolyte and acid-base disturbances: These require careful monitoring and correction 4

By implementing these evidence-based strategies, clinicians can effectively manage both AKI and CKD, potentially reducing mortality, morbidity, and improving quality of life for affected patients.