What is the optimal management for a pediatric patient with AKI (Acute Kidney Injury) secondary to RPGN (Rapidly Progressive Glomerulonephritis), Stage 2 Hypertension, and Moderate Anemia?

Management of Pediatric AKI Secondary to RPGN with Stage 2 Hypertension and Moderate Anemia

This 4-year-old with AKI secondary to RPGN requires immediate intensification of immunosuppressive therapy with high-dose corticosteroids (prednisolone 60 mg/m²/day or 2 mg/kg/day), optimization of blood pressure control targeting <90th percentile for age/sex/height, and initiation of anemia management while closely monitoring for complications. 1

Immediate Diagnostic Priorities

Complete the diagnostic workup urgently to guide immunosuppressive therapy:

• Perform infectious screening immediately to exclude post-infectious glomerulonephritis or other infectious causes before escalating immunosuppression 1
• Obtain genetic testing using massively parallel sequencing or whole-exome sequencing as first-line diagnostic measure, as genetic forms may not respond to immunosuppression 2, 1
• Assess for systemic disease including complement levels (C3, C4), ANCA panel, anti-GBM antibodies, ANA, and anti-dsDNA to identify specific RPGN etiology 1
• Do not delay treatment while awaiting genetic results if clinical presentation suggests immune-mediated disease 1

Immunosuppressive Therapy Escalation

The current prednisolone dose of 15 mg PO daily is inadequate for RPGN management:

• Increase prednisolone to 60 mg/m²/day (approximately 2 mg/kg/day) for a 4-year-old with RPGN, which translates to roughly 16-20 mg daily for an 8 kg child 3
• Continue high-dose corticosteroids for minimum 4-6 weeks before assessing response, as average time to remission is 3-4 months 3
• Consider adding cyclophosphamide (2 mg/kg/day for 8-12 weeks) if no response to steroids or if crescentic glomerulonephritis is confirmed on biopsy, with cumulative dose not exceeding 200 mg/kg in children 3
• Alternative: calcineurin inhibitors (cyclosporine or tacrolimus) may be used if contraindications to cyclophosphamide exist 3, 2

Blood Pressure Management Optimization

Current regimen (atenolol 12.5 mg daily, nifedipine 20 mg BID) requires adjustment:

• Target blood pressure ≤50th percentile for age, sex, and height (approximately 95-100/55-60 mmHg for a 4-year-old) given presence of proteinuria and AKI 3
• The recent hypertensive emergency (140/96 mmHg) indicates inadequate control requiring immediate intensification 3
• Increase nifedipine dose cautiously or add additional antihypertensive agent from different class 3
• Add ACE inhibitor or ARB (e.g., enalapril 0.08 mg/kg/day or lisinopril 0.07 mg/kg/day) for dual benefit of blood pressure control and antiproteinuric effect, monitoring closely for hyperkalemia and acute GFR decline 3
• Monitor for postural hypotension regularly when escalating antihypertensive therapy 3

Acute Kidney Injury Management

Current AKI requires close monitoring and supportive care:

• Monitor kidney function daily including serum creatinine, electrolytes (particularly potassium), and urine output (currently adequate at 4.1 ml/kg/hr) 3
• Avoid nephrotoxic medications and adjust drug dosing for reduced GFR 3, 4
• Maintain euvolemia - avoid intravenous fluids and saline when possible; concentrate oral fluid intake if necessary to avoid marked edema 3, 1
• Do not administer albumin infusions based on serum albumin levels alone; reserve for clinical indicators of hypovolemia (prolonged capillary refill, tachycardia, hypotension, oliguria) 3, 1
• Consider RRT initiation if develops severe hyperkalemia, metabolic acidosis, uremic symptoms, or fluid overload refractory to diuretics 3
• Current furosemide 15 mg BID (2 mg/kg/day) is appropriate for maintaining urine output 3

Anemia Management

Moderate anemia in context of AKI requires evaluation and treatment:

• Evaluate for causes beyond erythropoietin deficiency including iron deficiency, blood loss, hemolysis, and nutritional deficiencies 5, 4
• Check iron studies (ferritin, transferrin saturation), reticulocyte count, and peripheral smear 5
• Initiate iron supplementation if iron deficiency identified, as correction improves anemia and may reduce future ESA requirements 5
• Consider erythropoiesis-stimulating agents if hemoglobin <10 g/dL and iron replete, though use judiciously given cardiovascular risks 6, 5
• Target partial correction of anemia (hemoglobin 10-11 g/dL), not complete normalization, as this is associated with improved outcomes 5

Monitoring for Complications

Intensive monitoring is essential given multiple organ system involvement:

• Daily assessment of blood pressure, urine output, weight, and volume status 3, 4
• Monitor for electrolyte disturbances including hyperkalemia (risk increased with ACE-I/ARB), metabolic acidosis, hyperphosphatemia 4
• Assess for thromboembolism risk - RPGN with nephrotic-range proteinuria carries high thrombotic risk; consider prophylactic anticoagulation if serum albumin <2.5 g/dL with additional risk factors 3, 2
• Screen for infections given immunosuppression - current mild subcostal/intercostal retractions on room air with SpO2 93% requires close respiratory monitoring 3
• Monitor for steroid-related complications including hyperglycemia, hypertension exacerbation, growth suppression, and behavioral changes 3

Critical Pitfalls to Avoid

• Do not delay immunosuppression while awaiting complete diagnostic workup if clinical presentation strongly suggests immune-mediated RPGN 1
• Do not use inadequate steroid dosing - the current 15 mg daily dose is insufficient for RPGN and should be increased to 60 mg/m²/day 3
• Do not target complete normalization of blood pressure too rapidly, as this may worsen renal perfusion in setting of AKI; gradual escalation with close monitoring is essential 3
• Do not overlook infection screening before escalating immunosuppression, as infectious causes require antimicrobial therapy rather than increased immunosuppression 1
• Do not assume genetic forms will respond to immunosuppression - genetic testing results should guide therapy duration and intensity 2, 1
• Do not administer albumin based on laboratory values alone - reserve for true clinical hypovolemia 3, 1

Multidisciplinary Follow-up

This complex case requires coordinated subspecialty care:

• Maintain close nephrology follow-up with consideration for transfer to tertiary pediatric nephrology center if not already at one 1
• Involve pediatric cardiology for management of hypertension and assessment of left ventricular hypertrophy, which develops early in pediatric CKD 6
• Nutritional support to ensure adequate growth and development despite dietary restrictions 3
• Plan for long-term monitoring even if remission achieved, as AKI survivors require assessment for CKD development, particularly in pediatric population where stakes of missing nascent CKD are higher 3