What is the management strategy for acute kidney injury (AKI) in pediatric patients after congenital heart disease surgery?

Management of Acute Kidney Injury in Pediatric Patients After Congenital Heart Surgery

The management of AKI in pediatric patients after congenital heart disease surgery should focus on early identification of at-risk patients, optimization of hemodynamics, careful fluid management, avoidance of nephrotoxins, and consideration of renal replacement therapy when indicated. 1

Risk Assessment and Prevention

• AKI complicates 22-36% of cardiac surgeries in children, with 11.5% developing severe AKI and 6.4% requiring renal replacement therapy within 48 hours 1
• Risk factors include abnormal baseline creatinine, longer cardiopulmonary bypass time, selective cerebral perfusion, preoperative aminoglycoside use, and small kidneys on ultrasound 1, 2
• Urinary biomarkers (tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7) can identify patients at risk for AKI as early as 1 hour after cardiopulmonary bypass 1

Fluid Management

• Use isotonic crystalloids rather than colloids for volume expansion in patients at risk of AKI 1, 3
• Implement goal-directed fluid therapy using standardized algorithms with quantified goals for blood pressure, cardiac index, systemic venous oxygen saturation, and urine output 1
• Monitor for and avoid fluid overload, as increased percentage fluid overload (%FO) is a significant risk factor for developing AKI and is associated with worse outcomes 4, 2
• Starch-containing fluids should be avoided in patients at risk of AKI 1

Hemodynamic Management

• Implement vasopressors in conjunction with fluids in patients with vasomotor shock 1, 3
• Monitor and optimize cardiac output to ensure adequate renal perfusion 1
• Use protocol-based management of hemodynamic and oxygenation parameters in high-risk perioperative settings 1, 3
• Consider increasing cardiopulmonary bypass flow during surgery to improve renal oxygenation 1

Medication Management

• Avoid nephrotoxic agents when possible in at-risk patients 1, 3
• Discontinue angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) for 48 hours post-surgery 1
• Use aminoglycosides only when no suitable, less nephrotoxic alternatives are available 1, 3
• When aminoglycosides are necessary, administer as a single daily dose rather than multiple doses with close monitoring of drug levels 1, 3
• Use lipid formulations of amphotericin B rather than conventional formulations when antifungal therapy is required 5, 3
• Adjust medication dosages for patients with impaired kidney function 1, 3

Nutritional Support

• Provide nutrition preferentially via the enteral route when possible 1, 3
• Target total energy intake of 20-30 kcal/kg/day in patients with any stage of AKI 1, 3
• Do not restrict protein intake to prevent or delay RRT initiation 1, 3
• Administer protein at 0.8-1.0 g/kg/day in noncatabolic AKI patients without need for dialysis, and 1.0-1.5 g/kg/day in patients with AKI on RRT 1

Renal Replacement Therapy (RRT)

• Consider early initiation of RRT, particularly in cases with fluid overload 1
• The decision to initiate RRT should be based on the patient's clinical status, including degree of fluid overload, electrolyte abnormalities, and acid-base status 5

Monitoring and Follow-up

• Closely monitor kidney function, including urine output and creatinine 1
• Monitor serum concentrations of nephrotoxic medications 1
• Ensure early follow-up after discharge for pediatric patients with AKI, as they are at higher risk for developing chronic kidney disease 5
• The pediatric population should receive follow-up within 3 months post-discharge, especially those with severe AKI 5

Interventions Not Recommended

• Diuretics should not be used to prevent AKI but may be used to manage volume overload in established AKI 1, 3
• Low-dose dopamine is not recommended to prevent or treat AKI 1, 3
• Fenoldopam is not recommended to prevent or treat AKI 1, 3
• Atrial natriuretic peptide is not recommended to prevent or treat AKI 1, 3
• Aminophylline has not shown benefit in preventing AKI in children after congenital heart surgery with cardiopulmonary bypass 6

Common Pitfalls and Caveats

• Failure to identify high-risk patients early in the perioperative period 1
• Overzealous fluid resuscitation leading to fluid overload 1, 4, 2
• Inadequate monitoring of medication levels when using potentially nephrotoxic drugs 1, 3
• Delaying RRT initiation in patients with significant fluid overload 1, 7
• Assuming that mild AKI is benign, when all stages of AKI require careful monitoring and follow-up 5, 4