Treatment

• Initiate treatment for the underlying cause of AKI based on the presumed mechanism.

  • Prerenal: Correct adverse hemodynamic factors and replace the depleted volume as needed.

  • Postrenal: Relieve the urinary tract obstruction.

  • Intrinsic: Consider a trial of IV fluids; identify and treat underlying causes that require specific interventions.

• Consider indications for acute dialysis and early nephrology consultation.

• Provide supportive care to all patients.

  • Hold potentially nephrotoxic substances, ACE-Is, ARBs, NSAIDs, and nonessential medications.

  • Adjust the dosing of essential renally cleared medications.

  • Manage volume status and blood pressure to optimize kidney perfusion.

  • Identify and manage complications (e.g., electrolyte disturbances, acidosis, fluid overload).

  • Consider additional supportive care measures (e.g., nutritional support, VTE prophylaxis).

AKI management is primarily supportive. Currently, there are no specific pharmacotherapies for AKI. [9]

Avoid coadministering RAAS inhibitors and NSAIDs in patients with reduced renal perfusion (e.g., in congestive heart failure, renal artery stenosis) because doing so can significantly decrease their GFR.

• Indications; consider urgently for:

  • Complications refractory to medical management

    • Refractory fluid overload

    • Electrolyte imbalances

    • Acid-base disturbances

  • Acute poisoning (e.g., by ethylene glycol); see “Approach to the poisoned patient.”

  • Uremic symptoms

• Modalities include:

  • Hemodialysis and/or hemofiltration (i.e., by CRRT or intermittent hemodialysis)

  • Peritoneal dialysis

• Epidemiology: AKI is common in critically ill newborns (approx. 30% of NICU patients). [43]

• Etiology [44]

  • ∼85% prerenal

  • ∼10% renal

  • ∼5% postrenal

• Infant risk factors

  • Perinatal: prematurity, low birth weight, asphyxia, congenital heart disease

  • Inflammatory: NEC, sepsis

  • Iatrogenic: nephrotoxic medications, cardiac surgery, ECMO therapy

• Diagnostics: Modifications to KDIGO staging [42]

  • Baseline serum creatinine in neonates is defined as the lowest previously measured value.

  • The cut-off for AKI stage 3 is a serum creatinine level ≥ 3 times baseline OR ≥ 2.5 mg/dL.

  • Accurate measurement of urine output in neonates poses challenges (esp. regarding urine collection) but is still being used to diagnose and stage AKI.

  • Other diagnostic biomarkers, e.g., cystatin C, are currently being investigated to improve early and accurate detection of AKI in neonates. [42]

  • See “Diagnostics” section above.

• Management

  • Monitor serum creatinine and urine output in at-risk neonates.

  • Treat underlying causes.

  • Avoid/adjust nephrotoxic medications.

  • Provide supportive management (e.g., fluid, electrolyte, and nutritional).

  • Consider renal replacement therapy.