What is the best course of treatment for a patient with renal cortical necrosis, including management of impaired renal function and potential complications?

Management of Renal Cortical Necrosis

The primary treatment for renal cortical necrosis is aggressive supportive care with early dialysis initiation, fluid and electrolyte management, prevention of thrombotic and infectious complications, and long-term renal replacement therapy planning, as most patients will not recover renal function and will require chronic dialysis or transplantation. 1

Immediate Diagnostic Confirmation

• MRI is the preferred non-invasive diagnostic method showing characteristic low T2 signal rim at the corticomedullary junction and absent cortical enhancement post-contrast 1
• IV contrast-enhanced CT with immediate and delayed images can identify the wedge-shaped areas of non-enhancement in the renal cortex 2
• Renal biopsy confirms cortical infarction when imaging is equivocal, though this is rarely necessary given characteristic imaging findings 3, 4

Acute Phase Management

Fluid and Hemodynamic Stabilization

• Provide adequate fluid resuscitation with normal saline (0.9%) to maintain renal perfusion, avoiding potassium-containing solutions like Lactated Ringer's as potassium levels rise markedly even with intact residual function 2
• Monitor central venous pressure targeting 8-12 mmHg to guide volume status without causing fluid overload 5
• Assess peripheral perfusion, capillary refill, pulse rate, blood pressure, and jugular venous pressure continuously 5

Renal Replacement Therapy

• Initiate hemodialysis early for anuria, severe hyperkalemia, metabolic acidosis, or uremic symptoms rather than waiting for biochemical deterioration 1, 6
• Most patients (61.5%) become dialysis-dependent long-term, so early planning for permanent vascular access is essential 6
• Continue dialysis support for at least 3 months before assessing for any potential recovery, as rare cases show delayed partial recovery 7

Prevention of Complications

Anticoagulation for thrombosis prevention:

• Consider therapeutic anticoagulation if thrombotic microangiopathy is the underlying cause (present in 48.7% of obstetric cases) 6
• Antiplatelet therapy with aspirin may be used in patients with atherosclerotic disease 2
• Adjust anticoagulant dosing for renal dysfunction: enoxaparin should be given once every 24 hours (not twice daily) when creatinine clearance <30 mL/min 2

Infection control:

• Aggressive antibiotic therapy for sepsis, which is present in all mortality cases 6, 4
• Septic abortion and puerperal sepsis account for 30.6% of obstetric RCN cases 6
• Monitor for nosocomial infections given prolonged hospitalization (22.7% of patients) 6

Address Underlying Etiology

• In obstetric cases: Treat postpartum hemorrhage, manage thrombotic microangiopathy, and address septic complications aggressively 6
• In trauma cases: Early imaging and vascular intervention are essential; renal artery dissection or pseudoaneurysm requires urgent surgical repair, though prognosis for renal salvage is poor once cortical necrosis develops 3
• In meningococcal sepsis: Administer intravenous antibiotics, corticosteroids, immunoglobulins, and consider plasmapheresis for Waterhouse-Friderichsen syndrome with concomitant RCN 4

Long-Term Management

Chronic Kidney Disease Care

• Monitor renal function with serum creatinine and eGFR regularly to track progression 1
• Manage anemia with erythropoiesis-stimulating agents and iron supplementation as indicated 1
• Address mineral bone disorder with phosphate binders, vitamin D analogs, and calcium supplementation 1
• Strict blood pressure control (target <130/80 mmHg) to prevent further kidney damage and cardiovascular complications 1

Transplant Planning

• Early referral to transplant center for evaluation, as most patients will require kidney transplantation for definitive treatment 6
• Mortality rate is 11.7% in acute phase, with sepsis and multiorgan dysfunction present in all fatal cases 6

Critical Pitfalls to Avoid

• Do not delay dialysis initiation waiting for spontaneous recovery; the average time to presentation is 8.7 days from inciting event, and early intervention improves outcomes 6
• Avoid reflexive fluid boluses in oliguric patients without assessing volume status, as fluid overload worsens outcomes 5
• Do not use potassium-containing fluids even if initial potassium is normal, as levels rise rapidly 2
• Recognize that patchy cortical necrosis (35.4% of cases) may have slightly better prognosis than diffuse involvement, but recovery remains unlikely 6