What is the management of acute renal failure?

Management of Acute Kidney Injury (AKI)

Immediately discontinue all nephrotoxic medications (NSAIDs, aminoglycosides, ACE inhibitors/ARBs) and restore intravascular volume with crystalloids or albumin—these are the most critical initial interventions that directly impact mortality and recovery. 1

Initial Assessment and Diagnostic Classification

Define AKI Severity Using KDIGO Criteria

• Stage 1: Serum creatinine increase ≥0.3 mg/dL within 48 hours OR ≥50% increase within 7 days OR urine output <0.5 mL/kg/h for 6-12 hours 2
• Stage 2: Serum creatinine increase 2-2.9 times baseline OR urine output <0.5 mL/kg/h for ≥12 hours 2
• Stage 3: Serum creatinine increase ≥3 times baseline OR ≥4.0 mg/dL OR urine output <0.3 mL/kg/h for ≥24 hours OR anuria for ≥12 hours OR initiation of renal replacement therapy 2

Classify AKI Type Through Targeted Evaluation

• Prerenal (60-70% of cases): Check for volume depletion, hypotension, heart failure, or cirrhosis; calculate fractional excretion of sodium (FENa <1% suggests prerenal) 3, 4
• Intrinsic renal: Look for nephrotoxin exposure, sepsis, rhabdomyolysis, or glomerulonephritis; urinalysis showing casts, proteinuria, or hematuria suggests intrinsic disease 3
• Postrenal: Perform renal ultrasonography in all patients, particularly older men, to identify obstruction 3

Immediate Management Priorities

Remove All Modifiable Risk Factors

• Withdraw nephrotoxic medications immediately: NSAIDs, aminoglycosides, vancomycin, ACE inhibitors/ARBs (in acute setting), contrast agents 1, 3
• Stop diuretics in patients with suspected hypovolemia or prerenal AKI 1
• Avoid morphine, codeine, and tramadol as first-line opioids in renal failure 1

Optimize Hemodynamics and Volume Status

For Prerenal AKI:

• Restore intravascular volume with isotonic crystalloids (balanced solutions preferred over 0.9% saline) 1, 4
• In cirrhotic patients with Stage 1 AKI: Administer intravenous albumin 1 g/kg body weight daily for 2 consecutive days 1, 2
• Maintain mean arterial pressure ≥65 mmHg; use vasopressors if fluid resuscitation alone is insufficient 5

For Volume Overload:

• Identify fluid overload through clinical assessment and consider fluid removal strategies 2
• Avoid excessive volume administration, particularly in patients with acute lung injury 6

Monitor Response and Progression

• Reassess within 48-72 hours with serial serum creatinine measurements to determine response or progression 1
• Track urine output hourly in critically ill patients 2
• Monitor electrolytes (particularly potassium), acid-base status, and volume status continuously 3

Specific Interventions by Clinical Context

Contrast-Associated AKI Prevention

• Pretreat high-risk patients with sodium bicarbonate infusion before radiocontrast procedures (absolute risk reduction 11.9%, relative risk 0.13) 4
• Consider acetylcysteine for patients undergoing radiocontrast procedures (absolute risk reduction 19%, relative risk 0.11) 4

Sepsis-Associated AKI

• Optimize fluid administration and oxygen delivery as cornerstones of resuscitation 5
• Use antibiotics with least nephrotoxic potential 7
• Maintain adequate perfusion pressure with vasopressors if needed 5

Cirrhosis-Associated AKI

• Albumin is preferred over crystalloids for volume expansion 1, 2
• Discontinue diuretics and nephrotoxic agents 1

Indications for Renal Replacement Therapy (RRT)

Initiate RRT for absolute indications:

• Refractory hyperkalemia unresponsive to medical management 3
• Volume overload causing pulmonary edema refractory to diuretics 3
• Intractable metabolic acidosis 3
• Uremic complications: encephalopathy, pericarditis, or pleuritis 3
• Certain toxin removal 3

RRT Modality Selection

• Continuous renal replacement therapy (CRRT) is preferred over intermittent hemodialysis in hemodynamically unstable patients 5, 6
• CRRT dosing: Effluent volume of 20-25 mL/kg/h 5, 6
• Anticoagulation: Regional citrate is first choice unless contraindicated; use unfractionated or low-molecular-weight heparin as alternative 6
• Buffer: Bicarbonate-based solutions preferred over lactate, especially in circulatory shock, liver failure, or lactic acidemia 6

Vascular Access for RRT

• Use uncuffed nontunneled dialysis catheters for acute initiation 6
• Preferred vein order: Right internal jugular → femoral → left internal jugular → subclavian (avoid subclavian due to thrombosis/stenosis risk) 6
• Always use ultrasound guidance for catheter insertion 6
• Obtain chest radiograph after internal jugular or subclavian placement before first use 6

Common Pitfalls to Avoid

• Do not use dopamine or loop diuretics to prevent or treat established AKI—they are ineffective and potentially harmful 4
• Do not delay RRT initiation based solely on BUN/creatinine thresholds; consider broader clinical context including volume status, electrolytes, and acid-base balance 6
• Avoid 0.9% saline when balanced crystalloid solutions are available, as saline may worsen kidney outcomes 2
• Do not use lactate-buffered solutions in patients with liver failure or lactic acidosis 6

Ongoing Management and Prevention

• Optimize nutrition to support recovery 7
• Limit blood transfusions to situations where hemoglobin is dangerously low 7
• Implement team-based approaches for prevention, early diagnosis, and aggressive management 3
• Recognize high-risk patients: older age, sepsis, hypovolemia/shock, cardiac surgery, contrast exposure, diabetes, preexisting CKD, heart failure, liver failure 3