What is the protocol for managing a patient with acute kidney injury?

Acute Kidney Injury Management Protocol

Immediately discontinue all nephrotoxic medications (NSAIDs, ACE inhibitors, ARBs, aminoglycosides), hold diuretics and beta-blockers, search rigorously for infection, and initiate volume resuscitation with isotonic crystalloids targeting euvolemia. 1, 2

Initial Assessment and Diagnosis

• Define AKI presence using any of: serum creatinine increase ≥0.3 mg/dL within 48 hours, creatinine ≥1.5× baseline within 7 days, or urine output <0.5 mL/kg/h for 6 hours 1
• Stage severity according to creatinine and urine output changes, as higher stages predict worse outcomes 1
• Monitor biochemistry with serum urea, creatinine, and electrolytes at least every 48 hours (more frequently in high-risk patients) 1
• Perform diagnostic paracentesis in cirrhotic patients to exclude spontaneous bacterial peritonitis 1

Immediate Interventions

Medication Management

• Stop all nephrotoxic drugs unless absolutely essential, including NSAIDs, ACE inhibitors, ARBs, and aminoglycosides 1, 2
• Hold diuretics and nonselective beta-blockers when AKI is diagnosed 1
• Avoid dopamine, diuretics, N-acetylcysteine, or recombinant human insulin-like growth factor 1 for AKI treatment—these lack efficacy 1

Fluid and Hemodynamic Management

• Use isotonic crystalloids (not colloids or starch-containing fluids) for initial volume expansion 1, 2
• Target euvolemia through daily clinical examination and fluid balance monitoring 1
• Maintain mean arterial pressure >65 mmHg using vasopressors in conjunction with fluids if vasomotor shock is present 2
• Monitor fluid status daily by clinical examination and strict intake/output records 1

Nutritional Support

• Provide 20-30 kcal/kg/day total energy intake, preferably via enteral route 2
• Administer 0.8-1.0 g/kg/day protein in noncatabolic AKI patients without dialysis 2
• Increase to 1.0-1.5 g/kg/day protein in patients requiring renal replacement therapy 2

Renal Replacement Therapy (RRT) Indications

Emergent Indications (Initiate Immediately)

• Severe hyperkalemia with ECG changes (peaked T waves, widened QRS, bradycardia) 3
• Severe metabolic acidosis with impaired respiratory compensation 3
• Pulmonary edema unresponsive to diuretics 3
• Uremic complications (encephalopathy, pericarditis, bleeding) 3
• Severe symptomatic dysnatremia resistant to medical management 3

RRT Modality Selection

• Use continuous RRT (CRRT) in hemodynamically unstable patients requiring vasopressors, those with acute brain injury, or when intracranial pressure is a concern 4, 1, 3
• Use intermittent hemodialysis in hemodynamically stable patients for faster correction of severe hyperkalemia 3
• Both modalities have equivalent outcomes in randomized trials, so choose based on hemodynamic stability and local expertise 4

CRRT Parameters (When Selected)

• Modality: CVVHDF preferred 3
• Effluent dose: 20-25 mL/kg/hour 3
• Replacement fluid: Bicarbonate-based 3
• Anticoagulation: Regional citrate if no contraindications 3

Intermittent Hemodialysis Parameters (When Selected)

• Blood flow rate: 300-400 mL/min 3
• Dialysate flow rate: 500-800 mL/min 3
• Target Kt/V: 1.2-1.4 per session for 3 sessions weekly 3
• Dialysate: Bicarbonate-based 3
• Potassium bath: 0-1 mEq/L if severe hyperkalemia; 2 mEq/L for maintenance 3
• Calcium bath: 2.5 mEq/L 3
• Ultrafiltration rate: Limit to <13 mL/kg/hour to avoid intradialytic hypotension and further renal injury 3

Vascular Access

• Use uncuffed non-tunneled dialysis catheter of appropriate length and gauge 4, 3
• Preferred insertion sites (in order): right internal jugular vein, femoral vein, left internal jugular vein, subclavian vein (last choice due to stenosis risk) 3
• Always use ultrasound guidance for insertion 3

Special Considerations

Hepatorenal Syndrome

• When creatinine remains >2× baseline despite initial measures, treat with albumin plus vasoactive agents for HRS-AKI 1

Contrast-Induced AKI Prevention

• Do not withhold IV contrast in life-threatening conditions where imaging has important therapeutic implications 4
• Modern contrast agents carry far fewer risks than previously thought, and significant injury is unusual with normal or mildly reduced baseline kidney function 4
• Volume expansion with sodium bicarbonate and oral N-acetylcysteine lack efficacy based on PRESERVE and POSEIDON trials 4

Transition from CRRT to Intermittent Hemodialysis

• Consider transition when vasopressor support has stopped, intracranial hypertension has resolved, and positive fluid balance can be controlled by intermittent hemodialysis 4

Monitoring During RRT

• Vital signs: Hourly with assessment for hypotension 3
• Electrolytes and acid-base status: Every 2-4 hours initially 3
• Pre- and post-dialysis weights: Each session 3
• Urine output: Monitor if any residual function present 3

Assessment of Renal Recovery

• If dialysis continues beyond 14 days, assess renal recovery weekly with pre-dialysis creatinine and residual kidney function measurements 3
• Proteinuria is associated with worse long-term outcomes and serves as a valuable risk-stratification tool in the post-AKI period 4
• RRT modality choice does not impact recovery, so base selection on shared decision-making, local expertise, and patient characteristics 4

Follow-Up After AKI

• Monitor for development or progression of chronic kidney disease after AKI 1
• Prioritize follow-up evaluation for patients with risk factors for CKD progression, particularly those who suffered severe AKI requiring temporary RRT 1
• Assess patient-centered outcomes including quality of life and functional recovery 4

Critical Pitfalls to Avoid

• Never continue nephrotoxic medications during AKI recovery phase 2
• Do not use dopamine, diuretics, or N-acetylcysteine as AKI treatments—they are ineffective 1
• Avoid excessive ultrafiltration rates (>13 mL/kg/hour) that can cause intradialytic hypotension and worsen kidney injury 3
• Do not delay RRT when emergent indications are present—life-threatening complications require immediate intervention 3