Initial Management of Acute Kidney Injury
The initial management of acute kidney injury (AKI) should focus on fluid resuscitation with isotonic crystalloids, removal of nephrotoxic agents, and close hemodynamic monitoring to prevent further kidney damage and reduce mortality. 1, 2
Immediate Steps in AKI Management
1. Fluid Management
- Use isotonic crystalloids rather than colloids for initial volume expansion in patients at risk for or with AKI 1
- Normal saline or balanced crystalloid solutions are preferred first-line options
- Avoid hydroxyethyl starches which have been associated with increased AKI incidence 1
- Special consideration: Albumin may be rational in specific subgroups (patients with cirrhosis and ascites at 1 g/kg/day for two consecutive days) 1
2. Medication Review and Adjustment
- Review and withdraw all potentially nephrotoxic medications 1, 2:
- NSAIDs
- Aminoglycosides
- Certain contrast agents
- Vasodilators
- Reduce or withdraw diuretic therapy 1, 2
- Adjust medication doses based on current GFR 2
3. Hemodynamic Support
- Use vasopressors in conjunction with fluids in patients with vasomotor shock 1
- Norepinephrine is preferred over dopamine as first-line vasopressor 1
- Target appropriate blood pressure to maintain renal perfusion
4. Metabolic Management
- Target plasma glucose of 110-149 mg/dL (6.1-8.3 mmol/L) in critically ill patients 1
- Monitor and correct electrolyte imbalances, particularly hyperkalemia 2, 3
- Manage metabolic acidosis if present 2
Monitoring and Assessment
Laboratory Monitoring
- Daily measurement of serum creatinine, BUN, electrolytes 2
- Urinalysis and fractional excretion of sodium to help determine AKI etiology 3
- Monitor acid-base status 2
Volume Status Assessment
- Track fluid balance (intake and output)
- Assess for signs of volume overload or depletion
- Consider ultrasonography of the kidneys to rule out obstruction, particularly in older men 3
Nutritional Support
- Provide 20-30 kcal/kg/day total energy intake 1
- Protein recommendations 1, 2:
- 0.8-1.0 g/kg/day in noncatabolic AKI patients without dialysis
- 1.0-1.5 g/kg/day in patients on RRT
- Up to 1.7 g/kg/day in patients on CRRT and hypercatabolic patients
- Prefer enteral nutrition when possible 1
Indications for Renal Replacement Therapy
Consider RRT when the following are present and refractory to medical management 2, 3:
- Severe hyperkalemia
- Volume overload unresponsive to diuretics
- Severe metabolic acidosis
- Uremic symptoms (encephalopathy, pericarditis, pleuritis)
- Need to remove certain toxins
Protocol-Based Management
Consider protocol-based management of hemodynamic and oxygenation parameters in high-risk patients, particularly in:
Common Pitfalls to Avoid
- Fluid overload: While adequate resuscitation is essential, excessive fluid administration can worsen outcomes and delay renal recovery 4, 5
- Inadequate monitoring: Failure to closely monitor kidney function, electrolytes, and fluid balance can lead to missed opportunities for intervention 2
- Continued nephrotoxic exposure: Failure to promptly discontinue nephrotoxic medications can worsen AKI 1, 2
- Delayed nephrology consultation: Consider early nephrology consultation for Stage 2 AKI with comorbidities or any Stage 3 AKI 2
- Overly aggressive fluid removal: Once euvolemic, avoid rapid fluid removal (>1.5-2 L/day) which can cause hemodynamic instability 2
Special Considerations
Cirrhosis
- More cautious approach to fluid management due to altered hemodynamics 1, 2
- Consider albumin for volume expansion (1 g/kg/day for two days) 1
- More frequent monitoring of renal function 2
Heart Failure
- Balance need for decongestion against risk of worsening AKI 2
- Cautious reintroduction of diuretics once euvolemic 2
By following this structured approach to AKI management, focusing on early intervention, appropriate fluid management, and careful monitoring, you can improve outcomes and reduce the risk of progression to chronic kidney disease 6.