From the Guidelines
Management of renal acute kidney injury (AKI) should prioritize identifying and treating the underlying cause, maintaining adequate renal perfusion, and preventing further kidney damage, as recommended by the most recent guidelines 1. To achieve this, the following steps should be taken:
- Ensure adequate renal perfusion by maintaining appropriate fluid balance, correcting hypovolemia with isotonic fluids like normal saline or lactated Ringer's solution, and avoiding fluid overload in hypervolemic patients.
- Monitor hemodynamics closely, targeting a mean arterial pressure of at least 65 mmHg to maintain renal perfusion, as suggested by previous guidelines 1.
- Discontinue nephrotoxic medications, including NSAIDs, aminoglycosides, and certain contrast agents, to prevent further kidney damage, as emphasized by the KDIGO conference 1.
- Adjust medication dosages for reduced kidney function using estimated GFR, and monitor serum creatinine, BUN, electrolytes, and urine output (goal >0.5 mL/kg/hr) daily.
- Manage electrolyte imbalances promptly, particularly hyperkalemia, which may require calcium gluconate, insulin, or sodium bicarbonate for urgent treatment.
- Consider renal replacement therapy for refractory hyperkalemia, volume overload, severe acidosis (pH <7.2), uremic symptoms, or certain toxin ingestions, as recommended by the KDIGO guideline 1.
- Provide nutritional support with adequate protein (0.8-1.0 g/kg/day) while avoiding excessive nitrogen load, as suggested by the KDIGO commentary 1. The underlying pathophysiology of AKI involves decreased renal perfusion, direct tubular injury, or obstruction, so treatment must address these specific mechanisms to promote kidney recovery, as highlighted by the KDIGO consensus conference 1.
From the Research
Definition and Classification of Acute Kidney Injury (AKI)
- Acute kidney injury (AKI) is defined as an increase in serum creatinine or a decrease in urine output over hours to days 2.
- AKI can be categorized as prerenal, intrinsic renal, or postrenal based on the underlying cause 2, 3.
Management of AKI
- Initial evaluation and management of AKI includes laboratory work-up, medication adjustment, identification and reversal of underlying cause, and referral to appropriate specialty care 2.
- Measures to prevent AKI include optimization of volume status and avoidance of nephrotoxic medications 4.
- General management principles for AKI include determination of volume status, fluid resuscitation with isotonic crystalloid, treatment of volume overload with diuretics, discontinuation of nephrotoxic medications, and adjustment of prescribed drugs according to renal function 3.
- Pharmacist-led quality-improvement programs and AKI care bundles can improve outcomes in patients with AKI 3.
Role of Diuretics in AKI Management
- Furosemide, a potent loop diuretic, is frequently used in different stages of AKI, but its clinical roles remain uncertain 5.
- The severity of AKI has a significant effect on the diuretic response to furosemide, and a good 'urinary response' may be considered as a 'proxy' for having some residual renal function 5.
- The current evidence does not suggest that furosemide can reduce mortality in patients with AKI, but it may be useful in achieving fluid balance to facilitate mechanical ventilation in patients with acute lung injury without haemodynamic instability 5.
Importance of Early Diagnosis and Prevention
- Early determination of etiology, management, and long-term follow-up of AKI are essential, as even one episode of AKI increases the risk of cardiovascular disease, chronic kidney disease, and death 2.
- Awareness campaigns and education for health-care professionals on diagnosis and management of AKI, coupled with electronic early warning systems, can improve outcomes 6.
- Prevention and early diagnosis are key, as no interventions to improve outcomes of established AKI have yet been developed 6.