What is the best approach for treating and managing acute kidney injury in an adult patient with a history of hypertension or diabetes?

Management of Acute Kidney Injury in Adults with Hypertension or Diabetes

The cornerstone of AKI management is immediate identification and treatment of the underlying cause, aggressive nephrotoxin avoidance (particularly the "triple whammy" of NSAIDs + diuretics + ACE-I/ARB), careful fluid balance optimization, and structured follow-up based on AKI severity and duration. 1, 2

Immediate Diagnostic Workup

• Obtain kidney ultrasound urgently to exclude urinary tract obstruction, particularly after correcting any hypovolemia 1, 2
• Perform urinalysis with microscopic examination to detect hematuria, proteinuria, acanthocytes, or cellular casts that indicate glomerular disease or tubular injury requiring different management 2, 3
• Check spot urine protein-to-creatinine ratio as proteinuria indicates irreversible intrinsic kidney disease and predicts progression to chronic kidney disease 2
• Measure serum electrolytes, CO2, creatinine, and BUN every 4-6 hours initially to monitor for life-threatening complications 2, 3
• Consider cystatin C measurement in older patients where sarcopenia and low muscle mass may underestimate kidney dysfunction when using creatinine alone 2

Critical Medication Management (Highest Priority)

• Immediately discontinue NSAIDs, which cause both direct tubular toxicity and renovasoconstriction 1, 3
• Temporarily hold ACE inhibitors and ARBs during acute illness, particularly when combined with diuretics—this "triple whammy" combination more than doubles AKI risk 1, 2, 3
• Hold diuretics when AKI is diagnosed to prevent worsening kidney function 3
• Avoid aminoglycosides unless clearly superior for infection treatment, and if used, carefully dose and monitor levels 1
• Adjust doses of all renally eliminated medications based on current kidney function and reassess frequently as GFR changes 1, 2, 3

Critical pitfall: Continuing furosemide during AKI causes ongoing kidney damage and increases mortality risk 2

Fluid Balance and Hemodynamic Optimization

• Assess volume status through physical examination including jugular venous pressure, peripheral edema, lung auscultation for crackles, and daily weights 2, 4
• For hypovolemic patients, provide fluid repletion with isotonic crystalloids (NaCl 0.9% or balanced solutions) 1, 4, 5
• For euvolemic or hypervolemic patients, implement fluid restriction to prevent worsening volume overload 2
• Avoid fluid overload, which worsens outcomes—monitor weight, blood pressure, and volume status at every clinical contact 1, 2
• Maintain blood pressure using vasopressors in vasodilatory shock 4, 6

Critical pitfall: Overly aggressive fluid administration in non-hypovolemic patients worsens outcomes and can lead to respiratory compromise 2, 3

Monitoring and Treatment of Complications

• Evaluate and treat electrolyte abnormalities, metabolic acidosis, volume overload, elevated blood pressure, anemia when eGFR falls below 60 mL/min/1.73 m² 1
• Monitor for hyperkalemia, uremic complications (encephalopathy, pericarditis, pleuritis) that may require urgent intervention 2, 7
• Avoid overly rapid correction of hyponatremia, which can lead to osmotic demyelination syndrome 2, 3

Renal Replacement Therapy Indications

Initiate RRT for life-threatening complications: 1, 3, 7

• Severe hyperkalemia refractory to medical management
• Severe metabolic acidosis (intractable)
• Uremic complications (encephalopathy, pericarditis, pleuritis)
• Refractory volume overload causing pulmonary edema
• Severe oliguria unresponsive to fluid resuscitation
• Removal of certain toxins

RRT dosing and modality: 8

• Continuous RRT is preferred in hemodynamically unstable patients; otherwise, choice of modality does not impact outcomes 8, 4
• Deliver effluent volume of 20-25 ml/kg per hour when continuous RRT is used 8
• Discontinue RRT when kidney function has recovered or when RRT becomes inconsistent with shared care goals 8

Critical pitfall: Delayed escalation when clear indications for RRT exist increases mortality 2, 3

Structured Follow-Up Based on AKI Severity

Patients requiring nephrology follow-up within 1 week: 8, 1

• Stage 2-3 AKI
• Prolonged AKI (>3-6 days)
• Multiple comorbidities (diabetes, hypertension, cardiovascular disease)
• Pre-existing CKD Stage 4
• History of prior AKI

All AKI patients: 1

• Check serum creatinine and eGFR at minimum 3 months after hospital discharge to assess for incomplete recovery or progression to CKD 1
• Document the AKI episode prominently in the medical record 1
• Monitor albuminuria and eGFR regularly in diabetic patients to detect superimposed AKI on CKD 1

Special Considerations for Diabetes and Hypertension

• Patients with diabetes are at higher risk for AKI than those without diabetes and require more vigilant monitoring 1
• SGLT2 inhibitors do not significantly increase AKI risk despite theoretical concerns about volume depletion 1
• Continue monitoring albuminuria and eGFR regularly in diabetic patients to detect superimposed AKI on CKD 1

Patient Education and Long-Term Risk Mitigation

• Educate patients to avoid NSAIDs (including over-the-counter preparations) 1, 3
• Instruct patients to seek prompt medical attention during intercurrent illnesses (infections, vomiting, diarrhea) 1
• Counsel on "sick day protocol": temporarily hold ACE-I/ARB and diuretics during acute illnesses causing volume depletion 8

Critical pitfall: Do not assume recovery is complete just because creatinine returns to baseline—patients remain at increased long-term risk of cardiovascular events, CKD progression, and death 1, 2

Research Gaps and Evolving Evidence

The 2020 KDIGO conference identified several areas requiring further investigation: 8

• Optimal indications and targets for fluid and vasoactive drugs
• Confirmed hazard from 0.9% saline compared with balanced solutions
• Timing of ACE-I/ARB discontinuation and re-initiation in different clinical contexts
• Optimal timing, dose, and modality of RRT

Until definitive evidence emerges, prioritize balanced crystalloids over 0.9% saline when possible 8, and base RRT decisions on clinical judgment incorporating hemodynamic stability, fluid status, and metabolic derangements 8.