Management of Acute Kidney Injury: Indian Context
I must clarify that the evidence provided does not contain specific Indian guidelines for AKI management. However, I will provide evidence-based recommendations using the most recent international guidelines (KDIGO) that are universally applicable, including in India, with specific attention to the context of a young adult with fever and impaired renal function.
Diagnosis and Staging
Define AKI using KDIGO criteria: serum creatinine increase ≥0.3 mg/dL within 48 hours, OR increase to ≥1.5 times baseline within 7 days, OR urine output <0.5 mL/kg/h for 6 consecutive hours 1, 2.
Staging System
- Stage 1: Creatinine 1.5-1.9 times baseline OR ≥0.3 mg/dL increase, OR urine output <0.5 mL/kg/h for 6-12 hours 3, 1
- Stage 2: Creatinine 2.0-2.9 times baseline, OR urine output <0.5 mL/kg/h for ≥12 hours 3, 1
- Stage 3: Creatinine ≥3.0 times baseline OR ≥4.0 mg/dL (with acute rise >0.3 mg/dL), OR urine output <0.3 mL/kg/h for 24 hours, OR anuria for 12 hours, OR initiation of renal replacement therapy 3, 1
Critical point: Small creatinine increases (≥0.3 mg/dL) independently increase mortality approximately four-fold, so early detection is paramount 1.
Immediate Assessment in Febrile Patient
Establish Baseline Creatinine
Use the most recent known creatinine from medical records—this is superior to any estimation method 1. If unavailable, back-calculate using MDRD equation assuming GFR of 75 mL/min/1.73 m² 1.
Determine Etiology in Febrile Context
In tropical febrile illnesses (highly relevant to India), AKI incidence reaches 41.1%, with scrub typhus (51.2%), falciparum malaria (10.4%), enteric fever (8.7%), dengue (7.6%), and leptospirosis (3.3%) being common causes 4.
Order these essential tests immediately 1:
- Serum creatinine, BUN
- Complete blood count with differential (to identify infection, hemolysis, thrombotic microangiopathy)
- Urinalysis with microscopy
- Urine chemistry (fractional excretion of sodium)
- Serum electrolytes (sodium, potassium, chloride, bicarbonate)
Urinalysis Interpretation
- Hematuria (>50 RBCs/HPF) + proteinuria (>500 mg/day): Consider glomerular disease 1
- Renal tubular epithelial cell casts: Suggests acute tubular necrosis 1
- FENa <1%**: Prerenal AKI; **FENa >2%: Acute tubular necrosis 1
Caveat: Do not rely on BUN:Cr ratio alone—it is unreliable for distinguishing prerenal from intrinsic AKI 5.
Volume Status Assessment—The Critical Decision Point
The single most important management decision is distinguishing true hypovolemia from volume overload, as indiscriminate fluid administration worsens outcomes 5.
Clinical Signs to Assess
- Volume overload: Jugular venous distension, pulmonary edema, peripheral edema 5
- Volume depletion: Hypotension, tachycardia, poor skin turgor 5
Fluid Management Strategy
Use isotonic crystalloids (NOT colloids or albumin) for initial volume expansion in patients at risk for or with AKI 3. The evidence is clear:
- Hydroxyethyl starch increases mortality, dialysis requirement, and bleeding compared to crystalloids in septic patients 3
- Albumin shows no mortality benefit over crystalloids in critically ill patients 3
- Colloids cost more without providing superior outcomes 3
Special consideration for malaria-induced AKI: Overzealous fluid resuscitation may fail to prevent AKI and increase risk of acute lung injury requiring ventilation 3.
Nephrotoxin Withdrawal
Immediately discontinue all nephrotoxic agents regardless of AKI etiology 5:
- NSAIDs
- ACE inhibitors/ARBs
- Aminoglycosides
- Contrast agents
- Any other nephrotoxic medications
Withdraw or reduce diuretics temporarily, as they falsely elevate fractional excretion of sodium and can perpetuate volume depletion 5.
Monitoring Protocol
Measure serum creatinine every 2-4 days during hospitalization to assess AKI progression 6, 5.
Monitor for life-threatening complications:
- Hyperkalemia >6.0 mEq/L: Most immediately dangerous complication 5
- Daily electrolytes
- Strict input/output records
- Oliguria (<0.5 mL/kg/h for >6 hours) may indicate need for renal replacement therapy 5
Renal Replacement Therapy Indications
Consider RRT for 5:
- Oliguria persisting despite fluid optimization
- Severe hyperkalemia
- Severe metabolic acidosis
- Uremic symptoms (pericarditis, encephalopathy)
- Refractory fluid overload
Nephrology Referral Criteria
Emergent nephrology referral for 2:
- Stage 2 or 3 AKI
- Stage 1 AKI with concomitant decompensated condition
- Unclear etiology
Urgent referral if 2:
- No improvement with treatment
- Suspected glomerulonephritis
Post-Recovery Follow-Up
Even with complete "recovery," patients remain at significantly increased long-term risk of recurrent AKI, progression to CKD, cardiovascular events, and mortality 3, 5.
- Check creatinine every 2-4 weeks for 6 months post-discharge
- Refer to nephrology if creatinine fails to return to within 115% of baseline
- Evaluate at 3 months for resolution, new-onset CKD, or worsening of pre-existing CKD 3
- Avoid unnecessary nephrotoxins indefinitely 3
- Monitor blood pressure, fluid status, proteinuria regularly 3
Acute Kidney Disease (AKD) Staging Beyond 7 Days
If AKI persists beyond 7 days but less than 90 days, classify as AKD 3:
- Stage 0A: No evidence of damage/functional loss (but still vulnerable) 3
- Stage 0B: Ongoing injury markers (proteinuria, hypertension) OR loss of renal reserve 3
- Stage 0C: Creatinine <1.5× baseline but not returned to baseline 3
- Stages 1-3: Same as AKI staging 3
Common Pitfalls to Avoid
Do not use eGFR for medication dosing in AKI—it overestimates true renal function in non-steady state conditions 6, 5. Use Cockcroft-Gault creatinine clearance instead 6.
Do not wait for creatinine to reach 1.5 mg/dL before diagnosing AKI—this outdated threshold often indicates GFR has already fallen to ~30 mL/min 1.
In patients receiving diuretics, do not rely on urine output criteria alone 1.
Time to reach diagnostic thresholds varies by baseline kidney function: 50% creatinine increase takes 4 hours with normal baseline but 27 hours with stage 4 CKD 7.