Key Points
- Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
- Use system-specific risk tools to guide testing and disposition.
- Order high-yield tests first; escalate imaging when indicated.
- Start evidence-based initial therapy and reassess frequently.
Algorithm
- Primary survey and vitals; IV access and monitors.
- Focused history/physical; identify red flags and likely etiologies.
- Order system-appropriate labs and imaging (see Investigations).
- Initiate guideline-based empiric therapy (see Pharmacology).
- Reassess response; arrange consultation and definitive management.
Clinical Synopsis & Reasoning
Approach AKI by distinguishing pre‑renal, intrinsic, and post‑renal causes. Trend creatinine and urine output, perform urinalysis with microscopy, and assess hemodynamics and exposures (nephrotoxins, contrast, ACEi/ARB, NSAIDs). Point‑of‑care ultrasound helps evaluate volume status and obstruction. Anticipate complications—hyperkalemia, acidosis, and fluid overload—that drive urgent interventions.
Treatment Strategy & Disposition
Optimize perfusion with judicious fluids when hypovolemic; discontinue nephrotoxins and adjust drug dosing. Treat hyperkalemia and severe acidosis promptly; initiate renal replacement therapy for AEIOU indications. Coordinate imaging with contrast only when benefits outweigh risks, using preventive strategies. Disposition depends on trajectory and complications—ICU for refractory electrolyte/volume issues or hemodynamic instability; otherwise monitored ward care.
Epidemiology / Risk Factors
- CKD/AKI, nephrotoxins; obstruction
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| BMP | Renal/electrolytes | AKI/lyte changes | |
| UA ± culture | Hematuria/proteinuria/infection | Findings vary | |
| Renal ultrasound (selected) | Obstruction | Hydronephrosis |
AEIOU — Dialysis Triggers
| Indication | Examples |
|---|---|
| Acidosis | pH ≤7.1 refractory |
| Electrolytes | K ≥6.5 or any with ECG changes |
| Intoxications | Lithium, ethylene glycol (selected) |
| Overload | Refractory pulmonary edema |
| Uremia | Pericarditis, encephalopathy |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Balanced crystalloids | Volume expansion | Immediate | Pre-renal AKI | Fluid overload risk |
| Hold nephrotoxins | N/A | Immediate | Stop NSAIDs, ACEi/ARBs if needed | — |
| Loop diuretic (for overload) | Na-K-2Cl inhibition | Hours | Symptomatic volume removal | Electrolyte loss |
Prognosis / Complications
- Reversibility by cause; electrolyte/volume complications
Patient Education / Counseling
- Explain red flags and when to seek emergent care.
- Reinforce medication adherence and follow-up plan.
Notes
Prefer lactated Ringer’s or Plasma-Lyte for resuscitation. Use FE_Urea in diuretic-treated patients. Coordinate contrast timing if unavoidable; use lowest dose and pre/post-hydration.