Acute Kidney Injury (AKI) Management (KDIGO)

Algorithm Steps

1. ▶

   Start

   Suspected Acute Kidney Injury

   Patient with rising creatinine or decreased urine output

   1. ◆

      Decision

      Apply KDIGO AKI Criteria

      Does patient meet AKI definition?

      • SCr increase ≥0.3 mg/dL within 48h, OR
      • SCr increase ≥1.5× baseline within 7 days, OR
      • Urine output <0.5 mL/kg/h for 6 hours
      1. ✓

         Outcome

         AKI Not Present

         Monitor if at risk, reassess if clinical change

      2. ●

         Action

         Stage AKI Severity

         Determine AKI stage based on KDIGO criteria

         • Stage 1: SCr 1.5-1.9× baseline OR ≥0.3 mg/dL increase OR UO <0.5 mL/kg/h ×6-12h
         • Stage 2: SCr 2.0-2.9× baseline OR UO <0.5 mL/kg/h ×≥12h
         • Stage 3: SCr ≥3× baseline OR SCr ≥4.0 mg/dL OR UO <0.3 mL/kg/h ×≥24h OR Anuria ×12h OR Need for RRT
         1. ●

            Action

            Identify Etiology

            Determine pre-renal, intrinsic, or post-renal cause

            • Pre-renal: Hypovolemia, hypotension, heart failure, sepsis
            • Intrinsic: ATN, AIN, glomerulonephritis, vascular
            • Post-renal: Obstruction (BPH, stones, malignancy)
            • Check: FENa, urine sediment, renal ultrasound
            1. ◆

               Decision

               Obstruction Present?

               Renal ultrasound shows hydronephrosis?

               1. ●

                  Action

                  Relieve Obstruction

                  Urgent urological intervention

                  • Foley catheter for bladder outlet obstruction
                  • Urology consult for ureteric obstruction
                  • Nephrostomy if needed
                  1. ●

                     Action

                     Supportive Management

                     Optimize hemodynamics and avoid nephrotoxins

                     • Volume resuscitation if hypovolemic (crystalloid preferred)
                     • Target MAP ≥65 mmHg
                     • Stop nephrotoxins (NSAIDs, aminoglycosides, contrast)
                     • Adjust drug dosing for renal function
                     • Avoid hyperglycemia
                     1. ●

                        Action

                        Monitor & Reassess

                        Serial assessment of kidney function

                        • Daily creatinine monitoring
                        • Strict fluid balance
                        • Monitor for complications (hyperkalemia, acidosis, volume overload)
                        • Reassess etiology if not improving
                        1. ◆

                           Decision

                           Urgent RRT Indications?

                           Life-threatening complications despite medical therapy?

                           • Refractory hyperkalemia (K+ >6.5 with ECG changes)
                           • Severe metabolic acidosis (pH <7.1)
                           • Refractory pulmonary edema
                           • Uremic complications (encephalopathy, pericarditis)
                           1. ⚠

                              Warning

                              Initiate RRT

                              Urgent renal replacement therapy indicated

                              • CRRT preferred in hemodynamically unstable
                              • Intermittent HD if stable
                              • Nephrology consultation required
                              1. ✓

                                 Outcome

                                 Nephrology Follow-up

                                 All Stage 3 AKI or RRT require nephrology referral

                           2. ●

                              Action

                              Continue Supportive Care

                              Await renal recovery with ongoing management

                              1. ✓

                                 Outcome

                                 Renal Recovery

                                 Monitor for CKD development post-AKI