Red Flags
- Severe AKI with oliguria + hyperkalaemia (K+ ≥6.5 with ECG changes) or refractory acidosis or fluid overload — emergency RRT (haemodialysis or CRRT)[1]
- AKI with rhabdomyolysis (CK ≥5000) — aggressive IV crystalloid; monitor compartments; alkalinise if clinically indicated[1]
- Sudden anuria with palpable bladder or hydronephrosis on bedside scan — post-renal obstruction; urgent catheter or nephrostomy[1]
- Drug-induced AKI from nephrotoxin (NSAIDs, aminoglycosides, vancomycin, contrast, ACE-i in volume depletion) — stop drug; volume optimise; consider alternatives[1]
First-line treatment
Interventions
- Resuscitation and source control[1]Identify and treat precipitating cause: sepsis (early antibiotics + source control), volume depletion (crystalloid), cardiogenic shock (inotropes), nephrotoxin removal
- Volume optimisation[1]Crystalloid (balanced solution preferred over 0.9% saline in non-traumatic AKI per BaSICS/PLUS); avoid synthetic colloids; assess volume status repeatedly — over-resuscitation causes congestion-induced AKI
- Avoid further nephrotoxins[1]Stop NSAIDs, ACE-i/ARB if hypotensive, aminoglycosides, vancomycin (where alternative possible), iodinated contrast where deferable. Dose-adjust all drugs per current eGFR (assume GFR ~10 in oligo-anuric AKI)
- Renal replacement therapy (RRT)[1]Indications (AEIOU): refractory Acidosis, Electrolytes (hyperkalaemia, hypercalcaemia), Intoxication (e.g., toxic alcohols, salicylates, lithium), Overload (refractory pulmonary oedema), Uraemic complications (encephalopathy, pericarditis). Earlier vs later initiation neutral in stable patients (STARRT-AKI)
First-line drug therapy
| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Hyperkalaemia management[1] | Acute potassium-lowering bundle | Calcium gluconate 10% 10 mL IV slow push (cardiac membrane stabilisation if ECG changes); insulin 10 U + dextrose 50 mL of 50% IV; salbutamol 10–20 mg nebulised; bicarbonate 50–100 mmol IV if acidaemic; sodium polystyrene sulfonate (Kayexalate) 15–60 g PO/PR | Per weight per paediatric guidelines | Definitive treatment is RRT if refractory or recurrent |
| Loop diuretic (furosemide)[1] | Loop diuretic | 40 mg IV bolus then titrate; furosemide stress test (1 mg/kg) predicts progression to RRT | 1 mg/kg IV | Symptomatic fluid overload only; does NOT change AKI trajectory or mortality; do not give for oliguria alone |
Hyperkalaemia management[1]
Acute potassium-lowering bundle
- Adult
- Calcium gluconate 10% 10 mL IV slow push (cardiac membrane stabilisation if ECG changes); insulin 10 U + dextrose 50 mL of 50% IV; salbutamol 10–20 mg nebulised; bicarbonate 50–100 mmol IV if acidaemic; sodium polystyrene sulfonate (Kayexalate) 15–60 g PO/PR
- Paediatric
- Per weight per paediatric guidelines
Definitive treatment is RRT if refractory or recurrent
Loop diuretic (furosemide)[1]
Loop diuretic
- Adult
- 40 mg IV bolus then titrate; furosemide stress test (1 mg/kg) predicts progression to RRT
- Paediatric
- 1 mg/kg IV
Symptomatic fluid overload only; does NOT change AKI trajectory or mortality; do not give for oliguria alone
Safety-net
- Maintain hydration but avoid over-drinking; track urine output and fluid balance daily during illness[1]
- Stop NSAIDs, ACE-i, ARBs, and SGLT2 inhibitors during acute illness with vomiting, diarrhoea, or fever — they can worsen AKI; restart only when stable[1]
- Recovery may take days to weeks; some patients have residual CKD — follow up creatinine and ACR after discharge[1]
Referral criteria
- AKI Stage 3 OR refractory hyperkalaemia OR pulmonary oedemaICU and nephrology for RRT[1]
- Suspected glomerulonephritis (haematuria, dysmorphic RBCs, proteinuria, RBC casts)Nephrology for urgent biopsy and immunosuppression decision[1]
- Post-renal obstruction (hydronephrosis on US)Urology for catheterisation or nephrostomy[1]
- AKI not recovering at 7 daysNephrology[1]
Clinical summary
Diagnosis, staging, and management of AKI per KDIGO criteria with bundle-based care for prevention, source control, and renal replacement decisions.