• Increase in Serum Creatinine by =0.3 mg/dl within 48 hours; or
• Increase in Serum Creatinine to =1.5 times baseline occurred within the prior 7 days; or
• Urine volume <0.5 ml/kg/hour for 6 hours.

• Dehydration
• Sepsis
• Haemorrhage
• Hypoalbuminemia
• Cardiac failure

• Glomerulonephritis
• Post-infectious
• Lupus erythromatosus
• Henoch Scholein purpura
• Membranoproliferative
• Haemolytic uremic syndrome
• Acute tubular necrosis (vasomotor nephropathy)
• Renal vein thrombosis
• Rhabdomyolysis
• Tumours
• Tumour lysis syndrome
• Drugs/Toxins

• Posterior urethral valve
• Obstructive uropathy
• Tumour/ Urolithiasis
• Neurogenic bladder
• Urethral obstruction

• RISK-Creatinine clearance < 25% with urine output < 0.5ml/kg/hr for 8 hours
• INJURY-Creatinine clearance < 50% with urine output < 0.5ml/kg/hr for 16 hours
• FAILURE-Creatinine clearance < 75% with urine output < 0.3ml/kg/hr for 24 hours
• LOSS -Persistent Failure > 4 weeks
• END STAGE- Persistent failure >3 months

• Prior history of throat infection(2-4 weeks)
• History of petechiae(HSP)
• Signs of dehydration
• Symptoms of hypertension/hypotension
• Oedema
• Rash/ arthritis
• Abdominal mass

• Bloods- Anaemia ( in SLE/ Renal vein thrombosis/ Hus)
• Leukopenia ( in Sepsis/ SLE)
• Thrombocytopenia ( in SLE/Renal vein/ thrombosis)
• Metabolic acidosis/ renal functions(  increased Urea, potassium, phosphorus, hypocalcaemia)
• Complement levels ( reduced C3 in post infectious/ SLE)
• Antibodies (ASLO/ ANCA)
• Urine microscopy ( Glomerular disease has haematuria. proteinuria, RBC casts)
• WBC/ casts suggest – Tubulointestinal disease
• Urinary indices (Osmolality/ sodium/ specific gravity/ fractional excretion of sodium help differentiate causes- see below)
• Chest X-ray- For features of heart failure
• Renal Ultrasound- for Hydronephrosis/ obstruction)
• Renal Biopsy- after discussion with Nephrologist

Urine indices in prerenal

• Elevated Specific gravity->1.020
• High urine osmolality- > 500 mOsm/kg
• Low urine sodium- <20 mEq /L
• Fractional excretion of sodium < 1%

• Low Specific gravity- <1.010
• Low urine osmolality- < 350 mOsm/kg
• High urine sodium- > 40mEq/L
• Fractional excretion of sodium >2 %

• In infants with urinary tract obstruction – Catheterise and measure output
• In Prerenal (Hypovolemic) with no features of cardiac failure- Normal Saline Bolus( 20 ml/kg). Repeat if necessary
• If no urine passage in 2 hours, treat as Intrinsic renal failure
• If sepsis, start appropriate antibiotics and maintain BP with nor-adrenaline infusion
• Mannitol( 0.5 g/kg) and Furosemide ( 2-4 mg/kg) single dose after circulation established
• If no urine production then consider Furosemide infusion
• Consider Dopamine infusion to improve renal perfusion- (3-5 g/kg per minute)

If no urine production with this measures

• STOP diuretics
• Strict Input/ Output chart
• Fluid restriction– 400ml/ m2/ 24hr +  fluid equal to urine output+ Gastric losses
• Bloods daily
• Treat hyperkalaemia( See Hyperkalaemia section)
• Metabolic acidosis (pH < 7.15) with IV Sodium bicarbonate to bring pH to 7.2. Give remaining bicarbonate orally
• Treat Hypocalcaemia with lowering Serum phosphorus(Phosphate binders. Calcium is given only in Tetany)
• Treat Hyponatremia (See hyponatremia section)
• Treat Hypertension with
  • Water/ salt restriction
  • Diuretics
  • Calcium channel blockers-Amlodipine( 0.1-0.5mg/kg/24 hour- BD)
  • Beta blockers- Propranolol(0.5- 8mg/kg/24 hrs BD)
  • In severe cases- Sodium Nitroprusside infusion (0.5-10 g/kg per minute) or labetalol (0.25 to 3 mg/kg/hr)
• If Anaemia ( Hb <7 gm/dL then fresh packed blood transfusion over 4-6 hours)

• Volume overload
• Hyperkalaemia
• Severe metabolic acidosis
• Neurological symptoms
• Hypocalcaemia – refractory
• Blood urea nitrogen > 100mg/dL