Acute Kidney Injury (AKI) 🧪

• AKI is defined by a rapid decline in renal function over hours to days.
• KDIGO criteria: ↑ serum creatinine by ≥26.5 μmol/L within 48h, or ≥1.5x baseline in 7 days, or urine output <0.5 mL/kg/h for >6 hours.
• Important due to risk of fluid/electrolyte imbalance and need for timely intervention.

• Any recent nephrotoxic meds (e.g. NSAIDs, ACEi, contrast)?
• Fluid status and recent intake/output?
• Any previous renal function data?
• Ask nurse to: check catheter patency, input/output accuracy, perform bladder scan if needed.

• Pre-renal: dehydration, hypovolaemia, heart failure
• Renal: sepsis, nephrotoxins, glomerulonephritis, rhabdomyolysis
• Post-renal: obstruction from prostate, stones, blocked catheter

• Symptoms: reduced urine output, confusion, lethargy, oedema
• Risk factors: recent illness, infection, fluid loss, medications
• Ask about urinary symptoms, previous AKI/CKD, recent imaging with contrast

• Vitals: HR, BP, temp, RR, SpO₂
• Fluid status: mucous membranes, JVP, oedema, cap refill
• Bladder palpation, DRE if obstructive cause suspected

• Bloods: U&Es, creatinine, FBC, CRP, CK if rhabdo suspected
• Urinalysis ± urine microscopy
• Renal ultrasound if obstructive cause suspected
• ECG if hyperkalaemia suspected
• VBG for acid/base balance and lactate

• Stop nephrotoxic drugs
• Volume resuscitation if hypovolaemic (250–500ml crystalloid)
• Insert/flush catheter if needed
• Treat sepsis or obstruction if present
• Monitor fluid balance and labs regularly

• Hyperkalaemia or severe acidosis
• Volume overload with pulmonary oedema
• Severe or persistent AKI (Stage 2–3)
• Suspected need for dialysis
• Obstructive cause with no response to initial management

Related NICE guidance