Acute Kidney Injury (AKI) formerly known as “acute renal failure” results in rapid reduction in kidney function associated with a failure to maintain fluid, electrolyte and acid-base homeostasis. The UK NCEPOD published a report in 2010 on AKI that revealed many deficiencies in the care of patients with AKI. The UK Renal Association has published the final draft of Clinical Practice Guidelines for Acute Kidney Injury on the 08/01/2011. In our study we determined retrospectively the occurrence of this problem in a District General Hospital and its impact on recovery after lower limb arthroplasty.

Data was collected retrospective study over 3 months between Oct to Dec 2010 from theatre registers and the hospital database system. 359 patients were identified. Preoperative (baseline) and postoperative blood investigations included Creatinine, Urea, K+, Na+, GFR, Haemoglobin were analysed. Data collection also included type of anaesthesia, timing of operation, duration of procedure and estimated blood loss. From the hospital database system and clinic letters we collected length of stay and time required for blood results to come back to baseline.

A diagnosis of Acute Kidney Injury was based on the International Kidney Disease Improving Global Outcomes (KDIGO) staging classification as recently recommended by UK Renal Association. Stage I Creatinine increase by ≥ 26 μmol/L from baseline, Stage II Creatinine increase by 200-300% and Stage III Creatinine increase ≥ 300%.

In our study 11.97% (43/359) of patients developed acute kidney injury following lower limb Arthroplasty. 18 patients (42%) developed Stage I (Cre increase ≥ 26 μmol/L), 17(39%) developed Stage II (Cre increase 200-300%) and 8 patients (19%) developed Stage III (Cre increase ≥ 300%) AKI. Most of these patients were operated during the afternoon session. Patients with acute kidney injury stayed longer in hospital (11.7days) compared to similar age group of patients (6.35days) admitted during the same period. 25% of patients took more than a month for renal parameters to come down to normal.

AKI is a new definition and the incidence in our hospital is higher than the 1% expected nationally. Patients with AKI are often complex to treat and specialist timely referral and transfer to renal services if appropriate should be considered. The etiology of Acute Renal Injury is very complex and includes gentamicin antibiotic prophylactic, rapid blood loss in elderly frail patients, non-steroidal pain killers and preexisting cardiac and renal pathology.

The need for careful postoperative observation cannot be overemphasised together with judicious blood replacement as required. Acute Kidney Injury following lower limb arthroplasty is a sensitive marker of postoperative care. A successful surgical outcome may not mean a successful renal outcome. Patients with AKI are often complex to treat the new AKI definition and staging system allows an earlier detection and management of this condition. Further prospective audit with large number of patients are required.