Incidence, care quality and outcomes of patients with acute kidney injury in admitted hospital care

Abstract

Background/introduction: Acute kidney injury (AKI) is common in acute hospital admission and associated with worse patient outcomes.

Aim: To measure incidence, care quality and outcome of AKI in admitted hospital care.

Design: Forty-six of 168 acute NHS healthcare trusts in UK caring for 2 million acute hospital admissions per annum collected information on adults identified with AKI stage 3 (3-fold rise in serum creatinine or creatinine >354 µmol/l) through routine biochemical testing over a 5-month period in 2012.

Methods: Information was collected on patient and care characteristics. Primary outcomes were survival and recovery of kidney function at 1 month.

Results: A total of 15 647 patients were identified with biochemical AKI stage 3. Case note reviews were available for 7726 patients. In 80%, biochemical AKI stage 3 was confirmed clinically. Among this group, median age was 75 years, median length of stay was 12 days and the overall mortality within 1 month was 38%. Significant factors in a multivariable model predicting survival included age and some causes of AKI. Dipstick urinalysis, medication review, discussion with a nephrologist and acceptance for transfer to a renal unit were also associated with higher survival, but not early review by a senior doctor, acceptance for transfer to critical care or requirement for renal replacement therapy. Eighteen percent of people did not have their kidney function checked 1 month after the episode had resolved.

Discussion/conclusions: This large study of in-hospital AKI supports the efficacy of biochemical detection of AKI in common usage. AKI mortality remains substantial, length of stay comparable with single-centre studies, and much of the variation is poorly explained (model Cox and Snell R² = 0.131) from current predictors.