The initial development and assessment of an automatic alert warning of acute kidney injury

Abstract

Background: Acute kidney injury (AKI) recognition by clinicians has been shown to be suboptimal. Little work has focused on the use of an automated warning of a rise in a patient's creatinine, indicating AKI.

Methods: Over 3 months in 2008 we ran a prospective observational study of 'alerts' sent by our Integrated Clinical Environment pathology system, identifying all patients with a ≥ 75% rise in their creatinine from its previous value. Information was collected on subsequent renal function, comorbidities and other potential predictors of survival.

Results: In the 3-month period 463 adults with a first episode of AKI were identified by an alert; 87% were hospital inpatients. Median follow-up was 404 days. In-hospital mortality was 36% for those who were admitted. After performing Weibull survival analysis, significant predictors of poorer survival were the presence of metastatic, haematological or lower risk malignancy, a residential or nursing home address and higher age, number of non-malignant comorbidities or C-reactive protein level. Predictors of better survival were higher serum albumin level or nadir GFR during the episode and Indian subcontinent ethnicity. A receiver-operator curve for a prognostic score developed from the analysis showed an area under the curve of 0.84.

Conclusions: The alerts identified a group of AKI patients who are at moderately high risk of death. The prognostic score using a combination of covariates shows early promise. Both the alerts and the score warrant further development as tools for earlier intervention in AKI.