Feasibility of an electronic fluid balance chart to detect and understand the significance of oliguric acute kidney injury in a general ward setting: a prospective observational cohort study.

Background: Outside critical care environments, few studies have assessed the significance of oliguric acute kidney injury (AKI). This study investigated the feasibility of an electronic fluid balance chart to diagnose oliguric AKI. Data were used to determine if oliguric AKI was met earlier than creatinine AKI and to establish outcomes of those who developed AKI.

Methods: A single-centre prospective cohort study investigated Kidney Disease Improving Global Outcomes oliguric and creatinine AKI criteria on general surgical wards.

Results: 2,149 cases were included in the analysis. Incidence of oliguric AKI was significantly higher than creatinine criteria (73 versus 10.1%) and detection occurred earlier (2.1 versus 6.1 days, p<0.05). In cases with oliguric AKI, 8.1% also developed AKI by creatinine criteria. In cases not meeting oliguric AKI criteria, fewer cases developed creatinine AKI, as compared to those meeting oliguric AKI criteria (7.9% versus 11%, p=0.043). There was a high incidence of missing data.

Conclusions: Oliguric AKI was met in a high proportion of cases and occurred earlier than by changes in creatinine. Barriers to consistency of recording must be addressed before oliguric criteria could be implemented in clinical practice.