Incidence, clinical characteristics and outcomes of acute kidney injury
in hospitalised patients -- the relevance of presence on admission
versus post-admission syndrome onset
Abstract
Background and aims: Acute kidney injury (AKI) is a common clinical
syndrome that has been consistently linked with increased morbidity and
mortality risk. Prognosis, as well as incidence, varies depending on
patients characteristics and health care setting. We aimed to evaluate
the incidence of AKI and related outcomes in a population of
hospitalised patients taking into account the time of onset and severity
of the syndrome. Methods: This retrospective study included adult
patients admitted to a tertiary care hospital between January 1, 2013,
and December 31, 2015, who had at least one inpatient serum creatinine
(SCr). We distinguished between AKI apparent at admission (CA-) and
afterwards during hospitalisation (HA-AKI). Results: The incidence of
AKI was 15.2 %, of which 68% of episodes developed during hospital
care. Baseline characteristics of CA-AKI and HA-AKI were similar, but
CA-AKI patients were more likely to have more severe episodes and
shorter length of stay than patients with HA-AKI (30.9% vs 14.5% with
AKI stage 3 and 8.1 vs 14.8 days, respectively). We found a strong,
gradual association (after multivariate adjustment) between stage of AKI
and mortality. Irrespective the type of AKI, stage 3 was related to the
five-fold risk of in-hospital death and a two-fold risk of death at the
6th-month in comparison to No AKI. Conclusions: One in six of
hospitalised patients experienced AKI, and almost two-thirds of events
developed during the hospital stay. There were no differences in
short-term mortality between AKI type, but the risk of death related to
the severity of the syndrome.