Early postoperative change in serum creatinine predicts acute kidney injury after cardiothoracic surgery: a retrospective cohort study.
BACKGROUND
Acute kidney injury (AKI) is one of the most severe complications after cardiothoracic surgery (CTS). However, diagnosis of AKI by elevation of serum creatinine (SCr) misses a critical time period for prevention and treatment of AKI. We have observed that patients who develop AKI show a smaller SCr decrease after CTS than those without AKI. Hence, we hypothesized that the magnitude of the SCr change (ΔSCr) measured early after CTS can predict subsequent AKI.


METHODS
We conducted a retrospective analysis from January 2014 to December 2016 to examine the association of ΔSCr with AKI. ΔSCr was calculated as follows: (early postoperative SCr on intensive care unit [ICU] admission) - (preoperative SCr). Established risk factors and demographics were included in the multivariate-adjusted logistic regression model. AKI was defined by SCr criteria of the Kidney Disease: Improving Global Outcomes group.


RESULTS
Among 252 patients who underwent CTS, 69 developed AKI. The median ΔSCr was - 0.14 mg/dL (range - 0.96-0.45). Patients were divided into three groups based on ΔSCr: Group 1, ≤ - 0.2 mg/dL (n = 84); Group 2, > - 0.2 to < - 0.1 mg/dL (n = 76); and Group 3, ≥ - 0.1 mg/dL (n = 92). In the multivariate analysis, Group 3 had a significantly higher incidence of AKI than Group 1 (odds ratio, 7.34; 95% confidence interval 2.55-23.3). ΔSCr was an independent risk factor for AKI (odds ratio for every 0.1-mg/dL increase in ΔSCr, 1.55; 95% confidence interval 1.23-1.97).


CONCLUSIONS
A minor change in the SCr level early after CTS can predict subsequent AKI just after ICU admission.
['Oka|Hideaki|H|', 'Yamada|Shunsuke|S|', 'Kamimura|Taro|T|', 'Harada|Atsumi|A|', 'Tsuruya|Kazuhiko|K|', 'Nakano|Toshiaki|T|http://orcid.org/0000-0001-9235-5615', 'Kitazono|Takanari|T|']
D058186:Acute Kidney Injury D000368:Aged D000369:Aged, 80 and over D006348:Cardiac Surgical Procedures D003404:Creatinine D005260:Female D005919:Glomerular Filtration Rate D006801:Humans D016015:Logistic Models D008297:Male D008875:Middle Aged D011183:Postoperative Complications D012189:Retrospective Studies D019616:Thoracic Surgical Procedures
Serum creatinine Acute kidney injury Cardiothoracic surgery