Even minor alteration of plasma creatinine after open abdominal surgery is associated with 30-day mortality: A single-centre cohort study.

Abstract

Postoperative acute kidney injury is common and associated with increased length of hospital stay, costs and mortality. The impact from postoperative subclinical changes in plasma concentration of creatinine (p-creatinine) on postoperative mortality has received less attention. In this study, the association between the postoperative change of p-creatinine and all-cause mortality was investigated. A single-centre register-based, retrospective study was conducted including patients ≥60 years undergoing open abdominal surgery from 2000 to 2013. Postoperative p-creatinine change was analysed for association with 30-day mortality following adjustment for age, gender, surgical setting and surgical procedure. Main findings A total of 3,460 patients were included in the study of whom 67.6% underwent emergency surgery. The 30-day mortality rate was 18.3%, and a given 10μmol/L daily postoperative increase in p-creatinine was associated with an increased mortality risk with an odds ratio (OR) of 2.67 (95% CI; 2.28-3.14, P<0.001). In patients undergoing emergency surgery, a daily 10μmol/L increase in p-creatinine increased the risk for a fatal outcome a 2.39 OR (CI 95%; 2.05-2.78), P<0.001). In patients undergoing elective surgery, a similar increase in p-creatinine increased risk of postoperative death with a 28.85 OR (CI 95%; 10.25-81.19). Even a minor postoperative p-creatinine increase following open abdominal surgery below the criteria for acute kidney injury was associated with increased 30-day mortality in patients aged 60 years or above.