Minor Postoperative Increases of Creatinine Are Associated with Higher Mortality and Longer Hospital Length of Stay in Surgical Patients.
BACKGROUND
Surgical patients frequently experience postoperative increases in creatinine levels. The authors hypothesized that even small increases in postoperative creatinine levels are associated with adverse outcomes.


METHODS
The authors examined the association of postoperative changes from preoperative baseline creatinine with all-cause in-hospital mortality and hospital length of stay (HLOS) in a retrospective analysis of surgical patients at a single tertiary care center between January 2006 and June 2012.


RESULTS
The data of 39,369 surgical patients (noncardiac surgery n = 37,345; cardiac surgery n = 2,024) were analyzed. Acute kidney injury (AKI)-by definition of the Kidney Disease: Improving Global Outcome group-was associated with a five-fold higher mortality (odds ratio [OR], 4.8; 95% CI, 4.1 to 5.7; P < 0.001) and a longer HLOS of 5 days (P < 0.001) after adjusting for age, sex, comorbidities, congestive heart failure, preoperative hemoglobin, preoperative creatinine, exposure to radiocontrast agent, type of surgery, and surgical AKI risk factors. Importantly, even minor creatinine increases (Δcreatinine 25 to 49% above baseline but < 0.3 mg/dl) not meeting AKI criteria were associated with a two-fold increased risk of death (OR, 1.7; 95% CI, 1.3 to 2.4; P < 0.001) and 2 days longer HLOS (P < 0.001). This was more pronounced in noncardiac surgery patients. Patients with minor creatinine increases had a five-fold risk of death (OR, 5.4; 95% CI, 1.5 to 20.3; P < 0.05) and a 3-day longer HLOS (P < 0.01) when undergoing noncardiac surgery.


CONCLUSIONS
Even minor postoperative increases in creatinine levels are associated with adverse outcomes. These results emphasize the importance to find effective therapeutic approaches to prevent or treat even mild forms of postoperative kidney dysfunction to improve surgical outcomes.
From the Department of Anesthesiology and Intensive Care Medicine, Campus Charité Mitte and Campus Virchow-Klinikum, Charité-University Medicine Berlin, Berlin, Germany (F.K., F.B., C.D.S.); SoStAna GmbH, and Department of Biometry, Charité-University Medicine Berlin, Berlin, Germany (K.-D.W.); Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, Colorado (A.A.G.); Institute for Molecular Cardiovascular Research, RWTH Aachen University, University Hospital, Aachen, Germany (F.K., J.J.); and Department of Anesthesiology, Organ Protection Program, University of Colorado School of Medicine, Aurora, Colorado (H.K.E.).
Felix
F
Kork
Felix
F
Balzer
Claudia D
CD
Spies
Klaus-Dieter
KD
Wernecke
Adit A
AA
Ginde
Joachim
J
Jankowski
Holger K
HK
Eltzschig
D000368:Aged; D003404:Creatinine / Q000097:blood*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013514:Surgical Procedures, Operative / Q000009:adverse effects*
D003404:Creatinine