Albumin administration is associated with acute kidney injury in cardiac surgery: a propensity score analysis.
BACKGROUND
The risk of acute kidney injury (AKI) with the use of albumin-containing fluids compared to starches in the surgical intensive care setting remains uncertain. We evaluated the adjusted risk of AKI associated with colloids following cardiac surgery.


METHODS
We performed a retrospective cohort study of patients undergoing on-pump cardiac surgery in a tertiary care center from 2008 to 2010. We assessed crystalloid and colloid administration until 36 hours after surgery. AKI was defined by the RIFLE (risk, injury, failure, loss and end-stage kidney disease) risk and Acute Kidney Injury Network (AKIN) stage 1 serum creatinine criterion within 96 hours after surgery.


RESULTS
Our cohort included 984 patients with a baseline glomerular filtration rate of 72 ± 19 ml/min/1.73 m(2). Twenty-three percent had a reduced left ventricular ejection fraction (LVEF), thirty-one percent were diabetics and twenty-three percent underwent heart valve surgery. The incidence of AKI was 5.3% based on RIFLE risk and 12.0% based on the AKIN criterion. AKI was associated with a reduced LVEF, diuretic use, anemia, heart valve surgery, duration of extracorporeal circulation, hemodynamic instability and the use of albumin, pentastarch 10% and transfusions. There was an important dose-dependent AKI risk associated with the administration of albumin, which also paralleled a higher prevalence of concomitant risk factors for AKI. To address any indication bias, we derived a propensity score predicting the likelihood to receive albumin and matched 141 cases to 141 controls with a similar risk profile. In this analysis, albumin was associated with an increased AKI risk (RIFLE risk: 12% versus 5%, P = 0.03; AKIN stage 1: 28% versus 13%, P = 0.002). We repeated this methodology in patients without postoperative hemodynamic instability and still identified an association between the use of albumin and AKI.


CONCLUSIONS
Albumin administration was associated with a dose-dependent risk of AKI and remained significant using a propensity score methodology. Future studies should address the safety of albumin-containing fluids on kidney function in patients undergoing cardiac surgery.
Department of Pharmacy, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. anne.julie.frenette@umontreal.ca.|Faculty of Pharmacy, University of Montreal, 2900 Blvd Edouard-Monpetit, H3T 1J4, Montreal, QC, Canada. anne.julie.frenette@umontreal.ca.|Research Center, Hôpital du Sacré-Coeur de Montréal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. anne.julie.frenette@umontreal.ca.
Anne Julie
AJ
Frenette
Research Center, Hôpital du Sacré-Coeur de Montréal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. josee.bouchard.1@umontreal.ca.|Department of Nephrology, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. josee.bouchard.1@umontreal.ca.|Faculty of Medicine, University of Montreal, 2900 Blvd Edouard-Monpetit, H3T 1J4, Montreal, QC, Canada. josee.bouchard.1@umontreal.ca.
Josée
J
Bouchard
Department of Pharmacy, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. pascaline.bernier@umontreal.ca.
Pascaline
P
Bernier
Department of Pharmacy, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. annie.charbonneau.5@umontreal.ca.
Annie
A
Charbonneau
Department of Pharmacy, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. long.thanh.nguyen@umontreal.ca.
Long Thanh
LT
Nguyen
Department of Nephrology, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. jp@complices.qc.ca.|Faculty of Medicine, University of Montreal, 2900 Blvd Edouard-Monpetit, H3T 1J4, Montreal, QC, Canada. jp@complices.qc.ca.
Jean-Philippe
JP
Rioux
Research Center, Hôpital du Sacré-Coeur de Montréal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. stephan.troyanov@umontreal.ca.|Department of Nephrology, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. stephan.troyanov@umontreal.ca.|Faculty of Medicine, University of Montreal, 2900 Blvd Edouard-Monpetit, H3T 1J4, Montreal, QC, Canada. stephan.troyanov@umontreal.ca.
Stéphan
S
Troyanov
Department of Pharmacy, Hôpital du Sacré-Coeur de Montreal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. david.williamson@umontreal.ca.|Faculty of Pharmacy, University of Montreal, 2900 Blvd Edouard-Monpetit, H3T 1J4, Montreal, QC, Canada. david.williamson@umontreal.ca.|Research Center, Hôpital du Sacré-Coeur de Montréal, 5400 Blvd Gouin West, H4J 1C5, Montreal, QC, Canada. david.williamson@umontreal.ca.
David R
DR
Williamson
D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000175:diagnosis; D000368:Aged; D000418:Albumins / Q000008:administration & dosage* / Q000009:adverse effects*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000639:trends; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000139:chemically induced* / Q000175:diagnosis; D057216:Propensity Score; D012189:Retrospective Studies; D012307:Risk Factors
D000418:Albumins