Obesity and post-cardiopulmonary bypass-associated acute kidney injury: a single-center retrospective analysis.
OBJECTIVE
The authors specifically explored the association of obesity (based on body mass index [BMI]) and the risk of developing acute kidney injury after cardiopulmonary bypass (AKICPB).


METHODS
Single-center retrospective study.


METHODS
Academic medical center.


METHODS
After IRB approval, 376 eligible adults who underwent cardiac surgery with cardiopulmonary bypass between 2006-2010 were included in the final retrospective analysis. Patients undergoing "off-pump" procedures, cardiac transplants, repair of congenital heart disease, and patients with preoperative circulatory assist devices were excluded.


RESULTS
The overall incidence of developing AKICPB in this population based on the Acute Kidney Injury Network serum creatinine criteria was 39% (147 of 376). Among the BMI classes, the morbidly obese cohort (ie, BMI>40 kg/m(2)) had a significantly greater risk of developing AKICPB than those in lower BMI classes. BMI>40 kg/m(2) was significantly associated with development of AKICPB even after accounting for covariates (ie, diabetes mellitus, hypertension, age, severity of illness, and CPB time) (overall p = 0.018). The odds ratio of AKICPB in the BMI>40 kg/m(2) cohort relative to BMI<25 kg/m(2) was 2.39 (95% CI: 0.98, 5.82; p = 0.055), with no significant difference in risk of developing AKICPB among the 4 lower BMI classes.


CONCLUSIONS
BMI>40 kg/m(2) is associated with a significantly higher risk of developing of AKICPB.
Department of Anesthesia, Division of Critical Care, Vanderbilt University, Nashville, TN. Electronic address: avinash.b.kumar@vanderbilt.edu.
Avinash B
AB
Kumar
Department of Biostatistics, University of Iowa, Iowa City, IA.
M
M
Bridget Zimmerman
Department of Nephrology, University of Iowa Hospitals and Clinics, Iowa City, IA.
Manish
M
Suneja
D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000209:etiology; D000368:Aged; D015992:Body Mass Index; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology*; D012121:Respiration, Artificial; D012189:Retrospective Studies; D016896:Treatment Outcome
BMI; acute kidney injury; cardiopulmonary bypass; morbid obesity