Background
Acute kidney injury (AKI) is a frequent event after cardiac surgery with
increased mortality and morbidity. We explored frequency, risk factors, and
associated morbidity and mortality of AKI after isolated coronary artery
bypass grafting (CABG) surgery at a single institution.
Methods
All consecutive adults undergoing CABG surgery from March 2013 to October
2016 were assessed for development and severity of AKI based on Acute Kidney
Injury Network (AKIN) criteria. The patients were also investigated
regarding their need for renal replacement therapy (RRT), predictive risk
factors, and associated outcomes, including duration of mechanical
ventilation, mortality, intensive care unit (ICU) and hospital length of
stay.
Results
Of 1737 patients in the study, 275 (15.8%) developed AKI. Twenty-five (12.8%)
cases required RRT. Patients with AKI had longer ventilation time, ICU and
hospital length of stay (
P
<0.001). Mortality rates were
28 (10.2%) and 22 (1.5%) in patients with and without AKI, respectively
(
P
<0.001). There was a strong association between
advanced age (aOR=1.016, 95% CI=1.002-1.030,
P
=0.028),
diabetes (aOR=1.36, 95% CI=1.022-1.809,
P
=0.035), on-pump
surgery (aOR=2.63, 95% CI=1.543-4.483,
P
<0.001),
transfusion of more than 1 unit of red blood cells (aOR=2.154, 95%
CI=1.237-3.753,
P
=0.007), and prolonged mechanical
ventilation and development of AKI (aOR=2.697, 95% CI=1.02407.071,
P
<0.001). AKI was seen less frequently in those with
opium abuse (aOR=0.613, 95% CI=0.409-0.921,
P
=0.018).
Conclusion
We demonstrated that advanced age, diabetes, on-pump surgery, red blood cell
transfusion, and prolonged mechanical ventilation were independent positive
risk factors for the development of AKI after isolated CABG while opium
abuse was a protective factor.