Acute renal failure in patients undergoing cardiothoracic surgery in a community hospital

Acute renal failure (ARF) following cardiothoracic surgery (CTS) is a major complication that increases postoperative morbidity and mortality. Recognizing patients at risk for ARF may lead to modified operative techniques, preoperative drug choice, or improved informed consent. The study objective was to identify and confirm preoperative and intraoperative risk factors for ARF following CTS in a community-based population.

A retrospective analysis of the medical records of all patients who underwent CTS at a community hospital between December 1, 1998 and December 31, 2004 was conducted. Off-pump CTS patients, patients younger than 18 years, and patients with end-stage renal disease requiring dialysis prior to surgery were excluded. Data collected included preoperative creatinine concentration, sex, diabetes status, prior myocardial infarction, preoperative medication, hypertension, cross-clamp time, and perfusion time. Analyses included Pearson chi2 and t test for comparison of demographics. Logistic regression was used for calculating odds ratios along with confidence intervals both in the univariate and multivariate models.

Of the 2556 patients who underwent CTS, 477 (18.7%) developed ARF postoperatively and 43 (1.7%) developed ARF requiring dialysis. Independent risk factors included preoperative creatinine concentrations > 1.3 mg/dL, type I diabetes, male sex, hypertension, and preoperative diuretics.

This study confirms several variables that predict ARF in patients undergoing CTS in a community-based setting. It is the first to show an independent association between preoperative diuretics and postoperative ARF