Association of Perioperative Serum Sodium Level Fluctuation and Postoperative Complications in Coronary Artery Bypass Graft Surgery

Background: Electrolyte abnormalities arecommonin coronary artery bypass graft surgery (CABG) using cardiopulmonary bypass (CPB). Changes in serum sodium (Na) concentration more than 15 meq/L in perioperative period (Delta Na > 15) is considered as significant fluctuation. The aim of this study was evaluating the relationship between the significant fluctuation of serum Na level and the complications after coronary artery bypass graft surgery. Methods: In this prospective observational study 59 patients who were candidates for CABG with CPB were enrolled into the study. We recorded patients’ demographic data, arterial blood gas analysis (ABG), serum electrolytes including Na levels from anesthesia induction, during and after CPB up to 24 hours after admission in ICU. Postoperative complications until discharge from ICU were compared between patients with significant Na fluctuation and those without it. Results: Thirty-nine patients had serum sodium fluctuation equal and more than 15 mEq/L (Delta Na 15 group). This group was compared with those who had minor Na variation (Delta Na < 15; n = 20). The Na > 15 mEq/L fluctuation group had higher serum Na and lactate levels, lower base excess in ABG. Patients with at least one postoperative complication, were older and had lower ejection fraction and more sodium fluctuations. Logistic regression analysis showed that serum sodium fluctuation more than 15mEq/l was independently associated with post CABG complications. Conclusions: Perioperative serum sodium fluctuation more than 15mEq/L was independently associated with postoperative complications in patients undergoing CABG.