Intraoperative blood glucose concentration fluctuation is closely related to short-term clinical outcomes in patients after off-pump coronary artery bypass graft

Abstract

Objective To investigate the effect of intraoperative fluctuation in blood glucose concentration (BGCF) on short-term clinical outcomes in patients after off-pump coronary artery bypass graft (CABG) .Methods Two hundred and fourteen ASA Ⅰ -Ⅲ patients ( NYHA grade Ⅰ -Ⅲ ) of both sexes aged 18-64 yr with body mass index 23-29 kg/m2 underwent elective off-pump CABG. Their left ventricular ejection fraction was ≥30% .Blood samples were obtained once an hour for determination of blood glucose concentration (BGC) between 10 min after induction of anesthesia and 10 min after closure of sternum. The maximum and minimum BGCs were record-ed . Intraoperative BGCF was defined as the difference between the maximum and minimum BGCs. Other factors which may influence clinical outcome were also recorded, including prolonged ICU stay ( ≥24 h), prolonged me-chanical ventilation ( ≥12 h) , postoperative complications (cardiac insufficiency secondary to operation, arrhyth-mia, myocardial infarction, respiratory insufficiency, stroke, infection, pleural effusion and surgical bleeding) and prolonged postoperative hospital stay ( ≥ 7 d) . The patients were divided into 2 groups using intraoperative BGCF 400 mg/L as cutoff point: group L < 400 mg/L and group H ≥400 mg/L. Receiver operating characteristic (ROC)curve was used to evaluate if intraoperative BGCF was a good index of postoperative outcomes. Results The area under the ROC curve of intraoperative BGC against prolonged ICU stay was 0. 804 (0.739-0. 869), against prolonged mechanical ventilation 0. 604 ( 0.415-0.793 ), against postoperative complications 0.801 ( 0.720-0. 882 )and against postoperative hospital stay 0.615 (0.523-0.707). The duration of ICU stay was significantly longer and the incidences of complications and prolonged postoperative hospital stay were higher in group H than in group L (P < 0.01). Conclusion Intraoperative BGCF is closely related to postoperative outcomes in patients after offpump CABG. The patients with the BGC≥400 mg/L has a poor prognosis. Key words: Blood glucose; Prognosis; Coronary artery bypass, off-pump