Effect of Intraoperative Goal-directed Balanced Crystalloid versus Colloid Administration on Postoperative Cardiac Outcome

Background : N-terminal pro brain natriuretic peptide (NT-proBNP) and troponin T are released during myocardial wall stress and/or ischemia and are strong predictors for postoperative cardiovascular complications. However, the effect of goal-directed crystalloid versus colloid administration on NT-proBNP and troponin T, especially in relatively healthy patients undergoing moderate- to high risk abdominal surgery, still remains unclear. Thus, we evaluated in this subanalysis the effect of a goal-directed crystalloid versus a goal-directed colloid fluid regimen on postoperative cardiac outcome. Methods: 30 patients were randomly assigned to receive additional fluid boluses of 6% hydroxyethyl starch 130/0.4 and 30 patients to receive lactated Ringer´s solution. Intraoperative fluid management was guided by oesophageal Doppler according to a previously published algorithm. The primary outcome were differences of maximum NT-proBNP (maxNT-proBNP) and maximum troponin T (maxTnT) concentrations during the first two postoperative days between both study groups. We defined maxNT-proBNP and maxTnT as maximum values measured 2 hours after surgery and on the first and second postoperative day. Results: In total 56 patients were analysed. There was no significant difference in postoperative maximum NT-proBNP between the colloid group (258.7 ng/L (IQR 199.4 to 782.1)) and the crystalloid group (440.3 ng/L (IQR 177.9 to 691.2)) during the first 2 postoperative days ( P = 0.29). 5 patients in the colloid group and 7 patients in the crystalloid group developed MINS ( P = 0.75). Conclusions: Postoperative cardiac outcome as defined by cardiac biomarkers was not significantly affected by goal-directed colloid administration; however, there was a tendency of lower maximum NT-proBNP concentrations in patients receiving colloids. Trial registration: ClinicalTrials.gov (NCT01195883)