Oesophageal Doppler-guided fluid administration in colorectal surgery: critical appraisal of published clinical trials.

The evidence underpinning oesophageal Doppler monitoring (ODM)-guided fluid administration in colorectal surgery has not been critically appraised despite quantitative meta-analyses. A qualitative systematic review of the methodology and findings of all published randomised-controlled trials (RCTs) exploring ODM-guided fluid administration in major abdominal surgery was conducted. Four, well-designed single-centre trials inclusive of 393 patients in total have primarily demonstrated that ODM-guided intraoperative fluid administration decreases hospital length of stay (LOS) and complications by optimising intraoperative cardiac parameters. One subsequently published RCT shows that ODM-guided fluid administration predisposes to a greater LOS and significantly increased complications. However, all the trials have been hampered by imprecise definitions with heterogeneity in patient selection, intraoperative fluid administration strategies and methods of outcome assessment. ODM-guided fluid administration has only been investigated in the setting of laparoscopic colonic surgery and within an optimised perioperative care protocol in one trial, where it was not shown to be beneficial. Nevertheless, it was recommended for use in this context before the trial was even published. ODM-guided fluid administration has not been compared with intraoperative fluid restriction. Current evidence regarding the use of Doppler-guided fluid administration is limited by heterogeneity in the trial design, and the initial clinical benefits observed may be largely offset by recent advances in surgical techniques and perioperative care.