The effect of goal-directed crystalloid versus colloid administration on postoperative pulmonary function: A substudy of a randomized controlled clinical trial

Abstract Background: Pulmonary function is impaired after major abdominal surgery and might be improved by restrictive fluid administration. Under the assumption of a fluid sparing effect of colloids we tested the hypothesis that an intraoperative colloid-based goal-directed fluid management strategy improves postoperative pulmonary function parameters compared to goal-directed crystalloid administration. Methods: We performed a preplanned, single-center substudy within a recently published trial evaluating the effect of goal-directed crystalloids versus colloids on a composite of major complications. 60 patients undergoing major open abdominal surgery were randomized to Doppler-guided intraoperative fluid replacement therapy with lactated Ringer’s solution (n = 31) or 6% hydroxyethyl starch 130/0.4 (n = 29). A blinded investigator performed bedside spirometry (Spirobank-G, Medical International Research; Rome, Italy) preoperatively as well as 6-, 24-, and 48 hours postoperatively. Results: Median total intraoperative fluid requirements were significantly higher during crystalloid administration compared to patients receiving colloids (4567 ml vs. 3044 ml, p = 0.01). 6 hours after surgery pulmonary function parameters did not differ significantly between the crystalloid - and the colloid group: forced vital capacity (FVC): 1.6 l (1.2 - 2 l) vs.1.9 l (1.5 - 2.4 l), p = 0.15; forced expiratory volume in 1 second (FEV1): 1.1 l (0.9 - 1.6 l) vs. 1.4 l (1.2 - 1.7 l), p = 0.18; peak expiratory flow (PEF): 2 l.sec -1 (1.5 - 3.6 l.sec -1) vs. 2.3 l.sec -1 (1.8 - 3.4 l.sec -1 ), p = 0.23. Similarly, postoperative time weighted averages of FVC (p = 0.50), FEV1 (p = 0.96) and PEF (p = 0.39) did not differ significantly. Conclusion: Intraoperative goal-directed colloid administration did not significantly improve postoperative pulmonary function parameters in patients undergoing open abdominal surgery compared to goal-directed crystalloid administration.Trial Registration: ClinicalTrials.gov (NCT00517127, registered on August 16th, 2007, https://clinicaltrials.gov/ct2/show/NCT00517127) and EudraCT (2005-004602-86)