Assessment of the impact of two perioperative volume replacement solutions in oncological abdominal surgery on the occurrence of metabolic acidosis: comparison between Plasmafunfin and Ringer Lactate

Background: Among the volume replacement solutions, there are two major classes of crystalloids: unbalanced (such as saline solution) and balanced. Balanced solutions can potentially reduce perioperative complications. The Plasmafundin solution has a more physiological and homeostatic profile, since it uses different buffers than the Ringer's Lactate solution, but it is more expensive. The aim of this study was to compare two balanced crystalloid solutions in terms of acid-base and hydroelectrolyte balance and clinical outcomes in the perioperative period. Methods: This is a pragmatic, single center, prospective, controlled, randomized, double-blind study. 153 adult patients undergoing major elective abdominal oncologic surgery under general anesthesia who required intensive post-operative support were randomized. The patients were followed up until the end of the first 24 hours after surgery. Cost and analyses were performed, and at the end of a 180-day period also survival analyses were performed. A p-value < 5% was considered significant. Results: Of the 153 patients randomized, 134 were included in the protocol. There was no difference in surgical time (p=0.383), nor in the volumes administered intraoperatively (p=0.932) and in the first 24 hours of the perioperative period (p=0.371), nor in the respective water balances (p=0.573 and p=0.864, respectively). There was no difference in intraoperative bleeding (p=0.890), or use of vasoactive drugs (0=0.071), or hemodynamic variables, or in the need for renal replacement therapy during follow-up (no cases of renal failure during this period in either group). The groups were similar in terms of severity at ICU admission according to SAPS3 (p=0.177). In laboratory terms, better transient laboratory parameters (restricted to the intraoperative period) were observed in the group that received Plasmafundin for Lactate (lower after 30 min (p<0.001) and after 4 hours from the start of the infusions (p<0, 001)).