Influence of liberal versus "restricive" intraoperative fluid administration on elimination of a postoperative fluid load

Background., Previously, the authors found "liberal" fluid administration (approximately 3 1 Ringer's lactate [RL]) to improve early rehabilitation after laparoscopic cholecystectomy, suggesting functional hyovolemia to be present in patients. p receiving "restrictive" fluid administration (approximately 1 l RL). Because volume kinetic analysis after a volume load may distinguish between hypovolemic versus normovolemic states, the authors applied volume kinetic analysis after laparoscopic cholecystectomy to explain the difference in outcome between 3 and 1 l RL. Methods: In a prospective, nonrandomized trial, the authors studied 20 patients undergoing laparoscopic cholecystectomy. Ten patients received 15 ml/kg RL (group 1) and 10 patients received 40 ml/kg RL (group 2) intraoperatively. All other aspects of perioperative management were standardized. A 12.5 ml/kg RL volume load was infused preoperatively and 4 h post-operatively. The distribution and elimination of the fluid load was estimated using volume kinetic analysis. Results: Patient baseline demographics and intraoperative data did not differ between groups, except for intraoperative RL, having a median of 1,118 ml (range, 900-1,400 ml) in group 1 compared with a median of 2,960 ml (range, 2,000-3,960 ml) in group 2 (P < 0.01). There were no significant preoperative versus postoperative differences in the size of the body fluid space expanded by infused fluid (V), whereas the clearance constant k(r) was higher postoperatively versus preoperatively (P = 0.03). The preoperative versus postoperative changes in volume kinetics including V were not different between the two groups. Conclusions: Elimination of an intravenous fluid load was increased after laparoscopic cholecystectomy per se but not influenced by the amount of intraoperative fluid administration.