Intraoperative pleth variability index-based fluid therapy and elderly gastrointestinal surgical outcomes: a randomized controlled trial

Abstract BACKGROUND: Intraoperative goal-directed fluid therapy(GDFT) have been reported to reduce postoperative complications of the patients undergoing major abdominal surgery. The clinical benefits of pleth variability index(PVI) directed fluid management for gastrointestinal(GI) surgical patients remain unclear. Therefore, this study aimed to evaluate the impact of GDFT based on the PVI on elderly GI surgical outcomes. METHODS: This randomised controlled trial was conducted in two university teaching hospitals from November 2017 to December 2020. A total of 220 older adults undergoing GI surgery were randomised to the GDFT group or conventional fluid therapy（CFT）group (n=110 each). The primary outcome was a composite of complications within 30 postoperative days. The secondary outcomes were cardiopulmonary complications , time to first flatus, postoperative nausea and vomiting (PONV)and postoperative length of stay(PLOS) RESULTS: The total volumes of fluid administered were less in the GDFT group than in the CFT group (2500(2000, 3100)vs2075(1900, 2600), P=0.008). In intention-to-treat analysis, we found no difference in overall complications between groups: (41.3%) (CFT group) vs (43.0%) (GDFTgroup) (OR=0.935; 95% CI, 0.541-1.615; P=0.809). The proportion of cardiopulmonary complication was higher in CFT group compared with GDFT group(19.2% vs 8.4%; OR=2.593, 95% CI, 1.120-5.999; P =0.022 ). No other differences were identified between two groups. CONCLUSIONS: Among elderly patients undergoing GI surgery, intraoperative GDFT based on the simple and noninvasive PVI did not reduce the occurrence of composite postoperative complications but was associated with a lower cardiopulmonary complication compared with usual fluid management.