Preoperative volume assessment using bioelectrical impedance analysis for minimizing blood loss during hepatic resection

BACKGROUND Maintaining low central venous pressure (CVP) is an effective strategy to reduce blood loss during hepatic resection. As an alternative to measuring CVP, which requires the placement of a central venous catheter, bioelectrical impedance analysis (BIA) is a noninvasive method recently used for monitoring volume status in critically ill patients. METHODS We investigated 192 patients who underwent hepatic resection from January 2017 to December 2020. The ratio of extracellular water:total body water (ECW/TBW), as an index of volume status, was measured using InBody S10 (Biospace, Seoul, Korea). The correlation between the ECW/TBW and CVP was determined, and their influences on operative outcomes were analyzed. RESULTS ECW/TBW and CVP showed a significant correlation; an ECW/TBW <0.378 correlated with a CVP <5 mmHg (R2 = 0.839, P<0.001). Estimated blood loss (EBL) was significantly increased in patients with an ECW/TBW ≥0.378 compared to those with a ratio <0.378 (508 ± 321 vs. 324 ± 193, mL, P<0.001). Identified predictors for an EBL ≥500 mL were operative time (odds ratio [OR], 1.008; 95% confidence interval [CI], 1.001-1.015; P = 0.021) and an ECW/TBW <0.378 (OR, 0.263; 95% CI, 0.121-0.572; P = 0.001). CONCLUSIONS BIA can be utilized for preoperative volume assessment to minimize blood loss during hepatic resection.