Perioperative Interstitial Fluid Expansion Predicts Major Morbidity Following Pancreatic Surgery: Appraisal by Bioimpedance Vector Analysis

To evaluate whether perioperative bioimpedance vector analysis (BIVA) predicts the occurrence of surgery-related morbidity.

BIVA is a reliable tool to assess hydration status and compartimentalized fluid distribution.

The BIVA of patients undergoing resection for pancreatic malignancies was prospectively measured on the day prior to surgery and on postoperative day (POD)1. Postoperative morbidity was scored per the Clavien-Dindo classification (CDC), and the Comprehensive Complication Index (CCI).

Out of 249 patients, the overall and major complication rates were 61% and 16.5% respectively. The median CCI was 24 (IQR 0.0-24.2), and 24 patients (9.6%) had a complication burden with CCI≥40. At baseline the impedance vectors of severe complicated patients were shorter compared to the vectors of uncomplicated patients only for the female subgroup (P=0.016). The preoperative extracellular water (ECW) was significantly higher in patients who experienced severe morbidity according to the CDC or not [19.4L (17.5-22.0) vs. 18.2L (15.6-20.6), P=0.009, respectively] and CCI≥40, or not [20.3L (18.5-22.7) vs. 18.3L (15.6-20.6), P=0.002, respectively]. The hydration index on POD1 was significantly higher in patients who experienced major complications than in uncomplicated patients (P=0.020 and P=0.025 for CDC and CCI, respectively).At a linear regression model, age (β=0.14, P=0.035), sex female (β=0.40, P<0.001), BMI (β=0.30, P<0.001), and malnutrition (β=0.14, P=0.037) were independent predictors of postoperative ECW.

The amount of extracellular fluid accumulation predicts major morbidity after pancreatic surgery. Female, obese and malnourished patients were at high risk of extracellular fluid accumulation.