Bioelectrical Impedance Vector Analysis for Assessing Metabolic Phenotype and Fluid Status in Septic Shock: A...

Area of Science:

• Critical Care Medicine
• Physiology
• Medical Technology

Background:

• Septic shock management lacks bedside tools for fluid distribution and cellular function assessment.
• Current methods may lead to fluid overload and increased mortality.
• Bioelectrical Impedance Vector Analysis (BIVA) is a non-invasive technique for body composition assessment, but its prognostic value in septic shock is undefined.

Purpose of the Study:

• To evaluate the prognostic value and application criteria of BIVA in septic shock.
• To assess BIVA's ability to monitor fluid distribution and cellular function.
• To explore BIVA's role in guiding fluid resuscitation and predicting outcomes.

Main Methods:

• A prospective observational study enrolled 128 adult patients with septic shock.
• BIVA parameters, hemodynamic indices, and serum lactate were monitored dynamically.
• Receiver operating characteristic (ROC) curve analysis and Cox regression identified prognostic cutoffs and predictors.

Main Results:

• Initial phase angle (PhA) ≤ 3.10° and hydration fraction >74% independently predicted 30-day mortality.
• The Extracellular Water/Intracellular Water (ECW/ICW) ratio strongly correlated with lactate levels, improving acute kidney injury prediction.
• Positional BIVA testing combined with upper-arm pressure gradient accurately predicted fluid responsiveness.

Conclusions:

• BIVA serves as an effective tool for individualized metabolic and fluid management in septic shock.
• PhA and hydration status are robust prognostic indicators.
• BIVA offers innovative, non-invasive methods for assessing fluid responsiveness and understanding the link between tissue edema and hypoperfusion.