BIOELECTRICAL-IMPEDANCE ANALYSIS PREDICTS OUTCOME IN PATIENTS WITH SUSPECTED BACTEREMIA

Fluid shifts from intracellular to extracellular water (ICW to ECW) ar e a feature of sepsis, caused by increased vascular permeability and c ell catabolism. Changes in ECW and total body water (TBW) were assesse d in a prospective observational study of patients with bacteremia by a bedside technique, and its prognostic impact determined; In 78 hospi tal patients with fever, the resistance ratio (Rinf/RO) and estimated ECW/TBW ratio from multifrequency bioelectrical impedance analysis, an d serum albumin concentration were measured. Rinf/RO and ECW/TBW ratio s decreased from day 0 to 2 in patients with significant bacteremia (n = 31), but not in patients with doubtful or negative blood cultures ( n = 22 and 25), Increased Rinf/RO at baseline, and further increase of ECW/TBW from day 0 to 2, were associated with lower rate of recovery after 1 week and with higher mortality. Baseline Rinf/RO above the med ian (0.75) had positive and negative predictive values of 0.31 and 0.9 5 for death. This prognostic effect was independent of underlying dise ase and blood culture result in a multivariate model. Hypoalbuminemia at baseline was predictive of outcome, but changes in albumin from day 0 to 2 were unrelated to blood culture results or outcome. In patient s with bacteremia,fluid shifts from intracellular to extracellular,vat er occur early are rapidly reversible by antibiotic treatment but are associated with adverse prognosis. Bioelectrical impedance deserves fu rther study as a tool for bedside monitoring of patients with bacterem ia.