Relationship between fluid bolus administration and the prognostic role of serum albumin in patients with sepsis.

Background: Serum albumin plays a pivotal role in the exchange between interstitial and vascular compartments, and reduced levels of this biomarker appear to be associated with negative prognosis in septic patients. The correlation between the volume effect in sepsis therapy and the kinetics of serum albumin is unclear.

Aim: To investigate the relationship between serum albumin and fluid bolus in relation to its prognostic role in septic patients.

Methods: A single-center prospective observational study conducted from September 2022 to February 2024. All patients with sepsis admitted from the Emergency Department to the Intermediate Medical Care Unit (IMCU) were considered. Post-fluid bolus serum albumin was obtained after fluid bolus. The albumin value was correlated with the volume effect of the fluid bolus, and multivariate models were performed to evaluate its potential independent effect on 30-day mortality.

Results: 179 patients were enrolled. Pre-fluid bolus serum albumin was 2.55 g/dL (SD 0.51) with a multivariate OR for 30-day mortality of 1.170 (95 % CI 1.055-1.297, p = 0.003). After the fluid bolus, which resulted in a fluid balance percentage of +23.1 % (SD 7.1) and a mean Fractional Plasma Dilution of -0.48 (SD 0.18), albumin showed a mean decrease of -0.28 g/dL (SD 0.28) with a multivariate OR for 30-day mortality of 1.198 (95 % CI 1.065-1.348, p = 0.003). Post-fluid bolus albumin was negatively correlated with cumulative fluid balance and hemodilution.

Conclusions: The volume effect of fluid bolus is correlated with a decrease in serum albumin, and low albumin levels are associated with a high risk of mortality.