Plasma Albumin Changes During Admission for Bloodstream Infection as Prognostic Predictors After Discharge-A...

Background: With a half-life of 18-20 days, rapid declines in plasma albumin (PA) levels may reflect increased vascular loss of PA, e.g., as seen with inflammatory insults. Methods: Our study included 11,562 adult patients with first-time bloodstream infection (BSI) in a geographically well-defined Danish region between 2007 and 2016, all with ≥2 PA specimens during BSI admission and discharged alive from the hospital. We assessed mortality 1-30, 31-90, 91-365, and >365 days after discharge. Predictors were the BSI admission's first or last PA specimen's level, grouped into <25, 25-34, and ≥35 g/L as well as combinations of these (reflecting changes [none, increase, or decrease]). We applied Cox's regression analyses for a baseline model with age, sex, comorbidity, and BSI microorganisms as well as the baseline model with amendments of the first, last, or change in the PA levels. We further computed areas under the ROC curves (AUROCs) to assess how much the PA covariates changed AUROCs for the baseline model. Results: The last PA group and the changes between the first and the last PA group were the strongest predictors, with little differences between these. Lower PA level groups predicted higher mortality, especially up to 90 days. For 1-30 day mortality, the hazard ratio was 3.69 for the last PA group of <25 g/L and 0.31 for ≥35 g/L (reference: 25-34 g/L). AUROCs for the baseline model were 0.72 for the 1-30 and 0.73 for the 31-90-day mortality whereas the amendment of the PA changes increased these areas to 0.79 and 0.76, respectively. Higher AUROCs (range 0.83-0.90) were seen in non-comorbid patients, in patients aged <65 years, and in the lower quartile of days between the first and the last PA specimen. Conclusions: The BSI admission's last PA specimen was a strong mortality predictor, especially up to 90 days. Higher AUROCs were found in younger, non-comorbid patients, and in patients with higher velocity of the PA changes. These results corroborate that hypoalbuminemia is mainly a marker of acute events.