Retrospective Evaluation of the Association of Hypoalbuminemia With Acute Treatment Outcomes in Methicillin-Susceptible Staphylococcus Aureus Bacteremia.

BACKGROUND

Cefazolin and antistaphylococcal penicillins (ASP) are first-line agents for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. These agents are substantially protein-bound; however, scant data exist evaluating the impact of hypoalbuminemia on microbiologic and patient outcomes for this indication.

OBJECTIVE

The purpose of this study was to assess whether hypoalbuminemia is associated with delayed blood culture clearance in patients with MSSA bacteremia being treated with cefazolin or ASPs as definitive therapy.

METHODS

This retrospective cohort study included patients admitted for MSSA bacteremia between January 1, 2006 and December 31, 2019, with a serum albumin obtained between the date of an initial positive blood culture result and 72 hours following initiation of definitive therapy with cefazolin or an ASP. The primary outcome was the rate of persistently positive blood cultures, defined as failure to clear blood cultures within 72 hours of definitive therapy initiation. Patients with a serum albumin ≤2.5 g/dL were compared with those with an albumin >2.5 g/dL. Propensity score weighting was used to account for differences in cohort characteristics.

RESULTS

A total of 123 patients were included. After propensity score weighting, patients with hypoalbuminemia had a higher rate of persistently positive blood cultures, both in the overall cohort (45.0% vs 13.2%, P < .001) and in the subgroups of cefazolin (33.0% vs 9.1%, P = .015) and ASP (60.1% vs 18.3%, P = .001) when analyzed separately. After propensity weighting in the combined cohort, the length of stay was longer in the hypoalbuminemic cohort, but no differences in mortality were observed.

CONCLUSIONS AND RELEVANCE: Hypoalbuminemia was associated with a delayed 72-hour blood culture clearance in patients with MSSA bacteremia treated with either cefazolin or ASPs.