Association of Early Albumin Administration with Clinical Outcomes in Patients Hospitalized with Spontaneous...

Background/Objectives: Spontaneous bacterial peritonitis (SBP) is a serious complication of decompensated cirrhosis and is associated with acute kidney injury (AKI), organ failure, and death. Intravenous albumin is recommended in SBP because it reduces renal impairment and mortality, particularly in patients at higher risk of circulatory dysfunction and hepatorenal complications. However, the prognostic impact of early albumin administration on clinical outcomes in hospitalized SBP patients remains incompletely characterized in real-world practice. This study aimed to assess the association between early albumin administration and clinical outcomes in patients hospitalized with SBP compared to those without early albumin. Methods: A retrospective cohort study was conducted using the TriNetX US Collaborative Research Network, including adults hospitalized with SBP through February 2026. Patients were divided into those receiving early albumin administration (n = 1248) and those without early albumin (n = 4932) within 24 h of index SBP diagnosis. Propensity score matching (1:1) balanced cohorts (n = 1230 each) for demographics, comorbidities, liver disease severity surrogates, medications, and laboratory values. Relative risks (RR), risk differences (RD), and hazard ratios (HR) were calculated using propensity-matched and Cox proportional hazard models. Results: Early albumin administration was associated with significantly lower all-cause mortality (RR 0.620; 95% CI: 0.441-0.871; p = 0.005 at 5 days; RR 0.770; 95% CI: 0.651-0.910; p = 0.002 at 90 days). Secondary outcomes showed reduced risks for acute kidney injury (RR 0.654; 95% CI: 0.553-0.774; p < 0.001 at 5 days; RR 0.798; 95% CI: 0.706-0.903; p < 0.001 at 90 days), hepatorenal syndrome-AKI (RR 0.598; 95% CI: 0.445-0.804; p < 0.001 at 5 days; RR 0.756; 95% CI: 0.613-0.932; p = 0.009 at 90 days), vasopressor requirement (RR 0.633; 95% CI: 0.489-0.820; p < 0.001 at 5 days; RR 0.712; 95% CI: 0.572-0.887; p = 0.002 at 30 days), and renal replacement therapy (RR 0.533; 95% CI: 0.324-0.878; p = 0.011 at 5 days; RR 0.642; 95% CI: 0.442-0.932; p = 0.019 at 30 days). Cox models confirmed statistically significant risk reductions for all primary and secondary outcomes, including ICU admission (HR 0.82; 95% CI: 0.73-0.92; p = 0.001) and 30-day readmission (HR 0.84; 95% CI: 0.73-0.97; p = 0.015). Associations were strongest in the early period and attenuated over time. Conclusions: Early albumin administration was associated with reduced risks of mortality, AKI, HRS-AKI, and hemodynamic instability in patients hospitalized with SBP, with attenuation over time. These findings support timely implementation of guideline-concordant albumin therapy, although residual confounding cannot be excluded.