Variation of the Dose of Norepinephrine in Septic Shock Patients Treated with an IgM- and IgA-Enriched Immunoglobulin Preparation: Secondary Analysis of a Prospective Multicenter Observational Study

Background/Objectives: The role of intravenous immunoglobulins (eIg) in septic shock remains controversial, and the identification of patients most likely to benefit from therapy is still uncertain. Emerging evidence suggests that dynamic parameters may outperform static baseline measurements in predicting outcomes and guiding treatment decisions. This study aimed to evaluate the prognostic value of baseline variables and their temporal changes in septic shock patients treated with eIgs. Methods: We analyzed data from the SORRISO prospective observational registry including 248 septic shock patients treated with eIgs. Baseline clinical and biochemical variables were recorded at treatment initiation (D0), and their changes were evaluated over the D0–D4 interval. Multivariable logistic regression models were used to assess predictors of outcome, focusing on both static and dynamic parameters. Results: Overall ICU mortality was 38.3%. Several baseline variables showed associations with outcome in univariable analyses; however, norepinephrine trajectory emerged as the most consistent independent predictor across multivariable models. Patients with increasing NE requirements (NE-UP) had significantly higher mortality than those with decreasing doses (NE-DOWN) (66.7% vs. 23.0%, p < 0.0001). The association remained significant across all adjustment strategies (OR range 4.31–8.12, all p < 0.05), whereas no baseline or post-treatment immunological variables retained independent statistical significance. Conclusions: In septic shock patients treated with eIgs, early changes in vasopressor support may represent a key prognostic indicator and a potentially useful tool for patient monitoring, outperforming static baseline variables. Monitoring norepinephrine trajectory may support a more personalized approach to eIg therapy and guide clinical decision-making.