Outcomes of septic shock in immune thrombocytopenia

Abstract Background: Immune thrombocytopenia (ITP) is a chronic autoimmune disorder marked by immune-mediated platelet destruction and dysregulation. Patients with ITP may also be exposed to immunosuppressive therapies such as corticosteroids, rituximab, or splenectomy, which may further compromise host defense mechanisms. Despite these factors, limited data exist on the impact of ITP on outcomes in the setting of septic shock. This study evaluates inpatient outcomes in adults hospitalized with septic shock, comparing those with and without a comorbid diagnosis of ITP using a nationally representative dataset. Methods: We performed a retrospective analysis of adult septic shock hospitalizations captured in the National Inpatient Sample (2016–2022). Cases were stratified based on a diagnosis of ITP. The analysis used discharge weights to generate nationally representative estimates. The primary outcome was in-hospital mortality. Secondary outcomes included length of stay (LOS), total hospitalization charges, transfusion requirements, thrombotic events, and use of respiratory support. Multivariable logistic and linear regression models were used to evaluate the association between ITP and outcomes. All analyses were adjusted using these methods, and statistical significance was defined as p < 0.05. Results: Among an estimated 4,412,069 adult septic shock hospitalizations nationwide, 14,810 (0.3%) involved patients with ITP. The ITP group was slightly younger (65.6 vs. 66.3 years, p = 0.018), more often female (49.4% vs. 47.0%, p = 0.009), and had a higher comorbidity burden (mean Charlson Comorbidity Index: 3.7 vs. 3.3, p < 0.001). In-hospital mortality was significantly higher in patients with ITP (37.2% vs. 33.7%, p < 0.001), with an adjusted odds ratio (aOR) of 1.154 (p < 0.001). Mean LOS was longer in the ITP group (16.5 vs. 12.6 days, p < 0.001), with an adjusted increase of 3.6 days (p < 0.001). Total hospital charges were also significantly higher for ITP patients ($287,531 vs. $207,297, p < 0.001), corresponding to an adjusted difference of $75,643 (p < 0.001). ITP was associated with higher odds of packed red blood cell transfusion (22.7% vs. 15.3%, adjusted increase of 59.7%, p < 0.001), pulmonary embolism (4.6% vs. 3.5%, adjusted increase of 39.2%, p < 0.001), and deep vein thrombosis (3.6% vs. 2.7%, adjusted increase of 34.7%, p = 0.003). Use of mechanical ventilation was lower in ITP patients (43.0% vs. 45.4%, adjusted decrease of 9.7%, p = 0.009), while non-invasive ventilation was more common (9.9% vs. 8.8%, adjusted increase of 13.8%, p = 0.038). Differences in acute kidney injury and disseminated intravascular coagulation were not statistically significant. Conclusion: In this weighted national analysis of adult septic shock hospitalizations, patients with a comorbid diagnosis of immune thrombocytopenia experienced higher mortality, longer hospital stays, and greater resource utilization compared to those without ITP. Increased rates of transfusion and thromboembolic complications further underscore the complexity of managing septic shock in this population. These findings highlight the need for heightened clinical awareness and tailored management strategies for adults with ITP who develop septic shock.