Intraosseous versus intravenous fluid resuscitation in gastrointestinal tumor-related acute hemorrhage: impact on 30-day mortality and lactate clearance.

This retrospective study evaluated the impact of intraosseous infusion (IO) versus traditional intravenous infusion (IV) on 30-day mortality and clinical outcomes in 518 patients with acute gastrointestinal bleeding (AGIB) secondary to gastrointestinal tumors from January 2022 to July 2024. Patients were divided into IO (n=217) and IV (n=301) groups based on initial resuscitation strategy. Compared to IV group, the IO group demonstrated higher first-attempt catheterization success rate, shorter vascular access time, and faster blood pressure recovery (all P<0.001), alongside higher 6-hour lactate (LA) clearance (34% vs. 22%, P<0.001) and lower 30-day mortality (11.98% vs. 18.6%, P=0.016). Multivariate analysis identified IO infusion as protective factor for lactate metabolism (HR=0.289, 95% CI: 0.092-0.864), while advanced age (HR=1.125), diabetes (HR=3.23), and low LA clearance (HR=0.016) were independent risk factor for mortality. Causal mediation analysis revealed that 6-hour LA clearance mediated 68% of the IO-associated mortality reduction (P<0.001), whereas diabetes history was not a significant mediator (P=0.156). Complication rates were comparable between groups (P>0.05). These findings indicate that IO infusion improves survival in AGIB due to gastrointestinal tumors by rapidly restoring hemodynamics and enhancing lactate metabolism. The mortality benefit is primarily driven by accelerated LA clearance rather than comorbidities like diabetes. Given its safety profile comparable to IV, IO infusion should be prioritized in critical care settings.