Effects of pneumatic tube systems on next-generation viscoelastic coagulation test devices in septic patients and healthy individuals: Results of the randomized controlled VETaPT trial

Abstract Background Rapid coagulation assessment is essential in critical care to enable timely correction of coagulopathy. Viscoelastic testing (VET) supports this goal but may be affected by mechanical stress during transport by pneumatic tube systems (PTS). As PTS are widely used to expedite sample delivery, evaluating the robustness of next-generation VET and platelet function assays under these conditions is crucial for reliable, time-sensitive diagnostics in intensive care. This study investigated the impact of PTS transport on VET and platelet function testing in healthy individuals and septic patients, including quantitative analysis of acceleration forces. Methods This randomized trial subjected blood samples from 46 healthy volunteers and 45 septic patients to manual and PTS transport. Acceleration was quantified via three-axis accelerometry. Samples were analyzed using ClotPro®, ROTEM®, TEG® PlateletMapping®, and Multiplate®. Primary objective was the difference in test results following both transport modes. As pre-specified in the protocol, logistic regression modeled the probability of a clinically relevant EX-test clotting time (CT) change (≥ 10 s) within each cohort. Given the absence of associations, secondary equivalence analyses (TOST [two one-sided tests] and bootstrap) assessed whether observed effects were within pre-specified bounds. Results Neither logistic regression nor correlation analysis indicated an effect of mechanical stress on variable changes (all ρ < 0.5; p > 0.01). Across platforms, most viscoelastic and platelet function variables remained within predefined equivalence margins after PTS transport. Exceptions were TEG® PlateletMapping® HKH-R and, by bootstrap, ADP/AA-inhibition. In healthy volunteers, equivalence was confirmed for all variables (TOST p < 0.001). In septic patients, minor shifts remained within clinically acceptable limits, with equivalence confirmed for ClotPro® IN-test CT (± 16 s, p – = 0.036; p + < 0.001), EX-test MCF (± 2 mm, both p < 0.001), ROTEM® INTEM CT (± 16 s, both p < 0.001), Multiplate® TRAP (± 10 U, p– = 0.001; p + < 0.001), and TEG® PlateletMapping® ADP/AA inhibition (± 5%, both p < 0.05). Conclusions Most next-generation viscoelastic and platelet assays are robust to PTS-induced stress. Coagulation diagnostics can include PTS transport without compromising validity. Only selected TEG® PlateletMapping® variables exhibited variability, indicating limited robustness. Trial registration: The study is retrospectively registered with the German Clinical Trials Register (DRKS00036231; https://drks.de/search/de/trial/DRKS00036231/details on 20.02.2025).