Falsely decreased FVIII activity following pneumatic tube transport

The pneumatic tube system (PTS) is widely used for sample delivery. We aimed to investigate the impacts of PTS on hemostasis assays.

Triplicate samples from 30 healthy volunteers were delivered to the core laboratory manually by human courier or via the 500 m long-distance PTS or via the 1000 m long-distance PTS. Comparisons of 19 hemostasis tests were conducted.

Although PT, INR, APTT, FII, FV, FVII FIX, FX, FXII, DD, α2-PI, and PC had statistical significance (all P < .05), all had low average bias remaining within clinical acceptable limits. PTS transportation only resulted in a statistically significant and clinically relevant decrease in FVIII activity. In the 500 m-PTS group, 66.7% (20/30) of samples for FVIII testing had a bias greater than 8.3%. Moreover, in the 1000 m-PTS group, 96.7% (29/30) of samples had a bias of over 8.3%, and the maximal bias achieved 42.1%.

Pneumatic tube system in our institution could be used to deliver blood samples for hemostasis tests evaluated in this study except FVIII activity assay.