Effect of Pneumatic Tube Delivery System Rate and Distance on Hemolysis of Blood Specimens

Abstract

We evaluated the effects of pneumatic tube system (PTS) transport rates and distances on routine hematology and coagulation analysis. PTS effects on centrifuged blood samples were also examined. The study was completed at Dicle University Hospital, which has the longest pneumatic tube system in Turkey. Blood samples were collected at three different locations within the hospital and an emergency department, and delivered to the central laboratory by the PTS or a human carrier. Samples were transported at different rates and over varying distances. Each specimen's potassium (K) and lactic dehydrogenase (LDH) levels, in both the serum and plasma, were tracked to monitor hemolysis. Measurements of LDH and K were obtained using heparin or citrate. A positive correlation was observed between distance and hemolysis in serum samples transported at 4.2 m/sec, and at 3.1 m/sec for more than 2200 m (r = 0.774 and r = 0.766, respectively). Distance and hemolysis were also correlated in non-centrifuged samples (r = 0.871). The alterations in plasma LDH and K levels at different rates and PTS lengths were not statistically significant. The rate of hemolysis in PTS transported samples, dependent on PTS length and rate, may seriously affect routine tests of non-centrifuged samples.