Evaluation of Pneumatic-Tube System for Delivery of Blood Specimens

Abstract

Abstract Blood specimens from normal individuals and patients (with and without blood dyscrasias) were sent through a 1,423-m pneumatic-tube system that included two monitoring devices, three switches, and 67 bends (62 with a 152-cm radius and 5 with a 76-cm radius), and then returned to the central laboratory. Each specimen was thus subjected to twice the trauma it usually would receive during transit. After transit, these specimens and duplicates kept in the laboratory were analyzed in the same manner for serum or plasma Na, K, Cl, CO2, Ca, Pi, LDH, urea, uric acid, glucose, creatinine, total protein, fibrinogen, hemoglobin, and bilirubin. Filling the tubes completely with blood and using a foam-rubber-Iined vinyl insert to hold the specimen tubes in the carrier decreased the differences attributable to transportation. Allowing the blood to clot before transport did not alter the results. Increases attributable to transport occurred only in hemoglobin, LDH, and K. Values were altered considerably less when the transported aliquot made only one leg of the trip via pneumatic tube. The alterations observed for the remaining analyses were within laboratory error. The pH of whole blood and the mean for PCO2 were not significantly altered, while the mean value for PO2, was increased 1.7 (0.5 to 4.5) mm Hg on transport.