Evaluation of an Improved Pneumatic-Tube System Suitable for Transportation of Blood Specimens

An improved version of a pneumatic-tube system built by Amsco, Inc. (Erie, Pa.) and its subsidiary ATC (San Rafael, Calif.) for blood-sample transportation incorporated two innovations: The sample carrier travels at a lower speed than in the previous conventional systems, and it is decelerated gradually on arrival. This tube system was pilot tested for efficiency by running blood-filled Vacutainer tubes through the 63.6-rn (210-feet) tube 10 times, a total running distance of 636 m. Serum lactate dehydrogenase and acid phosphatase activities, and potassium, all sensitive chemical indicators of erythrocyte membrane damage, were measured in blood specimens in partially or totally filled Vacutainer tubes and the results compared with those obtained from controls. No alterations were found in serum test results after 10 or 20 repetitive cycles in the totally filled tubes, but significant changes did occur in partially filled tubes after 20 cycles. If the limitations are observed, this system appears to be suitable for blood-specimen transportation.