G-forces and pneumatic tube systems

An Australian colleague reports that they are building a new 1000 bed tertiary hospital and the blood bank is to be about 750 feet from the operating rooms (OR) and the emergency department (ED). They are interested to use a pneumatic tube system (PTS) to manage the delivery of blood products over the distances between the blood bank, OR and ED. They have reviewed the information in the following previous discussions:

• Can Pneumatic Tube Systems in a Hospital Be Used for Transporting Blood Components?
• How do large hospitals transport blood products to patient care areas for transfusion?
• Increased breakage rate of leukoreduced Red Blood Cells transported in a pneumatic tube system
• Practical concerns regarding the location of a hospital blood bank away from the operating room
• What is an effective strategy to assure that a blood product dispensed via a pneumatic tube system is administered to the correct recipient?
• Issuance protocols for dispensing blood products using a pneumatic tube system

but have an additional concern, namely does anybody know what g-force the blood products will be exposed to in a PTS system. They cannot find any information about the g-forces and are unsure what effect the PTS g-force might have on blood products. They have seen local and international reports of hemolysed diagnostic blood specimens sent in a "faulty" PTS. (Clinical Biochemistry Volume 42, Issue 12, August 2009, Pages 1265-1269. The inquiring Australian adds that given how regulated the industry is, he is surprised that there are not more references quantifying the g-forces to which blood products might be exposed. He points out that we do daily QC on our reagents, cold rooms / refrigerators/ freezers, etc., but we send blood products long distances at 6-8 metres per second (estimated 25 mph) without hesitation. In the inquiring colleague's opinion, PTS systems are essentially black holes into which carriers are sucked, and fortunately the carriers make it to their destination. However, we have no knowledge of the forces during the travel. Blood banks routinely expose blood to centrifugal forces in centrifuges and apheresis machines, but we know the forces to which that blood is being exposed.

The following comments have been received in response.

ADDENDA Jan. 30, 2010

1. The Medical Director of a Transfusion Center in Denmark reports that they routinely subject units of blood to 4000 g during centrifugation. The responding physician searched the internet under "g forces & car crash" and found a calculation of g-force if a car is stopped in 0.2 seconds at a speed of 100 km/hour - it added up to 14.2 g. If this holds true, the maximum g-force applied to an RBC component traveling at 25mph/40 km/h would be around 6 g. He surmises that therefore, no harm should be expected.

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