Changes in blood gas samples produced by a pneumatic tube system.

AIMS To investigate the effect of a pneumatic tube system (PTS) on the results of samples sent for blood gas analysis to a central laboratory. METHODS Blood gas samples were analysed immediately or sent via the PTS to the laboratory for analysis. In addition, samples sent via the PTS in a pressure sealed container were compared with those sent non-pressure sealed to the laboratory. RESULTS Samples sent via the PTS had significant alterations in their pO(2) values, which were not seen when samples were carried by hand to the laboratory. There was no effect on pCO(2) and pH values. The use of a pressure sealed container abolished the alteration in pO(2) values seen. CONCLUSIONS Samples for blood gas analysis should be transported via a PTS using a pressure sealed container to avoid artefacts in the pO(2).