Assessing Pneumatic Tube Systems with Patient-Specific Populations and Laboratory-Derived Criteria

To the Editor:The October 2011 issue of Clinical Chemistry highlights the importance of monitoring pneumatic tube systems (PTSs) to control preanalytical factors that may affect laboratory results (1, 2). Two important themes emerge: ( a ) the possible requirement of more-frequent monitoring if the PTS produces changes in the 3-axis acceleration (i.e., forces) and ( b ) consideration for specific populations of patients (i.e., hematology and/or oncology patients) whose blood samples may be more susceptible to PTS. As Felder noted, the work by Streichert et al. may usher in a new practice for monitoring PTS by means of data loggers (1, 2); however, in the interim, laboratories will be required to monitor PTSs with split-sample testing. In this regard, the number of studies and approaches that have assessed the impact of PTSs on the quality of samples has been surprisingly limited (3). Moreover, the available guidelines have mainly suggested that PTSs be evaluated and that certain analytes may be affected by the automated system (e.g., lactate dehydrogenase), whereas others (e.g., aspartate aminotransferase) may not (4). Additional questions arising from the study of Streichert et al. are whether samples from healthy …