The increasing burden of phlebotomy in the development of anaemia and need for blood transfusion amongst trauma patients.

Background: Diagnostic laboratory tests are an integral part of the management of trauma patients, however, may be responsible for significant iatrogenic blood loss. The purpose of this study was to examine how phlebotomy practises have changed over time, and to assess the impact of these practises on patient outcomes.

Methods: A continuous series of injured patients admitted to a level I trauma centre (March-April 2004) was compared to the same period in 2009. All diagnostic tests and blood volumes withdrawn for each patient were tabulated. Primary outcomes were in-hospital mortality and length of stay (LOS); secondary outcomes were development of anaemia (Hgb<9 g/dl) and need for blood transfusion. A cost analysis was performed to determine the financial impact of the blood tests ordered.

Results: The 360 patients in 2009 and 384 patients in 2004 demonstrated no significant differences in demographics or clinical data. When outcomes were compared, there were no significant differences in hospital LOS, ICU LOS or mortality. From 2004 to 2009, the mean number of laboratory tests per patient increased significantly (21.2±32.5 to 28.5±44.4, p=0.003). The total blood volumes drawn during the hospital stay also increased significantly (144.4±191.2 ml to 187.3±265.1 ml, p=0.025). For ICU patients (329.7±351.0 ml to 435.9±346.3 ml, p=0.048). There was a 25% increase in costs due to laboratory blood tests over the study period. For ICU patients, a 36% increase in costs was observed.

Conclusions: From 2004 to 2009, there was a significant increase in the utilisation of diagnostic laboratory tests in the management of the injured patient with no demonstrable improvements in mortality or LOS. Further prospective evaluation of these results is warranted.