Written by Clay Smith
Mean lactate values run in a satellite lab elsewhere in the hospital vs in an ED-based lab were artefactually elevated by 10%, or 0.22 mmol/L (2.21 vs. 1.99).
Why does this matter?
Lactate is often used as a marker of sepsis severity, and lactate clearance as a way to gauge progress in resuscitation. But is the lactate high just because it takes so darn long to run the sample?
Would you run that lactate sometime this week, please?
This was a clever before and after study at a single center comparing a total of about 20,000 lactate measurements, about 10,000 done when the blood gas lab was not in the ED and was located elsewhere in the hospital and about 10,000 after the same analyzer was moved into the ED. The two groups were well matched as far as demographics and emergency severity index scores. They found that the mean lactate when run in the satellite lab was 2.21, whereas the ED-based lactate mean was 1.99. This was highly statistically significant. It appeared that the increased time needed to run the sample in a satellite lab artefactually increased the lactate by 0.22 mmol/L, a 10% increase.
Relocation of blood gas laboratory to the emergency department helps decrease lactic acid values. Am J Emerg Med. 2018 Mar 20. pii: S0735-6757(18)30234-1. doi: 10.1016/j.ajem.2018.03.042. [Epub ahead of print]
Peer reviewed by Thomas Davis