Troponin Timing

[cjgiedt]

Hi All,

Just curious-- if a troponin level is drawn late, do you draw the next one six hours after the late draw, or six hours after the late draw was SUPPOSED to be done?

Thanks

[nrsang97, BSN, RN]

Well if they are every 6 hours and the one is drawn say at 8 hours, then I would draw 6 hours from the most recent draw.

[Anna Flaxis, BSN, RN]

How were they ordered? If this is a serial enzyme measurement intended to detect a trend, then the 6 hour troponin should be drawn six hours after the initial troponin or suspected injury.

For instance, patient presents to ED with s/s cardiac ischemia. An initial troponin is drawn, and serial enzymes are ordered for 3, 6, and 9 (and possibly 12 and 24) hours from the initial draw. In this case, you would draw the 6 hour troponin six hours from the initial draw- because the intent is to identify a trend.

If the troponins are ordered Q6 hours, then you would draw six hours after the last one was drawn.

[Dogen]

If this is a serial enzyme measurement intended to detect a trend, then the 6 hour troponin should be drawn six hours after the initial troponin or suspected injury.

Yeah... they should always be ordered as serial troponins timed off the first lab, because the size of the infarction and thus mortality are linearly correlated with peak troponin levels. So, timing them from the initiation of symptoms is ideal (TnI peaks in ~30ish hours), and off the baseline blood draw is the next best thing.

But our hospitalists almost always order them Q6hrs.