D-Dimer query

[Verbena17]

Hi
If the D-Dimer range (>500) is positive, is that a definite negative cut off for anything score below that or can a high score below 500 still be meaningful?

Would a score of 494 be significant or because it’s not 500+ means it totally ok?

It depends on the context of why the test was done and what other conditions that person has as other things can cause a raised d dimer. There is also an age adjustment as well so the listed cut off between negative and positive isn't always that black and white as it can be higher in older people and not mean that person potentially has a PE for example

Sorry just to add in case the bit about age adjustment didn't make sense. In some trusts the age adjustment isn't on the result. The clinician is expected to do that themself so may not show up on a print out of results

Aha thanks. So it does mention age adjustment for older people but he’s only 18.
The test was for the exclusion of PE & DVT.
He was admitted by ambulance for 6hrs of sharp stabbing chest pain and tachycardia. He developed a dry cough at same time but that disappeared over next few days.

As PP suggested - it needs to be interpreted in the context of the history, examination findings and any other investigations that were done & the best person/people to do that is the ones who saw him and ordered the test. A negative d-dimer is useful at excluding thromboembolism, but borderline/high results are less helpful.

When I had my bilateral pulmonary emboli a couple of years ago my d-dimer was 2800. However, even at that level I wasn’t officially diagnosed with the PE until it was proven by the CT scan as other things can caused raised D-Dimer. (I was also diagnosed with bacterial pneumonia and pleurisy and I had an increase to my normal chronic pulmonary oedema.) I was 59 at the time. I hope your son is feeling better.

He is feeling mostly better thanks, although he still has heart pain sometimes but more of a dull ache than sharp stabbing.

He did have a clear chest x-Ray at A&E that night and full bloods (CRP was raised to 47) and the troponin test, which was <5, so they did do everything I can think of to make sure everything was ok.