D-Dimers

[maloneys]

I wonder if someone might help shed some light here. Post-op day 4, abdo abcess drainage patient who went from room air to tachypneic 30-40 and 100% FiO2 over a couple of hours. I did a D-dimer as I suspected a possible PE. Came back 6000. Doc said it would be elevated since the patient is 4 days post-op, and you need a result of 10 000 for it to indicate PE.

Then a few days later, 3 day post-op cystectomy, same symptoms as patient above, D-dimer 3120, but ultrasound showed PE.

I don't understand! Please help! Many thanks in advance.

[%63theend]

We do d dimers on our chest pain patients. It's standard protocol. Any d dimer out of normal range and the chest pain pt goes for a chest CT.

I had a patient who was admitted with dehydration (not chest pain). Her dehydration had been resolved but I noted she had a respiratory rate of 29. Pt was also suddenly very fatigued and winded even getting up in bed when she had been walking the halls earlier in the day. I called the doc who ordered a d dimer. It came back at 2,000. Sent her for a chest CT and she had bilateral PE's. I've seen PE's in other nurse's patients with d dimers around 1,000 but in my own patients and in my friend's patient's I've not seen PE's with high d dimers below 1,000. In other words, I don't suspect a PE with a d dimer of 400. But >1,000 and I think it is possible-likely and >2,000 I expect a positive.

I should mention this is in a med-surg unit. Not in ICU. (Didn't realize I was posting in an ICU forum)