D-Dimers - page 3

by maloneys

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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. ... Read More


  1. 2
    Quote from maloneys
    So in these cases, both patients should have been scanned then!
    Well, not necessarily. The contrast Chest CT Scan obviously gave you the diagnosis in both cases. However, what was the initial hesitation to get a CT Scan? Like I mentioned previously, there are patients that we worry about subjecting to IV dye (poor kidney function, dye allergy). In those cases, there are other things that can help with the diagnosis of PE.

    One, you can do a Dulpex Ultrasound of the legs and if a DVT is positive, then you will anticoagulate anyway. If there is high suspicion for a PE based on presentation, you can safely deduct that there is a source of a PE from the legs and a PE is likely.

    You can also do transthoracic echocardiogram or a 2-D Echo. PE is a clot in the pulmonary arterial circulation. You know that the RV pumps blood to the pulmonary arteries - if there is a significant PE, the RV will show strain on the 2-D Echo due to difficulty pumping blood through the pulmonary circulation. Evidence of R heart strain is a strong diagnostic indicator of a PE.

    Another test that was being done more commonly in the past is a V/Q Scan which only gives you PE probabilities and will not detect smaller PE's.
    Esme12 and maloneys like this.
  2. 1
    Quote from Esme12
    I am confused...how did an ultrasound see a Pulmonary emboli?
    I was also interested in this. Also a D-dimer only >10000 for PE? How does that work.
    Esme12 likes this.
  3. 1
    Quote from juan de la cruz

    Well, not necessarily. The contrast Chest CT Scan obviously gave you the diagnosis in both cases. However, what was the initial hesitation to get a CT Scan? Like I mentioned previously, there are patients that we worry about subjecting to IV dye (poor kidney function, dye allergy). In those cases, there are other things that can help with the diagnosis of PE.

    One, you can do a Dulpex Ultrasound of the legs and if a DVT is positive, then you will anticoagulate anyway. If there is high suspicion for a PE based on presentation, you can safely deduct that there is a source of a PE from the legs and a PE is likely.

    You can also do transthoracic echocardiogram or a 2-D Echo. PE is a clot in the pulmonary arterial circulation. You know that the RV pumps blood to the pulmonary arteries - if there is a significant PE, the RV will show strain on the 2-D Echo due to difficulty pumping blood through the pulmonary circulation. Evidence of R heart strain is a strong diagnostic indicator of a PE.

    Another test that was being done more commonly in the past is a V/Q Scan which only gives you PE probabilities and will not detect smaller PE's.
    This guy is very intelligent. What he said ^
    maloneys likes this.
  4. 0
    Hesitation to do a scan was lack of docs to read the scan at night, due to absence of docs.

    Thank you very much for taking the time to do this teaching! I'm very appreciative.
  5. 1
    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)
    Last edit by Rizz on Mar 13, '13
    maloneys likes this.


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