ISTH DIC scoring system
The ISTH group produced a simple scoring system for the
diagnosis of DIC depending on the Platelet count, the PT, the
fibrinogen level and critically the FDP/D-Dimer results:
|1. Platelet count
>3s but <6s
A total score of ≥5 = DIC as long as the score is associated
with a clinical disorder known to cause DIC. If the score is ≥5 you
must ring the ward/medic and make them aware of the risk of
Guidance Note: D-dimer testing in the diagnosis of
venous thromboembolism (VTE) in hospital patients
- VTE is highly unlikely in patients who are judged by means of a
clinical scoring system to be clinically unlikely to have VTE, and
who have a negative D-dimer test.
- D-dimer testing has very limited usefulness to aid diagnosis in
patients where the clinical probability of VTE is high.
- D-dimer is frequently raised in hospital inpatients without
- D-dimer is increased in infection, cancer, inflammation,
surgery, trauma, ischaemic heart disease, stroke, pregnancy, sickle
cell disease and trait.
- D-dimer testing is not useful in the diagnosis of VTE in
patients with concomitant diseases.
- There is a decrease in the specificity of D-dimer testing for
VTE with increasing age (ie D-dimer testing is less reliable in
- D-dimer should not be used to exclude VTE in children. The
negative predictive value of D-dimer in children with suspected VTE
has not been validated and levels may vary with age.
D-dimer testing should only be requested in patients with a low
clinical probability of VTE, or in the assessment of recurrence
risk for VTE post completion of anticoagulant therapy.
In patients with a high clinical probability of VTE, or in
patients with co-existing illness, D-dimer testing is unlikely to
add any useful diagnostic value and should not be requested.
Reference: Thacil J et al, Appropriate use of
D-dimer in hospital patients. Am J Med 2010, 123,