Waikato and Thames - 2.7 mL sodium citrate tube (light blue)
1.8 mL paediatric sodium citrate tube (light blue)
Mon - Sun, 24hrs
Innovance D-Dimer (Waikato), AQT D-Dimer (Taumarunui, Te Kuiti, Tokoroa). Reported as Fibrinogen Equivalent Units (FEU)
DDimer cut off values
|Age||D-Dimer cut-off values|
|>50 years||Age x 10|
Choosing Clinical Laboratory Tests Wisely Guidelines:
D-dimer has limited specificity and will be positive in many hospitalised patients without venous thromboembolism (VTE).
Low risk patients in whom diagnostic testing is indicated should have Pulmonary Embolism (PE) excluded by a negative D dimer, not imaging. Don’t request any diagnostic testing for suspected PE unless indicated by Wells Score (or Charlotte Rule) followed by PE Rule-out Criteria (in patients not pregnant).
Restrict testing to those patients with a high enough clinical suspicion of VTE to merit further investigation, not to rule out the remote possibility of VTE:
Do not request a D-dimer in post-operative patients.
500uL platelet poor plasma