A 24 year old female has the following haematology and coagulation profile post admission to the intensive care unit following post partum haemorrhage.

Test

Value

Normal range

WCC

5.6

(4.0-11.0)

Hb

60*

(115-165G/L)

Platelets

30*

(150-400 X 109/L)

PT

30.6*

(10.5-13.5 sec)

APTT

>150*

(21-36 sec)

D Dimer

>10*

(<0.4 microgram/ml FEU)

Fibrinogen

0.8*

(1.1-3.2G/L)

a) What is the likely cause of these coagulation abnormalities?

b) In this context, list  3 likely causes of this coagulation profile.

c) What does an elevated D-dimer indicate ?

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College Answer

a) What is the likely cause of these coagulation abnormalities?
DIC

b) In this context, list  3 likely causes of this coagulation profile.

  • Pre-eclampsia
  • AF embolism
  • Sepsis
  • Intra-uterine foetal death
  • Mismatched / massive transfusion

c) What does an elevated D-dimer indicate ?
Tests fibrinolysis. It measures the break down of the X linked fibrin

Discussion

The college asks for one likely cause of this coagulopathy. DIC is the standard answer with this sort of history. More broadly, differentials for thrombocytopenia and pan-coagulopathy could also include massive transfusion and severe liver disease.

There is quite a large number of potential peripartum causes for DIC:

  • Abruptio placentae
  • Placenta accreta
  • Amniotic fluid embolism
  • Retained dead fetus
  • Abortion induced with hypertonic fluids (saline or urea)
  • Intrauterine sepsis
  • Incompatible blood transfusion

Fibrin degradation products seem to be a valuable adjunct for the laboratory diagnosis of DIC.

In essence, a D-dimer is a small protein breakdown product, consising of two crosslinked D-fragments of fibrin.

A longer explanation, with pictures and extensive bibliography, is also available.

The presence of an elevated D-dimer confrms that somewhere fibrin is being degraded.

References

References

Slofstra, Sjoukje, Arnold Spek, and Hugo ten Cate. "Disseminated intravascular coagulation." The Hematology Journal 4.1 (2013): 295-302.

Levi, Marcel, and Hugo Ten Cate. "Disseminated intravascular coagulation."New England Journal of Medicine 341.8 (1999): 586-592.

Letsky, Elizabeth A. "Disseminated intravascular coagulation." Best Practice & Research Clinical Obstetrics & Gynaecology 15.4 (2001): 623-644.

Carr, J. Meehan, M. McKinney, and J. McDonagh. "Diagnosis of disseminated intravascular coagulation. Role of D-dimer." American journal of clinical pathology 91.3 (1989): 280-287.

Adam, Soheir S., Nigel S. Key, and Charles S. Greenberg. "D-dimer antigen: current concepts and future prospects." Blood 113.13 (2009): 2878-2887.