Coagulation Case Studies

Patient from ICU: PT= 15.4
APTT= 67.9
1:1 mix PT = 14.9
APTT = 65.0
No other additional information-
How do you proceed?


What needs to be determined?


How does one prove this?

A 26 year old women in her sixth month of pregnancy has the following workup.
PT= 11.5 sec (10.5-12.5)
APTT = 33.9 (26.2-34.2)
vW Risto co-factor: 86% (50-150%)
vW antigen: 92% (50-150%)

Are these results normal? Will this patient be okay to deliver this baby?
Should any other tests be ordered?

Patient presents with the following results:
PT= 12.4 (11.5-12.5)
APTT = 56.2 (26.6-32.6)
1:1 mix 42.5
PNP 28.2

What test would you do?
Will this patient bleed?

A 42 year old female presents with symptoms of a DVT, this is her second episode.
Currently she is on oral contraception. Family history includes maternal grandmother died from a stroke at the age of 50, and mother presented with a DVT at the age of 55 after being placed on hormones for menopause.
Patient test results as follows:
PT = 10.1 (10-12 sec)
APTT = 26.1(26-36 sec)

What tests should be ordered?
Screening tests are normal, since this is her second episode, and their is a family history, testing for thrombophilia should be performed- such as Protein C, S, ATIII, Factor VIII, and Activated Protein C resistance.

Should Genetic testing be done? Most likely it should be done, but initially the patient needs to be treated regardless of the cause.

Should this patient be removed from OC? Since it is a second episode that appears to be unprovoked, it looks like the patient should be removed. Otherwise, Depending on the patients results, as well as their other risk factors, (smoking,sedentary, obese,)

What would you do??I would not take OC since there is a recurrance of VTE, patient should be advised to exercise and be aware of their weight.

A 68 year old women has hematuria. A PT and APTT are performed results are as follows:
PT= 34.7
APTT =88.5
1:1 mix PT = 32.2
APTT= 89.0
Thrombin Time = 12.1 (11.5-19.0)
What would be the next line of testing, possible diagnosis and treatment?

Little girl with multiple problems, has a PT and APTT performed-
PT= 32 seconds
APTT =76 seconds
1:1 mix= PT= 12.1
APTT = 32.1 seconds correct into normal range
Factor deficiency?
Common pathway: II, V, and X all normal
VIII, IX, XI and XII all normal

What do these results mean?

ANSWERS TO CASE STUDIES:

We know the disorder is in the common pathway-
and that it is a factor deficiency. Both the PT and APTT correct into the normal range-
large correction- this little girl has a fibrinogen deficiency.
A thrombin time should also be performed should be prolonged-
A reptilase time will be prolonged, this will confirm no heparin on board and truly a fibrinogen deficiency.
Also, if there was heparin on board the mixing study would not correct (remember heparin is an inhibitor)
The next step is to see if this is due to a quantitative or qualitative defect of fibrinogen. If antigen testing is normal and activity is abnormal this is a dsyfunctional molecule or a qualitative defect. If both are decreased there would be a quantitative defect.
The FDA just approved treatment with fibrinogen concentrates, prior to that the treatment was cryoprecipitate.

A in-patient has a prolonged APTT - that is all that you know-
How do you cost effectively work up this patient- so as to maximize the information you give to the clinician and minimze the costs to the laboratory?

Your first line of testing on an inpatient is to make sure the sample is not contaminated with heparin. The best test for residual heparin is a thrombin time. If this is normal, you can proceed with your next line of testing- which would be to look for an inhibitor or a factor deficiency. If the test is prolonged, and the fibrinogen is normal, you most likely have heparin in the sample. You can request another sample, or you can treat the plasma with Hepzyme (SIEMENS) which will neutralize the heparin and you can now test the sample.
You can then go on to do your mixing study, and based on that result work up either an inhibitor or a factor deficiency.

Testing in this manner is the most cost effective way to approach this prolonged APTT.