University Hospital of Wales Paediatric Intensive Care Unit Guideline Printed on Wed 23-jul-08
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Last updated March 7, 2019 8:21 AM

0300 0300 789

02920 744622

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029 2184 7322


Noah's Ark Childrens Hospital for Wales
Heath Park
CF14 4XW
02920 747747

Blood products


10 - 15ml/kg
Keep Hb > 10g/dl in acute resuscitation phase - (generally first 24 hours)
Transfusion threshold for stable critical care patients 7g/dL


15 ml/kg if APTT or PT > 1.5 X normal


5ml/kg if Fibrinogen < 1.0
FFP contains some fibrinogen, so if received FFP, recheck fibrinogen level before ordering cryoprecipitate


Transfusion thresholds (for impaired platelet production)
< 10
< 20 and DIC, or platelets likely to fall by 10 by time of next sample
< 50 and acute bleeding
< 100 and CNS bleeding or multiple trauma

D/W consultant if ITP or previous intrauterine transfusions
Check platelet increment 30mins after transfusion, high consumption eg. sepsis may need repeat transfusions

Coagulation tests

Activated partial thromboplastin time (APTT)

Also known as partial thromboplastin time with kaolin, PTTK, this tests the intrinsic and common pathways.


Artefactual prolongation of the APTT may be due to the presence of heparin in the sample, difficult or slow collection, addition of an incorrect volume of blood to the tube, delay in mixing blood with the citrate anticoagulant, suboptimal specimen storage or a prolonged interval between collection and testing.

Prothrombin time (PT)

This tests the extrinsic and common pathways.
More sensitive than the APTT for the detection of coagulation factor deficiencies due to vitamin K deficiency, liver disease.
The results are expressed as an international normalised ratio (INR) when the test is used to monitor oral anticoagulant therapy. The INR is not, however, valid for other patients, especially those with liver disease.


An abnormal result is most often due to


Thrombin time

Investigation of possible acquired or inherited disorders of haemostasis; occasionally indicated in the investigation of unexplained thrombosis.


Prolonged by

Reptilase Time
Reptilase is a thrombin-like enzyme that differs from thrombin in its specificity and extent of cleavage of the fibrinogen molecule. Reptilase is inhibited only slightly or not at all by Heparin and fibrin degradation product (FDP), thus making it useful in the differential diagnosis of a prolonged thrombin time (TT).


Prolonged by:

A reptilase time is only needed in the presence of a prolonged thrombin time. In this case, if the reptilase time is normal, the presence of heparin is confirmed.
If it is prolonged, heparin can be excluded and other causes of prolonged thrombin time may be pursued such as: hypofibrinogenemia and dysfibrinogenemia.

Activated clotting time (ACT)
This is performed as a 'bedside' test. It is used to quantify the heparin effect during haemofiltration. The normal range is 100-140 seconds.
Clinical use of the ACT in assessing adequacy of heparinisation


Prolonged by