Download Examination Coagulation Screen Paediatric Purpose of test To

Examination
17771
Coagulation Screen Paediatric
Purpose of test
To assess the clotting factors in case of unexplained or
prolonged bleeding, a family history of a bleeding disorder,
to prepare for a procedure when the liver is function is
abnormal, to monitor blood product support. Prothrombin
time (PT), activated partial thromboplastin time (APTT)
and fibrinogen concentration are measured
Sample
Blood
Sample Tube/Container
Blue top (citrate)
Sample Volume
1.8ml x1
Special Precautions
- Use venous blood whenever possible; blood from
indwelling catheters should never be used
- coagulation factors are easily activated or denatured so it
is essential to withdraw blood without undue stasis and
without frothing – tourniquet should be released as soon
as blood is flowing freely
- the first few millilitres used for other tests (if no other
tests required discard first bottle and send second bottle)
- bottle MUST be filled to the frosted fill line level with ‘BD
Vacutainer’ around the top of the bottle. This is the
minimum acceptable volume that meets the correct blood
to anticoagulant ratio
- the bottle must be within the expiry date
- invert several times to mix blood with anticoagulant
Request Form:
Clinical Chemistry & Haematology Requests
Laboratory
Haematology
Biological reference range
PT 9-13 seconds
APTT 23-31 seconds
Fib 1.8-4.0 g/L
Clinical decision values
PT <9 sec or APTT <23 sec may indicate in vitro
activation. Prolonged times may be of clinical significance
depending on result and clinical indications. Raised
fibrinogen may be due to inflammatory response.
Fibrinogen deficiency may be due to consumption or
defective production
Factors affecting performance Failure to observe special precautions.
Time from venepuncture to test should not be >4 hours.
Haemolysis
Turnaround times:
ED and inpatient emergency pathways:1 hour
Routine inpatient pathway:4 hours
GP pathway: 24 hours
Patient preparation
No specific requirements
Note: Printed documents are not controlled
Page 1 of 2
Instructions for patient
collected sample
Not applicable
Sample transportation
Use biological sample box for transportation to the
laboratory from outside the hospital and between
hospitals; specific transport bags are used within the
hospital
Special handling needs
Maintain at normal room / van temperatures.
Do not freeze or overheat
Patient consent required
Implied consent
Specific rejection criteria
Generic rejection applies.
Incorrectly filled samples (both under- and overfilled),
haemolysed samples, samples not meeting special
precaution and transport criteria
Additional information
Sample should reach the laboratory within 4 hours of
venepuncture
References
Note: Printed documents are not controlled
Page 2 of 2