Coagulation Screen

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Assay

Coagulation Screen

Key Words

Coagulation Screen, APTT, PT, , Thrombin Time, Fibrinogen

Specimen Collection

3.0ml Citrate (Green lid). 1.4ml Citrate for paediatric (Green lid). Fill to mark.

Turnaround time

4 hours.

Test indications

Investigation of bleeding tendency, Disseminated Intravascular Coagulation, Hereditary or acquired fibrinogen abnormality (qualitative and quantitative).

Interferences

Lipaemia, haemolysis, anticoagulants, antiphospholipid syndrome. Samples will be processed up to 24 hours from the time of collection. However, samples older than 8 hours at processing may begin showing interferences due to sample degradation and should be interpreted with caution. The antibiotic oritavancin has been shown to react with certain coagulation reagents; it may artificially prolong the APTT for approximately 120 hours (5 days) post-dosage and the PT INR for approximately 12 hours post-dosage.

Reference Range

See table below. Please note that while ratios for INR and APTT will remain the same, the time in seconds for PT and APTT may change slightly when new reagent lots are started. If interpreting these results in seconds, please refer to the reference ranges printed on the report at the time of authorisation for the correct reference range. Adult reference ranges established in-house from local population. Paediatric reference ranges from: Williams, M., Chalmers, E. and Gibson, B. (2002). The investigation and management of neonatal haemostasis and thrombosis. British Journal of Haematology, 119(2), pp.295-309.

Minimum retesting interval

N/A

TEST AGE / GENDER REFERENCE RANGE UNITS
INR (PT) Premature, Day 1 0.90 - 1.38 (11 - 17) Ratio (Seconds)
Premature, Day 5 0.85 - 1.30 (11 - 16) 
Premature, Day 30 0.85 - 1.16 (11 - 15)
Premature, Day 90 0.85 - 1.24 (11 - 16)
Premature, Day 180 0.85 - 1.28 (11 - 16)
Full term up to 5 days 0.80 - 1.25 (10 - 16)
Full term at 1 month 0.90 - 1.15 (11 - 14)
Full term at 3 months 0.90 - 1.15 (11 - 14)
Full term at 6 months 0.80 - 1.25 (10 - 16)
6 months - Adult 0.80 - 1.25 (10 - 16)
APTT Premature, Day 1 0.91 - 2.65 (26 - 74) Ratio (Seconds)
Premature, Day 5 0.90 - 2.47 (25 - 69)
Premature, Day 30 0.90 - 2.08 (25 - 58)
Premature, Day 90 0.94 - 1.69 (26 - 47)
Premature, Day 180 0.72 - 1.78 (20 - 50)
Full term up to 5 days 1.10 - 1.70 (31 - 48)
Full term at 1 month 1.1 - 1.6 (31 - 45)
Full term at 3 months 1.0 - 1.45 (28 - 41)
Full term at 6 months 1.05 - 1.30 (30 - 37)
6 months - Adult 0.80 - 1.20 (22 - 34)
Fibrinogen Premature, Day 1 1.50 - 3.73 g/L
Premature, Day 5 1.60 - 4.18
Premature, Day 30 1.50 - 4.14
Premature, Day 90 1.50 - 3.52
Premature, Day 180 1.50 - 3.60
Full term up to 5 days 2.30 - 4.00 
Full term at 1 month 2.00 - 4.00
Full term at 3 months 1.75 - 4.00
Full term at 6 months 1.80 - 4.00
6 months - Adult 2.00 - 4.50
Thrombin Time All 11.0 - 17.0 Seconds