Clauss Fibrinogen

Department of Haematology

Notes

• Blood samples should ideally reach the laboratory within 2 hours. Samples greater than 24 hours old will not be tested.
  
• Coagulation tests must be performed on samples taken by clean venesection, and filled to the appropriate level (in line with black arrow or the frosted line. Note with the frosted line this is the minimum fill line).
  
• Overfilled, underfilled, haemolysed and lipaemic samples will give erroneous results and will not be processed.
  
• Samples should not be taken from indwelling lines that have been flushed with Heparin as contamination frequently occurs despite the initial draw.
  
• Test performed at GRH and CGH
  
• See also: Clotting Screen
  

Criteria for Testing

A Clauss Fibronogen assay will be performed as part of any Clotting Screen request.

Sample Requirements

3.5ml, 3.0ml or 2.0ml Trisodium Citrate tube

Sample Storage and Retention

• Pre analysis storage: do not store, send to laboratory within 2 hours.
  
• Sample retention by lab: Citrate samples are retained for a minimum of 24 hours at 15-30°C. If specialist coagulation tests are requested, one or more aliquots may be frozen until analysis (or up to two months) at between -15 and -40°C. After analysis, these samples will be retained for a further 24 hours at 15-30°C.
  

This test can be added on to a previous request as long as there is sufficient sample remaining and the sample is less than 24 hours old.

Turnaround Times

• Clinical Emergency: 30 minutes
  
• Other Urgent samples: 60 minutes
  
• Routine: within 2 hours
  

Reference Ranges

Fibrinogen: 1.50 - 4.50g/l

Alert / Critical Values

Low fibrinogen results of <1.5g/L should be telephoned.

Laboratory Clinical Interpretation

Low levels may be found in:

• DIC
• Liver disease
• Congenital hypofibrinogenaemia
• Fibrinolytic therapy
• Severe bleed

High levels may be found in:

• Pre-thrombotic states
• Cardiovascular disease
• Neoplastic disease
• Inflammatory conditions