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).
  
• Overfilled, underfilled and haemolysed 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 4 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