A comparison of fibrinogen measurement using TEG(®) functional fibrinogen and Clauss in cardiac surgery patients.
BACKGROUND
Viscoelastic methods of estimating fibrinogen measure clot formation under platelet inhibition; these methods are gaining in popularity because of their convenience and speed. The aim of this study was to compare the results of the TEG(®) functional fibrinogen (FF) assay with the Clauss fibrinogen method in a group of patients presenting for cardiac surgery and to assess whether they gave equivalent results.


METHODS
As part of a larger study evaluation a transfusion algorithm for use in cardiac surgery, 320 paired samples of TEG(®) FF and Clauss fibrinogen were compared. These were taken from 160 patients undergoing cardiac surgery at two time points - prior to heparinisation and 10 min after the administration of protamine. The results of the two fibrinogen measurements were also analysed in relation to the platelet count at the time.


RESULTS
There was no significant correlation between the TEG(®) FLEV and Clauss fibrinogen at baseline (R(2) = 0.106) or 10 min postprotamine (R(2) = 0.025) The TEG(®) FF maximal amplitude and the Clauss were also found to have no significant correlation (at baseline R(2) = 0.061), at 10 min postprotamine (R(2) = 0.260). Bland-Altman analysis showed no significant agreement between the two methods.


CONCLUSIONS
The TEG(®) FF does not produce results equivalent to those of the Clauss fibrinogen regardless of platelet count.
Anaesthesia, Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool, UK.
S
S
Agarwal
Perfusion, LHCH, Liverpool, UK.
R I
RI
Johnson
Clinical Analyst, LHCH, Liverpool, UK.
M
M
Shaw
D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D006348:Cardiac Surgical Procedures; D005340:Fibrinogen / Q000032:analysis*; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D010976:Platelet Count; D019095:Point-of-Care Systems / Q000592:standards*; D011479:Protamines / Q000627:therapeutic use; D012044:Regression Analysis; D013916:Thrombelastography / Q000379:methods / Q000592:standards*; D013927:Thrombosis / Q000517:prevention & control*
D000925:Anticoagulants; D011479:Protamines; D005340:Fibrinogen; D006493:Heparin
Fibrinogen