Temporal changes in ROTEM®-measured coagulability of citrated blood samples from coagulopathic trauma patients.
BACKGROUND
Rotational thromboelastometry (ROTEM(®)) relies on citrated blood samples, which are regarded as biologically stable for up to 4 h after venepuncture. However, this recommendation is based on data from normal volunteers. The aim of this study was to evaluate possible temporal changes in the coagulability of blood samples from coagulopathic trauma patients.


METHODS
This is a prospective series of 10 coagulopathic (maximum clot firmness, MCF<40 mm) trauma patients. ROTEM(®) EXTEM (tissue factor activated) and FIBTEM (tissue factor activated, cytochalasin D inhibited) analyses were performed on samples obtained on admission, and after approximately 60 min of storage in an incubator, at 37°C.


RESULTS
There were statistically significant differences between the median EXTEM MCF (22 mm vs 54 mm, p<0.001) and α angle (30.5 vs 59.5°, p=0.004) of the analyses performed immediately after sampling, and 51 min (median) subsequently, but not coagulation time (CT, p=0.133), clot formation time (p=0.0625) or maximum lysis (ML, p=0.154). There were also no differences in median FIBTEM MCF (p=1.00) or CT (p=0.877) between the immediate and delayed analyses.


CONCLUSIONS
Repeated ROTEM(®) EXTEM analysis of citrated samples from coagulopathic trauma patients shows a spontaneous improvement in coagulability with time. The absence of parallel changes on FIBTEM analysis suggests that this effect may be due to a change in platelet function.
Royal Army Medical Corps, United Kingdom. j.o.jansen@gmx.com
J O
JO
Jansen
D
D
Luke
E
E
Davies
P
P
Spencer
E
E
Kirkman
M J
MJ
Midwinter
D000328:Adult; D055826:Afghan Campaign 2001-; D001753:Blast Injuries / Q000097:blood*; D001777:Blood Coagulation; D001778:Blood Coagulation Disorders / Q000097:blood* / Q000628:therapy; D001780:Blood Coagulation Tests / Q000379:methods*; D005260:Female; D006487:Hemostasis; D006801:Humans; D008297:Male; D010865:Pilot Projects; D010976:Platelet Count; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013916:Thrombelastography; D013997:Time Factors; D014950:Wounds, Penetrating / Q000097:blood*