Thromboelastography as an Adjunct Tool to Assess Coagulation Disturbances in Isolated Traumatic Brain Injury Patients

1
Thromboelastography as an Adjunct Tool to Assess
Coagulation Disturbances in Isolated Traumatic
Brain Injury Patients Asaph Nini MD1, David
Livingstone MD1, Elena Mishuk MD1, Alexander
Kogan MD2, and Eran Segal MD3 1General ICU,
Department of Anesthesiology and Intensive Care,
Sheba Medical Center, 2Department of Cardiac
Surgery, Sheba Medical Center, 3 Intensive Care
Unit, Assuta Medical Center, Tel Aviv, Israel
Introduction Coagulation disorders are common
after traumatic Brain Injury (TBI), may
contribute to morbidity and mortality, and have
prognostic implications (1). These disorders are
complex and dynamic over time, making clinical
evaluation of coagulation status of the patients
difficult (2). Thromboelastography (TEG) has been
suggested as a tool for rapid assessment of such
states. TEG is an ex vivo test of clot formation
and lysis, providing a holistic assessment of
clot evolution over time, and clot strength. A
360?L sample of blood is introduced into a bin
that is then rotated around a torque sensor. As
clot forms, stronger forces are applied to the
sensor, until maximal strength is reached. Later,
as fibrinolytic processes take over, clot
strength gradually declines. Several parameters
are useful in basic TEG analysis. The time to the
beginning of force generation, termed R, reflects
activation of the coagulation cascade. The rate
of increase in strength, measured as angle ?,
reflects fibrinogen activity. The maximal
strength (MA), reflects platelet function, and
the rate of decrease in strength over 30 minutes
(LY30), as percent, reflects fybrinolysis. The
aim of this pilot study is to survey the
contribution of Thromboelastography in the
assessment of coagulation status in patients
with isolated TBI.
Results Ten patients with isolated traumatic
brain injury were evaluated using TEG. Reasons
for tests included workup for suspected bleeding,
screening for hypercoagulable states, or planned
invasive procedures. Three of these patients
showed increased LY30, indicating thrombolysis,
and two patient showed prolongation of the R
value, indicating prolonged clotting time. Two
patients showed increased Maximal Amplitude (MA),
indicating a hypercoagulable state.
Hypercoagulability 2/10
Increased Fibrinolysis 3/10
Hypocoagulability 2/10
Normal Test 3/10
Table I Summary of Results
Discussion Coagulation disorders in TBI
patients, causing both hypo and hyper
coagulation, can be revealed by TEG. Limitations
of current study This is a pilot survey, with
consequent limitations, particularly sample size,
timing of TEG tests and follow up tests,
systematic comparison to standard tests, and
effect of test results on clinical decision
making and outcome. Additionally, study
population should be expanded to multitrauma
patients who also suffered TBI. It is important
to note that standard TEG, used in this study,
does not reflect disorders of platelet
activation. Conclusions Thromboelastography is a
useful adjunct tool in the assessment of
coagulation status in isolated TBI patients, and
may help in clinical decision making in such
patients. Further work, relating
thromboelastography results, prognosis and
management are warranted.
Fig II Top TEG showing a prolonged K value,
flat angle and low Max Amplitude, indicating a
combined disorder of coagulation factors,
Fibrinogen and platelets. Middle TEG showing
increased LY30, indicating enhanced fibrinolysis.
Bottom Same patient 24 hrs later, after
treatment with Tranexamic acid.
Fig I Normal thromboelastogram
Financial Disclosure None of the authors report
any conflict of interests
References Harhangi B.S., Kompanje F.J.O.,
Leebeek F.W.G. and Maas A.L.R. Acta Neurochir
(Wien) 2008 150 165-175 Stein S.C. and Smith
D.H. Neurocrit Care 2004 1 479- 488 Salooja N
and Perry D.J. Blood Coagulation and Fibrinolysis
2001 12327-337
Methods Existing TEG database was surveyed for
tests from patients with isolated TBI. Tests were
examined for signs of bleeding tendency or
hypercoagulability.