perioperative bleeding. 5 Other studies have
yielded similar findings for patients undergoing
cardiac surgery. 6
Considering the potentially devastating
outcomes of perioperative bleeding, the European
Task Force for Advanced Bleeding Care in Trauma
and the European Society of Anaesthesiology
recommend immediate intervention for patients
presenting haemorrhagic shock, and continual
evaluation of the coagulation status before,
during, and after surgery. 2,4 Conventional tests
measuring coagulation parameters such as the
international normalised ratio (INR), activated
partial thromboplastin time (aPTT) and platelet
counts are of very limited value for detecting and
predicting the risk of bleeding before surgery or
other invasive procedure. Oftentimes, the results
are not specific (for example, INR and aPTT assess
the initiation phase of coagulation, making it
possible to have a false normal result, whereas
platelet counts can only detect platelet
dysfunction that is not induced by drugs and not
acquired) or detailed enough, and they can come
too late to initiate effective haemostatic control in
a timely manner. 7
The implementation of point-of-care (POC)
devices for coagulation analyses may help identify
the often multifactorial causes of bleeding at all
phases of perioperative care with only a small
volume of whole blood, allowing for the
screening of coagulopathies onsite, in the
operating room or the intensive care unit. Two
types of POC devices are currently available:
viscoelastic, for the diagnosis of plasmatic
disturbances of haemostasis and fibrinolysis as
well as low platelet counts; and aggregometric,
for the identification of platelet dysfunction,
either caused by COX-1 inhibitors (for example,
aspirin) or adenosine diphosphate receptor
antagonists, or acquired platelet dysfunctions.
Their main disadvantage is the impossibility
of identifying coagulopathy caused by
hypothermia/hyperthermia or anomalies in pH,
calcium ion concentration or haematocrit that
affect haemostasis. 7
Viscoelastic methods are based on
thromboelastography and measure the time until
the start of clotting, the dynamics of clotting, and
the stability of blood clots over time. These
techniques offer advantages relative to standard
laboratory coagulation tests, namely rapid
detection of coagulation anomalies resulting from
the use of antithrombin agents and prediction of
a need for massive blood transfusion, occurrence
of thromboembolic events, and mortality in
surgical and trauma patients. 2,7 By contrast, the
incorporation of platelet function assessment via
aggregrometry in blood management resulted in
the reduction in the number of patients requiring
massive transfusions or transfusions of red blood
cells compared with conventional laboratory
analyses, thus leading to fewer transfusion-related
complications and reduced costs. 8
Initial management of perioperative
bleeding and treatment escalation
The first measures to limit further loss of blood
include damage control surgery, coiling, and
packing strategies as well as timely correction of
acidosis and hypothermia, hypocalcaemia, and
anaemia. In severely injured patients,
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