Page 65 - JSOM Winter 2019

Therefore, we propose use of an additional mnemonic acro- which can be confused with hemorrhagic shock. Later, during
nym, SMART, to assist with the recall of key strategies in the re- prolonged field care, other causes of shock may have to be
suscitation of casualties with hemorrhage in trauma. Providers considered, including sepsis and venous thromboembolism.
should be taught to initiate the use of this mnemonic acronym
when caring for a patient with visible catastrophic hemorrhage With greater understanding of the underlying processes has
or a patient with traumatic injuries who, on structured assess- come clearer evidence for treatment strategies that address
ment (e.g., by using the MARCH or C-ABCDE approach), is these problems. In 2016, Rossaint et al. published the up-
21
suspected of being at risk of life-threatening hemorrhage. dated European guideline for the management of major
bleeding and coagulopathy after trauma. Recent revision of
the Tactical Combat Casualty Care guidelines also included
Management of Hemorrhagic Shock
in Trauma Patients specific evidence-based recommendations about the hierar-
chy of early blood-product administration to patients with
The pathogenesis of the coagulopathy that occurs in patients hemorrhagic shock. The 2016 European guideline includes
22
after traumatic injury is complex but has been increasingly 39 evidence-based recommendations that cover all aspects of
well described in recent years. Brohi et al. in 2003 observed care, from initial resuscitation through quality management
15
that there is a coagulopathy seen in trauma patients that can- strategies. Key recommendations include that evidence-based
not be attributed solely to the adverse effects of fluid replace- treatment algorithms are implemented and that checklists are
ment given during resuscitation. The authors suggested the used to guide patient care.
traumatic process itself results in the release of factors that
contribute to this coagulopathy. Hess et al. in 2008 described SMART Mnemonic Acronym: Recommendations
16
some of the complex mechanisms that contribute to this co-
agulopathy. After traumatic injury, tissue factors are released S – Start the clock
that initiate both coagulation and fibrinolysis. The hypoperfu- • Minimize the time from point of injury to surgical con-
sion that results from untreated severe hemorrhage then causes trol of bleeding.
acidosis, which, in turn, leads to additional imbalance of nor- • Minimize time to resuscitation with blood products.
mal clotting mechanisms. This coagulopathy contributes to Life-threatening bleeding must be stopped as quickly as possi-
additional bleeding and, hence, worsening tissue perfusion. ble by whatever means, including surgical intervention. Death
Hypoperfusion, in turn, causes a reduction in oxygen delivery, of trauma patients who have suffered significant torso injury
leading to tissue ischemia and accumulation of lactate. This occurs very rapidly, and so the time from injury to hemor-
has been described as causing an “oxygen debt.” Although rhage control must be minimized. Shackelford et al. have
19
23
17
such a debt can lead to irreversible organ failure, it has also also highlighted the beneficial impact of early blood product
been suggested that it causes failure of endothelial function administration on survival.
which, combined with acute traumatic coagulopathy, may – Stop the bleeding
constitute “blood failure.” The early use of blood products • Tourniquet use
18
to restore blood function toward normal is a key strategy to • Immediate bleeding control procedure
minimize the ischemic insult to all organs. The reintroduction of effective field limb tourniquets has led
to a demonstrable improvement in survival for patients with
Injudicious resuscitation attempts with room temperature crys- life-threatening hemorrhage from the extremities. For the
talloid fluids can then lead to hemodilution and hypothermia, management of junctional hemorrhage, other techniques and
both of which can cause further disruption of coagulation. devices have become available, and so the use of these devices
Early treatment, therefore, is directed at stopping bleeding, is emphasized in this mnemonic.
maintaining tissue perfusion with the optimum resuscitation M – Maintain perfusion
fluids available, countering hyperfibrinolysis, preventing hy- • Fluid therapy in the hypotensive bleeding patient
pothermia, and titrating blood products to further maintain • Target systolic blood pressure of 100mmHg
perfusion and replace clotting components. Emerging evidence If there are any delays in time to hemorrhage control, then
from the Afghanistan conflict emphasizes the survival bene- organ perfusion must be maintained with appropriate prod-
fit of blood-product administration as soon as possible after ucts. Failure to maintain perfusion causes critical reduction
injury. Prehospital administration of plasma reduces 30-day in oxygen delivery to vital organs, and so care providers must
19
mortality when used by civilian air medical transport teams. instigate fluid therapy with the optimum available fluid to
20
These actions can be summarized as follows: maintain critical perfusion. Although a strategy of hypoten-
sive resuscitation may be appropriate for a short duration
• Start the clock and stop the bleeding in patients without evidence of traumatic brain injury, pro-
• Maintain perfusion longed or profound hypotension below 100 mmHg should be
• Administer antifibrinolytics avoided. If blood pressure monitoring is unavailable in par-
24
• Retain heat ticularly austere environments, then providers should consider
• Titrate blood products and calcium; think of alternative loss of radial pulses as a trigger to initiate fluid therapy but
causes of shock
should monitor for return of pulses to avoid excessive fluid
A vital strategy in the resuscitation of shocked patients with administration.
traumatic injuries in any environment, but particularly in aus- A – Administer tranexamic acid
tere and resource-poor healthcare settings, is to monitor the • Tranexamic acid for a patient who is bleeding or at risk
patient’s response to resuscitation and always consider that of significant hemorrhage
there may be alterative causes of shock. Shock due to ten- The CRASH 2 trial demonstrated a clear survival benefit for
sion pneumothorax may develop rapidly in severely injured patients with traumatic injuries at risk of significant hemor-
patients, or they may experience neurogenic shock, both of rhage when tranexamic acid was administered within 3 hours

SMART Treatment for Hemorrhage in Trauma | 63