Hemorrhagic shock Flashcards
Name questions to ask in history-taking in the trauma patient (5)
AMPLE
* Allergies
* Medications
* Past medical history - relevant
* Last meal
* Does the patient recall EVENTS leading up to, or involving, the accident?
Describe : Shock (1)
Inadequate cellular perfusion leading to insufficient oxygen delivery to the tissues
Describe : Hemorrhagic shock (1)
- Decreased tissue oxygenation resulting from a blood volume deficit.
Name stages of shock (3)
-
Compensated stage : Shock is initially compensated by mechanisms that strive
to normalize cardiac output and arterial pressure. Within seconds, baroreceptors
and chemoreceptors elicit powerful sympathetic stimulation that vasoconstricts
arterioles and increases heart rate and cardiac contractility. -
Progressive stage : The arterial pressure falls as increased cardiac output and
vasoconstriction can no longer compensate for the severity of hypoperfusion. Affected patients may be awake but generally have notable tachycardia, hypotension, and cool, clammy skin. - Irreversible stage : the body is unable to recover, and death becomes inevitable.
Name ATLS classification of hemorrhage
The possibility of bleeding should be assessed in five areas. Name them.
- external bleeding (eg, scalp/extremity lacerations)
- thorax (eg, hemothorax and aortic injury);
- peritoneal cavity (g, solid organ lacerations and large vessel injury)
- pelvis/retroperitoneum (eg, pelvic fracture);
- soft-tissue compartments (eg, long-bone fractures).
Laboratory studies that aid (but are not necessary) in evaluating acute blood loss are
what? (4)
- hemoglobin
- hematocrit
- base deficit
- lactate levels.
Describe hemoglobin and hematocrit levels in the setting of acute hemorthage (6)
- hemoglobin and hematocrit levels may or may not be decreased since they * measure concentration, not absolute amounts
- loss of whole blood will not decrease the red blood cell concentration or the percentage of red cells in blood.
- The initial minor drops in hemoglobin and hematocrit levels are the result of mechanisms that compensate for blood loss by drawing fluid into the vascular space.
- Hemoglobin and hematocrit levels will continue to fall secondary to dilution, as early blood loss must be replaced with a crystalloid solution.
- Because of these factors, it can be difficult to
- assess the quantity of early blood loss with laboratory values.
Describe lactate levels in hemorrhagic shock (7)
- With the ongoing metabolic acidosis of hemorrhagic shock, an increased base deficit and lactate level will be seen.
- Both lactate and base deficit levels indicate systemic acidosis, not local tissue ischemia.
- These tests reflect global indices of tissue perfusion, and normal values may mask areas of under-perfusion as a consequence of normal blood flow to the remainder of the body.
- It is therefore not surprising that abnormal lactate and base deficit levels are poor prognostic indicators of survival in patients with shock.
- However, lactate level trends can be used to determine the extent of tissue hypoxia and adequacy of resuscitation.
- Normalization of base deficit and serum lactate within 24 hours after resuscitation is a good prognostic indicator of survival.
- Of note, because lactate is metabolized in the liver, it is not a reliable value in patients with liver dysfunction.
Describe : “Damage control resuscitation” (3)
Resuscitation” the initial management of hemorrhagic shock emphasizes patient stabilization as a bridge to definitive management, generally by surgeons in the operating room.
Preservation of oxygenation and function of the critical organs and tissues is the guiding principle, with three key goals:
* (1) blood pressure support
* (2) avoidance of the coagulopathic “lethal triad;” and
* (3) hemostasis.
Describe blood pressure support (3)
- Initial volume infusion of crystalloid (normal saline, lactactdd ringers)
- Transfusion protocols for hemorrhagic shock that involve the early infusion of several
units of readily available red blood cells, platelets, and fresh-frozen plasma (FFP). Ratio 1:1:1 - Vasopressors (Norepinephrine)
What’s the blood pressure goal during hemorrhagic shock resuscitaiton? (4)
- concept of permissive hypotension is now more widely accepted.
- The blood pressure is allowed to remain low (mean arterial pressures of 60-70 mm Hg or a systolic blood pressure of 80-90 mm Hg).
- It is theorized that peri-hemorrhage, the artificially increased blood pressure by aggressive fluid resuscitation may disrupt endogenous clot formation and promote further bleeding.
- Therefore, permissive hypotension may counterintuitively improve tissue perfusion by preventing clot destabilization and therefore reducing blood loss.
Name patients who are NOT candidates for permissive hypotension
- with traumatic brain injuries who require maintenance of their cerebral perfusion pressure
- those with a history of hypertension, heart failure, or coronary artery disease (they may develop stroke or myocardial infarction in response to hypotension).
Describe : Algorithm for assessment/management of the trauma patient.
