Shock Basic Trauma Course

1. ShockBasic Trauma Course Shock is a condition which results from inadequate organ perfusion and tissue oxygenation.

2. Compensatory Mechanisms • Cardiac Output is the most influential factor determining oxygen delivery and is the primary compensatory mechanism for increasing oxygen delivery to the tissues when needed. • Other compensatory mechanisms are the increased rate and depth of respirations and an increase in the sympathetic response signaled by vasoconstriction , decreased urine output, (in an effort to maintain circulating volume.)

3. Hypovolemic Shock • The initial goals of the ER are: • To maximize oxygen delivery to the patient • To control further blood loss • Fluid resuscitation. • Blood Replacement If the patient arrives with no IV access, immediately establish Two large bore IV sites using 14 or 16 gauge IV. • Fluid Resuscitation • Initial fluid bolus given as rapidly as possible… Adult: 1-2 liters Child: 20ml/kg Patient’s response is observed and further therapeutic decisions is based on response.

4. Cardiogenic Shock • Results from inadequate circulating blood volume. • Cardiogenic shock is the loss of contractile function of the heart. • This type of shock can be the result of a myocardial infarction and blunt cardiac injury. • The result is a decreased ejection fraction and decreased cardiac output.

5. Case Study • A 65 Year old male, s/p MVC, presents to the ER by EMS. There is an obvious seatbelt mark across the chest, the patient is dyspneic, cool, and cyanotic. VS: B/P 88/56, P 124, R 28. He is complaining of chest pain and tells you he has a history of a past MI. • Would you consider that the patient may have had another MI which caused the crash with possible subsequent chest trauma? • Is this patient exhibiting signs of shock? • What would your initial intervention be? • What types of diagnostic tests would you expect to see ordered? • Would you expect to see dysrythmias in this patient? Why or why not? • In obtaining a history from EMS, with regard to chest trauma, what would you ask? From the information above, this patient is at risk for what developments?

6. Obstructive Shock • Results from mechanical obstruction of the flow of blood through the central circulation system due to obstruction or compression of the major vessels. • Possible causes of obstructive shock are: • Dissecting Aortic Aneurysm. • Cardiac tamponade. • Tension pneumothorax. • Pulmonary embolism, (most frequent). • Evisceration of the abdominal contents into the thoracic cavity.

7. Distributive Shock • This type of shock is characterized by abnormal placement of the intravascular volume. There is a disruption in the SNS control of the tone of the blood vessels, which lead to vasodilation and maldistrubution of blood volume and flow. • Three forms of distributive shock are: • Septic shock • Neurogenic shock • Anaphylactic shock. Septic and anaphylactic shock in early trauma are rare. We will focus on Neurogenic Shock

8. Neurogenic Shock • This type of shock is not the same as spinal shock. • Spinal shock is the loss of spinal reflexes found in acute spinal cord injury patients. • Neurogenic shock is the loss of sympathetic vasomotor function. • The result is vasodilation in the systemic vasculature. Venous return is decreased since blood pools in the periphery. The result is a decrease in cardiac output. • In neurogenic shock the patient will exhibit bradycardia, warm and flushed skin and hypotension.

9. Treatment of Shock • Administer oxygen via nonrebreather mask • Control external bleeding • Initiate intravenous fluid replacement • Initiate blood product replacement • Type-specific and crossmatched blood • O-negative is universal donor • Fresh frozen plasma, cryoprecipitate, or platelets • Insert gastric tube • Insert urinary catheter • Attach cardiac leads and monitor • Attach pulse oximeter • Consider peripheral vasoconstrictors for patients in neurogenic shock • Prepare patient for surgery