Chapter 6, Shock

Question 1

What is shock?

Answer 1

A physiological state of inadequate tissue perfusion that results when oxygen delivery, uptake, and utilization are insufficient to meet the metabolic demands of cells and organs.

Inadequate tissue perfusion for cellular metabolism

Question 2

What is preload?

Answer 2

The central venous pressure or volume of blood return to the heart at the end of diastole.

Question 3

What is afterload?

Answer 3

The pressure that the heart must overcome to pump blood into systemic circulation; it is a component of systemic vascular resistance.

Question 4

What is contractility?

Answer 4

The capability of the ventricles to contract, forcefully ejecting blood.

Question 5

What are the 3 stages of shock?

Answer 5

Compensated
Decompensated/Hypotensive
Irreversible

Question 6

How is the transition from compensated to decompensated shock defined?

Answer 6

By hypotension.

Question 7

What changes to blood flow occur in compensated shock?

Answer 7

Blood is shunted to the heart, brain, and lungs and away from the skin and splanchnic circulation.

Question 8

What occurs during decompensated/hypotensive shock?

Answer 8

Compensatory mechanisms begin to fail and are unable to support or improve perfusion.

Question 9

What occurs during irreversible shock?

Answer 9

Tissues and cells throughout the body become ischemic and necrotic, resulting in multiple organ dysfunction.

Ischemia, necrosis, organ dysfunction

Question 10

How is the body’s vascular response to shock activated?

Answer 10

Baroreceptor activation: sense decrease in stretch which triggers Epi & NE release.
Chemoreceptor activation: sense changes in blood O2 levels (peripheral) & CO2 and pH which increases respiratory rate and depth, and blood pressure.

Question 11

What does the adrenal gland stimulate the release of in addition to catecholamines?

Answer 11

Cortisol and aldosterone to raise blood glucose and promote renal retention of water and sodium.

Question 12

What is one of the earliest pulmonary responses to inadequately perfused tissue?

Answer 12

Tachypnea resulting from metabolic acidosis stemming from anaerobic metabolism.

Question 13

Cerebral autoregulation maintains a constant cerebral vascular blood flow as long as the MAP is maintained at what value?

Answer 13

50-150 mmHg

Question 14

Hypoperfusion of the kidneys triggers the adrenal gland to improve tissue perfusion in which 2 ways?

Answer 14

Vasoconstriction
Retention of water

Question 15

The trauma Triad of Death consists of which elements?

Answer 15

Hypothermia
Acidosis
Coagulopathy

Question 16

What are the 4 types of shock?

Answer 16

Hypovolemic (volume problem)
Cardiogenic (pump problem)
Obstructive (mechanical problem)
Distributive (vessel problem)

Question 17

What are etiologies of obstructive shock?

Answer 17

Tension pneumothorax
Cardiac tamponade
Air embolism

Question 18

What are etiologies of cardiogenic shock?

Answer 18

Blunt cardiac injury
MI
Dysrhythmias
Cardiomyopathy
Toxicologic pathologies

Question 19

What are etiologies of distributive shock?

Answer 19

Anaphylactic shock
Septic shock
Neurogenic shock

Question 20

What is damage control resuscitation and its 2 strategies?

Answer 20

Restoration of homeostasis through the control of hemorrhage, administration of blood, and other interventions aimed to prevent the triad of death.

Hypotensive resuscitation
Hemostatic resuscitation

Question 21

What is hypotensive resuscitation (permissive hypotension)?

Answer 21

Limited fluid resuscitation (crystalloid solutions) enabling a lower than normal blood pressure.

Question 22

What is hemostatic resuscitation?

Answer 22

Optimizing tissue and cellular oxygenation and perfusion by preventing further losses through hemodilution coagulopathy.

1:1:1 (platelets, PRBC, plasma)

Question 23

How should crystalloid fluid management be approached in the adult trauma patient?

Answer 23

Maximum of 1 liter
500 mL boluses
Until SBP of 90 mmHg

Question 24

How should crystalloid fluid management be approached in the pediatric trauma patient?

Answer 24

20 mL/kg bolus if over 28 days
May repeat 1-2 times

Question 25

How should crystalloid fluid management be approached in the neonatal trauma patient?

Answer 25

10 mL/kg

Question 26

Why is a Massive Transfusion Protocol (MTP) beneficial?

Answer 26

Leads to early blood, plasma, and platelet transfusions with improved outcomes.

Question 27

Why should calcium replacement be considered following a massive transfusion?

Answer 27

Citrate in blood products binds with calcium.
Calcium is a vital part of the clotting cascade (worsen hypovolemic shock via continued bleeding).

Question 28

When can an autotransfusion be considered in the trauma patient?

Answer 28

When there is an isolated hemothorax without diaphragmatic perforation.

Question 29

What is the purpose of resuscitative endovascular balloon occlusion of the aorta (REBOA)?

Answer 29

To stop life-threatening hemorrhage within the chest, abdomen, and pelvis.

Question 30

What is damage control surgery?

Answer 30

Surgery intended to stop the bleeding, restore normothermia, and treat coagulopathy and acidosis.
Prevent/resolve Triad of Death.
Not definitive or complete repair.

Question 31

What is the purpose of administering Tranexamic acid (TXA), a synthetic version of Lysine, to the trauma patient?

Answer 31

Prevents clot dissolving.
Inhibits activation of plasminogen.

Question 32

What SBP is a criterion for trauma team activation?

Answer 32

SBP of less than 90 mmHg at any time.

Question 33

What may the blood pressure differences between the right and left arm indicate?

Answer 33

A thoracic aorta injury.

Question 34

What blood type is preferred in trauma resuscitation?

Answer 34

O-negative.
O-positive can be given to men and postmenopausal women.

Question 35

What is considered adequate urinary output in an adult?

Answer 35

0.5 mL/kg per hour (70 kg adult)

Question 36

How is oliguria determined?

Answer 36

Output of less than 0.5 mL/kg per hour for 2 consecutive hours.

Question 37

What addition is included in the Diamond of Death?

Answer 37

Hypocalcemia.