Shock

Question 1

What is shock?

Answer 1

Severe imbalance between O2 supply and demand, leading to inadequate cellular energy production

Question 2

Oxygen delivery =

Answer 2

CO x arterial O2 content

Question 3

Name some consequences of shock

Answer 3

Na+/K+ ATPase dysfunction
Cellular necrosis and apoptosis
Acidemia
Endothelial dysfunction
Activation of inflammatory and coagulation cascades
MODs
Death

Question 4

Three main types of shock

Answer 4

Circulatory
Hypoxic
Metabolic

Question 5

T/F: A vast majority of shock is metabolic

Answer 5

False - vast majority is circulatory

Question 6

What are the four types of circulatory shock?

Answer 6

Hypovolemic
Distributive
Obstructive
Cardiogenic

Question 7

Explain the physiology of hypovolemic shock

Answer 7

Decreased intravascular volume

Decreased preload

Decreased CO

Question 8

Name some causes of hypovolemic shock

Answer 8

Hemorrhage

Severe dehydration (GI, Renal)

Third space fluid loss

Severe burns

Question 9

What is meant by distributive shock?

Answer 9

Maldistribution of fluid from changes in vascular tone and increased vascular permeability

Decreased SVR +/- Preload +/- Contractility

“We’ve got fluid in the pipes, just not where it needs to be”

Question 10

How might anaphylactic shock be classified?

Answer 10

Distributive

Histamine-induced vasodilation

Question 11

Anaphylaxis is a kind of distributive shock. What are some other causes?

Answer 11

Septic shock
Neurogenic shock
Pheochromocytoma or extreme fear

Question 12

What is meant by obstructive shock?

Answer 12

Compression of heart or great vessel that interferes with venous return

Decreased diastolic filling and preload

Decreased CO

Question 13

What are some causes of obstructive circulatory shock?

Answer 13

GDV
Obstruction of vena cava
Tension pneumothorax
Cardiac tamponade
PPV

Question 14

Physiology behind cardiogenic shock

Answer 14

Decrease in forward flow from the heart due to “pump failure”

Primary decrease in CO

Question 15

What are some causes of cardiogenic shock?

Answer 15

Systolic failure
Diastolic failure
AV valve degeneration of defects
Brady or tachy-arryhythmias

Question 16

What is hypoxic shock? How common is this?

Answer 16

Decreased arterial oxygen content leading to decreased tissue oxygen delivery

Significantly less common than circulatory shock

Question 17

Severe pulmonary disease, anemia, or dyshemoglobinemias can lead to ____________ shock

Answer 17

Hypoxic

Question 18

What is metabolic shock?

Answer 18

Tissues are getting enough oxygen, but for some reason aren’t able to use it

Deranged cellular metabolism leading to inappropriate O2 tissue use

Question 19

Potential causes of metabolic shock

Answer 19

Severe hypoglycemia
Mitochondrial dysfunction

Question 20

T/F: regardless of the type of shock, the body tends to respond to all shock in a similar way

Answer 20

True

Question 21

Discuss the baroreceptor reflex in response to shock

Answer 21

Baroreceptors detect decreased volume and stretch d/t decreased CO

Signal sent to increase sympathetic tone leading to direct catecholamine release from the adrenal glands

Catecholamines increase HR, contractility, and peripheral vasoconstriction

Question 22

Discuss the role of chemoreceptors in response to shock

Answer 22

Located peripherally and centrally and sense changes in blood stream components

Result in increased respiratory rate and tidal volume (faster, deeper breaths)

Question 23

What is RAAS’s role in shock?

Answer 23

Decreased BP detected and RAAS activated

Angiotensin II vasoconstricts and promotes Na reabsorption

ADH promotes water reabsorption

Question 24

What is the hallmark for shock?

Answer 24

Hypotension

Question 25

What is the hyperdynamic phase and what types of shock is it associated with?

Answer 25

Initial vasodilation instead of vasoconstriction Seen w anaphylactic and septic shock

Question 26

What is the shock organ in cats? Dogs?

Answer 26

Cats = lungs Dogs = GIT

Question 27

What is the overall goal for the treatment of shock?

Answer 27

Restore O2 delivery to tissues asap

Question 28

What are some good initial treatments when managing shock?

Answer 28

Flow-by O2 Obtain IV access IV fluid bolus resuscitation (unless suspect cardiogenic shock)

Question 29

What kind of fluid bolus might we give in a shocky (non-cardiogenic) patient?

Answer 29

Isotonic crystalloid bolus 5-20mL/kg IV over 10-20 minutes Repeat as needed up to 90mL/kg in dogs and 66mL/kg in cats

Question 30

What should you always do following a fluid bolus?

Answer 30

REASSESS

Question 31

What is the mainstay of treating obstructive shock?

Answer 31

Removing the obstruction GDV - trocarize Pleural effusion - thoracocentesis Cardiac tamponade - pericardiocentesis

Question 32

A shocky patient comes in 3 days after a GI FB removal and small intestine R&A. Based on the history, you suspect dehiscence, subsequent septic peritonitis, and septicemia. What treatments can you initiate?

Answer 32

Broad-spectrum antibiotics Vasopressors like NE (remember that hyperdynamic phase?)

Question 33

A few hours after vaccine administration, a dog presents to the ER with a swollen face and difficulty breathing. Based on the history, you believe the dog might be in anaphylactic shock. What should you do?

Answer 33

Vasopressors like E (remember that hyperdynamic phase?) Anti-histamines

Question 34

Mainstays of treating cardiogenic shock?

Answer 34

Correct underlying etiology O2 therapy NO IV FLUIDS Minimize stress

Question 35

How often should patients that have undergone resuscitation be reassessed?

Answer 35

Every 5-10 minutes or after every therapeutic intervention during stabilization