Shock

Question 1

What is shock?

Answer 1

(A severe imbalance between oxygen supply and demand lead to inadequate cellular energy production)

Question 2

What are the two characteristics of the cardiovascular system that are pertinent to oxygen delivery?

Answer 2

(Cardiac output and arterial content of O2)

Question 3

What are the two characteristics of the cardiovascular system that are pertinent to cardiac output?

Answer 3

(Heart rate (which is determined by the sympathetic vs. parasympathetic NS) and stroke volume (which is determined by preload, afterload, and contractility))

Question 4

What is hypovolemic shock and how does it impact oxygen delivery?

Answer 4

(A decreased intravascular volume which = decreased preload which = decreased CO which = decreased oxygen delivery)

Question 5

What are the etiologies for hypovolemic shock?

Answer 5

(Hemorrhage, severe dehydration, third space fluid loss, and severe burns)

Question 6

What is distributive shock?

Answer 6

(A maldistribution of fluid d/t changes in vascular tone and increased vascular permeability = leaky vessels)

Question 7

What are etiologies for distributive shock?

Answer 7

(Histamine induced vasodilation = anaphylactic shock, cytokine-mediated endothelial dysfunction = septic shock, neurogenic shock, and pheochromocytomas or extreme fear = catecholamine release)

Question 8

What type of shock is associated with GDV, vena cava obstruction, tension pneumothorax, cardiac tamponade, and positive pressure ventilation?

Answer 8

(Obstructive shock → compression of heart or great vessel that interferes with venous return = decreased diastolic filling and preload = decreased cardiac output)

Question 9

What is cardiogenic shock?

Answer 9

(A decrease in forward flow from the heart failing to pump = a primary decrease in cardiac output)

Question 10

What are etiologies for cardiogenic shock?

Answer 10

(Systolic failure, diastolic failure, AV valve degeneration/defects, and brady or tachyarrhythmias)

Question 11

What type of shock is associated with severe pulmonary dz, anemia, and dyshemoglobinemias (CO toxicity, methemoglobinemia, etc.)?

Answer 11

(Hypoxic shock = decreased arterial oxygen content = decreased tissue oxygen delivery)

Question 12

What is metabolic shock?

Answer 12

(Deranged cellular metabolism leading to inappropriate O2 use in the tissues (tissues have plenty of O2 they just aren’t using it), etiologies can be severe hypoglycemia and mitochondrial dysfunction)

Question 13

What effect will the baroreceptors sensing decreased stretch have on the body?

Answer 13

(Will trigger release of catecholamines from the adrenals → increased heart rate, increased cardiac contractility, and peripheral vasoconstriction)

Question 14

What triggers increased respiratory rate and tidal volume as a compensatory mechanism in the face of shock?

Answer 14

(Chemoreceptors sensing changes in pH, CO2/O2, etc.)

Question 15

What is the purpose of activating the RAAS as a compensatory mechanism in the face of shock?

Answer 15

(Angiotensin II triggers peripheral vasoconstriction and renal reabsorption of sodium (water follows) and ADH triggers increased renal water absorption)

Question 16

What are the perfusion parameters used to monitor a patient in shock (or that go haywire to indicate an animal is in shock)?

Answer 16

(Heart rate (will be the first thing to change), pulse quality, MM color, CRT, peripheral temperature, and mentation)

Question 17

Why will a patient in anaphylactic shock or septic shock have red to injected MM, elevated temperatures, and bounding pulses?

Answer 17

(Bc those types of shock are characterized by initial vasodilation instead of vasoconstriction)

Question 18

What is the main difference between dogs and cats in shock?

Answer 18

(Cats who are bradycardic should be a worry for shock, whereas for dogs it tachycardia; otherwise cats do as they please when sick to reflect how they live normally)

Question 19

Why should you make sure to rule out cardiogenic shock as a cause for a shocky patient?

Answer 19

(Bc the tx is so different → no IV fluid bolus if cardiogenic shock)

Question 20

What is the mainstay fluid choice for IV boluses for treatment of shock?

Answer 20

(Isotonic crystalloids → 5-20 ml/kg IV over 10-20 minutes repeated as needed up to 90 ml/kg for dogs and 66 ml/kg for cats with immediate reassessment between each bolus; additional options (hypertonic saline, colloids, whole blood, etc. are on a case by case basis))

Question 21

What should you give to a patient with septic or anaphylactic shock in addition to fluid boluses, otherwise you’re not doing much?

Answer 21

(Vasopressors (bc its an issue of vasodilation), norepinephrine for septic and epinephrine for anaphylactic)