Shock

Question 1

Shock

Answer 1

generally a severe imbalances between oxygen supply and demand, leading to inadequate cellular energy production

Question 2

oxygen delivery =

Answer 2

cardiac output (CO) x arterial content of O2

Question 3

what are some of the consequences of shock to the cell? and the body?

Answer 3

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

Question 4

what are the 4 types of circulatory shock?

Answer 4

hypovolemic
distributive
obstructive
cardiogenic

Question 5

what is the most common type of shock?

Answer 5

hypovolemic

Question 6

Hypovolemic Shock

Answer 6

decreased intravascular volume -> decreased preload -> decreased cardiac output

This results from hemorrhage, severe dehydration (GI or renal), third space fluid loss and severe burns

Question 7

Distributive Shock

Answer 7

Maldistribution of fluid from changes in vascular tone and increased vascular permeability. Theres decreased systemic vascular resistance +/- preload +/- contractility. May be caused by anaphylactic shock due to histamine induced vasodilation or septic shock from cytokine mediated endothelial dysfunction. Neurogenic shock, Pheochromocytoma or extreme fear may also cause this form of shock

Question 8

T/F: distributive shock is when the volume is not getting where it needs to go and is often mixed with other forms of shock

Answer 8

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Question 9

Obstructive Shock

Answer 9

Compression of heart or great vessels that interfere with venous return -> decreased diastolic filling and preload -> decreased CO.

This can occur due to GDV, Obstruction of the vena cava, tension pneumothorax, cardiac tamponade and pericardial effusion, positive pressure ventilation.

Question 10

Cardiogenic Shock

Answer 10

Decrease in forward flow from the heart due to pump failure -> primary decrease in CO

This is caused by systolic failure (DCM), diastolic failure (HCM), atrioventricular valve degenerative defects, severe Brady or tachy arrhythmias

Question 11

Hypoxic Shock

Answer 11

This is a problem with oxygen content or hemoglobin in blood .

decreased arterial oxygen content -> decreased tissue oxygen delivery

caused by severe pulmonary disease, anemia, dyshemoglobinemias

Question 12

Metabolic shock

Answer 12

This is when there is deranged cellular metabolism leading to inappropriate O2 tissue use.

Its caused by severe hypoglycemia, and mitochondrial dysfunction.

Question 13

Describe compensatory mechanisms for shock

Answer 13

1. baroreceptor reflex -> increases HR and cardiac contractility causing vasoconstriction
2. chemoreceptors -> increase RR and tidal volume
3. RAAS activation -> peripheral vasoconstriction and renal reabsorption

—> angiotensin II -> further vasoconstriction

4. ADH -> increased renal water reabsorption

Question 14

hallmark of decompensated shock

Answer 14

low bp

Question 15

what is the most sensitive perfusion parameter?

Answer 15

HR, it may be the first to be abnormal

Question 16

anaphylactic and septic shock

Answer 16

These are characterized by initial vasodilation instead of vasoconstriction. The animal will be tachycardic, CRT< 1 second, red to injected mm, elevated temperature, and bounding pulses.

Question 17

how are cats different than dogs in shock?

Answer 17

Cats have unpredictable heart rate changes that rarely manifest signs of vasodilatory shock. Their “shock organ” = lungs (tachypneic) and they’re more likely to experience hypothermia and bradycardia

Question 18

T/F: cardiogenic shock has a drastically different treatment than other forms of shock

Answer 18

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Question 19

Point of care tests for shock patients

Answer 19

PCV/TS, blood glucose, lactate, blood pressure, ECG, POCUS, acid base and electrolyte panel

Question 20

In general, how should you restore O2 delivery to tissues as soon as possible?

Answer 20

1. flow by oxygen
2. obtain IV access
3. IV fluid bolus resuscitation

Question 21

when would you not give an IV fluid bolus for shock resuscitation?

Answer 21

cardiogenic shock

Question 22

Mainstay therapies of shock

Answer 22

isotonic crystalloids: 5-20ml/kg IV over 10-20 minutes

repeat as needed up to 90ml/kg (just give blood product if doing 90) in dogs or 66ml/kg in cats

Question 23

what is key after giving a bolus?

Answer 23

immediate reassessment

Question 24

Distributive shock treatment

Answer 24

1. obstructive: gastric trocarization. thoracocentesis, or pericardiocentesis
2. Septic: vasopressors, broad spectrum antibiotics
3. anaphylactic -> vasopressors (epinephrine), antihistamines

Question 25

norepi is given for __ shock while epi is given for __ shock

Answer 25

norepi is given for septic shock while epi is given for anaphylactic shock

Question 26

Treatment of Cardiogenic shock

Answer 26

Treat any underlying disease, give O2 therapy, **NO IV FLUIDS** and minimize stress. CHF = diurectics (furosemide), O2 therapy, +/- thoracocentesis Systolic dysfunction = positive inotropes (dobutamine, pimobendan)

Question 27

how often should you reassess a shock patient?

Answer 27

clinical reassessment every 5 to 10 minutes or after every therapeutic intervention during stabilization