Shock

Question 1

Shock is a pathophysiologic state with reduced systemic _______ causing tissue hypoxia

Answer 1

tissue perfusion

Question 2

shock results in what 5 things?

Answer 2

1. Compromised function (e.g., CNS, renal)
2. Acidemia
3. Inflammation
4. Coagulopathy
5. Cellular injury (reversible or irreversible):
   Endothelial injury / dysfunction (enhanced coagulation)
   Leakage of intracellular contents (e.g., LDH, ALT, AST – lab tests)

Question 3

Four primary causes of shock

Answer 3

1. Hypovolemic: intravascular volume loss
2. Cardiogenic: pump failure
3. Distributive: vasodilation (“hyperdynamic” shock)
4. Obstructive: blood vessels and heart

Question 4

Reversal of the cause of shock can reverse the ______ effects on tissues if it is recognized and treat quickly

Answer 4

hypoxic

Question 5

Systemic tissue perfusion is KEY (think ABC – A_____, B_____, C_____)

Answer 5

Airway, Breathing, Circulation

Question 6

Perfusion is determined by what 2 things?

Answer 6

1. Cardiac output (CO) = heart rate (HR) x stroke volume (SV)
2. Systemic vascular resistance (SVR)

Question 7

Systemic vascular resistance (SVR) is affected by what 3 things?

Answer 7

Vessel length (e.g., obesity)
Vessel diameter (constriction vs dilation)
Blood viscosity (e.g., hemoconcentration)

Question 8

Stroke Volume is affected by what 3 things?

Answer 8

preload (volume remaining in ventricle), afterload (resistance to ejection), and myocardial contractility (affected by cardiomyopathy)

Question 9

shock is caused by decreased __ or decreased ___.

Answer 9

Caused by decreased CO or decreased SVR

Question 10

Changes in CO or SVR will result in a compensatory change in the other factor, attempting to maintain _________ (e.g., decreased CO will result in an increase in SVR)

Answer 10

tissue perfusion

Question 11

______ results when the compensation is unable to maintain tissue perfusion at an adequate level

Answer 11

Shock

Question 12

reduction in perfusion due to vasodilation (e.g., decreased SVR due to anaphylaxis) may not be fully compensated for by increased ___(i.e., increased CO)

Answer 12

HR

Question 13

Hypovolemic Shock is Due to _______ compared to the total vascular capacity

Answer 13

reduced blood volume

Question 14

Hypovolemic Shock is Due to reduced blood volume compared to the total vascular capacity. This can be caused by what?

Answer 14

low diastolic filling pressure (reduced preload)

Question 15

Hypovolemic Shock causes

Answer 15

Rapid or excessive fluid loss:
Dehydration
Burns
Gastroenteritis (e.g., vomiting, diarrhea)

Blood loss:
Hemorrhage
Solid organ injury (e.g., spleen or liver rupture)
Abdominal aortic aneurysm (AAA) rupture
Other hemorrhage

Question 16

Signs and symptoms of Hypovolemic Shock

7 things

Answer 16

1. Hypotension (decreased blood volume)
2. Rapid, thready pulse (increased HR with decreased CO and difficult-to-feel pulse)
3. Pale, clammy skin (blood diversion to core organs)
4. Intense thirst (hypothalamic thirst response; elevated electrolytes, low water, hyperosmotic plasma with dehydration)
5. Tachypnea (caused by increased CO2, reduced O2 vs tissue needs) patient is becoming acidodic
6. Change in mental status (CNS hypoxia)
7. Decreased urine output (reduced GFR from reduced renal perfusion)

Question 17

Hypovolemic Shock: Renal Response

Decreased GFR leads to increased ____secretion

Answer 17

renin

Question 18

Decreased GFR leads to increased renin secretion. this Results in increase of what two things?

Answer 18

increased angiotensin and increased SVR

Question 19

increased angiotensin and increased SVR leads to ________ of arteriolar smooth muscle, and ________ secretion resulting in Na+ retention and K+ loss

Answer 19

Vasoconstriction
Aldosterone

Vasoconstriction of arteriolar smooth muscle
Aldosterone secretion resulting in Na+ retention and K+ loss

Question 20

what will Inadequate renal perfusion will result in?

Answer 20

loss of renal function

– azotemia, acidemia, etc.

Question 21

in Cardiogenic Shock, _____failure results in decreased CO

Answer 21

Cardiac pump

Question 22

causes of Cardiogenic Shock (4)

Answer 22

1. Increased ventricular filling pressure (e.g., restrictive cardiomyopathy)
2. Ventricular dilation (e.g., dilated cardiomyopathy)
3. Heart failure leading to hypotension and pulmonary edema
4. Myocardial infarction

Question 23

Compensatory mechanism in cardiogenic shock is to increase___ to ensure end organ/tissue perfusion

Answer 23

SVR

Question 24

Compensatory mechanism in Cardiogenic Shock is to increase SVR to ensure end organ/tissue perfusion. what is a negative aspect about this?

Answer 24

increases cardiac work load by increasing afterload

Question 25

Cardiogenic Shock: Myocardial Ischemia Ischemia results in decreased ventricular contractility and reduced CO from________.

Answer 25

LV dysfunction

Question 26

in cariogenic shock, Ischemia results in decreased ventricular contractility and reduced CO from LV dysfunction. Decreased arterial pressure results in ______ (sympathetic feedback)

Answer 26

increased HR

Question 27

As HR increases, _________ also increases

Answer 27

myocardial O2 requirement

Question 28

Increased O2 requirement results in increased HR, which in turn increases O2 requirement. this Exacerbates myocardial ischemia, resulting in severe _______. You will Need more O2 to heart: increase supply (O2 administration, NTG) or decrease use (rest)

Answer 28

cardiac decompensation

Question 29

type of shock that May result from any cardiac pump failure which reduces CO

Answer 29

Cardiogenic Shock: Other Dysfunction ``` examples: Cardiomyopathy (dilated or restrictive) Ventricular arrhythmia (flutter or fibrillation) Mechanical abnormalities: Valve dysfunction Ventricular-septal defect Ruptured ventricular wall aneurysm ```

Question 30

in Distributive Shock, “Vasodilatory”, caused by severely decreased ____

Answer 30

SVR

Question 31

in Distributive Shock, what increases to compensate for ↓ SVR?

Answer 31

heart rate

Question 32

causes of Distributive Shock (5)

Answer 32

1. Septic shock (most common) 2. Systemic inflammatory response syndrome (SIRS, from burns, pancreatitis, infection) 3. Anaphylaxis (IgE mediated) 4. Neurogenic shock (brain/spinal cord injury) 5. Addison disease crisis

Question 33

Sepsis and bacterial toxins (Staph aureus toxic shock syndrome) can cause what type of shock?

Answer 33

Distributive Shock

Question 34

Distributive Shock Results in aggressive acute phase response with what 4 things?

Answer 34

1. Leukocytosis 2. Fever 3. Complement activation 4. Cytokine release results in nitric oxide synthesis, causes widespread vasodilation and hypotension

Question 35

Reduced diastolic blood pressure Widened pulse pressure Flushed warm extremities with brisk capillary refill the above is seen with type of shock?

Answer 35

Early septic shock or “warm shock” (Hyperdynamic) | type of Distributive Shock

Question 36

Reduced systolic and diastolic blood pressure Pale, clammy extremities Pressure dependent decrease in vital organ perfusion Multiple organ dysfunction syndrome (abdominal organs, CNS, heart; also called multiple system organ failure) the above is seen with type of shock?

Answer 36

Late septic shock or “cold shock” (Hypodynamic) | type of Distributive Shock

Question 37

characteristics of Early septic shock or “warm shock” (Hyperdynamic) (3 things)

Answer 37

1. Reduced diastolic blood pressure 2. Widened pulse pressure 3. Flushed warm extremities with brisk capillary refill

Question 38

characteristics of Late septic shock or “cold shock” (Hypodynamic)

Answer 38

1. Reduced systolic and diastolic blood pressure 2. Pale, clammy extremities 3. Pressure dependent decrease in vital organ perfusion 4. Multiple organ dysfunction syndrome (abdominal organs, CNS, heart; also called multiple system organ failure)

Question 39

Anaphylactic shock is what type of shock?

Answer 39

type of Distributive Shock

Question 40

in Anaphylactic shock, there is a Massive activation of _____ (tissue) and _____(blood) by binding of surface IgE to allergin

Answer 40

mast cells basophils

Question 41

Anaphylactic shock causes a systemic release of what 3 things?

Answer 41

Systemic release of histamine, serotonin, leukotrienes

Question 42

Anaphylactic shock Results in _____, increased vascular permeability (loss of vascular volume to extravascular spaces)

Answer 42

vasodilation

Question 43

Anaphylactic shock signs

Answer 43

Signs of edema (angioedema), dyspnea (bronchiolar smooth muscle contraction, pulmonary edema), hypotension

Question 44

Obstructive Shock is caused how?

Answer 44

Reduced CO caused by extracardiac abnormalities: 1. Massive pulmonary embolus (inadequate return to left atrium) ``` 2. Tension pneumothorax (inadequate filling) Constrictive pericarditis (inadequate filling) ``` 3. Pulmonary HTN (inadequate return to left atrium) 4. Cardiac tamponade (inadequate filling)

Question 45

Prolonged Shock can lead to what two things?

Answer 45

Permanent CNS injury | Multiple organ dysfunction syndrome

Question 46

Why might Multiple organ dysfunction syndrome occur in prolonged shock?

Answer 46

Because of low pressure of abdominal organs, reduced visceral blood pressure results in kidneys, intestine, liver, heart, brain