Shock!

Question 1

Three important components of shock treatment:

Answer 1

1) optimization of volume status
2) optimization of oxygen demand
3) support of the circulation

Question 2

Define shock:

Answer 2

maldistribution of blood flow causing an imbalance between oxygen delivery and demand, leading to tissue hypoxia

Question 3

DOz (O2 delivery) =

Answer 3

CO (HR x SV) x CaO2

-arterial O2 content

Question 4

As preload increases, active tension_______.

Answer 4

increases

also, ventricular contraction increases and SV

Question 5

tension depends on the _________ of the heart.

Answer 5

inotropic state

Question 6

Barorecptors detect changes in _____. Cardiopulmonary mechanical baroreceptors detect changes in _______.

Answer 6

Blood pressure

central blood volume

Question 7

What are the five types of shock?

Answer 7

1) cardiogenic
2) hypovolemic
3) distributive
4) obstructive
5) neurogenic

Question 8

Etiologies of Cardiogenic Shock:

Answer 8

(when the pump fails!)

-MI, cardiomyopathy, myocarditis, arrhythmia, valve malfunction

Question 9

Etiologies of Hypovolemic Shock

Answer 9

(the tank is empty - intravascular volume loss)

-significant hemorrhage or severe hypovolemia (diarrhea, vomiting, dehydration)

Question 10

Etiologies of Distributive Shock

Answer 10

(the pipes are leaky)

-sepsis (absolute hypovolemia and cardiac depression), anaphylaxis, liver cirrhosis, pancreatitis

Question 11

Etiologies of Obstructive Shock

Answer 11

(problem filling the pump)

-cardiac tamponade, PE, tension pneumothorax

Question 12

Etiologies of Neurogenic Shock

Answer 12

loss of vascular tone due to abnl sympathetics (type of distrib shock)
-spinal cord injury, deep general anesthesia, reflux response to deep pain

Question 13

Which types of shock have significant decreases in CO?

Answer 13

those that correlate with a pump dysfunction: cardiogenic and obstructive

Question 14

What type of shock has a significant decrease in central venous pressure (CVP, or IVC or PCWP)?

Answer 14

hypovolemic, has a decreased preload!

Question 15

What type of shock has a significantly decreased SVR (systemic vascular resistance)?

Answer 15

distributive, has a decreased afterload

Question 16

If a pt. is cold, pale, clammy and has mottled skin associated with delayed cap refill, what type of shock are you thinking?

Answer 16

a low CO state, so cardiogenic or obstructive or hypovolemic

Question 17

What imaging method provides a noninvasive, real-time assessment of the causes of circulatory dysfunction?

Answer 17

Ultrasound!

-especially the focused echo

Question 18

Rapid Ultrasound in SHock (RUSH) protocol:

Answer 18

1) evaluate the heart (LV + RV size and fx)
2) assess the intravascular volume (fluid responsiveness)
3) evaluate the pipes (m aa + vv)

Question 19

Importance of lactate levels:

Answer 19

in low-flow states –> tissue hypoxia –> anaerobic metabolism –> increased lactate production

-also, increased glycolysis and decreased clearance (LF)

Question 20

Importance of SVO2 levels:

Answer 20

assesses the balance between O2 demand and supply. It will be decreased in those w/ low-flow states or anemia, but high-nl in those w/ distributive shock.

Question 21

The goal of resuscitation is to:

Answer 21

restore early and adequate O2 delivery.

It should be started while investigation of the cause is ongoing. Don’t wait!

Question 22

Fluid therapy in shock:

Answer 22

-intended to improve preload, SV and CO, but need to predict if the pt. will be fluid-responsive or not

Question 23

Medications used in shock:

Answer 23

B1 agonists (increases HR and contractility)
a-agonists (vasoconstriction)
ex) norepinephrine
inotropes to increase contractility

Question 24

Why should we mechanically ventilate?

Answer 24

-reduces the work of breathing and O2 demand of respiratory muscles, more O2 for other organs