Shock Flashcards
shock is circulatory failure causing inadequate ______ delivery to cells.
oxygen
What is the quick and dirty beside evaluation for shock? (think: CHAOS)
- Cardiogenic
- Hypovolemic
- Adrenal (distributive)
- Obstructive
- Septic (distributive)
Which of the following subdivisions of shock DOES NOT lead to reduced cardiac output?
a. hypovolemic
b. obstructive
c. cardiogenic
d. distributive
d. distributive
* distributive leads to low peripheral resistance*
What defines preload?
a. Load imposed on resting muscle that stretches the muscle to a new length
b. Velocity of muscle contraction when muscle load is fixed
c. Load which muscle must act against during contraction
a. Load imposed on resting muscle that stretches the muscle to a new length
What defines afterload?
a. Load imposed on resting muscle that stretches the muscle to a new length
b. Velocity of muscle contraction when muscle load is fixed
c. Load which muscle must act against during contraction
c. Load which muscle must act against during contraction
What defines contractility?
a. Load imposed on resting muscle that stretches the muscle to a new length
b. Velocity of muscle contraction when muscle load is fixed
c. Load which muscle must act against during contraction
b. Velocity of muscle contraction when muscle load is fixed
What are the 3 stroke volume determinants?
- preload
- contractility
- afterload
Contractility is the ______ ability for your heart to squeeze.
intrinsic
regardless of what the preload is
Delivery of oxygen (DO2) is related to what 2 factors?
CaO2 (arterial oxygen content) x Q (perfusion)
Normal arterial oxygen content (CaO2) is equal to _______ mL O2/dL.
20 mL O2/dL
Oxygen consumption (VO2) is equal to what?
VO2 = SaO2 (arterial) - SvO2 (venous)
What 3 factors determine your arterial oxygen content?
- hemoglobin
- SaO2 (arterial oxygen saturation)
- PaO2 (arterial oxygen tension)
What are 3 common etiologies of hypovolemic shock?
- hemorrhage
- third spacing (e.g. burns, pancreatitis)
- dehydration
What are 3 common causes of obstructive shock?
- cardiac tamponade
- PE
- tension pneumothorax
What are the 4 common causes of distributive shock?
- septic shock
- adrenal insufficiency
- neurogenic shock
- anaphylaxis
What is the mechanism of hypovolemic shock?
a. reduced ability of the heart to pump blood forward
b. reduced venous return leading to reduced preload and reduced C.O.
c. mechanical obstruction to normal venous return C.O.
d. dilatation of vasculature
b. reduced venous return leading to reduced preload and reduced C.O.
What is the mechanism of distributive shock?
a. reduced ability of the heart to pump blood forward
b. reduced venous return leading to reduced preload and reduced C.O.
c. mechanical obstruction to normal venous return C.O.
d. dilatation of vasculature
d. dilatation of vasculature
What is the mechanism of cardiogenic shock?
a. reduced ability of the heart to pump blood forward
b. reduced venous return leading to reduced preload and reduced C.O.
c. mechanical obstruction to normal venous return C.O.
d. dilatation of vasculature
a. reduced ability of the heart to pump blood forward
What is the mechanism of obstructive shock?
a. reduced ability of the heart to pump blood forward
b. reduced venous return leading to reduced preload and reduced C.O.
c. mechanical obstruction to normal venous return C.O.
d. dilatation of vasculature
c. mechanical obstruction to normal venous return C.O.
What is the first sign of critical illness?
tachypnea
What is the first sign of shock?
oliguria (low urine output)
What 2 labs do you want to get for shock?
- lactate
- SVO2/ScVO2 (venous oxygenation)
If O2 delivery is impaired tissues compensate by ___________.
increasing extraction
If O2 delivery is impaired tissues compensate by increasing extraction. This results in what?
reduced venous saturation returning to the right heart
