Shock and Other Inadequate States

Question 1

What is shock?

Answer 1

acute inadequate delivery of oxygen and other metabolic substrates to the tissues leading to irreversible organ dysfunction if prolonged and has a high mortality despite therapy

Question 2

What is it? PAWP

Answer 2

pulmonary artery wedge pressure as a measure of LV diastolic pressure/LVED volume

Question 3

What kind of shock?

low RA/RV pressure
low PAWP
low CO
increased SVR

Answer 3

hypovolemic (low RARV and PAWP due to low preload)

Question 4

What kind of shock?

normal RA/RV pressure
normal PAWP
increased CO
low SVR

Answer 4

distributive aka septic (low SVR)

Question 5

What kind of shock?

high RA/RV pressure
high PAWP
low CO
high SVR

Answer 5

cardiogenic (low CO with high RARV and PAWP)

Question 6

What kind of shock?

high RA/RV pressure
low PAWP
low CO
high SVR

Answer 6

obstructive (high RARV, low PAWP)

Question 7

What is the primary pathophysiologic derangement of hypovolemic shock?

Answer 7

decreased preload –> decreased SV/CO –> compensate with increased HR and increased SVR

Question 8

What is the primary pathophysiologic derangement of distributive shock?

Answer 8

excess vasodilation with maldistribution of blood flow/low o2 delivery (as in sepsis) –> leads to decreased SVR/increased CO early –> late decreased filling pressures, decreased CO/increased SVR

Question 9

What is the difference between warm and cold shock?

Answer 9

warm shock = early distributive (increased CO, low SVR)

cold shock = late distributive (decreased CO, increased SVR)

Question 10

What is the primary pathophysiologic derangement of cardiogenic shock?

Answer 10

reduction in CO leading to elevated filling pressures and compensatory increase in SVR usually due to loss of pump function as in an MI

Question 11

What is the primary pathophysiologic derangement of obstructive shock?

Answer 11

obstruction to right heart flow thereby reduces LV preload resulting in elevated right heart pressures and reduced SV, CO but high compensative SVR (e.g. pulmonary embolus)

Question 12

What is pericardial tamponade?

Answer 12

obstructive shock that limits diastolic filling b/c of flow of fluid into pericardium

Question 13

Difference between acute and chronic tamponade?

Answer 13

body can adjust to chronic tamponade and compensate by increasing pericardial compliance, etc. whereas acute tamponade can present acutely

Question 14

What is pulsus paradoxus?

Answer 14

inspiratory decrease in systolic pressure due to an exaggeration of the normal inspiratory decrease in filling of LV (normally inspiration increases right heart filling and reduces LV filling)

Question 15

3 stages of shock

Answer 15

1. preshock/compensation –> sympathetic activation leading to tachycardai, increased contractility, peripheral vasoconstriction // bp and co maintained initially
2. frank shock –> overwhelmed regulatory mechanisms, signs of end-organ dysfunction, fall in cardiac index, urine output, tachycardia
3. decompensation/end organ failure –> ischemic acute tubular necrosis, lactic acidosis, multi-system organ failure, death

Question 16

Tx of shock

Answer 16

treat underlying cause, ABCs, oxygen, fluids, vasoactive medications, inotropes