Shock states

Question 1

CVP- what is it? what is the normal range, what does it mean if it is elevated or decreased?

Answer 1

Central venous pressure-measure of the pressure exerted by fluid in right atrium; measures R sided heart function
normal range: 0-6 mm Hg
CVP elevated- increased fluid in right atrium- fluid overload, cardiogenic shock, heart failure exacerbation
CVP decreased- decrease amount of fluid in right atrium- dehydration, distributive shock (vasodilation)

Question 2

What is MAP? What is the formula?

Answer 2

Mean Arterial Pressure = SBP +2 (DBP)/3
average driving force in arterial system throughout cardiac cycle; useful for hemodynamic assessment- perfusion of organs- useful for titrating pressors

Question 3

What is PAP, normal range, what does high or low values indicated physiologically?

Answer 3

Pulmonary Artery Pressure- measure of systolic and diastolic pressures in the pulmonary artery (SBP: 15-25/ DBP: 5-15)
High- indicates increase in fluid in pulmonary artery, relating to conditions that decrease elasticity of pulmonary artery: hypervolemia, pulmonary hypertension
Low- decreased fluid in pulmonary artery- hypovolemia

Question 4

What is PCWP or PAOP- pulmonary capillary wedge pressure or pulmonary artery occlusion pressure
define normal range, and what low and high values indicate clinically

Answer 4

measures pressure in left ventricle at end diastole (max stretch) indicative of left sided heart function
normal range: 6-12 mm Hg
High- in conditions that increase pressure in left ventricle at end diastole- fluid overload, decreased elasticity of ventricle- cardiomegaly, heart failure
Low- in conditions that decrease pressure in LV at end diastole- hypovolemia
PCWP- can reflect tendency to develop pulmonary edema- how well the heart can tolerate increased fluid intake without back up into lung circulation.
**keep PCWP at lowest point to optimize cardiac performance and minimize pulmonary edema. If wedge pressure is increasing, then leading to fluid overload, risk for pulmonary edema, stress on the heart

Question 5

What is CO? what is the formula? what is normal range? when do high and low values occur clinically?

Answer 5

Cardiac output- amount of fluid (L) that heart pumps into systemic circulation
CO = HRxSV
normal range: 4-8 L/min
increase: tachycardia, hypervolemia, inotropic agents
decrease: bradycardia, hypovolemia, drugs that decrease contractility- beta blockers: labetalol, esmolol, propranolol

Question 6

What is the cardiac index (CI)? what is normal range?

Answer 6

cardiac output/ body surface area- more accurate measure than cardiac output because it takes into account body surface area- important for obese patients(?)
normal 2.5-4 L/min

Question 7

What is SVR? what is formula? normal range?

Answer 7

Systemic vascular resistance- resistance provided by systemic circulation against which LV must overcome to pump blood out of heart
SVR= MAP-CVPx80)/CO
Normal: 800-1200 dynes/sec/cm-5

Question 8

What is mixed venous O2 saturation (SVO2)? what device measures it? what do low and high values indicate?

Answer 8

Continuous display of mixed venous oxygen sat by PULMONARY ARTERY CATHETER; effectiveness of peripheral oxygen delivery
normal range: 60-80%
low: <60%- increased tissue extraction of O2- could be caused by decreased O2 supply from respiratory compromise, decreased CO or anemia or increased oxygen demand from fever, shivering, increased WOB
high: > 80% decreased tissue extraction of O2- increased O2 supply (should then decrease the FIO2 supplemental oxygen), decreased O2 demand (hypothermia), decreased effective delivery of O2- sepsis, shift of oxyhemoglobin curve to the left

Question 9

what’s the shock states with low SVR?

Answer 9

septic, anaphylactic, neurogenic

Question 10

what’s the only shock state with high SVO2 (mixed venous O2 saturation)

Answer 10

Obstructive shock (PE)

Question 11

what shock state has high CO then low CO

Answer 11

sepsis

Question 12

what are causes of hypovolemic shock?

Answer 12

bleeding, burns, DKA/ HHNK, dehydration

Question 13

what are causes of cardiogenic shock?

Answer 13

MI, ventricular aneurysm, dysrhythmia, pericardial tamponade, hypoxemia, pulmonary edema, acute valvular regurgitation, acute ventricular septal defect (neonatal)

Question 14

what are the hemodynamics of cardiogenic shock?

Answer 14

High: CVP, PCWP, SVR
Low: CO, SVO2

Question 15

what are the 3 types of distributive shock?

Answer 15

septic, anaphylactic, neurogenic

Question 16

what is qSOFA criteria?

Answer 16

low BP SPB < 100
high RR > 22
altered mentation GCS < 15
if 2/3 criteria met- greater risk for sepsis

Question 17

what vasopressor agents are used for sepsis, what are the first choices for neurogenic shock?

Answer 17

sepsis: norepi, dopamine, dobutamine
neurogenic: phenylephrine, norepi

Question 18

what are common causes of obstructive shock?

Answer 18

massive PE: most common
tension pneumo
acute cardiac tamponade
obstructed valvular disease 
disease of pulmonary vasculature

Question 19

what are hemodynamics for obstructive shock

Answer 19

decreased CO, high SVR, normal or decreased PCWP, increased CVP (d/t blockage in pulmonary artery)