Hyper/Hypotension

Question 1

what are the determinants of stroke volume

Answer 1

1. preload (venous return)
2. afterload
3. contractility

Question 2

what are the determinants of cardiac output

Answer 2

1. heart rate
2. stroke volume

Question 3

what are the determinants of systemic vascular resistance

Answer 3

1. systemic neurohormonal factors
2. local auto regulation
3. local tissue/vascular factors

Question 4

what are the determinants of MAP

Answer 4

1. cardiac output
2. systemic vascular resistance

Question 5

what is blood pressure

Answer 5

the force applied per unit area of vessel wall

affected by blood volume, compliance, and resistance

Question 6

arterial vs venous pressure

Answer 6

arteries: high pressure
veins: low pressure

allows blood to move from high to low pressure

Question 7

what is the major determinant of blood flow/maintaining tissue perfusion

Answer 7

blood pressure

(ohm’s law: deltaP = Q x R)

Question 8

what are short term BP regulatory mechanisms

Answer 8

baroreceptor reflex
ANS
myogenic control
local autoregulation

Question 9

what are long term BP regulatory mechanisms

Answer 9

RAAS
natriuretic peptides

Question 10

what happens if hypotension goes untreated

Answer 10

low BP –> poor tissue perfusion –> dec O2 delivery to vital organs –> shock –> organ failure –> death

Question 11

what happens if hypertension goes untreated

Answer 11

high BP –> high blood flow –> end organ damage –> heart failure –> arrhythmias and death

Question 12

does heart disease cause systemic hypertension

Answer 12

NO - but systemic hypertension can cause heart disease

Question 13

what are the end organs affected by hypertension

Answer 13

brain
heart
kidneys
eyes

evaluate function of these organs if patient is hypertensive

Question 14

ways to measure blood pressure

Answer 14

1. direct measure
2. standard oscillometry
3. doppler ultrasound

Question 15

direct BP measurement

Answer 15

arterial line is placed, machine calculates MAP

GOLD STANDARD but not clinically applicable

Question 16

standard oscillometry

Answer 16

BP cuff temporarily inflates to occlude arteries, then measures oscillations of the arterial wall as the cuff dilates and blood flows back in

MAP is measured, SBP and DBP are calculated

Question 17

doppler ultrasound

Answer 17

ultrasonic crystals emit ultrasonic waves and detect frequency shift between emitted and returning frequency to emit an audible signal

Question 18

what are the perfusion parameters during hypotensive shock

Answer 18

mentation: QAR, obtunded, stupor
MM: pale or injected, CRT >2 or <1 sec
HR: tachycardia, bradyarrhythmia, tachyarrhythmia, bradycardia (cats)
temp: cool extremities
pulses: poor/absent or bounding

Question 19

types of hypotensive shock

Answer 19

1. hypovolemic
2. cardiogenic
3. vasodilatory

Question 20

hypovolemic shock

Answer 20

decreased blood volume leading to hypotensive shock (hemorrhage, GI/kidney loss, GDV)

dec venous return –> dec preload –> dec SV, CO, MAP

Question 21

what causes tachycardia during hypovolemic shock

Answer 21

baroreceptor reflex - senses the drop in MAP and causes an increase in HR, contractility, and vasoconstriction

Question 22

cardiogenic shock

Answer 22

decreased cardiac function leading to hypotensive shock

primary or secondary cardiac disease

Question 23

vasodilatory shock

Answer 23

decreased vascular resistance leading to hypotensive shock
(sepsis, anaphylaxis, systemic inflammation w/o infection)

causes injected MM and CRT <1 sec

Question 24

how do you treat hypotension

Answer 24

PRIMARILY NEED TO TREAT UNDERLYING DISEASE

can treat symptom of hypotension by:
1. increasing preload
2. increasing SVR

Question 25

how to increase preload

Answer 25

administer shock dose of fluids to increase SV

NOT indicated for heart disease

Question 26

how to increase SVR

Answer 26

IV fluid therapy + vasopressors

vasopressors: NE, epi, dopamine, ADH

Question 27

systemic hypertension

Answer 27

failure of the body’s normal physiologic adaptations to normalize BP

leads to inc CO, SVR, or both –> inc. MAP

Question 28

situational hypertension

Answer 28

increases in blood pressure caused by anxiety or stress

if BP is abnormal –> take a second reading to confirm

if stressor is removed then BP will return normal

Question 29

chronic hypertension

Answer 29

can be primary (idiopathic) or secondary to underlying disease

Question 30

is primary or secondary chronic hypertension most common

Answer 30

secondary hypertension

Question 31

baroreceptor reset

Answer 31

baroreceptors become less sensitive to high BP with chronic hypertension

causes the set point of activation to become higher –> baseline BP becomes higher

Question 32

primary chronic hypertension

Answer 32

idiopathic; no clinically apparent systemic disease is identified; suggests that one or both of the neurohormonal and renal systems for regulating BP are abnormal

Question 33

secondary chronic hypertension

Answer 33

1. inc SNS (chronic stress, hyperthyroid, hyperadrenocorticism)
2. inc catecholamine (adrenal tumor)
3. inc volume (renal disease, hyperadrenocorticism, diabetes mellitus, hyperaldosteronism)
4. inc SVR (RAAS activation in renal disease, impaired production of vasodilators)

Question 34

effects of hypertension

Answer 34

increased afterload –> pressure overload –> concentric hypertrophy of ventricles –> decreased diastolic function

Question 35

maladaptive response to systemic hypertension

Answer 35

ventricular hypertrophy and vascular remodeling contribute to further damage and tissue hypoxia, infarction, and organ dysfunction

Question 36

treatment of hypertension

Answer 36

PRIMARILY NEED TO TREAT THE UNDERLYING DISEASE

treat the symptom of hypertension by:
1. blocking SNS (a1/a2, B blockers)
2. inhibiting RAAS (ACE inhibitors, ARBs)
3. peripheral vasodilation (amlodipine)