Blood Pressure

Question 1

Oxygen consumption and heart rate

Answer 1

-as oxygen consumption increases, rate the heart pumps increases

Question 2

Maintaining perfusion

Answer 2

-best way to maintain perfusion is to regulate MAP
-ensures that all organs in system receive perfusion
-if blood pressure decreases, a lot of organs will not get adequate perfusion because basic metabolism will be covered first

Question 3

Blood pressure

Answer 3

-the force of blood exerted on walls of the blood vessels
-critical for maintaining organ perfusion/blood flow
Ejection phase
-systolic blood pressure (SBP)
-peak rise in pressure

Question 4

Relaxation phase

Answer 4

-diastolic blood pressure (DBP)

Question 5

Pulse pressure eqn

Answer 5

Pulse pressure=SBP-DBP

Question 6

What causes Pulse pressure to increase?

Answer 6

-greater LV ejection (stroke volume)
-stiffer, non-compliant arteries

Question 7

What does general increase in blood pressure most likely indicate?

Answer 7

-most likely related to stroke volume
**pulse pressure= proxy for stroke volume

Question 8

What does systolic blood pressure change likely indicate?

Answer 8

-most likely linked to stiff arteries

Question 9

Mean arterial pressure (MAP)

Answer 9

-average pressure in the arteries during one cardiac cycle (includes SBP and DBP)
-indicator of organ perfusion

Question 10

Mean arterial pressure equation using pulse pressure

Answer 10

MAP= DBP + 1/3 (pulse pressure)
**DBP accounts for more because it accounts for 2/3rds of cardiac cycle

Question 11

Mean arterial pressure equation using cardiac output

Answer 11

MAP= (CO X SVR) + CVP
-cardiac output
-systemic vascular resistance
-central venous pressure

Question 12

Cardiac output

Answer 12

-volume of blood pumped per unit of time
-calculated as heart rate X stroke volume

Question 13

Systemic vascular resistance

Answer 13

-influenced by vascular volume of small arteries
*increase radius of arteries will decrease resistance and vice versa
-SVR inversely related to vascular volume

Question 14

Central venous pressure

Answer 14

-pressure in vena cava near right atrium (blood returning to heart/preload)
-often close to zero

Question 15

Mean arterial pressure, cardiac output, and the impact of vascular resistance

Answer 15

-an increase in cardiac output will increase MAP
-at a given cardiac output, an increase in systemic vascular resistance will result in an increase in MAP

Question 16

Tools to be used to determine Blood pressure

Answer 16

1.stethoscope- can find pulse
2. ECG or arterial palpation- can find pulse
3.doppler or sphygmomanometer- directly finds blood pressure
4.capillary refill time-indirect blood pressure
5.jugular vein distention- can find pulse

Question 17

Doppler

Answer 17

-blood moving towards the probe will make a sound
-inflate cuff, won’t hear noise. Deflate the cuff and once you hear the noise it indicates the vasculature opening.
-doppler readings supply systolic pressure

Question 18

Capillary refill time (CFT)

Answer 18

-pink mucous membranes; compress mucous membranes and measure the time it takes for colour to return to normal
*should be less than 1.5-2 secs

Question 19

Discoloured (grey, white) Capillary refill time

Answer 19

-indicator of poor circulation
-common with heart problems
-hypovolemias, low blood pressure, dehydration, shock, low or high pulse rate, anemia, capillary rarefaction

Question 20

Discoloured (red), fast capillary refill time

Answer 20

-uncommon, indicator of over perfusion
-high blood pressure, high pulse rate, local inflammation

Question 21

Jugular vein distention

Answer 21

-occurs when the central venous pressure is above normal healthy value. Blood can back up into the veins causing them to bulge and pulse

Question 22

Causes of jugular vein distention

Answer 22

-cardiac tamponade or pericarditis (restricted filling)
- vena cava obstruction (tumour in chest prevents blood from entering atria)
-tricuspid valve stenosis (valve can become stiff, the entry of blood from the atria to the ventricle is impeded)
-right sided heart failure or pulmonary hypertension (right ventricle does not empty during systole; increased afterload)