Basic Hemodynamic Monitoring

Question 1

Hemodynamic monitoring

Answer 1

Measures chamber pressures with the use of special monitoring catheters and equipment

Question 2

Mean arterial pressure (MAP)

Answer 2

average pressure at which blood moves through the arteries
How well patient is perfusing tissues & organs

NR: 70-100 mm Hg
Minimum of 60 mm Hg

Question 3

Calculate MAP

Answer 3

SBP + 2(DBP)/3

OR

(SBP-DBP)/3 + DBP

Question 4

Cardiac output

Answer 4

Cardiac output = (stroke volume)(heart rate)

Question 5

Average stroke volume

Answer 5

70-80 mL/beat

Question 6

Average HR

Answer 6

70 BPM

Question 7

Average cardiac output

Answer 7

3.5-8 L/min

Question 8

Three factors of stroke volume

Answer 8

Preload
Contractility
Afterload

Question 9

Range for stroke volume

Answer 9

60-130 mL/beat

Question 10

Diastole

Answer 10

Relaxation phase; all four chambers relax, allowing ventricles to fill in preparation for contraction

Question 11

Systole

Answer 11

Contraction phase; atria contract (atrial systole) and then ventricles contract (ventricular systole) which allows ventricles to fill completely before ejection of blood from chambers

Question 12

Preload

Answer 12

Amount of blood in each ventricle before blood is ejected;
End diastolic volume;
Determined by how much blood is returned to heart

Question 13

Afterload

Answer 13

Resistance needed to overcome pressure of semilunar valves; inverse relationship with SV
Direct relationship with mean systolic pressure
High Afterload = high BP

Question 14

Contractility

Answer 14

Squeeze of ventricles to be able to push out blood

Heart muscle not as effective with age

Question 15

Pulse oxygen saturation (SpO2)

Answer 15

Oxygen saturation detected by the pulse oximeter estimating the percentage of oxygen molecules bound to hemoglobin molecules
Hgb has high affinity for O & carries ~97% of all O2 (4 receptor sites)

Question 16

PO2

Answer 16

From arterial blood; give indication of how much O2 is dissolved in blood (NR: 80-100)
More accurate than SpO2

Question 17

SpO2

Answer 17

Pulse ox reading; percentage of oxygenated Hgb in blood

Question 18

Signs of low O2

Answer 18

Cap refill >2s, cold hands, groggy, low urine output, mottling (late sign, near death)

Question 19

Stroke Volume

Answer 19

Amount of blood pushed out from ventricles per beat

Question 20

How does increased stroke volume affect afterload?

Answer 20

Decreased Afterload (not enough to perfuse tissue)

Question 21

How does decreased stroke volume affect afterload?

Answer 21

Increased afterload (not enough velocity, heart too weak)

Question 22

What happens with decreased Contractility?

Answer 22

Poor blood flow
CHF
patient drowning in blood

Question 23

What occurs with decreased preload?

Answer 23

Decreased perfusion, patient coding

Question 24

What occurs with increased preload?

Answer 24

Increase in BP

Question 25

Compliance

Answer 25

How stiff, distended heart is (affects Contractility)

Low compliance = decreased heart function
ex. MI, myopathy

Question 26

What occurs with too much resistance?

Answer 26

Decreased opening of valves (not enough blood ejected)

Hypertension = “body builder”; increased resistance
Hypotension = “baby”; decreased resistance

Question 27

What is NR for cardiac output? Average?

Answer 27

3500 - 8000 mL/min

Average = 5500 mL/min

Question 28

What occurs if MAP remains elevated?

Answer 28

Heart will enlarge & grow thicker

Heart becomes weak & can lead to shorter lifespan

Question 29

Atheroma

Answer 29

Fatty deposits build up on inside of arteries increasing risk of blood clots, MI, stroke

Question 30

Other hemodynamic assess.

Answer 30

Capillary refill
Urine output (volume to heart is concern)
Skin temp. (Decreased temp. = decreased circulation, volume issue)
LOC

Question 31

Modeling

Answer 31

Blue tinge to skin, close to end of life