hemodynamics

Question 1

cardiac output

Answer 1

• best indicator of the condition of the hearts contractile (inotropic ability)
• volume of blood ejected by the heart in 1 min into the systemic circuit
• does not equate for differences in body size

Question 2

normal CO

Answer 2

4-8 l/min

Question 3

cardiac index

Answer 3

CO divided by an indiviuals body surface area

normal: 2.2-4

measured by PA cath

Question 4

CO = ____ x ____

Answer 4

SV x HR

Question 5

what is stroke volume

Answer 5

• volume of blod ejected by the left ventricle during each systole
• affected by three factors: preload, afterload, and contractility

Question 6

normal SV

Answer 6

60-100 ml

Question 7

what is preload

Answer 7

• The amount of stretch placed on cardiac muscle fibers just before systole.
• Volume of blood in the ventricle at the end of diastole
• Amount of myocardial stretch placed on the ventricular muscle fibers prior to systole application of Frank-Starling law of the heart
• Volume of blood creates a filling pressure

Question 8

causes of elevated preload

Answer 8

• volume overload
• LV dysfunction
• RV dysfunction
• valvular defects
• cardiac tamponade

Question 9

effects of increase preload on the heart

Answer 9

Increases stroke volume
Increases ventricular work
Increases myocardial oxygen requirements

Question 10

assessment of right sided elevated preload

Answer 10

JVD
Edema
Hepato-jugular reflux(HJR)

Question 11

assessment of left sided elevated preload

Answer 11

Orthopnea
Dyspnea
Cough
Crackles
S3

Question 12

ways to reduce preload

Answer 12

• Drugs that directly reduce blood volume, e.g. diuretics
• Drugs that promote vasodilation, e.g.
  Nitrates
• Patient positioning (semi/high fowlers)

Question 13

causes of decreased preload

Answer 13

Hypovolemia
Hemorrhage
Third spacing
Diuresis
Vasodilation

Question 14

assessment findings of a decreased preload

Answer 14

Tachycardia/hypotension
Dry, cool skin
Dry mucous membranes
Poor skin turgor
Alteration in LOC
Decreased urine output/vital organ perfusion

Question 15

right sided preload assessment

Answer 15

Right Ventricular End-Diastolic Pressure (RVEDP)
Right Atrial Pressure (RAP)
Central Venous Pressure (CVP)

Question 16

left sided preload assessment

Answer 16

Left Ventricular End-Diastolic Pressure (LVEDP)
Pulmonary Artery Wedge Pressure (PCWP) aka
Pulmonary Artery Occlusive Pressure (PAOP)
Pulmonary Artery Diastolic Pressure (PADP

Question 17

treatment to increase preload

Answer 17

volume administration
patient positioning - modified trendelenburg

Question 18

what is afterload

Answer 18

Increased ventricular wall tension or stress during systolic ejection

Pressure that the ventricle has to pump against to eject blood into the circulation during systole.

Most critical factor determining afterload is vascular resistance.
- Systemic vascular resistance (SVR)

Question 19

assessment of afterload

Answer 19

Mean arterial pressure (MAP) *not always correlated

Systemic Vascular Resistance (SVR)
- must have an invasive catheter to calculate SVR (must know cardiac output)

Pulmonary Vascular Resistance (PVR)

Question 20

what causes an elevated afterload

Answer 20

Vasoconstriction (increased SVR)

Medications
- Alpha 1 agonists

Catecholamine release (compensatory mechanisms)
- Hypovolemia
- Pain
- Hypoxia
- Hypothermia

Hypertension

Increased aortic impedance

Question 21

afterload reduction therapy

Answer 21

Vasodilator therapy
- Nitroprusside (Nipride)
- Calcium Channel Blockers (Nicardipine)
- ACE-Inhibitors (-pril)
- Angiotension Receptor Blockers (-sartan)

Question 22

what causes a decreased afterload

Answer 22

Vasodilation (decreased SVR)
Inadequate aortic valve function
Inflammatory response
Hyperthermia

Question 23

therapy to increase afterload

Answer 23

Vasopressor therapy e.g. Adrenergic stimulants
- Norepinephrine (Levophed)
- Phenylephrine (Neo-synephrine)
- Dopamine
- Vasopressin

Question 24

what is contractility

Answer 24

The inotropic action of the heart muscle during systole or the force of each ventricular contraction

Question 25

what factors influence contractility

Answer 25

Intracellular calcium and ATP availability Coronary artery perfusion Cardiac oxygen supply/demand balance Heart rate Blood pressure Valve competence

Question 26

assessment findings with low contractility

Answer 26

Tachycardia Cool, pale skin Decreased urine output Mental status changes Poor peripheral circulation

Question 27

how do we measure contractility

Answer 27

Cardiac output (CO) Cardiac Index (CI) Ejection Fraction (EF)

Question 28

interventions to increase contractility

Answer 28

increase preload positive inotropic agents

Question 29

interventions to decrease conractility

Answer 29

negative inotropic agents

Question 30

inotropic

Answer 30

myocardial contractility

Question 31

chronotropic

Answer 31

heart rate

Question 32

dromotropic

Answer 32

rate of electrical conduction

Question 33

beta 1 receptors

Answer 33

Located primarily in the heart. Stimulation produces: altered ventricular function + chronotropic + inotropic

Question 34

beta 2 receptors

Answer 34

Located in bronchial and vascular smooth muscle. Stimulation produces: bronchodilation

Question 35

alpha 1 receptors

Answer 35

Located primarily in vascular smooth muscle Stimulation produces vasoconstriction Increased SVR

Question 36

what is the phlebostatic axis

Answer 36

Reference level for placement of the transducer to ensure accuracy of measurements Point is located at the intersection of two imaginary reference lines: 1st line - 4th ICS at sternum drawn to side of body 2nd line - drawn midway between anterior and posterior chest (mid-axillary line)

Question 37

what MAP is needed to perfuse coronary arteries

Answer 37

>60

Question 38

ideal MAP

Answer 38

70-90

Question 39

# arterial lines pre procedure

Answer 39

allens test

Question 40

# arterial lines maintenance

Answer 40

Leveling & Zeroing Phlebostatic Axis Compare cuff pressure Check circulation Complications IF BP CHANGES QUICKLY: CHECK PT, CONNECTIONS & LEVEL OF TRANSDUCER

Question 41

what does CVP measure

Answer 41

CVP measures the pressure in the right atrium or vena cava. Provides information regarding intravascular blood volume Indirectly reflects right ventricular end-diastolic pressure (RVEDP) Measures right ventricular preload

Question 42

normal CVP

Answer 42

8

Question 43

which port is used to measure CVP

Answer 43

distal closest to right atrium

Question 44

complications to CVP monitoring

Answer 44

Infection Dislodgement Pneumothorax Thrombosis Air embolism

Question 45

PA pressure monitoring

Answer 45

Flow Directed Pulmonary Artery Catheter “AKA” Swan-Ganz Catheter Used to obtain intra cardiac data to diagnose/evaluate heart disease, shock states and any medical or surgical condition that compromises cardiac function and output; To evaluate patient response to treatment

Question 46

complications with PA monitoring

Answer 46

Pneumothorax Infection Ventricular dysrhythmias Pulmonary artery rupture or perforation Air embolus