Boot Camp Day 3 assessment handout - Cardiovascular Nursing

57 Pages·2014·2.69 MB·English

The 30 Minute Overview
Carol Jacobson MN, RN
Cardiovascular Nursing Education Associates
www.cardionursing.com
Cardiovascular System
 Function is to deliver
oxygenated blood to
all parts of the body
• Heart – pump
• Arteries – deliver
• Veins – return
• Volume – must be
adequate for tank size

 All must work well in
order for CV system
to do its job
Carol Jacobson MN, RN www.cardionursing.com 1
Definitions
 Cardiac Output: Volume of blood ejected by the
ventricle each minute
• Normal:4-8 liters/minute
 Cardiac Index: Adjustment made for body size
• Normal cardiac index: 2.5-4.5 liters/minute/m2
 Stroke Volume: Volume of blood ejected with
each beat.
• Normal 60-120 ml / beat
• Systolic BP is non invasive indicator
 Ejection Fraction: Percent of blood ejected from
the ventricle with each beat
• Used to evaluate LV function
• Normal: 55% to 75%

Right side versus left side systems
Anatomically the heart sits between
the two lungs, but physiologically
the lungs sit between the right
heart and the left heart.
Carol Jacobson MN, RN www.cardionursing.com 2
Determinants of Cardiac Output
CO = HR x SV

Preload Afterload Contractility

Venous tone Body Position Intrathoracic Intrapericardial
pressure pressure

Blood Volume Distribution of Atrial Kick LV Function
blood volume

PRELOAD

• Preload is ventricular fiber length
• Volume determines fiber length
• CVP is the clinical indicator of RV preload
• JVD is physical assessment parameter that reflects
RV preload
• PWP is the clinical indicator of LV preload
• Lung sounds are physical assessment parameter
that reflect LV preload
Carol Jacobson MN, RN www.cardionursing.com 3
Conditions That Alter Preload
 Hypovolemia (low
 Altered Size of Vascular
preload)
Space
• Hemorrhage
• Sepsis
• Dehydration
• Neurogenic shock
• Burns
• Spinal or epidural
• Overdiuresis
anesthesia
• Third Spacing (low albumin,
capillary leak secondary to • Anaphylaxis
CPB, ARDs) • Rewarming after cardiac
 High Preload surgery
• Hypervolemia • Venous dilating drugs
• Heart failure − NTG
• Renal disease − ACEI, ARBs
• Pulmonary HTN − Ca++ blockers
Pressure higher
• Tamponade − Nesiritide
but not volume
• Tension pneumo

Sympathetic NS & Circulating vasodilator or
vasoconstrictor mediators
Arteriolar Tone

SVR Aortic Pressure Aortic Stenosis
& Compliance HOCM

AFTERLOAD

• Afterload is the work done by a ventricle to
eject its volume
• PVR is clinical indicator of RV afterload
• SVR is clinical indicator of LV afterload
• Diastolic BP is a reflection of LV afterload
Carol Jacobson MN, RN www.cardionursing.com 4
Conditions That Alter Afterload
 Vasodilation
 Vasoconstriction
• Sepsis
• Hypertension
• Spinal or epidural
• SNS stimulation
anesthesia
• Compensatory
• Anaphylaxis
vasoconstriction
• Rewarming after
(hypothermia, shock)
cardiac surgery
• Drugs
• Arterial dilating drugs
− Phenylephrine
− Nipride
(Neosynephrine)
− ACEI
− Norepinephrine (Levophed)
− ARBs
− Milrinone − High-dose dopamine
− Ca++ channel blockers − Epinephrine
− Antihypertensives − Vasopressin
Hypoxemia
Ischemia
SNS Adrenals ↑H+ ↑CO ↓O
2 2

Ventricular Catecholamines Metabolic Drugs
Muscle Mass State

CONTRACTILITY

• Contractility is how efficiently the fibers
shorten regardless of how long they are

• No good direct measure of contractility
• LVSWI sometimes used as clinical indicator

Carol Jacobson MN, RN www.cardionursing.com 5
Conditions That Alter Contractility
 Increase  Decrease
• Pheocromocytoma • Myocardial infarction
• Hyperthyroidism • Cardiomyopathy
• Positive inotropic drugs • Ischemia
− Dobutamine • Hypoxia
− Dopamine • Acidosis
− Levophed
• Negative inotropic drugs
− Milrinone
− Beta blockers
− Digoxin
− Ca++ blockers
− Antiarrhythmics
− Some chemo agents
− Some anesthetics, sedatives

Hemodynamic Data:
What do we need to know?
CO = HR X SV
BP = CO X SVR
TISSUE OXYGENATION
Carol Jacobson MN, RN www.cardionursing.com 6
BP = CO x SVR
 BP value does not tell you WHY the BP
is low – must evaluate determinants
of BP and treat the cause
 Low BP could be due to:
• Low CO
− HR too slow or too fast
− Preload too low or too high
− Contractility low
• Low SVR
− Vasodilation due to sepsis, drugs,
anaphylaxis
Compensatory Mechanisms
 SNS stimulation occurs immediately
when BP and CO start to fall

 SNS stimulation causes tachycardia
and peripheral vasoconstriction
A decrease in stroke volume is actually the FIRST
change to occur, but unless you are monitoring SV
you will miss it – then you have to rely on these
compensatory changes.
Carol Jacobson MN, RN www.cardionursing.com 7
Rate = 120
 Heart Rate (Tachycardia)
• Early sign of decreased CO or BP due to
compensatory SNS stimulation
• An increase in HR can keep CO and BP
normal even when SV is low (for a while!)
• Tachycardia doesn’t tell us WHY the
patient needs an increased HR

 Peripheral vasoconstriction
• The first BP change to occur when SV is
reduced is a rise in diastolic pressure
• Pulse pressure decreases (SBP-DBP)
 Blood Pressure
• Can stay stable due to compensatory
tachycardia and vasoconstriction even when
SV is low (for a while!)
• A fall in BP is a late sign of decompensation

Monitor changes in HR and diastolic BP
over time to detect problems EARLY.
Carol Jacobson MN, RN www.cardionursing.com 8
So What We Really Want to Know From
Physical Assessment & Hemodynamic
Monitoring is:
 What is the stroke volume?
 There are some noninvasive methods of
obtaining CO that can give us SV:
• Doppler
− Esophageal – primarily in OR
− Noninvasive aortic flow
• Pulse contour analysis (Vigileo, PiCCO, LiDCO)
• Bioimbedance
• Bioreactance
 These methods are not in common clinical
use in many facilities.

 Unless you are using stroke volume
monitoring technology, you must
assess the determinants of SV to get
that information:
• Preload
• Afterload
• Contractility

Pulmonary artery catheter is an invasive
way to get some of this information
Carol Jacobson MN, RN www.cardionursing.com 9
 Selected Physical Assessment Techniques
• Neck vein evaluation
• BP evaluation
• Heart sound review
 Pulmonary Artery Catheter

Using Physical Assessment to
Obtain Hemodynamic Data
Preload
 Neck Veins
• JVD is indication of elevated RV preload

 Lung Sounds
• Rales or crackles can indicate elevated LV preload
Carol Jacobson MN, RN www.cardionursing.com 10