Transcript Oxygen Needs Interference with O2 Transport

Oxygen Needs
Interference
with
O2 Transport
Case Study
Oxygen Needs
Interference with O2 Transport
Coronary Artery Disease
Complications
Dysrhythmias
Pulmonary Embolism
Hypertension
Complication
Congestive Heart Failure
Peripheral Vascular / Arterial Disease
Oxygen Needs
Interference with O2 Transport
 Care
of Patients with:
Coronary Artery Disease
Risk Factors
Myocardial Infarction
Alterations in:
Rate & Rhythm (Cardiac Conduction)
Effect on Cardiac Output
Content Approach
 Anatomy
& Physiology Review
 Demographics/occurrence
 Pathophysiology
 Clinical Manifestation
 Medical / Surgical Management
 Nursing Process (APIE)
 Assessment - Nursing Actions - Education
Anatomy & Physiology
 Right
Heart
 Left Heart
 Systole
Valve Closure:
 Diastole
Valve Closure:
Cardiac Circulation
Myocardium
Anterior
Posterior
Cardiac Cycle
1.
2.
3.
4.
5.
Passive Filling – preload
Atrial contraction – Aortic & Pulmonic
semilunar valves close – S2
Isovolumetric ventricular contraction – all
valves closed
Ejection – ventricular systole – Mitral &
Tricuspid valves close – S1 - afterload
Isovolumetric ventricular relaxation – all valves
closed
Cardiac Cycle Phases
Heart Sounds & Stethoscope
Placement
Coronary Arterial System
Physiology: Oxygen Supply
to the Cardiac Muscle during
the Cardiac Cycle

Coronary artery oxygen deficit
during ventricular contraction & ejection (systole)

Coronary artery filling
during ventricular filling (diastole)
What is the impact of heart rate on coronary
artery filling?
Oxygen Supply to the Cardiac
Muscle during the Cardiac Cycle

The actual time available for diastole shortens significantly as the
heart rate increase
% of a Minute
70%
50%
33%

Heart Rate
60
120
188
Results: Less time for ventricular filling & coronary artery filling +
as HR increases, increased oxygen is needed each minute to eject
the same volume of blood.
Stroke volume: volume ejected in one heart beat
Cardiac Output: volume ejected in one minute
Cardiac Output = Stroke Volume x Heart Rate
Factors
Determining Myocardial Oxygen
Needs

Decreased Oxygen Supply:
 Noncardiac: Anemia, hypoxemia, pneumonia, asthma, COPD, low
blood volume
 Cardiac: Arrhythmias/dysrhythmias, congestive heart failure (CHF),
coronary artery spasm, coronary artery thrombosis, valve disorders

Increased Oxygen Demand or Consumption:
 Noncardiac: anxiety, cocaine use, hypertension, hyperthermia,
hyperthyroidism, physical exertion
 Cardiac: aortic stenosis, arrhythmias, cardiomyopathy, hypertension,
tachycardia
CAD - Demographics
CAD - Demographics
Comparison of death by CV Disease
and Breast Cancer – by Women’s Age
400
300
Cardiovascular
Disease
Breast Cancer
200
100
0
35-54
55-74
>=75
Coronary Artery Disease (CAD)
Pathophysiology
ASHD, IHD, CVHD = CAD
AHA
1.1 mil Americans will have an MI in 2003
460,000 will die
About half of those deaths occur within 1 hour of the
start of symptoms and before the person reaches the
hospital.
Major cause: Atherosclerosis—focal deposit of
cholesterol & lipids
CAD – Risk Factors

Unmodifiable: Age, Gender, Ethnicity, Genetic
predisposition/family history

Modifiable Major: Dyslipidemia--Elevated serum
lipids*, hypertension*, cigarette smoking,
obesity—visceral/central obesity

Modifiable Contributing: Diabetes Mellitus*,
stressful lifestyle
* may have genetic predisposition
CAD – Risk Factors

Metabolic Syndrome:
–
–
–
–
–
–
Insulin Resistance
Hyperglycemia >110mg/dL
Hypertension - > 130/85
Increased triglycerides >110mg/dL
Decrease HDL <40 men; < 50 women
Central Obesity
 men: waist > 40” women: waist > 35”
Risk Factors
One of the Major Modifiable
Physical Inactivity
Types of Plasma Lipoproteins

HDL –
 Contain more protein and less lipid
 Carry lipids away from arteries to liver for metabolism
 This process prevents lipid accumulation within arterial walls
 Higher levels are desirable

LDL –
 Contain more lipids than any other lipoproteins
 Affinity for arterial walls
 Increased levels correlate closely with an increased
incidence of atherosclerosis
 Lower levels are desirable

VLDL
 Contain of triglycerides
 Correlation with heart disease is uncertain
Plasma Lipoproteins
Atherosclerosis

Elevated serum lipids
Cholesterol > 200mg/dl
Triglyceride > 200mg/dl
HDL
< 35 mg/dl – major risk
45-59 mg/dl – average risk
> 60 mg/dl – negative risk
LDL
< 130 – desirable
130 – 159 mg/dl – borderline risk
> 160 mg/dl – high risk
Progressive Atherosclerosis
Drug Therapy for Dyslipidemia

Bile Acid Sequestrants (Questran) - Binds with bile salts

Niacin - Inhibits synthesis of VLDL & LDL

Fibric Acid Derivatives (Atromid)– Decrease VLDL

HMG CoA Reductase Inhibitors (Statins - Lipitor,
Pravachol, Zocor) – Block synthesis of cholesterol

Cholesterol Absorption Inhibitor (Zetia)– Inhibits
intestinal absorption of cholesterol
Natural Lipid Lowering Agents
Niacin - < LDL levels
 Omega-3 fatty acids – fish/flaxseed oil <Triglycerides & > HDL levels
 Milk thistle – Silymarin - > HDL levels
 Fiber - < Cholesterol
 Phytosterols - < Cholesterol
 Soy - < Cholesterol absorption from GI tract
 CoEnzyme Q10 – HMG CoA reductase inhibitors
– natural statins

Coronary Thrombogenesis
During an Acute Coronary
Syndrome
Angina
Clinical Manifestations
Angina – Chest Pain

Stable Angina Pectoris – intermittent, same pattern of onset,
duration, intensity of symptoms - 3-5 mins.

Silent Ischemia – 80% of patients with ischemia are asymptomatic

Prinzmetal’s Angina – variant – not precipitated by physical activity
– may be due to spasm

Nocturnal Angina – occurs at night but not necessarily during sleep
or in recumbent position

Angina Decubitis – recumbent position – relieved by standing

Unstable Angina – Unpredictable or may evolve from stable angina
– increasing frequency, duration, intensity
CAD
Clinical Manifestation – Diagnostics

History & Physical Examination

EKG / Echocardiogram / Stress Echocardiogram

Thallium Stress Test (perfusion scanning) cold spots where tissue is
inadequately perfused cardiac tissue

CAT scan- calcium score/CT coronary angiogram

MUGA (Multiple gated radioisotope scan) – left ventricular function

MRI of the heart

PET (Positron emission computed tomography) – evaluate coronary
artery patency
Normal Thallium Stress Test
Abnormal Thallium-Stress Test
CAD - Clinical Manifestation
Invasive Diagnostics

Cardiac Catheterization
Right sided:
 Catheter through the femoral vein through the vena cava into
right atrium and right ventricle – pulmonary artery – wedge
pressure
Left sided:
 Catheter through the femoral artery through the aorta into the
left atrium and left ventricle / openings of the coronary arteries
 Coronary arteriography: Injected dye with video & x-rays
CAD - Clinical Manifestation
Invasive Diagnostics
Cardiac Catheterization
Potential Complications
Catheter looping/breaking, dysrhythmias, allergic
reaction to contrast medium, arterial thrombosis,
myocardial infarction, hemorrhage, infection.
Patient Preparation
Informed consent; allergies – shellfish/iodine;
NPO x 6 hrs; explanation “flushed/tingling”; supine
– absolutely still
Postprocedure Care
Right Heart Catherization
Left Heart Catheterization
Coronary Angiography
Coronary Blockage - LAD
Cardiac Catheterization
Post Procedure Care

Assess:






VS q15 mins. x 2 hrs; q30 min x 2 hrs
Monitor cardiac rate and rhythm
Check site for bleeding
Extremity: Peripheral pulse check, temperature, color, sensation, mobility
Assess for chest pain, dizziness, dyspnea
Nursing Action:
 Straight at groin x 24 hours; pressure at site x 30 mins.
 Maintain IV KVO for 2 hrs; IV capped x 2 hrs; then d/c
 Encourage oral fluids

Patient/Family Education:




Rationale for all nursing actions
No squatting, sitting, lifting for 24 – 48 hours++
Report bleeding, swelling, discoloration, drainage
Change dressing after 24 hours – small dressing to bandaid
Clinical Manifestation
Myocardial Infarction
Lab Diagnostics

Cardiac Protein – Troponin T
More sensitive than CK
Elevates 3 hr – peak 24-48 hrs; normal 5-14 days

Cardiac Enzyme – Creatine kinase (CK-MB)
Released when cardiac cells die
Elevates 3 hrs – peak 12-24 hrs; normal 2-3 days

Cardiac Marker - Myoglobin
First to elevate
Lacks cardiac specificity
Normal range within 24 hours
Serum Cardiac Markers after MI
CAD – Angina Relationship
Coronary Artery Disease
/
\
Stable Angina Acute coronary syndrome
/
/
\
Unstable Angina > Myocardial Infarction
ST-elevated MI
Non-ST-elevated MI
CAD & Acute Coronary Syndrome
Heart With Muscle Damage and a
Blocked Artery
Myocardial Infarction
Myocardial Infarction
Acute Coronary Syndrome

Location correlates with coronary circulation
involved
Inferior Wall – Right coronary artery
Anterior Wall – Left anterior descending
Lateral, posterior or inferior – left circumflex

Healing Process
Within 24 hours – leukocytes & enzymes
Third day – collateral circulation developing
10-14 days – scar tissue is still weak
Vulnerable time – unstable state of healing + increased
activity
6 weeks – scar tissue replaces necrotic tissue
Normal myocardial tissue may compensate – ventricular
remodeling – can cause late congestive heart failure
Coronary Artery
Collateral Circulation
Angina
Medical Management

A
Aspirin / Antianginal therapy / ACE Inhibitor

B b-Adrenergic blocker / blood pressure

C

D Diet / Diabetes

E Education / Exercise
Cigarette smoking / Cholesterol
Angina- MI
Medical Management

B-Adrenergic Blockers – decreases rate, contractility,
afterload

Nitrates – peripheral vasodilation decreasing preload and
afterload / coronary artery vasodilation

Calcium Channel Blockers – Coronary & peripheral
vasodilation, decreases AV conduction and myocardial
contractility

Morphine – analgesic – reduces preload & myocardial
oxygen consumption

Angiotensin-Converting Enzyme Inhibitors – Vasotec /
Capoten - prevents Angiotensin I conversion to Angiotensin
II – HTN, CHF
Antiplatelet and Anticoagulant Agents in
unstable angina and NSTEMI
Oral anti-platelet agent
 Aspirin Initially 300 mg p.o. then 75 - 150 mg daily


Clopidogrel (Plavix) Initial loading dose of 300 mg then 75 mg daily
• Increased bleeding risk
Heparins
Heparin Sodium: Bolus: 60 U/kg IV bolus to a maximum of 4,000 units
Drip: 12 units/kg/h infusion to a maximum of 1 000 units/h
• Monitor PTT: keep at 50 - 70 seconds

Low-molecular-weight heparin - Enoxaparin 1 mg/kg subcut q12 hr
Precautions: • Peptic ulceration • Aspirin allergy • GI bleeding
Antiplatelet Drugs
used in unstable angina and NSTEMI
 Intravenous
– tirofiban (Aggrastat), eptifibatide (Integrilin)
 New class, GP IIb/IIIa inhibitors
– Abciximab (ReoPro) 0.25 mg/kg IV bolus 10 - 60 min
before PCI, than 10 μg/min IV - Infusion for 12 h
Precautions:
• Thrombocytopenia • Bleeding disorder • Surgery < 6 weeks
• Abnormal bleed < 30 d • Active GI ulceration
• Puncture of a non-compressible • Prior stroke, organic CNS pathology
• Any systolic BP > 180 mmHg during the acute event
Thrombolytic Drugs
Drugs that break down, or lyse, preformed clots

Tissue plasminogen activator
– plasminogen-streptokinase activator complex
(APSAC)
– streptokinase (Streptase)
– alteplase (t-PA, Activase)
– reteplase (Retavase)
Angina - MI
Invasive Medical Management

Percutaneous Coronary Intervention –
PCTA – Percutaneous transluminal
coronary angioplasty
Balloon-tipped catheter passed through just beyond
the lesion – balloon inflated – atherosclerotic plaque
is compressed
Reduction in lesion size by >50% in 90% of patients
Used in conjunction with thrombin inhibitors
Angina- MI
Invasive Medical Management

Stent Placement – may be placed during PCTA
– expandable meshlike structures to maintain
vessel patency – placed over the angioplasty site
to hold the vessel open
* Stents are thrombogenic –
IV antiplatelet agents
ASA/Plavix

Atherectomy – plaque is shaved away from
the coronary artery wall
Limited to use in larger portions of vessels

Laser Angioplasty – “cool” laser – no heat
Coronary Artery Stent Placement
Coronary Atherectomy
Angina - MI
Invasive Medical Management
 Complications
Abrupt closure of angioplasty site
 Stent thrombosis / embolization
Hemorrhage / vascular damage
Coronary spasm, Acute MI
Need for emergent coronary artery bypass
graft (CABG)
Fibrinolytic Contraindications

Absolute Contraindications
Active internal bleeding, active inflammatory bowel
disease, active peptic ulcer disease, acute pericarditis,
GI/GU bleeding within 6 months, Hx of hemorrhage
CVA, Neurosurgical procedure within 2 months,
Pregnancy, Suspected aortic dissection, Uncontrolled
HTN, >180/110

Relative Contraindications
Bacterial endocarditis, chronic Coumadin Therapy,
Diabetic hemorrhagic retinopathy, Poorly controlled
HTN
Angina - MI
Surgical Management
Coronary Artery Bypass Graft
(CABG)
construction of new vessels between the aorta to
beyond the obstructed coronary artery
(or arteries)
Saphenous vein or internal mammary artery
Palliative treatment for CAD – not a cure
Postoperative care: Care of cardiac patient with chest
tubes / sternotomy; pain management; short
ventilator support; early ambulation; 4-5 day hospital
stay
Coronary Artery Bypass
Coronary Artery Bypass
Complications of MI







Arrhythmias – lethal PVC’s within 4 hours of onset of
chest pain
Congestive Heart Failure
Cardiogenic Shock – severe left ventricular failure –
intra-aortic balloon pump & vasoactive medications
Papillary Muscle Dysfunction – Mitral valve
regurgitation – treat dyspnea, pulmonary edema &
decreased CO
Ventricular Aneurysm Pericarditis – 1-3 days post MI;
pleural friction rub & fever
Dressler Syndrome – pericarditis with effusion & fever
1- 4 wks post MI; elevated WBC & Sed Rate. Tx-Steroids
Pulmonary Embolism
Acute Coronary Syndrome
Pair Share





Discomfort or a heavy feeling in the chest can signal a heart attack.
A. True
B. False
Women do not frequently experience heart attacks.
A. True
B. False
African-American women die of heart attacks at the same rate as white women.
A. True
B. False
Some people who are experiencing the symptoms of a heart attack may wait
hours or even days before seeking needed medical care.
A. True
B. False
Being treated within about an hour of the first symptoms can make a significant
difference.
A. True
B. False
Acute Coronary Syndrome
Pair Share
Many heart attack victims say their heart attack wasn’t what they’d expected.
A. True
B. False
 A family member, such as a spouse, can persuade a loved one having a heart
attack to seek help immediately.
A. True
B. False
 Calling 9-1-1 for chest pain alone would probably turn out to be a waste of the
emergency medical personnel’s time.
A. True
B. False
 Most heart attacks occur in people over 65.
A. True
B. False
The major issue in delay is how long it takes for emergency medical personnel to
find the address and deliver the patient to the hospital.
A. True
B. False

Nursing Diagnoses
TOP 4
?????
Nursing Process
Nsg Dx: Acute Pain related to
Cardiac Ischemia

Assess: Chest pain—intensity, location,
duration, precipitating, alleviating factors;
Monitor cardiac rate & rhythm; effect of pain
medication; peripheral pulses; VS; Pulse
Oximetry

Nsg Action: Administer O2 NC; IV access;
position of comfort

Patient Education: Rationale for all
procedures; pain scale; instruct to report pain
Nsg Dx: Ineffective Tissue
Perfusion related to Myocardial
Injury

Assess: VS & Pulse Oximetry qh; continuous
cardiac monitoring; respiratory status if
Morphine IV is used; fluid balance – strict I&O
peripheral edema; heart & breath sounds

Nsg Action: Rest periods; Administer meds &
oxygen as ordered

Patient Education: Rationale for rest; energy
conservation
Nsg Dx: Anxiety related to
perceived or actual threat of death
 Assess:
verbal & nonverbal queues
 Nsg
Action: Calm, reassuring approach;
encourage verbalization of feelings, fears,
perceptions; family involvement;
 Patient
Education: Relaxation
techniques; simple instructions
Nsg Dx: Ineffective therapeutic
regimen management related to
lack of knowledge

Assess: Current knowledge level & readiness to
learn; family dynamics

Nsg Action: Assist pt in identifying small
successes; Assist pt is identifying lifestyle that
needs to be changed; Community referrals—
smoking cessation, cardiac rehab, support
groups,

Patient Education: Lifestyle changes,
Medications—desired effect/side effects;
comprehensive discharge plan—continuity with
community cardiac rehabilitation
Nsg Dx: Activity Intolerance
related to fatigue & chest pain

Assess: Monitor patient’s response to
medications, activity tolerance as increased;
Cardiac rate, rhythm, respiratory effort

Nsg Action: Include family; advance activity as
tolerated; supplement oxygen as needed

Patient Education: Teach patient energy
conservation – activity/rest – activities that will
promote independence and decrease oxygen
consumption; Cardiac Rehab: exercise & sexual
activity
Patient Education: Exercise
Guidelines post MI

Type of Exercise – regular, rhythmic & repetitive –
using large muscle groups

Intensity – determined by patient’s HR – should not
exceed 20 beats per min > resting HR

Duration – Build to 20 -30 mins

Frequency -- 3-4x/week

Warm-up/Cool-down – 5 mins before and after
aerobic exercise. Exercise should not be stopped
abruptly
Cardiac Rehab – Metabolic
Equivalents of Energy Expenditure
Patient Education:
Sexual Activity post MI

Plan of resumption of sexual activity should correspond to activity prior to MI

Physical training improves physical response to coitus

Food & alcohol < prior to sexual activity

Familiar & relaxed surroundings; positions of comfort

Avoid hot or cold showers

Foreplay is desirable – gradual increase in heart rate prior to orgasm

Prophylactic use of nitrates decreases angina

Orogenital sex places no undue strain on the heart

Anal intercourse may cause undue cardiac stress – vasovagal response
Emotional & Behavioral Response
to Acute MI

Denial – Ignores symptoms; minimizes severity; ignores activity
restrictions

Anger – “Why did this happen to me?”

Anxiety & Fear – Fear of death & disability –apprehension,
tachycardia, restlessness, hypochondria, projection of feelings

Dependency – reliant on staff; hesitant to leave ICU or hospital

Depression – Mourning period; realizes seriousness of situation

Realistic Acceptance – Focuses on optimum rehabilitation; plans
changes compatible with cardiac function