2013 103 notes 5

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The Respiratory and Cardiovascular System

HANDOUT 1 OXYGENATION:

A. Anatomy of the Cardiovascular System

1. Heart hollow, muscular organ that lies in the mediastinum rests on the diaphragm

a. Pericardium - encases the heart.- thin membranous sac containing 20-30 ml serous fluid- protects the heart from trauma and friction

b. Heart Wall - Epicardium: thin serous outer layer- Myocardium: thick muscular middle layer- Endocardium: smooth inner layer in contact with blood

c. Heart Chambers (separated by a membranous muscular septum)- Right Atrium

low-pressure receives systemic venous blood via superior & inferior vena cava

- Right Ventricle low-pressure receives blood from RA via tricuspid valve ejects deoxygenated blood via pulmonic valve to the pulmonary artery

- Left Atrium low-pressure receives oxygenated blood from the lungs via four pulmonary veins

- Left Ventricle high-pressure receives blood from atrium via mitral valve Ejects oxygenated blood to the aorta into systemic circulation

d. Heart Valves - AV (Atrioventricular valves )

Tricuspid Valve between right atrium and ventricle Mitral valve between the left atrium and ventricle

- Semilunar valves : between ventricles and artery Pulmonic valve between right ventricle and pulmonary artery Aortic valve between left ventricle and aorta

- Papillary musles Muscle bundles on the ventricular walls Chordae Tendinae: fibrous bands extending from the papillary muscles to the

valve cusps

e. Cardiac Conduction System - propagation of electricall impulses throughout the myocardium (precursor to heart muscle contraction)

Electrical Pathways SA (Sinoatrial) Node : pacemaker

o initiating rhythmic impulss t 60-100 impulses/minute

AV (Atrioventricular) Node : o receives impulses from the SA node, relays them to the ventricles

Bundle of His: o conducts impulses from the AV node (RBB & LBB)o RBB and LBB terminate in the Purkinje fibers

of 9Ms. April Anne D. Balanon

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Purkinje Fibers: o propagate electrical impulses into the endocardium and myocardium

Electrical Impulse Activity Phases of the electrocardiogramNormal Sinus Rhythm

f. Coronary Arteries - supply the heart with blood- Right Coronary Artery supplies blood to the right heart wall- Left Main Coronary Artery supplies blood to the left heart

2. The Vasculature

a. The Circulatory System - Pulmonary Circulation

low pressure low resistance right side of the heart pumps blood into the pulmonary circulation

- Systemic Circulation high pressure high resistance left side of the heart pumps blood into the systemic circulation

b. Blood Vessels - classified according to size, location and function

1. Arteries large diameter, thick-walled vessels carry blood away from the heart

2. Arterioles small, thick-walled vessels represent the major part of vascular resistance resistance vessels serve as "circulatory stopcocks" control the distribution of blood to various organs.

3. Capillaries extremely small, extremely thin-walled vessels (one cell thick) allow exchange of gases, nutrients, and other small molecules between the blood

stream and tissues in capillary hydrostatic pressure/permeability can lead to edema.

4. Venules small thin-walled vessels bring blood back to the heart highly distensible and contain a large fraction of the blood volume

5. Veins large diameter thin-walled vessels bring blood back to heart Distensible and contain a large fraction of the blood volume.


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B. Functions of the Cardiovascular Sytem

1. Heart

a. Cardiac Output volume of blood ejected by each ventricle in 1 minute (SV x HR)

Stroke Volume : amount of blood ejected by the left ventricle with each heart beat Heart Rate : number of heartbeats per minute (60-100)

b. Cardiac Cycle


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each complete heartbeat

Systole : contraction phase Diastole : relaxation (filling phase)

c. Heart Sounds results from vibrations caused by valve closure and ventricular filling

1st Sound S1, tricuspid and mitral valve closure2nd Sound S2, aortic and pulmonic valve closure3rd Sound S3, Ventricular Gallop

Normal below 30 y/o, Pathologic in older (rapid diastole)4th Sound S4, Atrial Gallop

Resistance to diastole due to hypertrophy or injury of ventricular wall

2. Vasculature- responsible for distributing blood to various tissues of the body.

3. Neurologic Factors Regulating Heart Functiona. Sympathetic Nervous System Stimulation (norepinephrine)

arteriolar vasoconstriction HR +inotropic f/x

b. Parasympathetic Nervous System (acetylcholine) HR slowed AV conduction

c. Chemoreceptors (carotid and aortic bodies) O2/CO2 = HR

d. Baroreceptors (aortic arch, carotid sinus, vena cava, PA, atria) HR = BP changes

C. Assessment

1. Health History

a. Chief Complaint Myocardial Ischemia/Infarction

Pain (sterna, upper abdomen)


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belt-squeezing, radiating to shoulders, neck, arms

Arrythmias/Ischemia Palpitations rapid & irregular/pounding heartbeat

Peripheral Vascular Diseasse Intermittent claudication (extremity pain with exercise)

Compromised Cardiac Function Dyspnea (DOB, SOB) Orthopnea Paroxysmal Nocturnal Dyspnea

Decreased CO2 Fatigue (with or without activity)

Sudden Decrease in CO2 Syncope (with or without dizziness)

Decreased Peripheral Perfusion Diaphoresis with clamminess and cyanosis

Heart Failure Edema/Weight gain greater than 3lb in 24 hours

b. History for Risk Factors

Non-Modifiable - Age, incidence post 40 y/o- Gender, greater in men but not after menopause- Race, mortality greater for nonwhites- + Family history of Cardiovascular Disease- other illness (diabetic) Minor Factors - Personality type - Sedentary living - Stress (may contribute to the dev’t of coronary heart disease)- Oral Contraceptive UseModifiable - Smoking (2-4x greater risk to CardioVD)- High calorie, fat, cholesterol, sugar and sodium diet - High serum lipids (Hyperlipidemia), best indicator is HDL:LDL- Hypertension (esp. elevated systolic pressure)- Obesity, contributes to severity of other factors- Sedentary Lifestyle

2. Physical Assessment

a. Vital Signs - PR, CR, BP, RR

b. Inspection distress, anxiety, altered LOC skin color (pallor, cyanosis) , buccal, peripheral

neck vein distention - reflects right atrial pressure (Jugular Vein Pressure, JVD) respirations (dyspnea, orthopnea) presence of edema - fluid volume overload nail clubbing - sign of chronic hypoxia capillary filling - measure of peripheral circulation (less than 3 secs.) venous stasis or arterial ulcers , check sacrum for those on bedrest


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varicose veins

c. Palpation PMI (Located at 5th intercostal space, Left MCL)

if too low indicates enlarged heart Thrills (palpable murmur) thrusts/heaves Peripheral pulses (carotid, brachial, radial, femoral, popliteal, dorsalis pedis, anterior

tibial) check all bilateral and compare Grade 0:no puls 1+:weak 2+:normal 3+:increased 4+:bounding

temperature - check bilateral

d. Auscultation heart rate rhythm heart sounds S1 (lub) and S2 (dub) murmurs

swishing sounds in-between heart sounds (Lub-swish-Dub) pericardial friction rub

rough, grating sound from inflamed pericardial sac Bruit, murmur heard outside of the heart

(carotid, jugular, temporal, abdominal, aortic, renal and femoral arteries) take B/P in both arms, lying, sitting and standing

e. Pulse Assessment note whether regular or irregular

Regular o evenly spaced, may vary slightly with respiration

Regularly Irregular o regular pattern overall with "skipped" beats

Irregularly Irregular o chaotic, no real pattern, very difficult to measure rate accurately

Tachycardia o pulse greater than 100 beats/minute

Bradychardiao pulse less than 60 beats/minute.

∞ Tachycardia and bradycardia are not necessarily abnormal. ∞ Athletes tend to be bradycardic at rest. Tachycardia is a normal response to stress or exercise.

f. BP Assessment inflate the cuff to 30 mmHg above the estimated systolic pressure, release

slowly. don’t use too small a cuff. The pressure will be 10, 20, even 50 mmHg too high

Maximum Cuff Pressure - When the baseline is known or hypertension is not suspected, it is acceptable in adults to inflate to 200 mmHg

be aware that there could be an ausculatory gap (a silent interval between the true systolic and diastolic pressures).

g. Perform Respiratory Assessment- cough, crackles, wheezing, hemoptysis, cheyne-stokes respiration

h. perform Abdominal Assessment- note liver enlargement /ascites, bladder distention, bruits just above the

umbilicus

3. Laboratory and Diagnostic Testsa. WBC count


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b. Lipid Profile cholesterol:LDL, HDL, trigylceridesc. Cardiac Enzymes (creatinine phosphokinase, troponin, lactate dehdrogenase)d. Blood Coagulation prothrombin, partial thromboplasitne. Chest radiograph heart sizef. ECG heart’s electrical activityg. Holter Montoring 24-hour ECGh. Exercise ECG ECG with physical stressi. Echocardiography cardiac (valvular) structures and fuctionj. Radionuclide Testing ventricular function, myocardial bloodflowk. Cardiac Catheterization chamber pressures and O2 saturationl. Arteriography coronary arteries (visualization)m. Ventriculography ventricles (visualization)n. Central Venous Pressure filling pressure of right ventricle, cardiac functiono. Pulmonary Artery Pressure left heart pressures Pulmonary Artery Wedge Pressurep. Arterial Line peripheral arterial pressures

D. Health Promotion

1. Modifying Risk Factors

2. Preventing Venous Stasisa. Leg Exercises

- for those with impaired mobility (bed-ridden)- contraction of muscles promote blood back to the heart

b. Application of Antiembolism Stockings- provide varying degrees of compression on different areas of the leg- exert external pressure decreasing venous blood from pooling in the

extremities- MUST fit properly, and be applied in the morning before client has gotten out of

bedc. Use of Pneumatic Compression Devices (intermittent or sequential)d. Avoiding Constriction

- garters, socks with elastic bands, orthopedic casts, leg-crossing

3. Edema Reductiona. Elevation of Limbs-no pressure on pointsb. Diet Teaching-restrict fat consumption ( 30% of daily caloric intake), limit salt intakec. Fluid Restriction-until balance is restored, monitor I&O

fluid retention=If greater than 2L wt gain > 1kg/day


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4. Positioning- lying flat promotes venous return

(heart works harder in the supine than in the upright position) - gravity enhances arterial flow- hyotensive: elevate legs 20 to 30 degrees

5. Pain Managementa. Chest Pain

stop all activity, rest, sit comfortably, avoid lying flat, administer O2, nitroglycerine SL, assess BP & PR

b. Claudication, Peripheral Ischemic Pain not life-threatening but crippling; avoid cold, cigarette smoking

6. Increased Activity & Energy Conservation gradual and progressive refrain using the Valsalva maneuver have constant rest periods space activities

7. Client Teaching recognition of warning signs:

perfusion promotion of blood flow & skin integrity avoidance of fatigue

8. Medications explain tx regimen to client and SO, provide written information

9. CPR

E. Nursing Diagnoses

1. Decreased Cardiac Output inadequate blood pumped by the heart to meet metabolic demands of the body (active or high

risk)

2. Ineffective Tissue Perfusion (Renal, Cerebral, Cardiopulmonary, Gastrointestinal, Peripheral)

decrease in oxygen resulting in failure to nourish the tissues at the capillary level

3. Activity Intolerance insufficient physiologic or psychological energy to endure or complete required or desired daily

activity

F. Overview of Cardiovascular Alterations1. Arrhythmias (Dysrhythmia)

any sinus rhythm deviating from normal2. Coronary Artery Disease

focal narrowing of large and medium-sized coronary arteries due to plaque formation3. Myocardial Infarction

destruction of myocardial tissue in heart regions abruptly deprived of blood supply (due to coronary blood flow)

4. Heart Failure (left sided or left ventricular & right-sided or right ventricular syndrome of pulmonary or systemic circulatory congestion caused by myocardial contractility ( CO2 to meet oxygen requirements of tissues

5. Acute Pulmonary Edema rapid fluid accumulation in the extravascular lung spaces (alveoli and interstitial)

6. Cardiac Arrest sudden, unexpected cessation of the heart’s pumping action and effecting circulation


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7. Endocarditis infection of the endocarium or heart valves due to bacteria/organsm invation (acute, subacute, chronic)

8. Pericarditis inflammation of pericardium (acute, chronic)

9. Pacemaker Implantation temporary or permanent electronic device to replace function of SA node pacer is in direct contact of the heart muscle wall, battery operated

10. Hemorrhage loss of a large amount of blood during a short period (internal, external, arterial, venous, capillary)

11. Valvular Disorders of the Heart stenosis (narrowing of the valve opening) regurgitation/insufficiency (failure of valve to close completely)


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2013 103 notes 5

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Transcript of 2013 103 notes 5