Perfusion – Flashcard

The flow of blood through the arteries and capillaries delivering nutrients and oxygen to cells and removing cellular waste products

Central and Tissue Perfusion

(Mechanism for blood delivery) -Generated by cardiac output (amount of blood pumped by the heart per minute) -Propels blood to various organs and tissues from patent arteries through capillaries and returns blood to the heart through patent veins -Clinical manifestations systemic (entire body is affected) when central perfusion impaired

-Volume of blood that flows through targeted tissues -Blood flows from arteries to capillaries, which are surrounded by smooth muscles. The force of ventricular contractions creates capillary hydrostatic pressure, which pushes blood through capillaries into the interstitial spaces to effectively deliver fluid, oxygen, and nutrients to various cells in the body.

unoxygenated blood through the pulmonary circulation

oxygenated blood through the systemic circulation

carry highly deoxygenated blood whereas pulmonary veins carry highly oxygenated blood.

From SA node → AV node → Bundle of His and Purkinje fibers → which causes ventricles to contract

pressure develops and closes the tricuspid and mitral valves, which prevents the backflow of blood into the atria. then the ventricular pressure results in ejection of blood into the aorta (from the left ventricle) and pulmonary arteries (from the right ventricle).

-higher than the pressure in the ventricles, blood moves from the atria to the ventricles. -The higher atrial pressures open the tricuspid and mitral valves, allowing the ventricles to fill up with blood (diastole). -Pressure from myocardial contractions supply blood to the peripheral vascular system.

provide blood to and from various tissues in the body.

that decreases blood flow to the myocardium may result in a myocardial infarction, reducing cardiac output.

is unable to pump effectively (cardiogenic shock), too much fluid is lost (hypovolemic shock), or systemic vasodilation occurs (anaphylactic, neurogenic, or septic shock) and central perfusion is unable to supply blood to peripheral tissues.

Impairment of central perfusion occurs when cardiac output is inadequate. Reduced cardiac output results in a reduction of oxygenated blood reaching the body tissues (systemic effect). If severe, associated with shock If untreated, leads to ischemia and infarction

Antihypertensives Antiarrhythmics Inotropics Antianginal agents Vasopressors Vasodilators

Impairment of tissue perfusion is associated with loss of vessel patency or permeability, or inadequate central perfusion Results in impaired blood flow to the affected body tissue (localized effect) Leads to ischemia and, ultimately, infarction if uncorrected

Anticoagulants Thrombolytics Lipid-lowering agents Vasodilators Antiplatelet agents and platelet inhibitors

Pacemaker insertion Electrical cardioversion Ablation therapy Intraaortic balloon pump Cardiac valve surgery Cardiac transplant

Bypass and/or graft surgery Stent or angioplasty Endarterectomy

-Perfusion assessment involves recognizing indicators of adequate and inadequate perfusion. -Central perfusion is noted by assessing heart rate and blood pressure. -Cerebral tissue perfusion is indicated by the patient's mental status (orientation to person, place, time, and situation); expected bilateral movement and sensation; clear speech, presence of carotid pulses; and absence of carotid bruit. -Peripheral tissue perfusion is evident when the patient's extremities are warm and appropriate color for race, and the dorsalis pedis and radial pulse rates are within normal limits (60-100 beats per minute) with regular rhythm, easily palpable, etc. Sufficient peripheral tissue perfusion also evident when capillary refill time is < 2 seconds. -Patients' self-report of adequate perfusion indicated by the presence of warm hands and feet in addition to the absence of continuous pain in fingers/toes/legs while walking. -When performing a health history, nurses should ask patients to describe and follow-up with any of the following symptoms: Pain Dyspnea Edema (swelling) Dizziness or fainting

Smoking (nicotine vasoconstricts) Elevated serum lipids (contributes to atherosclerosis) Sedentary lifestyle (contributes to obesity) Obesity (increases risk for Type 2 diabetes and atherosclerosis) Diabetes mellitus* (increases risk of atherosclerosis) Hypertension (increases work of myocardium)

Age (increases with age) Gender: men > women Family history Race

Cardiac Dysrhythmias Shock Heart failure Pulmonary hypertension Cardiac Dysrhythmias (e.g., atrial fibrillation, ventricular fibrillation) Valvular Heart Disease (e.g., aortic stenosis) Congenital Defects (e.g., ventricular septal defect) Shock: o Anaphylactic shock o Cardiogenic shock o Hemorrhagic shock o Neurogenic shock o Septic shock Other Conditions Associated with Central Perfusion include cardiomyopathy, endocarditis, heart failure, and pulmonary hypertension

Atherosclerosis Hyperlipidemia Hypertension Peripheral artery disease Pulmonary embolism Stroke Venous thrombosis

Laboratory tests Creatine kinase, lactic dehydrogenase, natriuretic peptides, troponin, homocysteine, C-reactive protein, serum lipids, platelets, prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR) Electrocardiogram (EKG) Cardiac stress tests Exercise or pharmacologic test Radiographic studies Chest x-ray, ultrasound, arteriogram

-Management dependent on the specific condition, but we will focus on some common interventions implemented in the treatment of conditions related to impaired perfusion. -Clinical management involves prevention of illness, early detection, and appropriate management of cardiovascular problems. -Primary prevention measures based on a heart-healthy lifestyle (e.g., eating a healthy diet, getting regular exercise, not smoking). See Box 15-2 below. -Secondary prevention focuses on screening (e.g., monitoring blood pressure and serum lipids), early diagnosis, and prompt treatment of any existing health problems, Collaborative Interventions: Nutrition Therapy Activity, Exercise, and Positioning Smoking Cessation Pharmacotherapy (e.g., vasodilators, vasopressors, diuretics, antidysrhythmics, anticoagulants, antiplatelet agents, thrombolytics, and lipid-lowering agents)

a.Reduce sodium (salt) intake to less than 1500 mg a day. b.Reduce saturated and trans fats to less than 10% of calories.

a.Adults >20 yrs: at least 150 minutes/week of moderate intensity activity b.Children 12-19 yrs: at least 60 minutes of moderate intensity activity every day

Refrain from smoking and have no exposure to environmental tobacco smoke.

a. Adults over 20 years of age: <120/80 mm Hg b. Children 8 to 19 years of age: <90th percentile

a. Adults >20 years of age <200 mg/dL b. Children 6-19 years of age <70 mg/dL

a. Adults >20 years of age: less than 100 mg/dL b. Children 12 to 19 years of age: less than 200 mg/dL

a. Adults >20 years of age: 25 kg/m2. b. Children 12-19 years of age: <85th percentile

Caused by decreased intravascular volume. There is reduced venous blood return to the heart, and ventricular filling decreases. Therefore, stroke volume, cardiac output, and blood pressure drops. Affects all body systems. If fluid loss is <500 mL, sympathetic response activation is generally sufficient to restore cardiac output and blood pressure to near normal (although pulse may still be elevated). If blood volume loss is sustained (1000 mL or more), shock progresses-heart rate and vasoconstriction increases; blood flow to the skin, kidneys, skeletal muscles, and abdominal organs decrease. Ultimately, the amount of blood flow is inadequate to oxygenate cells effectively and sustain cellular energy. Consequently, cellular anaerobic metabolism begins to occur, resulting in loss of physical integrity of cells. May cause multiple organ failure (and even death) if left untreated.

Emergency care measures Fluid resuscitation (e.g., intravenous fluids or blood) Oxygen therapy •Establishing and maintaining a patent airway and ensuring adequate oxygenation is critical Medications •Vasoactive drugs (cause vasoconstriction or vasodilation) and inotropic drugs (improve cardiac contractibility) may be administered when fluid replacement alone is not enough Patient should be positioned with the lower extremities elevated approximately 20 degrees, trunk horizontal, and the head elevated about 10 degrees (LeMone et al., 2011) Monitoring fluid status is essential in preventing shock, which includes daily assessment of weight, fluid intake, measurable fluid loss, and fluid loss that must be estimated (e.g., wound drainage).

Fluids, plasma expanders (albumin or synthetic), blood if appropriate Vasoconstrictors Epinephrine (Adrenaline) Norepinephrine (Levophen) Metaraminol (Aramine) Vasopressin (Pitressin) Inotropes Dopamine (Inotropin) Dobutamine (Dobutrex) Isoproterenol (Isuprel) Vasodilators (only in some forms of cardiogenic shock) Amniron (Inocor) Nitroglycerine (Tridil) Nitroprusside (Nipride)

Systolic blood pressure of 140 mmHg or higher, or diastolic blood pressure of 90 mmHg or higher based on the average of three or more readings taken on separate occasions (NHLBI, 2004). Exceptions to this include people being treated for hypertension and an initial reading of a systolic pressure of 210 mmHg or higher and/or a diastolic blood pressure of 120 mmHg or higher.

Systolic BP: 120 to 139 mm Hg OR Diastolic BP: 80 to 89 mm Hg

Persistently elevated systemic blood pressure with no identified cause

Elevated blood pressure resulting from an identifiable cause Common identifiable causes include kidney disease, renovascular disease (decreased blood flow to the kidneys), disorders of the adrenal cortex, pheochromocytoma, coarctation of the aorta, and sleep apnea.

High sodium intake Low potassium, calcium, and magnesium intake Obesity Excess alcohol consumption (regular consumption of 3 or more drinks a day) Insulin resistance Physical and emotional stress

Genetic factors Family history Age (incidence of hypertension goes up with increasing age) Race

Cardiac Coronary artery disease LV hypertrophy Cerebrovascular TIA, Stroke Peripheral Vascular Disease Renal Chronic renal failure Watch for increasing creatinine levels Retinopathy

"Silent killer" Symptoms of severe hypertension Fatigue Dizziness Palpitations Angina Dyspnea

•Occurs when the systolic pressure > 180 mmHg and the diastolic pressure > 120 mmHg. •Immediate treatment (within 1 hour) is critical to prevent renal, cardiac, and vascular damage, and reduce mortality and morbidity. •Usually occurs when patients suddenly stop taking their blood pressure medications or their hypertension is poorly controlled •Goal is to decrease blood pressure by no more than 25% within minutes to 1 hour, then toward 160/100 within 2-6 hours •Nursing care focuses on continuous monitoring of the blood pressure (every 5-30 minutes) and titrating drugs as ordered (e.g., vasodilator sodium nitroprusside) to decrease patient's blood pressure.

o Rapid onset o Blurred vision, papilledema o SBP >180 mmHg o DBP >120 mmHg o Headache o Confusion o Motor and sensory deficits

Decrease SBP < 140 mmHg and DBP < 90 mmHg diastolic Initial treatment consists of lifestyle modifications Lifestyle Modifications Include: Maintaining normal body weight; lose weight if overweight Dietary changes (e.g., DASH diet) Limit alcohol Engage in regular aerobic exercise Stop smoking Stress reduction

Weight Reduction Overweight persons have an increased incidence of hypertension and increased risk for CVD. Weight reduction has a significant effect on lowering BP in many people, and the effect is seen with even moderate weight loss. A weight loss of 22 lb (10 kg) may decrease SBP by approximately 5 to 20 mm Hg. When a person decreases caloric intake, sodium and fat intake are usually also reduced. Although reducing the fat content of the diet has not been shown to produce sustained benefits in BP control, it may slow the progress of atherosclerosis and reduce overall CVD risk. Weight reduction through a combination of calorie restriction and moderate physical activity is recommended for overweight patients with hypertension. DASH Eating Plan The DASH eating plan emphasizes fruits, vegetables, fat-free or low-fat milk and milk products, whole grains, fish, poultry, beans, seeds, and nuts. Compared with the typical American diet, the plan contains less red meat, salt, sweets, added sugars, and sugar-containing beverages. The DASH eating plan significantly lowers BP and these decreases compare with those achieved with BP-lowering drug. Additional benefits also include lowering of low-density lipoprotein (LDL) cholesterol.

Grains-7 to 8 servings per day Vegetables-4 to 5 servings per day Fruits-4 to 5 servings per day Nonfat/low-fat dairy products-2 to 3 serving per day Meats, poultry, and fish-2 or less 3 oz servings per day Nuts, seeds, and dry beans-4 to 5 serving per week Fats and oils-2 to 3 serving per day Sweets-5 servings per week

Physical Activity A physically active lifestyle is essential to promote and maintain good health. The AHA and American College of Sports Medicine recommend that adults perform moderate-intensity aerobic physical activity for at least 30 minutes most days (i.e., more than 5) per week or vigorous-intensity aerobic activity for at least 20 minutes, 3 days a week. The 30-minute goal can be accomplished by performing shorter periods of exercise that last at least 10 minutes or more. Additionally, combinations of moderate and vigorous activity are acceptable (e.g., walking briskly for 30 minutes on 2 days of the week and jogging for 20 minutes on 2 other days). For adults age 18 to 65, walking briskly at a pace that noticeably increases the pulse defines moderate-intensity aerobic activity. Jogging at a pace that substantially increases the pulse and causes rapid breathing is an example of vigorous activity for this age group. All adults should perform muscle-strengthening activities using the major muscles of the body at least twice a week. This helps to maintain or increase muscle strength and endurance. Additionally, flexibility and balance exercises are recommended at least twice a week for older adults, especially for those at risk for falls. Generally, physical activity is more likely to be done if it is safe and enjoyable, fits easily into one's daily schedule, and is inexpensive.

Avoidance of Tobacco Products Nicotine contained in tobacco causes vasoconstriction and increases BP, especially in people with hypertension. Smoking tobacco is also a major risk factor for CVD. The cardiovascular benefits of stopping tobacco use are seen within 1 year in all age groups. Strongly encourage everyone, especially patients with hypertension, to avoid tobacco use. Advise those who continue to use tobacco products to monitor their BP during use. Management of Psychosocial Risk Factors Psychosocial risk factors can contribute to the risk of developing CVD and to a poorer prognosis and clinical course in patients with CVD. These risk factors include low socioeconomic status, social isolation and lack of support, stress at work and in family life, and negative emotions such as depression and hostility. Frequently, these risk factors are clustered together. For example, there tends to be higher rates of depression in individuals who experience job stress. Psychosocial risk factors have direct effects on the cardiovascular system by activating the SNS and stress hormones. This can cause a wide variety of pathophysiologic responses, including hypertension Psychosocial risk factors can contribute to CVD indirectly as well, simply by their impact on lifestyle behaviors and choices. Screening for psychosocial risk factors is important. Make appropriate referrals (e.g., counseling), when indicated. Suggest behavioral interventions such as relaxation training, stress management courses, support groups, and exercise training for individuals who are not in acute psychologic distress.

Arteriosclerosis Loss of elasticity, thickening, and calcification of arterial walls Most common chronic arterial disorder Atherosclerosis is a form of arteriosclerosis in which fibrin and fat harden and obstruct arteries PVD a common manifestation of atherosclerosis PVD interferes with arterial blood flow to the lower extremities, which increases the risk for paresthesias, neuropathy, unhealing ulcers in the legs, necrosis, gangrene, and even amputation

Rest pain Occurs during periods of inactivity Often described as a burning sensation in the lower legs Increases when legs are elevated and decreases when legs are dependent Intermittent claudication Cramping or aching pain in the calves of the legs, thighs, and buttocks that occurs with a predictable level of activity Paresthesias (numbness, decreased sensation) Diminished or absent peripheral pulses Pallor with extremity elevation, dependent rubor when dependent Thin, shiny, hairless skin; thickened toenails Skin breakdown and discolored areas

Focus on maintaining tissue perfusion and slowing atherosclerotic process Smoking cessation Meticulous foot care Assess peripheral pulses, pain, temp., color, and capillary refill Regular, progressively strenuous physical activity Complementary Therapies

Treatment may include surgical revascularization Medications Medications that inhibit platelet aggregation (e.g., aspirin or clopidogrel (Plavix)) Cilostazol (Pletal) (mild vasodilator, improves claudication) Pentoxifylline (Trental) (decreases blood viscosity, increases red blood cell flexibility)

Gas exchange Pain Clotting Cognition Mobility Elimination Inflammation Patient education