chapter 34_ hypertension课件

Chapter 33: Hypertension,Overview of BP Pg. 507,Force produced by the volume of blood within the walls of arteries. Measured pressure reflects the ability of arteries to stretch and fill with blood, efficiency of heart as a pump and the volume of circulating blood,Overview of BP,Affected by age, body size, diet, activity, emotions, pain, position, gender, time of day and disease states *Use of Birth Control Pills*,Overview of BP,Studies of healthy persons show that blood pressure can fluctuate within a wide range and still be normal. It is important to obtain several measurements for comparison. *A diastolic elevation is more serious, reflecting pressure on arterial wall during the resting phase of the cardiac cycle*,Arterial Blood Pressure,Regulated by autonomic nervous system, kidneys and endocrine glands Normal ranges from 100/60 to 139/89 Tends to increase age, most likely from arteriosclerotic and atherosclerotic changes in blood vessels or other effects of chronic diseases.,Systolic BP,Systolic is determined by the force and volume of blood ejected from left ventricle during systole and the ability of arterial system to distend at the time of contraction,Systolic BP,The walls of the arteries are normally elastic & yield to the force & volume of ventricular contraction In older Pts, the SBP may be due to the loss of arterial elasticity (arteriosclerosis),Systolic BP,Narrowing of the arterioles, either by arteriosclerosis or some other mechanism that causes vasoconstriciton, peripheral resistance, which in turn SBP. This resistance is compared to the narrowing of a tube, such as a drinking straw or a garden hose. The narrower the lumen, the the pressure needed to move air or liquid through it.,Diastolic BP,Diastolic reflects arterial pressure during ventricular relaxation and depends upon resistance of arterioles and the diastolic filling times.,Diastolic BP,If arterioles are resistant (constricted) blood is under greater pressure,Hypertensive Disease Pg. 508,HTN = sustained of SBP 140 or DBP 90 or both.,Hypertensive Disease,When a cardiac abnormality results from elevated BP the term hypertensive heart disease is used. When vascular damage is present without heart involvement the term hypertensive vascular disease is used. When both heart disease and vascular damage term hypertensive cardiovascular disease is used,Essential & Secondary Hypertension,Essential Hypertension is sustained elevation of BP without any known cause-95% of cases Secondary hypertension is an elevation that results from or is secondary to some other disorder Essential HTN can be related to unknown cause and secondary is due to a known cause,Pathophysiology Pg 509,Blood pressure often increases with age and may run in families African Americans are affected at a higher rate than other ethnic groups risk with obesity, inactivity, smoking, excessive alcohol intake & ineffective stress management.,Pathophysiology,Hypernatremia increases blood volume and increases BP Low serum potassium may cause Na retention because the kidneys try to maintain a balanced number of cations (positive charge,Pathophysiology,Secondary HTN may accompany any primary condition that affects fluid volume or renal function or causes arterial vasoconstriction. Kidney disease, pheochromocytoma (tumor of adrenal gland), hyperaldosteronism, atherosclerosis and use of cocaine or other cardiac stimulants such as weight control drugs and caffeine and oral contraceptives,Pathophysiology,Regardless if Essential or secondary- both have same effect on organs Size of heart increases and heart failure develops Can cause angina as the myocardium does not receive enough oxygen It accelerates arteriosclerosis and atherosclerosis,Patho-Effects of Hypertension,Eyes, brain, heart and kidney are all affected by hypertension Hemorrhage of tiny arteries of retina can cause blindness CVA can occur MI and renal failure can occur,Signs and Symptoms Pg 509,May be asymptomatic. Called the “silent killer” May have throbbing or pounding headache Dizziness, fatigue, insomnia, nervousness Nosebleeds and blurred vision Angina or shortness of breath may be 1st symptom of hypertensive heart disease,Signs and Symptoms,Pulse may be bounding Flushed face from engorgement of of superficial blood vessels Peripheral edema Vascular changes in eyes, retinal hemorrhages or a bulging optic disk,Treatment,See table 33-1 page 508 for recommendations for BP checks Non-pharmacological interventions used first-wt. reduction, moderate exercise, decreased Na, no smoking or alcohol, diet low in fat,Drugs for HTN Table 33-1,Pg 511-refer & make sure you go over the nursing considerations!,Nursing Assessment Pg 510,Take BP in both arms in standing, sitting and lying position. Use appropriate size cuff Use same arm and same position when taking routine vitals Do cardiac assessment,Accelerated HTN Pg 513,Markedly elevated BP, accompanied by hemorrhages & exudates in the eye. If untreated, may progress to malignant HTN.,Malignant HTN,Dangerously elevated BP accompanied by papilledema (swelling of the optic nerve at its point of entrance into the eye),Malignant Hypertension Patho,Have an abrupt onset & if untreated, are followed by severe symptoms and complications. Fatal unless quickly reduced. Even with intensive tx the kidneys, brain, and heart may be permanently damaged Dangerously high and papilledema (swelling of optic nerve. Retinal hemorrhage leads to blindness Stroke, renal failure, left ventricular failure with pulmonary edema or MI if not lowered,Signs and Symptoms Pg. 513,Confusion, headache, visual disturbances, seizures and possible coma Sudden marked rise in BP causes chest pain, dyspnea and moist lung sounds Renal failure is evidenced by less than 30 ml/hr. Sudden, severe back pain accompanied by hypotension is indication that aortic aneurysm is dissecting or has ruptured. 160/115 or higher suddenly, brain swells,Emergency Treatment of Malignant,In true emergency goal is to lower BP within 1 to 2 hours Nitropress, nitroglycerine, Normodyne IV given if critical If not critical, Procardia, verapamil, captopril, minipress given orally. Oxygen given to reduce hypoxia-induced tachycardia,Nursing care Pg. 514,Give meds using pump, check rate