（高血压英文课件）Cerebrovascular-Stroke.ppt

1、Cerebrovascular disease is the most frequent neurological disorder of adults.It is the third leading cause of morbidity and mortality in the USA after heart disease and cancer.It includes any pathological process that involves the blood vessels of the brain.Most cerebrovascular disease is caused by

2、thrombosisthrombosis,embolism,or hemorrhagehemorrhage.The mechanism of each of these etiologies is different,but the ultimate result is damage to a focal area of the brain.A“brain attack”must be viewed as a A“brain attack”must be viewed as a medical emergency.medical emergency.To reverse cerebral is

3、chemia,patients To reverse cerebral ischemia,patients must be evaluated promptly.must be evaluated promptly.Ischemic brain injury occurs when Ischemic brain injury occurs when arterial occlusion lasts longer than 2 to arterial occlusion lasts longer than 2 to 3 hours.3 hours.Delay in seeking medical

4、 care may Delay in seeking medical care may eliminate the potential for tissue-eliminate the potential for tissue-saving therapy with thrombolytic saving therapy with thrombolytic agents.agents.Approximately 750,000 strokes occur every year in the USThe incidence in men is greater than in women.It i

5、s estimated that there are 3 million stroke survivors and that stroke is a leading cause of disability and a leading diagnosis for long-term care.Risk factors for stroke include smoking,hypertension,obesity,cardiac disease,hypercholesterolemia,diabetes,and use of birth control pills.Prevention effor

6、ts focus on lifestyle changes that can modify risk factors.In addition,the appropriate use of warfarin or aspirin in patients at risk for cardiac sources of emboli(e.g.,atrial fibrillation)constitutes primary prevention.When blood flow to any part of the brain is impeded as a result of a thrombus or

7、 embolus,oxygen deprivation of the cerebral tissue begins.Deprivation for 1 minute 1 minute can lead to reversible symptoms,such as loss of consciousness.Oxygen deprivation for longer periods longer periods can produce microscopic necrosis of the neurons.The necrotic area is then said to be infarcte

8、d.infarcted.If the neurons are ischemic only and have not yet necrosed,there is a chance to save them.The ischemic cascade begins within seconds to minutes after perfusion failure,creating a zone of irreversible infarction and surrounding area of potentially salvageable“ischemic penumbra.”A stroke c

9、aused by an embolus may be a result of blood clots,fragments of atheromatous plaques,lipids,or air.Emboli to the brain most often have a cardiac source,secondary to myocardial infarction or atrial fibrillationIf hemorrhagehemorrhage is the etiology of a stroke,hypertension often is a precipitating f

10、actor.Vascular abnormalities,such as arteriovenous malformations arteriovenous malformations and cerebral cerebral aneurysmsaneurysms,are more prone to rupture and cause hemorrhage in the presence of hypertension.The most frequent neurovascular syndrome seen in thrombotic and embolic strokes is due

11、to involvement of the middle cerebral artery.This artery mainly supplies the lateral aspects of the cerebral hemisphere.Infarction to that area of the brain can cause contralateral motor and sensory deficits.If the infarcted hemisphere is dominant,speech problems result,and dysphasiadysphasia may be

12、 present.Dysphasia:Dysphasia:difficulty in speaking and putting words into the correct orderA stroke is usually characterized by the sudden onset of focal neurological impairment.The patient may experience signs such as weakness,numbness,visual changes,dysarthria,dysphagia,or aphasia.dysarthriadysar

13、thria:difficulty in speaking words clearly,caused by damage to the central nervous systemdysphagiadysphagia:difficulty in Swallowingaphasia aphasia:a condition in which a person is unable to speak or write,or to understand speech or writing because of damage to the brain centres controlling speechTh

14、e manifestations of a stroke depend on the anatomical location of the lesion.If symptoms resolve in less than 24 hours,the event is classified as a transient ischemic transient ischemic attack(TIA).attack(TIA).Most TIAs last for only minutes to less than an hour,which further clouds recognition and

15、prompt treatment.Furthermore,the differential diagnosis of stroke includes ruling out intracerebral hemorrhage,SAH,subdural or epidural hematoma,neoplasm,seizure,or migraine headacheThe time of symptom onset to administration of thrombolytic therapy(or“time to needle”)should be within a 3-hour windo

16、w.patients history helps determine what has happened to the individual.It is important to obtain a description of the neurological event;how long it lasted;and whether the symptoms are resolving,completely gone,or the same as at the time of onset.Determination of risk factors for risk factors for st

17、rokestroke,such as hypertension,chronic atrial fibrillation,elevated serum cholesterol,smoking,oral contraceptive use,or a familial history of stroke,also aids in diagnosisCT scan of the brain without contrast,is obtained within 60 minutes of arrival Blood studies(including complete blood cell count

18、,electrolytes,glucose,and coagulation parameters,are obtained)neurological examination,and a screen performed using the National Institutes of Health Stroke Scale(NIHSS)Cerebral angiography has been the gold standard for evaluating cerebral vasculature.(ECG)should be obtained to assess for evidence

19、of arrhythmia or cardiac ischemiaAdditional tests that can be done are transesophageal echocardiography(TEE)and Holter monitoring.The management of an ischemic stroke comprises four primary goals:1.restoration of cerebral blood flow(reperfusion),2.prevention of recurrent thrombosis,3.neuroprotection

20、,4.supportive care.The focus of initial treatment should be to save as much of the ischemic area as possible.Three ingredients necessary to this area are oxygen,glucose,and adequate blood flow.The oxygen level can be monitored through(ABGs),and oxygen can be given to the patient if indicated.Hypogly

21、cemia can be evaluated with serial checks of blood glucose.Reperfusion may be accomplished by the use of IV tissue plasminogen activator(t-PA).Cerebral perfusion pressure is a reflection of the systemic blood pressure,ICP,functioning autoregulation in the brain,and heart rate and rhythm.The paramete

22、rs most easily controlled externally are the blood pressure and cardiac rate and rhythm.Arrhythmias usually can be corrected.If the patient is a candidate for thrombolytic therapy,treatment with t-PA begins in the emergency department,and he or she is then moved to the ICU for further monitoring.If

23、the individual is not a candidate for thrombolytic therapy,the complexity of the patients problems determines his or her placement in the ICU,medical unit,or stroke specialty unit.Thrombolytic agents:IV thrombolytic therapy should be initiated within 3 hours or less of the onset of neurological symp

24、toms.The direct administration of a thrombolytic into a vessel is an alternative to IV t-PA.Such administration is effective in acute ischemic stroke and can be given up to 6 hours after the onset of symptomssecondary treatment options for stroke include anticoagulation with antithrombotic and antip

25、latelet agents.If a patient experiences atrial fibrillation,anticoagulation with warfarin(Coumadin)may be necessary.Antiplatelet drugs include dipyridamole-ER,ticlopidine,clopidogrel,and aspirin.These agents discourage platelets from adhering to the wall of an injured blood vessel or other platelets

26、 and are given to prevent a future thrombotic or embolic eventIf the diastolic blood pressure is above approximately 105 mm Hg,it may need to be lowered gradually.This may be accomplished effectively with labetalol.The usual methods of controlling increased ICP can be instituted:hyperventilation;flu

27、id restriction;head elevation;avoidance of neck flexion or severe head rotation that would impede venous outflow from the head;and the use of osmotic diuretics(mannitol)to decrease cerebral edemaIn patients with carotid stenosis,carotid endarterectomy may be performed to prevent a stroke.AssessmentPlanEmotional and Behavioral ModificationCommunication(Expressive Expressive Dysphasia&Receptive Dysphasia)Dysphasia&Receptive Dysphasia)PATIENT EDUCATION AND DISCHARGE PLANNING