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العنوان
Hypertensive urgency and emergency; clinical update/
المؤلف
Mohamed,Hazem Saad Abd El Shafy
هيئة الاعداد
باحث / حازم سعد عبد الشافى محمد
مشرف / حازم سعد عبد الشافى محمد
مشرف / هشام محمد محمود العزازي
مشرف / هشام محمد محمود العزازي
تاريخ النشر
2013
عدد الصفحات
89.p:
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
العناية المركزة والطب العناية المركزة
تاريخ الإجازة
1/1/2013
مكان الإجازة
جامعة عين شمس - كلية الطب - ICU
الفهرس
Only 14 pages are availabe for public view

from 89

from 89

Abstract

Severe hypertension is a frequent condition among patients presenting to emergency departments. Historically, this has been referred to as a hypertensive crisis. In addition, these hypertensive crises have been further divided into either hypertensive emergencies or urgencies depending on the presence or absence of target organ damage, respectively. The Joint National Committee on prevention, detection, evaluation, and treatment of high BP provides a definition for hypertensive crisis in their seventh report (JNC 7), which consists of a BP greater than 180/110 mmHg.
The pathophysiology of hypertensive crisis is poorly understood. A sudden increase in BP seems to further accentuate shear stress in the vessel wall, which leads to additional endothelial damage, further activation of the neurohormonal (rennin -angiotensinII -aldosterone, sympathetic nervous system, and vasopressin) system, induction of oxidative stress and inflammatory cytokines. The coagulation cascade is also activated by the resultant platelet aggregation and fibrin deposition. These changes lead to vasoconstriction, thrombosis, and fibrinoid necrosis and result in hypoperfusion and ischemia.
Hypertensive crises (76% urgencies, 24% emergencies) represented more than one fourth of all medical urgencies/emergencies. Hypertensive urgencies frequently present with headache (22%), epistaxis (17%), faintness, and psychomotor agitation (10%) and hypertensive emergencies frequently present with chest pain (27%), dyspnea (22%) and neurological deficit (21%). Types of end-organ damage associated with hypertensive emergencies include cerebral infarction (24%), acute pulmonary edema (23%) and hypertensive encephalopathy (16%), as well as cerebral hemorrhage (4.5%). The most important factor that limits morbidity and mortality from these disorders is prompt and carefully considered therapy .
An accurate history is an important first step in the evaluation of patients presenting with severe elevations in BP. Physical examination should focus on the identification of any target organ damage. Additional parameters to monitor in the initial presentation include electrolytes, creatinine, blood urea nitrogen, complete blood count, electrocardiogram, chest radiograph, and urine analysis.
The management differs between these crises in both the rapidity of blood pressure correction and the medications used. Hypertensive emergencies must be treated immediately with intravenous antihypertensive medications. However, hypertensive urgencies may be treated with oral antihypertensive agents to reduce the blood pressure to baseline or normal over a period of 24–48 hr.
The ideal antihypertensive agent should provide immediate onset of action, a short to intermediate duration of action, be easy to titrate precisely, and have demonstrated safety and efficacy in the treatment of hypertension.
The best clinical setting in which to achieve this BP control is in the ICU, with the use of titratable IV hypotensive agents. With the development of pharmacological agents in the last decade, the traditional agent, nitroprusside, should be utilized significantly less given than the other agents such as esmolol, nicardipine and fenoldopam are now available and are equally effective with fewer adverse effects. Agents such as nifedipine and hydralazine should be abandoned because these agents are associated with significant toxicities or side-effects and increased mortality.