Treatment and Nursing Care of Hypertension

Abstract

vised-the Regitine test, the benzodioxane test, and the histamine test -to indicate a 'umor. Regitine and benzodioxane neutralize the hypertens ve effects of the epinephrine and norepincphrine which are produced by the tumor. Hence, a significant lowering of blood pressure following the injection of these agents suggests that the hypertension is due to the presence of a pheochromocytoma. Another rare, but surgically curable, form of hypertension is that associated with constriction of the aorta. In this instance a congenital defect causes a narrowing of the descending thoracic aorta. In the majority of cases of hypertension, however, the cause is unknown and this condition has been called essential Regardless of the cause of the hypertension, the end results will be the same essentially and will depend, in large measure, on the degree and duration of the hypertension. The persistent state of constriction results in marked thickening of the walls of the arterioles and if the hypertension is severe enough there is actual necrosis of these vessel walls. The development of athcrcsclerosis of the larger arteries, particularly the coronary, renal, and cerebral vessels, is accelerated. The sclerotic changes in the renal arteries and the arterioles may lead to gradual impairment of renal function; in the brain they may produce cerebral thromboses and hemorrhages; in the heart they may lead to a coronary occlusion with resulting myocardial infarction. The left ventricle in patients who have hypertension works harder than it does in people with normotension since it has to maintail. a normal output of blood against a high head of pressure. As a result it will dilate, hypertrophy, and may eventually fail to function. In many patients the hypertension remains very mild or the blood pressure may be elevated only at times of stress; at other times, such as in sleep, it may be quite normal. In general, and particularly in young male patients, the hypertension tends to progress and to become fixed. One way of classifying hypertension according to the grade of severity is by ophthalmoscopic examination of the optic fundi. Various degrees of narrowing of the retinal arterioles are listed as Grade I and II changes. Hemorrhages and exudates in the retina are classified as a Grade III change and always signify a severe degree of hypertension. The presence of edema of the optic nerve head (papilledema) represents a Grade IV