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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Situations requiring immediate lowering of systemic blood pressure are infrequent. Certain clinical syndromes resulting from or complicated by severe hypertension demand vigorous, usually parenteral, antihypertensive therapy. Such syndromes include (1) diastolic hypertension accompanied by sudden disruption of cerebral function, (2) dissecting or leaking aortic aneurysm; (3) accelerated or malignant hypertension, (4) toxemia of pregnancy when either the fetus' or the mother's life is immediately threatened, (5) some instances of diastolic hypertension and acute left ventricular failure, (6) uncontrolled hypertension in the patient who requires emergency surgery, (7) refractory elevation of the diastolic pressure in the kidney transplant patient, and (8) refractory hypertension complicating myocardial infarction or angina. Drugs useful in acutely lowering blood pressure include diazoxide, sodium nitroprusside, methyldopa intravenously, reserpine intramuscularly, and trimethaphan camsylate intravenously. Use of furosemide reinforces the hypotensive effect of these agents. Theoretical advantages and disadvantages of these agents are not always encountered in clinical use.
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PMID:Hypertension crisis. Recognition and management. 57 54

Blood pressure measurements were recorded in 95% of the men and 97% of the women aged 30 to 59 years in a small Israeli village populated by Jews of Kurdish origin and in which a high incidence of toxemia of pregnancy was previously observed. The prevalence of hypertension in the men, as well as in the women, was significantly higher in all age groups studied than in a sample of the general population. These findings support the hypothesis that toxemia of pregnancy is an expression of a preexisting hypertensive state rather than an etiological factor in the development of later hypertension in women.
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PMID:Prevalence of elevated blood pressure in a village community with a high incidence of toxemia of pregnancy. 59 93

Aspects of primary or secondary hypertension in relation to oral contraceptive use and pregnancy are discussed. Possible mechanisms of oral contraceptive-induced secondary hypertension and contraindications to the pill are listed. Hypertension as a contraindication to pregnancy is weighed in relation to sterilization and cases of term pregnancies in hypertensive patients are cited. Misdiagnosis of secondary hypertension as toxemia in most pregnant patients with elevated blood pressure is characterized in a review of a clinical study involving 4273 patients (Table 1). A method for differential diagnosis of hypertension in pregnancy which includes ophthalmoscopic examination and urinalysis is outlined (Figure 1). Suggested treatment for the pregnant patient with hypertension is a low sodium diet for the first 20 weeks of pregnancy followed by the stepped care program (Figure 2). The most desirable therapy for pregnant women with toxemia are diuretics during the early pathological phase (sodium retention and edema) with edema in the periorbital areas and hands as diagnostic indicators for this phase. The efficacy of diuretics (alone or combined with hypotensive agents) in hypertensive patients is evaluated with regard to maternal and fetal risks. Indications for termination of pregnancy or induction of labor in hypertensive or toxemic women are summarized.
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PMID:Contraception and pregnancy in the young female hypertensive patient. 62 59

The hypertensive encephalopathy is a syndrome consisting of a sudden elevation of arterial pressure usually preceded by severe headache and followed by convulsions, coma or a variety of transitory cerebral phenomena. The syndrome may complicate acute glomerulonephritis, toxemia of pregnancy and essential or malignant hypertension. Two syndromes must be differentiated from true hypertensive encephalopathy: 1. acute anxiety state with labile hypertension and 2. acute pulmonary edema due to hypertensive heart disease. At least in patients with acute anxiety states, the use of antihypertensive agents is usually not indicated. Since encephalopathy is always accompanied by increased vascular resistance and since clinical experience has demonstrated clearing of the sensorium, cessation of convulsions and release of vasoconstriction following reduction of blood pressure, the primary aim of therapy should be prompt lowering of arterial pressure. The two agents of choice are diazoxide and sodium nitroprusside. Stroke is differentiated from encephalopathy by the persistence of lateralizing signs. The aggressiveness of antihypertensive therapy in this situation depends on the severity of the hypertensive process. Rapid reduction of blood pressure is indicated in patients found to have accelerated hypertension while a more gradual lowering of pressure appears warranted for patients with chronic arterial hypertension and evidence of generalized arteriosclerosis.
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PMID:Management of hypertensive encephalopathy. 72 Oct 56

Adolescent pregnancy is associated with a high degree of risk for the mother and her baby which may be mitigated by good prenatal care, intensive nutritional counseling, and attention to social problems. A study of 222 predominately black, single adolescents who delivered at the University of Tennessee Center for the Health Sciences during the 2-month period between December 1977 and February 1978 revealed an increased incidence of hypertension and convulsive disorders as well as a high rate of toxemia and fetal distress during labor and delivery. Birth weights of less than 2500 gm were associated with a 12% incidence of prematurity, and nearly 15% of the newborns required intensive care (23 had high-risk Apgar scores at 1 minute and 18 at 5 minutes). Perinatal mortality was 54/1000. In this population, teenage pregnancy is viewed as an accepted and even welcome occurrence, supporting the finding that poor neonatal care is a prime cause of the increased complications of adolescent pregnancy. Comprehensive personal services are required to achieve patient compliance with prenatal medical care.
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PMID:Teenage obstetric complications. 73 27

Drugs used in the management of pregnancy-induced hypertension have been reviewed, and their value and adverse effects on both mother and fetus have been considered. Although magnesium and hydralazine remain the stalwarts of therapy, a number of other drugs have potential that may be realized in the future. Several new medications have promise in correcting the derangements of toxemia, but safety for the fetus has yet to be demonstrated. For the physician confronted with the complexities of old and new drugs in toxemia of pregnancy, the prayer of Lord Berkely may be just as appropriate in 1977 as it was dicades ago: From inability to let well enough alone, From too much zeal for the new, From too much contempt for what is old, From putting knowledge before wisdom and science before art, From making the cure of the disease more grievous than its endurnace, Good Lord, deliver us.
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PMID:Drugs used in the management of toxemia of pregnancy. 86 68

The following experiments demonstrate that the severity of toxemia is proportional to the degree of reduction in blood flow to the pregnant uterus. Blood pressure and blood flow variations were studied in 21 nonpregnant and pregnant dogs following the placement of a progressive stricture on the abdominal aorta below the renal arteries. The immediate effect of the stricture was a mild hypertension in half of the pregnant dogs; in addition, in all the dogs, the blood flow progressively dropped in the arteries below the stricture (femoral and uterine) while it remained constant in the arteries above (ovarian and renal). In 3 of 5 pregnant dogs the delayed effect of the aortic stricture was hypertension associated with all the other signs of experimental toxemia. Removal of the aortic stricture after 10 days immediately improved the blood flow below the stricture. No noticeable preferential distribution of blood toward the pregnant uterus was noted during the constriction.
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PMID:Hemodynamic studies in experimental toxemia of the dog. 89 98

Ovulation inhibiting oral contraceptives have an important pathological significance for the development of hypertension in women between the ages of 26-35. A hypertension reaction to oral contraceptives occurs predominantly in women who have a hereditary predisposition to hypertension or diabetes mellitus, who suffer themselves from diabetes mellitus, or who have shown toxemia in a previous pregnancy. Studies with rats show that hypertension could be due to vascular lesions, produced by estrogens, and by sodium retention, caused by progestagen. The reversibility of oral contraceptive hypertension is considered doubtful, contrary to other studies. The optimum oral contraceptive would be 1 that could eliminate the estrogen component, or at least minimize it, and which would be comprised of progestagens which would not cause sodium retention.
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PMID:[Clinical course and pathogenesis of oral contraceptive hypertension (author's transl)]. 91 53

Overt hypertension, developing in about 5% of Pill users, and increases in blood pressure (but within normal limits) in many more is believed to be the result of changes in the renin-angiotensin-aldosterone system, particularly a consistent and marked increase in the plasma renin substrate concentrations. The mechanisms for the hypertensive response are unclear since normal women may demonstrate marked changes in the renin system. In in vitro testing, in which renin was added in a constant amount to the serum of patients with oral contraceptive-induced hypertension, the capacity to generate angiotensin 2 was found to increase linearly with increases in substrate levels. These responses were maintained as much as 2 or more times that of normal. In normal subjects plasma renin in "excess" is absent, suggesting the possibility of some regulation mechanism. The ef fect of the volume component on angiotensin secretion caused by the estrogens in oral contraceptives could further explain the Pill-induced hypertension. A failure of the kidneys to fully suppress renal renin secretion could thus be an important predisposing factor. These observations provide guidelines for the prescription of oral contraceptives. A baseline blood pressure measurement should be obtained, and blood pressure and weight should be followed at 2- or 3-month intervals during treatment. Oral contraceptive therapy should be contraindicated for individuals with a history of hypertension, renal disease, toxemia, or fluid retention. A positive family history of hypertension, women for whom long-term therapy is indicated, and groups such as blacks, especially prone to hypertensive phenomena, are all relative contraindications for the Pill.
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PMID:Oral contraceptives--induced hypertension--nine years later. 96 41

To investigate the role of components of the renin-angiotensin-aldosterone system and plasma progesterone concentrations in the pathophysiology of hypertension in pregnancy, sequential measurements were made throughout pregnancy in 45 normotensive subjects, 41 other pregnant patients in whom hypertension became manifest only during pregnancy and 26 patients with chronic hypertension antedating pregnancy. Among the normotensive subjects plasma renin activity and substrate, plasma aldosterone and progesterone concentrations were elevated as early as the sixth week of gestation. While consistent, progressive, further increases were noted in renin substrate, aldosterone and pregesterone concentrations during pregnancy, plasma renin activity did not continue to rise. In both hypertensive groups, plasma renin activity and aldosterone concentration were significantly suppressed during the last trimester despite levels of renin substrate and progesterone that were not significantly different than those observed in normotensive pregnancy. These observations confirm earlier studies reporting suppression near term of plasma renin activity in toxemia and indicate from these prospective observations that they are secondary effects. These studies, in addition, demonstrate parallel suppression of plasma aldosterone concentration in toxemia. The current report also indicates that this suppression is not due to a decrease in renin substrate concentration and that a hypothesized deficiency of plasma progesterone, which was not observed in the hypertensive subjects, does not play a permissive role in the development of hypertension.
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PMID:Sequential changes in the renin--angiotensin--aldosterone systems and plasma progesterone concentration in normal and abnormal human pregnancy. 100 40


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