Primary hypertension

Fig. 7.1. Intracerebral hemorrhage, (a) A CT brain scan showing a typical deep "hypertensive" primary intracerebral hemorrhage, (b) These CT brain scans showing a right frontal arteriovenous malformation causing hemorrhage.

The determination of plasma renin responsiveness, however, is not sufficient to diagnose primary aldosteronism because suppressed PRA also occurs in about 25% of patients with essential hypertension. Primary aldosteronism can be differentiated from other hypermineralocorticoid states on the basis of inappropriate secretion of aldosterone. The demonstration of an elevated concentration of aldosterone in blood or urine in a patient with an unequivocally suppressed PRA concentration (a plasma aldosterone/ plasma PRA ratio >50) is presumptive evidence of primary aldosteronism. Because hypokalemia has a suppressive effect on aldosterone secretion, the potassium deficit should be replaced before aldosterone measurements are done. To establish aldosterone autonomy, the clinician may attempt to suppress aldosterone production with rapid volume expansion (see Box 51-10), with a potent mineralocorticoid (see Box 51-11), or as mentioned with captopril. Failure... 

Surprisingly, pulmonary edema does not occur in patients with severe pulmonary hypertension (primary pulmonary hypertension), even though their pulmonary artery pressure may be chronically elevated as high as 45 mm Hg above the normal value of 13 mm Hg. The reason for this is that the arterial bed is severely narrowed in pulmonary hypertension thus the alveolar capillaries are not exposed to the increased pressures and there is no engorgement of blood in the pulmonary vasculature (Ingram and Braunwald, 1980). 

Indications Edema associated with hepatic cirrhosis, nephritic syndrome, and heart failure, hypertension, primary hyperadosteronism Common drug examples ... 

Hypertension is one of the two principal risk factors of many cardiovascular diseases, such as coronary heart disease (CHD), stroke, and CHF. Individuals are considered hypertensive if their systoHc arterial blood pressure is over 140 mm Hg (18.7 Pa) or their diastoHc arterial blood pressure is over 90 mm Hg (12 Pa). Over 60 million people, or one-third of the adult population in the United States are estimated to be hypertensive (163). About 90% of these patients are classified as primary or essential hypertensive because the etiology of their hypertension is unknown. It is generally agreed that there is a very strong genetic or hereditary component to this disease. 

Treatment of essential or primary hypertension emphasizes not only the lowering of the elevated blood pressure, but also individualized therapy for each patient, providing each patient with minimized unnecessary side effects. The patient s cardiovascular morbidity and mortaUty should be decreased and end organ damage reversed or reduced (184,185). 

Hyperaldosteronism is a syndrome caused by excessive secretion of aldosterone. It is characterized by renal loss of potassium. Sodium reabsorption in the kidney is increased and accompanied by an increase in extracellular fluid. Clinically, an increased blood pressure (hypertension) is observed. Primary hyperaldosteronism is caused by aldosterone-producing, benign adrenal tumors (Conn s syndrome). Secondary hyperaldosteronism is caused by activation of the renin-angiotensin-aldosterone system. Various dtugs, in particular diuretics, cause or exaggerate secondary peadosteronism. 

Prostacyclin (epoprostanol) is one of the few drugs effective for the treatment of Primary Pulmonary Hypertension (PPH) a rare but frequently fatal illness of young adults. Increased blood pressure in the pulmonary circulation leads to right-heart failure. Continuous infusion of epoprostanol leads to a decrease in blood pressure however, it is unclear whether this is due to direct dilator activity of the IP receptor acting on smooth muscle, or a more indirect mechanism. 

Primary pulmonary hypertension is a disease of unclear etiology that is characterized by abnormally high mean pulmonary arterial pressures, in the absence of a demonstrable cause. A wide variety of pulmonary and cardiac diseases can lead to secondary pulmonary hypertension. 

ACE inhibitors do not completely block aldosterone synthesis. Since this steroid hormone is a potent inducer of fibrosis in the heart, specific antagonists, such as spironolactone and eplerenone, have recently been very successfully used in clinical trials in addition to ACE inhibitors to treat congestive heart failure [5]. Formerly, these drugs have only been applied as potassium-saving diuretics in oedematous diseases, hypertension, and hypokalemia as well as in primary hyperaldosteronism. Possible side effects of aldosterone antagonists include hyperkalemia and, in case of spironolactone, which is less specific for the mineralocorticoid receptor than eplerenone, also antiandrogenic and progestational actions. 

Before administering an NSAID, it is important for the nurse to determine if the patient has any history of allergy to aspirin or any otiier NSAID. The nurse determines if die patient has a history of gastrointestinal bleeding, hypertension, peptic ulceration, or impaired hepatic or renal function. If so, the nurse notifies the primary health care provider before administering an NSAID. 

In addition, when an adrenergic blocking drug is prescribed for hypertension, the primary care provider may want the patient to monitor his or her own blood pressure between office visits. This may enable the number of visits to the primary care provider office to be reduced and will help the patient learn to manage his or her own health (see Fhtient and Family Teaching Checklist Monitoring Blood Pressure). 

Complaints of a headache (especially an ocdpital headache) may indicate the occurrence of a hypertensive criss. The nurse should take the blood pressure and, if it is elevated, notify the primary health care provider immediately. The nurse should monitor the blood pressure at 15- to 30-minute intervals. The primary health care provider must be notified of any additional symptoms of hypertensive crisis. 

Antihypertensives are used in the treatment of hypertension. Although many antihypertensive drugs are available, not all drag may work equally well in a given patient. In some instances, the primary care provider... 

Each time the blood pressure is obtained, the nurse uses the same arm and the patient is placed in die same position (eg, standing, sitting, or lying down). In some instances, die primary care provider may order die blood pressure taken in one or more positions, such as standing and lying down. The nurse monitors the blood pressure and pulse every 1 to 4 hours if the patient has severe hypertension, does not have the expected response to drug therapy, or is critically ill. 

Never discontinue use of this drug except on the advice of the primary care provider. These drug control but do not cure hypertension. Skipping doses of the drug or voluntarily discontinuing the drug may cause severe, rebound hypertension. 

Notify the primary care provider if the diastolic pressure suddenly increases to 130 mm Hg or higher you may have malignant hypertension. 

B. expects the primary care provider to order that the drug dosage be gradually decreased during a period of 2 to 4 days to avoid rebound hypertension... 

During the ongoing assessment the nurse takes the vital signs daily more frequent monitoring may be needed if die patient is moderately to acutely ill or if the patient is taking epoetin alfa (because of the increased risk of hypertension). The nurse monitors the patient for adverse reactions and reports any occurrence of adverse reactions to the primary health care provider before the next dose is due. However, the nurse immediately reports severe adverse reactions. 

Diuretics are used in a variety of medical disorders. The primary health care provider selects the type of diuretic diat will most likely be effective for treatment of a specific disorder. In some instances, hypertension may be treated with the administration of an antihypertensive drug and a diuretic. The diuretics used for this combination tiierapy include the loop diuretics and the thiazides and related diuretics. The specific uses of each type of diuretic drug are discussed in the following sections. 

Avoid alcohol and nonprescription drug s unless their use has been approved by the primary health care provider. Hypertensive patients should be careful to avoid medications that increase blood pressure, such as over-the-counter drag s for appetite suppression and cold symptoms. 

If sgns of hyperthyroidism (eg, nervousness snxiety, increased appetite, elevated body temperature, tachycardia, moderate hypertension or flushed, warm, moist skin) are apparent, the nurse reportsthese to the primary health care provider before the next dose is due because it may be necessary to decrease the daily dosage. 

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