Dr. Luca Alina. Hypertension.
Dr. Luca Alina
Hypertension is a major cause of morbidity and mortality in the United States and in many other countries. The prevalence of hypertension in the United States for people aged 60-69 years is more than 50%. This prevalence increases to approximately 75% among those aged 75 years. Hypertension is now commonly discovered in children. The long-term health risks to these children with hypertension may be substantial
Common Causes of Hypertension by Age
BP is determined by the balance between cardiac output and vascular resistance. A rise in either of these variables, in the absence of a compensatory decrease in the other, increases mean BP, which is the driving pressure. Several factors regulate cardiac output and vascular resistance.
Factors that affect BP include the following:
The true incidence of hypertension in the pediatric population is not known. This vagueness partly stems from the somewhat arbitrary definition of hypertension. In adults, hypertension is defined on the basis of data from extensive studies that allowed for correlation of BP with adverse events, such as heartfailure or stroke.
Similar studies have not been performed in children, although reports from small populations of children provided compelling evidence of a relationship between hypertension and both ventricular hypertrophy and atherosclerosis. In children, the definition of hypertension is based exclusively on frequency-distribution curves for BP. As a consequence, estimations of the prevalence of pediatric hypertension lack a scientific basis. The number of children who might be defined as having hypertension and the frequency with which they develop complications during adulthood remains unknown.
Because of differences in genetic and environmental factors, incidences vary from country to country and even from region to region in the same country.
Height and weight affect BP. However, these relationships do not become evident until children are school aged. The Task Force on Blood Pressure Control in Children considered these factors when they published their normative data in 1987.
Numerous investigators have noted a correlation between the BP of parents and that of their offspring. Familial aggregation of BP is detectable early in life. Some data relate this association to concomitant obesity in both parent and child.
A well-taken history provides clues about the cause of hypertension and guides the nature and sequence of ensuing investigations.
Relevant information includes the following:
Presenting symptoms and signs are not specific in neonates and absent in most older children unless their hypertension is severe.
Signs and symptoms that should alert the physician to the possibility of hypertension include the following:
Measurement and recording of blood pressure (BP)
The first Korotkoff sound (ie, appearance of a clear tapping sound) defines the systolic pressure, whereas the fifth Korotkoff sound (ie, disappearance of all sounds) defines the diastolic pressure. The fourth (low-pitched, muffled) sound and the fifth sound frequently occur simultaneously, or the fifth sound may not occur at all. Diastolic BP must be recorded. When Korotkoff sounds can be heard down to 0 mm Hg, the BP measurement should be repeated with less pressure applied to the head of the stethoscope than was applied before.
Interpretation of BPs
Objective of physical examination: A primary objective of the physical examination is to identify signs of secondary hypertension, including the following:
Café au lait spots
Lymphedema of the feet in an infant is shown
Hairline and a shield-shaped chest.
Hyperconvex nails in Turner syndrome
In patients with hypertension, proceed from simple tests that can be performed in an ambulatory setting to complex noninvasive tests and finally to invasive tests.
Findings from the patient's history and physical examination dictate the appropriate order of tests.
The CBC count may indicate anemia due to chronic renal disease.
Blood chemistry may be helpful. An increased serum creatinine concentration indicates renal disease. Hypokalemia suggests hyperaldosteronism.
High urinary excretion of catecholamines and catecholamine metabolites (metanephrine) indicates pheochromocytoma or neuroblastoma.
Fasting lipid panels and oral (PO) glucose-tolerance tests are performed to evaluate metabolic syndrome in obese children.
Urine sodium levels reflect dietary sodium intake and may be used as a marker to follow up a patient after dietary changes are attempted.
Blood hormone levels may be measured. High plasma renin activity indicates renal vascular hypertension, including coarctation of the aorta, whereas low activity indicates glucocorticoid remediable aldosteronism, Liddle syndrome, or apparent mineralocorticoid excess. A high plasma aldosterone concentration is diagnostic of hyperaldosteronism. High values of catecholamine (epinephrine, norepinephrine, dopamine) are diagnostic of pheochromocytoma or neuroblastoma.
Drug screening is performed to identify substances that might cause hypertension.
Weight reduction should be a goal in overweight children with hypertension regardless of its etiology. Obesity and hypertension are closely correlated, particularly in adolescents.
Aerobic and isotonic exercises have a direct beneficial effect on BP. They help in reducing excess weight or maintaining appropriate body weight. Encourage participation in sports. Only patients with severe uncontrolled hypertension or cardiac abnormalities that require exercise restriction are exempt from aerobic and isotonic exercises.
Salt restriction probably benefits only a subgroup of patients with hypertension, particularly African American patients, who may have a defect in the cellular handling of sodium. However, given the excessive amount of salt in the typical American diet, reduced salt intake should be recommended to all patients with hypertension.
The Task Force recommends the Dietary Approaches to Stop Hypertension (DASH) eating plan
Stress-reducing activities can reduce BP when performed on a regular basis. However, this effect is lost when the activity is discontinued.
Potassium supplementation can decrease BP and reduce ventricular hypertrophy in adults. How potassium supplementation affects children with hypertension remains to be tested. However, avoiding potassium depletion (eg, from diuretic therapy) and prescribing a potassium-rich diet in patients without renal insufficiency appear reasonable.
When sleep-disordered breathing is discovered, weight loss, tonsillectomy and adenoidectomy, and/or use of continuous positive airway pressure may improve the patient's sleep and secondarily improve BP.
Management of hypertensive crisis
Anticonvulsant drugs are usually ineffective in treatment of a seizure due to a hypertensive crisis. However, seizures due to severe hypertension must be treated with a fast-acting antihypertensive drug.
Drugs currently used to treat hypertensive emergencies include nicardipine, labetalol, and sodium nitroprusside.
The goal of therapy is to decrease BP to normal. Clinicians should be familiar with the effect and adverse effects of these drugs. Patients must be supervised closely to avoid an excessively rapid decrease in BP, which may result in underperfusion of vital organs.