Laboratory Studies
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 choice of tests.
The complete blood count (CBC) may indicate anemia due to chronic renal disease. Blood chemistry may be helpful. An increased serum creatinine concentration indicates renal disease. Hypokalemia suggests hyperaldosteronism.
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 catecholamines (eg, epinephrine, norepinephrine, or dopamine) are diagnostic of pheochromocytoma or neuroblastoma.
On urine dipstick testing, a positive result for blood or protein indicates renal disease. Urine cultures are used to evaluate the patient for chronic pyelonephritis. High urinary excretion of catecholamines and catecholamine metabolites (metanephrine) indicates pheochromocytoma or neuroblastoma. Urine sodium levels reflect dietary sodium intake and may be used as a marker to follow a patient after dietary changes are attempted.
Fasting lipid panels and oral glucose-tolerance tests are performed to evaluate metabolic syndrome in obese children. Drug screening is performed to identify substances that might cause hypertension.
Echocardiography and Ultrasonography
Left ventricular hypertrophy (LVH) results from chronic hypertension. The finding of LVH on echocardiography confirms the chronicity of the hypertension and is an absolute indication for starting or intensifying treatment. LVH is symmetric, consisting of equivalent increases in in thickness for both the left ventricular portion of the ventricular septum and the left ventricular posterior wall. Left ventricular function must also be assessed.
Echocardiography is essential in the evaluation of suspected aortic coarctation. The aortic arch and its branches must be examined in precise anatomic detail.
Abdominal ultrasonography may reveal tumors or structural anomalies of the kidneys or renal vasculature. Renal scarring suggests excessive renin release. Asymmetry in renal size suggests renal dysplasia or renal artery stenosis. Renal or extrarenal masses suggest a Wilms tumor or neuroblastoma, respectively.
On Doppler studies, asymmetry in renal artery blood flow suggests renal artery stenosis.
Angiography
Angiography may reveal differences in the structure (diameter) of the renal vessels. Sampling of blood from renal arteries, renal veins, and aorta may reveal differences in renin secretion between the kidneys. A renin activity ratio of 3:1 between the kidneys is considered diagnostic of renal vascular hypertension.
On digital subtraction arteriography, asymmetry between the 2 renal arteries indicates renal artery stenosis.
24-Hour Blood Pressure Monitoring
Monitoring of blood pressure (BP) on a 24-hour basis may help in diagnosing so-called white-coat hypertension and provides information about the risk of target end-organ damage. White-coat hypertension is common because most children are uncomfortable at the physicians’ office, fearing invasive examinations, vaccinations, blood draws, and other factors. Use of 24-hour BP monitoring should be considered first in most uncomplicated cases of pediatric stage I hypertension.
Other Tests
Cardiac catheterization is not necessary in the evaluation of aortic coarctation.
Computed tomography (CT) and magnetic resonance imaging (MRI) with angiography can provide further anatomic definition of an aortic coarctation, but neither study is necessary for diagnosis.
Radionuclide imaging may be considered, with or without captopril; asymmetry suggests renal artery stenosis.
Polysomnography helps in identifying sleep disorders associated with hypertension. This test should be considered in obese children with a history of snoring, daytime sleepiness, or any sleep difficulties.
Retinal examination may reveal retinal vascular changes.
[Guideline] Task Force. Report of the Second Task Force on Blood Pressure Control in Children--1987. Task Force on Blood Pressure Control in Children. National Heart, Lung, and Blood Institute, Bethesda, Maryland. Pediatrics. Jan 1987;79(1):1-25. [Medline].
[Guideline] Task Force. Update on the 1987 Task Force Report on High Blood Pressure in Children and Adolescents: a working group report from the National High Blood Pressure Education Program. National High Blood Pressure Education Program Working Group on Hypertension Control. Pediatrics. Oct 1996;98(4 Pt 1):649-58. [Medline].
[Guideline] NHLBI. National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. Aug 2004;114(2 Suppl 4th Report):555-76. [Medline]. [Full Text].
Gruskin AB. Factors affecting blood pressure. In: Drukker A, Gruskin AB, eds. Pediatric Nephrology: Pediatric and Adolescent Medicine. 3rd ed. Basel, Switzerland: Karger; 1995:1097.
Gavrilovici C, Boiculese LV, Brumariu O, Dimitriu AG. [Etiology and blood pressure patterns in secondary hypertension in children]. Rev Med Chir Soc Med Nat Iasi. Jan-Mar 2007;111(1):70-81. [Medline].
Kapur G, Ahmed M, Pan C, Mitsnefes M, Chiang M, Mattoo TK. Secondary hypertension in overweight and stage 1 hypertensive children: a Midwest Pediatric Nephrology Consortium report. J Clin Hypertens (Greenwich). Jan 2010;12(1):34-9. [Medline].
Hanevold C, Waller J, Daniels S, Portman R, Sorof J. The effects of obesity, gender, and ethnic group on left ventricular hypertrophy and geometry in hypertensive children: a collaborative study of the International Pediatric Hypertension Association. Pediatrics. Feb 2004;113(2):328-33. [Medline].
Leung LC, Sung RY, So HK, et al. Prevalence and risk factors for hypertension in Hong Kong Chinese adolescents: waist circumference predicts hypertension, exercise decreases risk. Arch Dis Child. Sep 2011;96(9):804-9. [Medline].
[Guideline] University of Michigan Health System. Essential hypertension. Ann Arbor (MI): University of Michigan Health System; 2009 Feb. [Full Text].
Meyers RS, Siu A. Pharmacotherapy Review of Chronic Pediatric Hypertension. Clin Ther. Oct 7 2011;[Medline].
Schaefer F, Litwin M, Zachwieja J, Zurowska A, Turi S, Grosso A, et al. Efficacy and safety of valsartan compared to enalapril in hypertensive children: a 12-week, randomized, double-blind, parallel-group study. J Hypertens. Oct 21 2011;[Medline].
Aeberli I, Spinas GA, Lehmann R, l'Allemand D, Molinari L, Zimmermann MB. Diet determines features of the metabolic syndrome in 6- to 14-year-old children. Int J Vitam Nutr Res. Jan 2009;79(1):14-23. [Medline].
Gonzalez-Juanatey JR, Paz FL, Eiras S, Teijeira-Fernandez E. [Adipokines as novel cardiovascular disease markers. Pathological and clinical considerations]. Rev Esp Cardiol. Jun 2009;62 Suppl 2:9-16. [Medline].
Kshatriya S, Reams GP, Spear RM, Freeman RH, Dietz JR, Villarreal D. Obesity hypertension: the emerging role of leptin in renal and cardiovascular dyshomeostasis. Curr Opin Nephrol Hypertens. Oct 21 2009;[Medline].
Nakamura Y, Ueshima H, Okuda N, et al. Relation of serum leptin to blood pressure of Japanese in Japan and Japanese-Americans in Hawaii. Hypertension. Dec 2009;54(6):1416-22. [Medline].
| Age, y | 95th BP Percentile for Girls, mm Hg | 95th BP Percentile for Boys, mm Hg | ||
| 50th Height Percentile | 75th Height Percentile | 50th Height Percentile | 75th Height Percentile | |
| 1 | 104/58 | 105/59 | 103/56 | 104/58 |
| 6 | 111/74 | 113/74 | 114/74 | 115/75 |
| 12 | 123/80 | 124/81 | 123/81 | 125/82 |
| 17 | 129/84 | 130/85 | 136/87 | 138/87 |
| Infants | Children | Adolescents | |
| 1-6 y | 7-12 y | ||
| Thrombosis of renal artery or vein Congenital renal anomalies Coarctation of aorta Bronchopulmonary dysplasia | Renal artery stenosis Renal parenchymal disease Wilms tumor Neuroblastoma Coarctation of aorta | Renal parenchymal disease Renovascular abnormalities Endocrine causes Essential hypertension | Essential hypertension Renal parenchymal disease Endocrine causes |
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