Persistent systemic hypertension in infants and children

Hypertension in Pediatrics

Hypertension occurring during childhood and adolescence is being recognized more frequently today than in the past. Hypertension in the pediatric population differs from that in adults with respect to incidence, etiology, clinical presentation, and drug treatment. This article reviews both the pathophysiology and drug treatment of hypertension in pediatric patients. A plan for drug management is presented.

Renovascular Hypertension

Hypertension constitutes a major health problem and the challenge is to identify patients having ‘surgically’ curable renal vascular disease among the majority with so-called essential hypertension. The best of unsatisfactory diagnostic tests are renography and plasma renin activity both before and during angiotensin II blockade. The necessity of better screening tests has increased because of the recent advances in surgical techniques and especially percutaneous transluminal renal angioplasty. The latter has definitely become the method of choice for correction of suspected hemodynamically significant artery stenoses whenever technically feasible. With improved angioplasty techniques the risk of treating renal artery stenosis without hemodynamic and clinical importance (so-called cosmetic repair) has increased. Unfortunately randomized trials including surgery versus angioplasty are not available. It should be kept in mind that only after correction of the stenosis is achieved and the blood pressure has become normal, can the diagnosis of renovascular hypertension be made with certainty.

Peripheral facial nerve palsy in severe systemic hypertension: a systematic review

BACKGROUND

Signs of nervous system dysfunction such as headache or convulsions often occur in severe systemic hypertension. Less recognized is the association between severe hypertension and peripheral facial nerve palsy. The aim of this study was to systematically review the literature on the association of peripheral facial palsy with severe hypertension.

METHODS

Systematic review of Medline, Embase, Web of Science, and Google Scholar from 1960 through December 2011 and report of two cases.

RESULTS

The literature review revealed 24 cases to which we add two cases with severe hypertension and peripheral facial palsy. Twenty-three patients were children. Palsy was unilateral in 25 cases, bilateral in one case, and recurred in nine. The time between the first facial symptoms and diagnosis of hypertension was a median of 45 days (range, 0 days-2 years). In five case series addressing the complications of severe hypertension in children, 41 further cases of peripheral facial palsy were listed out of 860 patients (4.8%).

CONCLUSIONS

The association between severe hypertension and peripheral facial palsy is mainly described in children. Arterial hypertension is diagnosed with a substantial delay. Outcome is favorable with adequate antihypertensive treatment. The pathophysiology is still debated.

Acquired facial palsy with hypertension secondary to Guillain-Barre syndrome

Most cases of facial nerve paresis are idiopathic (Bell's palsy). However, rare and potentially dangerous conditions may present in this manner. We report 2 children presenting with unilateral lower motor neuron facial nerve palsy and hypertension. A diagnosis of Guillain-Barre syndrome was made in both; literature linking facial nerve palsy in childhood with hypertension and Guillain-Barre syndrome is reviewed.

Technetium-99m-L,L-ethylenedicysteine renal scan as a single-modality investigation for the evaluation of renal morphology and function: a comparative study with technetium-99m-dimercaptosuccinic acid*

AIM

To evaluate whether cortical scars can be detected using the summed images of technetium-99m-L,L-ethylenedicysteine (99mTc-L,L-EC) renal dynamic scan, and to compare the results with technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) scan. To evaluate the inter-observer variability for 99mTc-L,L-EC and 99mTc-DMSA scan reporting.

METHODS

One hundred and three patients were initially included in the study; 21 were excluded, five due to a single functioning kidney and 16 due to impaired renal function (serum creatinine>2.5 mg.dl(-1)). Eighty-two patients (39 females, 43 males), including 31 children, with a mean age of 33.4+/-11.3 years (range, 4 months to 74 years), underwent both 99mTc-DMSA and 99mTc-L,L-EC scintigraphy within a period of 14 days. 99mTc-L,L-EC images were regrouped into 2 min image sets, and the initial 2 min summed image (cortical phase) was used for the evaluation of scars. Three independent observers analysed both images separately on different days without being aware of the identity and clinical details of the patients. Their 99mTc-L,L-EC findings were compared with the consensus 99mTc-DMSA scan findings taken as reference.

RESULTS

The overall sensitivity of 99mTc-L,L-EC scans was 93% and the specificity was 96%. The inter-observer variability was 0.91 for 99mTc-L,L-EC and 0.94 for 99mTc-DMSA scan reporting, using the weighted kappa analysis at P<0.05.

CONCLUSIONS

99mTc-L,L-EC is an excellent single-modality comprehensive investigational agent for renal morphology, function and outflow tract evaluation with the added advantages of lower cost, convenience and low radiation exposure to the patient.

Secondary hypertension: evaluation and treatment

Most patients with hypertension in the United States have essential (primary) hypertension (95%), the cause of which is unknown. The remaining 5% of adults with hypertension have the secondary form of hypertension, the cause and pathophysiologic process of which are known. Internists and other primary care physicians refer to this as treatable or curable hypertension, because the hypertension can be managed or even controlled with medications. Similarly, the condition is called surgical hypertension by surgeons in the belief that once the cause is determined and identified, surgical intervention will result in cure of hypertension. Secondary causes of hypertension include renal parenchymal disease, renovascular diseases, coarctation of the aorta, Cushing's syndrome, primary hyperaldosteronism, pheochromocytoma, hyperthyroidism, and hyperparathyroidism. Occasionally included in this category are alcohol- and oral contraceptive-induced hypertension and hypothyroidism, but these conditions are not discussed herein. The evaluation of secondary hypertension is of interest and can bring together different facets of anatomy, physiology, pharmacology, and radiology in the medical and surgical treatment of these disorders. Despite enthusiasm that can be generated in the evaluation of these conditions, evaluation can be expensive and should not be conducted for all patients with hypertension. Features that aid in the diagnosis of secondary hypertension include the following: 1. Onset of hypertension before the age of 20 or after the age of 50 years. The presence of hypertension at a young age may suggest coarctation of the aorta, fibromuscular dysplasia, or an endocrine disorder. Hypertension found for the first time after the age of 50 years may suggest the presence of renovascular hypertension caused by atherosclerosis. 2. Markedly elevated blood pressure or hypertension with severe end-organ damage, as in grade III or IV retinopathy. These findings suggest the presence of renovascular hypertension or pheochromocytoma. 3. Specific body habitus and ancillary physical findings. For example, truncal obesity and purple striae occur with hypercortisolism, and exophthalmos is associated with hyperthyroidism. 4. Resistant or refractory hypertension (poor response to medical therapy usually necessitating use of more than three antihypertensive medications from three different classes). 5. Specific biochemical test that suggest the existence of certain disorders, such as hypercalcemia in hyperparathyroidism, hyperglycemia in Cushing's syndrome and pheochromocytoma, and unprovoked hypokalemia with renin-producing tumors, primary hyperaldosteronism, or renin-mediated renovascular hypertension. 6. Other characteristics that may suggest secondary hypertension such as abdominal diastolic bruits (renovascular hypertension), decreased femoral pulses (coarctation of the aorta), or bitemporal hemianopias (Cushing's disease). A combination of a good history and physical examination, astute observation, and accurate interpretation of available data usually are helpful in the diagnosis of a specific causation.

Endocrine causes of hypertension in children

Hypertension in children is not a common problem. When it is found, however, a pathologic cause can often be identified. The endocrine causes of hypertension in children are generally rare. We have reviewed the diverse and rare endocrine causes of hypertension in the pediatric population. Table 3 lists features of these conditions that assist in their diagnosis. In all patients with hypertension, a thorough history and physical examination may point to the diagnosis of endocrine or other causes of secondary hypertension. For a more detailed approach to these diagnoses, other reviews may be helpful. A phased laboratory evaluation similar to that suggested by Ogborn and Crocker facilitates in the evaluation of secondary hypertension. The critical screening tests from an endocrine point of view are plasma sodium, potassium, calcium, renin activity, and thyroid function tests, including T4, T3, and thyroid stimulating hormone. Measurement of a 24-hour urine collection for aldosterone, metanephrine, and catecholamines may be warranted if the previously mentioned studies are unrevealing. More specific studies also may be suggested by these preliminary evaluations and the history and physical examination. Further investigations should be done with the additional guidance of a pediatric endocrinologist.

Hypertension in infancy

Hypertension in infants is rare and requires a thorough evaluation. The incidence of hypertension in infancy has risen in recent years, reflecting both better monitoring methods and increasingly successful salvage of smaller and smaller newborns. Overall mortality and morbidity rates for uncontrolled hypertension in infants are unknown. With appropriate treatment, the prognosis for resolution of hypertension is good. In most cases, hypertension is short-lived and blood pressures return to normal even when medication is discontinued. Recent experience with improved antihypertensive agents in infancy has meant that nephrectomy for renovascular hypertension is rarely required. There is still much to learn about the indications for treatment of elevated blood pressures in infancy and the potential adverse effects of therapy. Infants with a history of neonatal hypertension should be followed closely because the long-term prognosis is not known and recurrence of hypertension remains a possibility. Because hypertension can develop in high-risk newborns following discharge from the nursery, these infants deserve routine blood pressure measurements as part of their outpatient follow-up.

Renal imaging in children with persistent hypertension

The role that imaging plays in the evaluation of the child with hypertension depends in large part on the results of thorough historical, physical, and laboratory examinations. How aggressively one searches for an underlying renal parenchymal or renovascular disorder must be individualized in each child. An individualized approach to renal imaging in children with hypertension is presented.

Evaluation of renal scars by technetium-labeled dimercaptosuccinic acid scan, intravenous urography, and ultrasonography: a comparative study

The objective of our prospective study was to compare the sensitivity and specificity of ultrasonography, intravenous pyelography, and dimercaptosuccinic acid scan in detecting scarred kidneys. Twenty-seven consecutive subjects with recurrent urinary tract infections, vesicoureteral reflux, scarred kidneys, or a combination of these problems had all three imaging procedures performed. With the total number of scars serving as the gold standard, the sensitivity (94%) and specificity (100%) in identifying renal scars in children were highest for the DMSA scan. Intraobserver (95%) and interobserver (90%) reliability were also high for the DMSA scan. However, the clinical interpretation of the increased sensitivity of the DMSA scan is unknown. Changes on the scan not identified by intravenous urography may not represent true scars. Research into the long-term significance of these scars is indicated.

Familial reflux: vesicoureteral reflux in all siblings of a family

A family is presented in which 4 of 4 (100%) siblings demonstrate vesicoureteral reflux on voiding cystogram. Mechanisms of inheritance are reviewed.

Screening of asymptomatic siblings of patients with vesicoureteral reflux

Familial trait in vesicoureteral reflux (VUR) has been revealed in many studies. This paper reports on 36 siblings of 25 patients operated for vesicoureteral reflux at our Department. Siblings aged 2 to 21 years were evaluated by urine examination, urine culture and voiding cystourethrogram (VCU) for VUR. All of the siblings were asymptomatic and VUR was found in only 4 of them (11%), unilateral in 3 cases and bilateral in one case. It is concluded that evaluation of siblings for VUR will be suitable for revealing the presence of urinary infection, and assessing them by VCU at the time they are first seen.

Reflux nephropathy

This article reviews current concepts of reflux nephropathy, including the pathophysiology, diagnosis, relationship to infection, role in causing end-stage renal disease, and appropriate treatment and management. The condition is defined from a epidemiologic point of view herein, and attention also is given to possible progressions this condition can take.

Imaging techniques in the evaluation of pediatric hypertension

Moderate or severe hypertension occurs in a small percentage of hypertensive children, but it is within this group that the surgically correctable causes of hypertension are found. Since cure rates up to 90% have been reported, it is important to diagnose a secondary cause of hypertension. Excretory urography is recommended to screen for renovascular hypertension and renal parenchymal disease. Renal scintigraphy can be substituted for the urogram, but the anatomical resolution is poorer. If renovascular hypertension is suggested by abnormal results of screening examination, arteriography should be part of the evaluation. Ultrasonography is reserved primarily for evaluating neonatal hypertension which most frequently is related to thrombosis. If this diagnosis is documented, renal function should be assessed with radionuclide techniques. If a hormonally active tumor is suspected, evaluation of the adrenals and retroperitoneum is accomplished best by CT.

Renovascular hypertension in childhood: a changing perspective in management

Seventeen children with renovascular hypertension caused by intrinsic renal artery lesions received treatment during the past 10 years. At presentation nine were asymptomatic, four had headaches, and one had epistaxis; three infants had anorexia and failure to thrive. Routine intravenous pyelogram and radionuclide renal scan findings were abnormal in 29% and 31% of patients, respectively. Arteriography showed a branch artery stenosis in seven patients and a main artery lesion in 10. A renal vein renin ratio of greater than or equal to 1.5 between the affected and the contralateral kidney was obtained in 10 of 17 patients. Of 16 patients available for follow-up, 15 are normotensive after a mean follow-up of 3.7 years. Cure was achieved by partial nephrectomy and ligation of a stenosed vessel in two and nephrectomy in five (three having undergone an unsuccessful angioplasty procedure). Autotransplantation or angioplasty was curative in a further six. Transluminal balloon angioplasty was attempted in seven patients but was successful in only two with main renal artery stenoses. With preservation of renal parenchyma as the main goal, medical and surgical therapy can be individualized for each patient.

Vesicoureteral reflux and reflux nephropathy

Vesicoureteral reflux (VUR) is mainly a primary phenomenon due to incompetence of the ureterovesical junction, mostly affecting a pediatric population. During micturition cystourethrography (MCU) reflux into the kidney--intrarenal reflux (IRR)--is occasionally seen. In areas with IRR the kidney surface may subsequently be depressed and the papillae retracted (reflux nephropathy (RN]. VUR may lead to hypertension and/or end-stage renal failure. Most commonly, VUR is discovered during evaluation for urinary tract infection, but it may also be present in patients with hypertension, toxemia of pregnancy, chronic renal failure and proteinuria, and it may be found in siblings of patients with VUR. For the time being VUR is demonstrated at radiographic MCU, whereas RN is diagnosed by demonstration of focal scars and of abnormal parenchymal thickness at urography. In children with VUR and no abnormalities of calyces or parenchymal defects standardized measurement of the parenchymal thickness at three sites may identify kidneys which are likely to develop focal scars. Quantitation of focal scarring should be performed in connection with a measure of the overall kidney size. The occurrence of IRR is dependent of the papillary morphology, intrapelvic pressure and urine flow. There may be an important relationship between renal ischemia and IRR in producing a 'vicious circle of deleterious effects' which, combined with parenchymal extravasation, may lead to RN. Treatment of VUR includes medical and surgical management. Since renal scarring may occur in infancy, prevention should focus on infants and young children. Infants and young children with severe VUR may have normal urograms. Therefore a MCU should also be performed, preferably with the recommended standardized technique.

Childhood hypertension: etiology, diagnosis, and treatment

The introduction of blood pressure measurements as an integral part of the routine care of children and adolescents has increased awareness of a significant incidence of hypertension in the pediatric age group. The concepts and principles discussed in this article provide a basis for the diagnosis and management of childhood hypertension.

Acquired renal scars in children

To determine the important factors involved in the etiology of renal scarring we studied 37 children with renal scars seen at our hospital since 1965. This is the second largest series reported to date. Children who had neurogenic bladders or any structural abnormalities of the urinary tract other than vesicoureteral reflex were excluded. The study group included 36 girls and 1 boy. The average age at first detection of renal scars was 5.7 years. Acute pyelonephritic episodes, which were treated early and aggressively, infrequently led to renal scarring. However, the initial prolonged or poorly treated episode of acute pyelonephritis was followed invariably by the development of renal scarring. The severity of renal scarring was related to the grade of vesicoureteral reflux (p less than 0.05), although some scars did develop in the absence of reflux. Neither the shape and position of the ureteral orifice nor the ureteral tunnel length correlated with the severity of renal scarring. Treatment with prophylactic antibiotics may have lessened the severity of renal scarring (0.1 less than p less than 0.2) but treatment with reimplantation surgery did not appear to alter the course of renal scarring. This study suggests that the key to the prevention of renal scarring is the early and aggressive treatment of acute pyelonephritis.

Familial vesicoureteral reflux: a prospective study

A prospective study was established to identify the incidence of vesicoureteral reflux in the siblings of patients with reflux. Of 78 patients with reflux 104 siblings were screened with an awake voiding cystogram and 34 (32 per cent) were found to have reflux. Of these 34 siblings 25 (73 per cent) had no abnormal voiding symptoms or history of urinary tract infection. The highest incidence of reflux was found in the siblings of those patients with radiographic evidence of renal scarring. Early detection and followup in this high risk group may be a vital tool in determining more about the natural history of vesicoureteral reflux and its relationship to renal damage.

Spironolactone therapy in infants with congestive heart failure secondary to congenital heart disease

The efficacy of treatment with spironolactone for congestive heart failure secondary to congenital heart disease was studied in 21 infants under 1 year of age. All received digoxin and chlorothiazide. In addition, group A (n = 10) was given supplements of potassium and group B (n = 11) received spironolactone. Daily clinical observations of vital signs, weight, hepatomegaly, and vomiting were recorded. Paired t test analysis showed significant reduction in liver size and weight (P less than 0.01) and respiratory rate (P less than 0.05) in group B, and less significant decreases in group A. The incidence of vomiting was slightly lower in group B. We conclude that the addition of spironolactone hastens and enhances the response to standard treatment with digoxin and chlorothiazide in infants with congestive heart failure.

The child-adolescent blood pressure study: I. Distribution of blood pressure levels in Seventh-Day-Adventist (SDA) and non-SDA children

Distribution of systolic and diastolic blood pressures (measured with an automated blood pressure recorder) of two large groups of children-3,159 from Seventh-Day Adventist (SDA) schools and 4,681 from non-SDA schools-are reported. They boys and girls were from four different ethnic groups and attended grades one through 10 in 29 Southern California schools. The analysis of the data failed to show significant differences in mean blood pressure levels between the two groups of children at all ages, despite marked differences in life-style between the two groups, and despite the fact that adults from the two population groups have marked differences in mortality from diseases associated with elevated blood pressure. A comparison between boys and girls showed significantly higher trends in mean systolic blood pressure for boys after age 12. Inter-ethnic comparisons of blood pressure revealed that Black children of both sexes had slightly higher mean blood pressure levels at all ages.

Facial palsy in an infant with coarctation of the aorta and hypertension

We report the unusual association of facial palsy and severe hypertension in an infant with coarctation of the aorta. The facial palsy resolved before the hypertension was cured.

The radiological evaluation of children with hypertension

The value of radiological examinations in hypertension was analyzed in a series of 44 children. An i.v. urography had been performed in 43 cases with a pathological finding in 19 (44%). Renal angiography, employed in 19 cases, revealed abnormal findings in 12 (63%) patients. Micturating urethrocystography performed in 16 children gave no additional important information. The only complication noted was thrombosis of the femoral artery subsequent to renal angiography in one child less than one year of age. The diagnosis of hypertension based mainly on the i.v. urography in 12 cases but the renal angiography gave additional important information in 6 children. One child with obstructive hydronephrosis was also found to have a renal artery stenosis at renal arteriography. Based on these results, and particularly because secondary hypertension may frequently be treated surgically, we consider extensive radiological investigation with renal angiography is mandatory before receiving a final diagnosis of essential hypertension, and before starting long-term treatment.

Central nervous system involvement in severe arterial hypertension of childhood

The case histories of 125 children with hypertension and no apparent primary CNS disease were analyzed for neurological symptoms or complications. Eleven children had neurological symptoms of high blood pressure. In only one of these patients was the diagnosis of arterial hypertension made before the observation of the neurological findings. The symptoms were severe headache in eight children, convulsions and coma in four, hemiplegia in two, and impaired vision and apraxia in one child. Symptomatology was rapidly reversed by antihypertensive treatment in four children, while six had long-term stigmata and one child died in hypertensive crisis. Because elevated arterial pressure can cause severe neurological disease, routine blood pressure measurement in children--especially those with neurological symptomatology--is stressed.

A survey of 164 Finnish children and adolescents with hypertension

A retrospective analysis was performed on 164 children and adolescents with persistent hypertension. Among the unselected 115 patients with hypertension seen within the last three years 47 (41%) exhibited renal disease, 37 (32%) coarctation of the aorta, 10 (9%) miscellaneous associated causes and 21 (18%) no associated cause (essential hypertension). A substantial number, 53/164, had a primary disease potentially curable by surgery, and in 37 patients the blood pressure was normalized postoperatively. The outcome depended mostly on the basic disease and the availability of chronic hemodialysis. 11/164 children have died, all because of terminal basic disease, and one with simultaneous hypertensive crisis. We thus recommend a thorough investigation in the case of a child with persistent hypertension.

Nonrenovascular renal hypertension in children

Hypertension in children has been reported with increasing frequency because of increased awareness of its occurrence by clinicians. Renovascular lesions have been stressed in the past. However, in recent years, a number of nonrenovascular renal lesions have received attention and form the basis for this report. Unilateral chronic atrophic pyelonphritis, segmental unilateral pyelonephritis, the Ask-Upmark kidney, and unilateral renal hypoplasia have been associated with curable hypertension. The subject of juxtaglomerular cell hyperplasia, which has variably been reported in these cases, is reviewed. Ureteral obstruction, in the form of uretero-pelvic or ureterovesical junction obstruction, solitary renal cysts, the unilateral multicystic kidney, renal trauma, and renal tumors (Wilms' tumor and juxtaglomerular cell tumors) may also be associated with hypertension in children. Pheochromocytoma must be ruled out in all cases. Because of renewed interest, these nonrenovascular renal causes of hypertension are now likely to be diagnosed with increased frequency.

Analysis of 100 children with severe and persistent hypertension

In 100 children with persistent hypertension seen over the past 5 1/2 years the commonest causes of hypertension were chronic glomerulonephritis, reflux nephropathy, coarctation of the aorta, and obstructive uropathy, accounting for some 70% of cases. 17 children have died, but in the remainder hypertension has been controlled by surgery, chronic haemodialysis, or by the use of pharmacological agents. Methyldopa was the commonest drug used, and the children appeared relatively resistant to the side effects of this and of other drugs, even when large doses were used. The improvment is the prognosis of severe hypertension in childhood indicated in this survey is largely due to the availability of chronic haemodialysis and transplantation for end-stage renal disease, but the advances in diagnositc methods and surgical techniques and the introduction of new drugs have also contributed.

Nomograms relating aldosterone excretion to urinary sodium and potassium in the pediatric population: their application to the study of childhood hypertension

The lability and diurnal variation of blood pressure in normal and hypertensive children were examined and found to be less than that described in adults. Nomograms were prepared relating urinary sodium and potassium to urinary aldosterone in children ranging in age from infancy to 22 years. These nomograms reveal that the relation of aldosterone excretion to sodium excretion is described by a hyperbolic function. Most values for normal children, children with mild essential hypertension and children with severe essential hypertension fell between two hyperbolic curves representing the 5th and 95th percentile, respectively. Hypertensive children with low and high plasma renin activity were found to have an inappropriately high level of urinary aldosterone excretion in relation to urinary sodium excretion. No relation was found between potassium and aldosterone excretion. By means of these nomograms the normal standards for aldosterone excretion in children were refined, permitting classification of hypertensive children into distinct groups. This classification may have prognostic significance.