Hypertension in Children

Proper measurement

• Bladder of cuff is 2/3 length of the upper arm and encircles the arm
• Korotkoff phases:
• K1 is systolic BP
• K4 (muffling) is diastolic BP in 12 years and younger children
• K5 (disappearance) is diastolic BP in older than 12 years children
• Children should site; infants should be supine
• Right arm at level of heart
• Inflate cuff 20 mmHg above point where the radial pulse disappears
• Circadium rhythm: nadir of BP early morning hours and peak in the afternoon

Definition of Hypertension

• Use norms for age, sex and height percentile
• 1977 study by the National Heart, Lung, and Blood Institute
• 1987 study by AAP Second Task Force on BP control in Children (70,000) children
• High normal BP: between 90-95%
• Moderate HTN: between 95-99%
• Severe HTN: persistently at or above 99%
• Hypertensive urgency: elevated BP without end-organ damage
• Hypertensive emergency: elevated BP with evidence of end-organ damage

Causes of Hypertension

• "Likelihood of arriving at a diagnosis is directly related to the degree of BP elevation and is inversely related to the age of the child"
• Renal parenchymal disease is cause of 60-80% of hypertension in children
• Coarctation of the aorta is the most common non-renal etiology (5-15% of cases)
• Renal artery stenosis causes less than 5% of cases of pediatric hypertension (or 5-25% in other studies)
• Endocrine: excess mineralocorticoids (congenital adrenal hyperplasia) or catecholamine (pheochromocytoma, neuroblastoma)

 

Adapted from the Task Force on Blood Pressure Control in Children, Report of the Second Task Force on Blood Pressure Control in Children.  Pediatrics 79:1-25 (1987).

Newborns	Renal artery thrombosis, renal artery stenosis, congenital renal malformation, coarctation of the aorta, bronchopulmonary dysplasia
infancy-6 years	Renal parenchymal disease, coarctation of the aorta, renal artery stenosis
6-10 years	Essential hypertension (including obesity), renal artery stenosis, renal parenchymal diseases
Adolescence	Essential hypertension (including obesity), renal parenchymal diseases

History

• Family history of renal disease, hypertension, stroke
• PMH of UTIs, fevers, hematuria, dysuria, edema, umbilical artery catheterization
• Medications including OCPs, toxins, illicit drugs
• Sweating, flushing, palpitations, fever, weight loss
• Headaches, vomiting, irritability, seizures or other neurological signs
• Decreased urine output, edema

Physical Exam

• Growth
• CHF (tachypnea, hepatomegaly)
• Femoral pulses, four extremity BPs
• Thyroid
• Neurological exam and Funduscopic (papilledema, hemorrhage, edema, infarcts)
• Abdominal bruit
• Abdominal masses

Evaluate

• If BP over 95%
• If BP persists over 90-95% for four weeks

Labs

Basic:
 

CBC

Electrolytes, calcium

BUN/Cr

Uric acid

Urinalysis, culture

Lipid Profile

Renal Ultrasound

Extended:
 
• ECG
• CXR
• Echocardiogram
• Urinary catecholamines
• DMSA scan
• Abdominal ultrasound
• Captaprel enhanced MagIII
• Renal vein  renins.  Renal arteriography, angioplasty
• Lipid profile
• Peripheral plasma renin

Treatment

• Reduce the BP gradually (30-40% in the first 6 hours; 30% over the next 12-36 hours; last 30% over the next 48-96 hours)
• If not life-threatening
• Hydralazine (Apresoline) iv (onset 10-20 minutes, reflex tachycardia)
• Nifedipine (Procardia) orally 0.25 to 0.5 mg/kg (onset 5-15 minutes; flushing and dizziness).  Avoid if CNS bleed is present.
• If life-threatening
• ABCs
• vascular access
• Sodium nitroprusside (Nipride) iv titrated *only in the PICU*
• Diazoxide (Hyperstat) iv: hypotension with coma, renal failure, etc.
• Labetalol (Normodyne) iv titrated
• General
• Weight reduction
• Exercise
• Salt and fat restriction
• Decreased stress
• Avoid stimulants, OCPs, decongestants, cigarettes
• Correct underlying cause

References

• Sadowski, Robert.  1996.   "Hypertension in pediatric patients" American Journal of Kidney Diseases, 27(3)
• Gutgesell, H.  1997.  "Common cardiovascular problems in the young" American Family Physician 56(8)
• Elkasabany, A.  1998.  "Prediction of adult hypertension by K4 and K5 in Children".  Journal of Pediatrics 132(4)
• Dillon, M.  1997.  "The Diagnosis of Renovascular Diseases".  Pediatric Nephrology 11
• Moss and Adams.  1995. Heart Disease in Infants, Children and Adolescents.  Williams and Wilkins.
• Fleisher and Ludwig.  1996.  Synopsis of Pediatric Emergency Medicine.  Williams and Wilkins.

Acknowlegment