hypertension in children
DESCRIPTION
Hypertension In Children. October, 2003. What are we doing here? 1. The Whys and Whats of hypertension. Importance, epidemiology, definition. 2. The Hows of testing. Technique, cuff size. 3. The Evaluation. Coexisting disease, sustained, organ damage, - PowerPoint PPT PresentationTRANSCRIPT
HypertensionIn
Children
October, 2003
What are we doing here?
1. The Whys and Whats of hypertension.
Importance, epidemiology, definition.
2. The Hows of testing.
Technique, cuff size.
3. The Evaluation.
Coexisting disease, sustained, organ damage,
curable, benefit from tx, acute vs chronic?
4. The Treatment.
Meds, lifestyle
The Whys and Whats
Sustained elevated blood pressures associated with LVH, and chronic macro and micro-vascular injury – kidneys, brain, heart, peripheral vasculature.
Acute elevations associated with encephalopathy, renal dysfunction/failure, CHF, stroke in otherwise healthy organs.
Effects of Hypertension
Prevalence
1 - 3% of children have hypertension
increases in adolescents
9 - 30 % of adults (and maybe 90%
eventually?)
Blood Pressure Standards
1996 Update on the 1987 task force report on
high blood pressure in children and
adolescents
Standard tables based on age, sex, and height
Pediatrics 88(4):649-658, 1996
Interpretation of Blood Pressure
Normal < 90 %tile
High Normal 90 - 95 %tile
Hypertension > 95 %tile
Classification of Hypertension
Significant 95 - 99 %tile
–no acute target organ injury
Severe > 99 %tile
Blood Pressure Guestimates – 95th percentile Blood
Pressures for a 50th percentile Child
Systolic BP at 1 to 17 years = 100 + (age in years x 2)
Diastolic BP at 1 to 10 years = 60 + (age in years x 2)
Diastolic BP at 11 to 17 years = 70 + (age in years)
Somu et al Arch Dis Child 2003; 88:302
Severe Hypertension (99th percentile) – add 8
With two caveats:
Is it chronic or acute?
Is there acute or chronic end organ damage?
As always, you treat the patient and not the number.
The Hows of Testing
The Right Cuff Bladder width 40% of
arm circumference
measured midway
between olecranon
and acromion
Cuff should cover 80-
100% of upper arm
circumference
Standard Position
Patient seated 3-5 minutes rest Right arm supported Brachial artery at heart
level
Thigh BP
Supine
Cuff guidelines as for
arm
Korotkoff Sounds
K4 muffling
K5 disappearance
Age limitations
Evaluation
Sustained, coexisting disease, organ damage, curable, benefit from tx, acute or chronic?
take your time to evaluate if hx and physical do not suggest an acute, escalating problem
repeated bp checks with appropriate cuff in office or at home
consider abpm
Sustained?
Patient ROS
abdominal pain, dysuria, frequency, nocturia, enuresis, cola colored urine, polyuria (intrinsic renal)
joint pain or swelling, fatigue, rash, Raynaud’s (autoimmune)
headaches, dizziness, epistaxis, visual problems weight loss, sweating, pallor, fever, palpitations
(catecholamine secreting tumor, thyroid) muscle cramps, weakness, constipation
(hyperaldosteronism with hypokalemia)
PMH/Social Hx
Umbilical artery catheter Substance abuse - steroids, cocaine Medications - steroids, amphetamines,
sympathomimetics, oral contraceptives, calcineurin inhibitors, NSAIDS
Herbals – ma huang/ephedra
Family History
hypertension myocardial infarction cerebrovascular disease diabetes mellitus hyperlipidemia pheochromocytoma polycystic kidney disease
Physical Examination
general pallor and edema (renal disease) low leg pressures & high arm pressures (coarctation
of the aorta) bruits (renovascular disease or arteritis) café-au-lait spots or neurofibromas
(neurofibromatosis) moon facies, buffalo hump (Cushing syndrome)
Physical Examination - 2
Bell palsy, neurologic deficits
fundi with a-v nicking, arteriolar narrowing, flame
lesions
features of Turner syndrome
features of Williams syndrome
Etiology: Newborn Renal artery thrombosis
Renal artery stenosis
Renal vein thrombosis
Congenital renal abnormalities
Coarctation of the aorta
Bronchopulmonary dysplasia
Etiology: 1 to 6 years
Renal parenchymal diseases
Coarctation of the aorta
Renal artery stenosis
Etiology: 6 to 10 years
Renal artery stenosis
Renal parenchymal disease
Essential hypertension
Etiology: Adolescence
Essential hypertension
Obesity
Renal parenchymal disease
Renal artery stenosis
Renal Causes of Secondary HTN in Children
Nephropathy
Renal Malformation
Obstructive
Nephropathy
Pyelonephritis
Segmental
hypoplasia
Renovascular
Wilms’ Tumor
Trauma
Metabolic
(cystinosis,
oxalosis)
CV Causes of Secondary HTN in Children Aortic Coarctation
Patent Ductus Arteriosus
Renal Artery Stenosis
Arteriovenous Fistula
Aortic Insufficiency
Polycythemia
Takayasu’s Arteritis
Endocrine Causes of Secondary HTN in Children Obesity
Pheochromocytoma
Hyperthyroidism
Congenital Adrenal Hyperplasia
17-hydroxylase Deficiency
Primary Hyperaldosteronism
Cushing’s Syndrome
Causes of Secondary HTN in Children
Neurogenic Tumors Neurofibromatosis Neuroblastoma
Central Nervous System Increased Intracranial Pressure Dysautonomia
Causes of Secondary HTN in Children
Drug Exposure Sympathomimetic agents Glucocorticoids Fracture immobilization Scoliosis repair Burns Heavy metal exposure (lead, cadmium) Scorpion bites
Tailor Evaluation
History and Physical Examination
Age of patient
Severity of disease
Evaluation: High Normal
Family History Social History
– tobacco use
– drugs Examination
– weight
– target organ injury
Evaluation: Phase I
Serum electrolytes
BUN and creatinine
Urinalysis and culture
Echocardiography
+ Hematocrit, plasma lipids
+ Renal ultrasound with doppler
Evaluation: Phase II
plasma renin/aldo
catecholamines
– 24 hour urine
– plasma
Evaluation: Phase III
Directed by history, physical and prior
studies
VCUG, DMSA
Renal biopsy for nephropathy
CT or MRI for tumor
Evaluation: Phase III continued
steroid suppression/stimulation
adrenal scintigraphy/MIBG
renal angiography for renal artery
stenosis
Reasons to consider arteriogram
Severe resistant hypertension without other etiology
Increased PRA with normal noninvasive tests
Bruit
Solitary kidney with severe hypertension
Renal ArteriographyTrachtman et al, P. Neph 14:816-819
Abnormal Normal(N=12) (N=16)
Age 11.8 11.5
Sex (M:F) 6:6 6:10
Race (W:B:O) 5:5:2 9:6:1
Duration (mo) 12.1 9.8
Peak BP 182/113 175/102
Creatinine 1.1 1.0
Prior Rx 4 5
Abnormal imaging studies
Renal US 5/9 1/9
Renal scan 2/3 2/3
Chronic TherapyNon-pharmacologic
Primary hypertension
– weight control
– exercise
– stress reduction
– dietary (salt and calories)
– elimination of contributory medications
– smoking cessation
Chronic TherapyPharmacologic
Diuretics Beta-adrenergic blockers Angiotensin converting enzyme inhibitors ARB’s Calcium channel blockers Vasodilators Alpha-1-adrenergic blockers Alpha-2-agonists Selective aldosterone antagonists (Eplerenone) Dopamine-1 agonist (Fenoldopam)
Diuretics Concerns
– Lipid disorders Contraindications
– salt wasting nephropathy– athletes in hot weather
Reserve for those with Renal Disease Thiazide - GFR 50 - 100 % Furosemide - GFR < 50% Aldactone - Hyperaldosterone states
– Nephrotic syndrome, CHF, Liver failure
Beta-blockers Concerns
– Hyperlipidemia– Asthma– Cardiovascular effects
Cardioselective – Atenolol– Metoprolol
Non-selective– Propranolol
Angiotensin Converting Enzyme Inhibitors Cautions
– Renal Artery Stenosis– Solitary Kidney– Renal Failure– Infants – Hyperkalemia– Cough– Angioedema
Calcium Channel Blockers
Short acting v. Long acting
Action: dilate peripheral arterioles by
blocking calcium transit
Nifedipine
Amlodipine
Felodipine
(Verapamil, Diltiazem)
Vasodilators Side effects
– Tachycardia
– Water retention
Hydralazine
Minoxidil
Diazoxide
Sodium Nitroprusside
Alpha-1-Adrenergic Blockers
Side effect first dose hypotension
Modest potency
Prazosin/doxazocin
Phenoxybenzamine/phentolamine
pheochromocytoma
Central Alpha-2-Agonists Side effects
– Somnolence
– Rebound hypertension Indications
– Attention Deficit Disorder Clonidine Methyldopa Guanabenz
Combination action
Labetalol – alpha (weak) and beta (non selective)
po or iv
lipids unchanged
Antihypertensives in NewbornsDiazoxide iv Initial: 1-2 mg/kg/dose
Max: 5 mg/kg/dose q 2-6 hrs prnNitroprusside iv Initial: 0.25-0.5 mch/kg/min,
double q 15-30 minHydralazine iv, po Initial: 0.1-0.5 mg/kg/dose q 3-6 hrs
Max: 2 mg/kg/dose q 6 h (po 2x iv dose)Propranolol iv,po Initial: po 0.25 mg/kg/dose q 6-8 hrs
Max: po 1-4 mg/kg/dose q 6-8 hrsInitial: iv 0.01-0.15 mg/kg/dose q 6 hrsMax: iv 4 mg/kg/dose q 6 hrs
Captopril po Initial: 0.01 mg/kg/dose q 6 hrsMax: 0.1-1.0 mg/kg/dose q 6 hrs
Hypertensive EmergenciesNicardipine 1-3 mcg/kg/min iv
Labetalol 1-3 mg/kg/hr iv
Esmolol Load 500 mcg/kg, then 50-250 mcg/kg/min
Nitroprusside0.5-0.8 mcg/kg/min iv
Enalapril 5-10 mcg/kg/dose iv q 6-12 hrs
Diazoxide 1-2 mg/kg/dose iv q 10-15 min
Phentolamine0.1-0.2 mg/kg/iv (pheo)
Nifedipine 0.25-0.5 mg/kg po (max dose 20 mg)
Hydralazine 0.1-0.5 mg/kg iv ( max dose 25 mg)
Propranolol 0.01-0.05 mg/kg iv over 1 hr (max 10 mg)
Lasix 1-4 mg/kg iv
Fenoldopam 0.1 – 0.8 mcg/kg/min