Management of Hypertension in Children

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Management of Hypertension in Children

• Carlos A. Delgado, M.D.FAAP
• Div. Pediatric Emergency Medicine
• Emory University School of Medicine
• CHOA

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Enregistrement de la pression artérielle à l'aide
d'un capteurintroduit dans l'aorte première
méthode historique de mesurede la pression
artérielle (1732, Stephen Hales).
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The Sphygmomanometer - Riva Rocci's instrument
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Dudgeon's wrist sphygmograph, c. 1890

• Marey's wrist sphygmograph, c. 1857.

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• The Korotkoff sounds

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Objectives

• Recall key elements necessary for the diagnosis
  and management of hypertension in children.
• Discuss various pharmacological treatment options
  for the management of hypertensive urgencies and
  emergencies

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Hypertension basics

• Primary hypertension
• Significant health problem, with
  overweight/obesity being a major contributor to
  much of the pre-hypertension and stage1
  hypertension.
• Body mass index (BMI) should be calculated and
  plotted on the CDC growth curves in pediatric
  patients.
• The prevalence of hypertension increases with
  increased BMI hypertension is present in about
  30 percent of those with BMI above the 95th
  percentile.

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Prevalence

• Estimated at 1-2 with an increase in primary
  hypertension likely due to the rising trend
  towards childhood obesity
• Overweight prevalence is aprox 20
• 31 Hispanics
• 22 African American
• 15 White
• 11 Asian

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Prevalence of Elevated Blood Pressure

• Hispanics 25
• African American 19.5
• White 9.5
• Asian 4.5

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Prevalence of Hypertension Compared to BMI
Pediatrics 1133475-482March 2004
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Definitions

• Hypertensive Emergency is a severely elevated
  blood pressure with evidence of target organ
  injury- most commonly the CNS system, kidneys,
  or cardiovascular system.
• Hypertensive Urgency is a severely elevated blood
  pressure with no evidence of secondary organ
  damage but if left untreated will imminently
  result in target organ injury.

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How to measure a blood pressure

• Patient resting in seated position right arm at
  the level of the heart.
• Blood pressure cuff
• The width of the inflatable bladder should be at
  least 40 of the arm circumference at a point
  midway between the acromion process and the
  olecranon
• Cuff too large BP artificially low
• Cuff too small BP artificially high
• Abnormal BP should be verified by auscultation
  with a sphygmomanometer.

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Pediatric hypertension

• 1987/2004 Task Force on Blood Pressure Control in
  Children Hypertension is the average systolic
  and/or diastolic blood pressure persistently
  above the 95th percentile.
• Severe hypertension that above the 99th
  percentile.

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Pediatric hypertension

• The blood pressure must be obtained on three
  separate occasions. If the systolic and diastolic
  blood pressure falls into different categories,
  classify by the higher category.
• - NORMAL BLOOD PRESSURE is defined as a systolic
  and diastolic blood pressure below the 90th
  percentile for gender, age and height percentile
  (utilizing the Center for Disease Control (CDC)
  growth curves).
• -PRE-HYPERTENSION is defined as the 90th
  percentile to less than 95th percentile or if BP
  greater than 120/80 even if below the 90th
  percentile (up to below the 95th percentile).
• - STAGE 1 HYPERTENSION is defined as a blood
  pressure between the 95th percentile and the 99th
  percentile plus 5mmHg.
• -STAGE 2 HYPERTENSION is defined as a blood
  pressure above the 99th percentile plus 5mmHg.
• -WHITE COAT HYPERTENSION is defined in a
  patient with blood pressure above the 95th
  percentile in the physicians office or clinic,
  who is normotensive outside the clinical setting.
  1987/2004 Task Force on Blood Pressure Control
  in Children

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Hypertension

• Systolic BP elevation is an important factor in
  the morbidity of hypertension in children and
  adults
• Mild to moderate BP elevation is associated with
  increased left ventricular mass
• Elevation of systolic BP is more closely related
  with LV morphology
• Among hypertensive pts prevalence on LVH ranges
  from 30-70
• Treatment of hypertension should be directed to
  normalization of systolic BP

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Hypertension management

• The indications for antihypertensive drug
  therapy
• secondary hypertension and
• insufficient response to lifestyle modification.
• Pharmacological therapy should be initiated with
  a single drug.
• Acceptable classes for use in children include
  ACE inhibitors, angiotensin receptor blockers,
  beta-blockers, calcium channel blockers and
  diuretics.

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BP Goal

• The goal for antihypertensive treatment in
  children should be reduction of BP to below the
  95th percentile unless concurrent conditions are
  present, in which case BP should be lowered to
  below the 90th percentile.

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Hypertensive Emergencies

• Usually accompanied by signs of hypertensive
  encephalopathy and typically causing seizures.
• Should be treated with intravenous
  antihypertensive that can produce a controlled
  reduction in BP aiming to
• decrease the BP by lt 25 over 1st 8 hours and
  normalizing the BP over 26 to 48hrs.

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Hypertensive Urgencies

• Less serious symptoms such as
• headache,
• vomiting
• Can be treated by either intravenous or oral
  antihypertensives

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Common causes of hypertension in children
Age group Cause
Newborns Renal vessel thrombosis Renal artery stenosis Congenital renal anomalies Coartation of the aorta
Early Childhood 1-6 yrs Renal parenchymal disease Renovascular disease Coartation of the aorta
School age 6- 10 yrs Renal parenchymal disease Renovascular disease Essential hypertension
Adolescence Essential hypertension Renal parenchymal disease Renovascular disease Drugs
Pheochromocytoma and Cushing Disease should be
considered in all age groups
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Clinical Assessment

• History
• Prior history of HTN
• Abrupt withdrawal of meds
• Symptoms
• Visual changes, CNS disturbance, renal disease,CV
  compromise
• Flushing, tachycardia, weight changes,
• Umbilical vessel catheterization, GU anomalies,
  recent head injury, medication use, drugs of
  abuse
• Family history of hypertension or stroke

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Physical examination

• Vital signs , pulse oximetry
• 4 limb blood pressures
• Accurate weight
• Fundoscopic examination
• Neurologic examination including mental status
• Cardiovascular examination
• Renal artery bruits, edema, growth failure

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Ancillary investigations

• CXR
• EKG
• CT head
• UA and serum BUN and creatinine
• CBC to r/o HUS or anemia
• Renal ultrasound
• Plasma renin
• MRA/Duplex Doppler flow studies/3-D CT

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Management

• Persistent mild to moderate BP elevation
• Close follow up with outpatient evaluation and
  management.

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Management

• BP should be reduced no more than 25 in the
  first 2 hours, then reduced gradually over the
  next 3-4 days.
• IV route for medication administration is
  preferred- better titration and predictable
  absorption.

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Drugs

• Sodium Nitroprusside
• Labetalol
• Metoprolol
• Nicardipine
• Esmolol
• Hydralazine
• Fenoldopam
• Nifedipine
• Lisinopril
• Amlodipine

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Sodium Nitroprusside

• Arterial and venous vasodilator
• No chronotropic or inotropic effects
• Extremely short half-life
• Easily titrated to effect
• Dose 0.3-0.5 micrograms/kg/min.
• Maximum 8 mcg/kg/min
• Most patients will respond at rates of 3
  mcg/kg/min

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Sodium Nitroprusside

• Its rapid vasodilatory effects cause reflex
  stimulation of sympathetic nervous system
  resulting in tachycardia
• Long term therapy( gt 24hrs) may lead to
  accumulation of cyanide and thiocyanate.

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Fenoldopam( Corlopam)

• Fenoldopam is a selective dopamine agonist
• In both an oral and parenteral form, the drug
  causes peripheral vasodilatation by stimulating
  dopamine-1 adrenergic receptors.
• Intravenous fenoldopam may provide advantages
  over sodium nitroprusside because it can induce
  both a diuresis and natriuresis, is not light
  sensitive, and is not associated with cyanide
  toxicity.
• There is no evidence for rebound hypertension
  after discontinuation of fenoldopam infusion.

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Fenoldopam

• Selective dopamine agonist causing vasodilatation
  of the renal, coronary, cerebral and splacnic
  vasculature reducing MAP.
• Successful controlled hypotension in spinal
  fusion and in PICU
• Peak effect in 5-15 minutes
• Infusion 0.1-2 ?g/kg/min
• Side effects reflex tachycardia, Increased ICP
  and IOP

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Labetalol

• Both ? and ? sympathetic blocker
• May be safer that sodium nitroprusside
• Reduces vascular resistance
• Difficult to titrate due to long half life
• Continuous infusion or bolus
• Infusion- 0.2 to 3 mg/kg/hr
• Intermittent bolus 0.2- 1 mg/kg
• Efficacious in those with renal disease
• Caution asthma,CHF, diabetes

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Metoprolol (TOPROL-XL )

• ?1- selective blocker
• Doses 0.2 mg/kg "low," 1.0 mg/kg "medium," or
  2.0 mg/kg "high")
• The most common adverse events
• Headache 11.7
• upper respiratory tract infection 6.8
• dizziness 4.2 and cough 2.5

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Esmolol ( Breviblock)

• Ultrashort cardioselective ?- adrenergic blocking
  agent
• Primary use in the perioperative management of
  tachycardia and hypertension in patients at risk
  of developing hemodynamically-induced myocardial
  ischemia.
• Infusion loading 100-500 ?g/kg followed by
  infusion of 50-300 ?g/kg/min
• Caution in asthmatics, bradycardia, and CHF

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Nicardipine (Cardene)

• Calcium channel blocker
• Blocks movement of Ca across vascular smooth
  muscle decreasing preventing contraction total
  vascular resistance.
• Advantages Lack of decreased cardiac output and
  limited effects on chronotropic and inotropic
  effects on the heart.
• Can be given IV
• Rare hypotensive episodes
• Limited experience in children

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Nicardipine

• Dose 0.5 1 ?g/kg/min to max of 3
  ?g/kg/min
• Infusion should be increased every 3-5 minutes to
  desired effect
• Fast onset of action
• Adverse effects increased ICP, headache nausea,
  hypotension
• Cimetidine increases effects

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Hydralazine

• Potent arterial vasodilator to reduce systemic BP
• Onset of action is 5-30 mins
• Duration of action 4-12 hrs
• Dose 0.1-0.5 mg/kg/dose max 20 mg every 4-6 hr
• Losing popularity

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Nifedipine

• Reported adverse cardiac and neurologic sequelae
  due to hypotension in adults
• Reported rebound hypertension causing adverse
  neurologic events in children associated with the
  use of short acting nifedipine. Calcium channel
  blocker- decrease peripheral vascular resistance
• Dose 0.25mg/kg
• Blaszac study J Peds 2001- no significant
  complications

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Nifedipine

• Sublingual or orally best absorption is to bite
  and swallow
• Recommended oral administration to be limited to
  hypertensive urgencies

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Lisinopril (Zestril)

• Lisinopril is ACE inhibitor.
• It is used to treat mild to severe high blood
  pressure as well as congestive heart failure.
  Lisinopril is given as a tablet.
• Side effects
• Dizziness
• Rash
• Dry cough

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Lisinopril(Zestril)

• For people not on diuretics, the initial starting
  dose is usually 10 milligrams, taken 1 time a
  day. The long-term dosage usually ranges from 20
  to 40 milligrams a day, taken in a single dose.
• Diuretic use should, if possible, be stopped
  before using lisinopril.
• Renal disease needs dose adjustments, depending
  on kidney function

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Lisinopril(Zestril)

• Dose is 0.07 milligrams per day up to a total of
  5 milligrams per day.
• Zestril is not recommended in children younger
  than 6 years old or in children with poor kidney
  function.

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Amlodipine ( Norvasc )

• Amlodipine is a calcium channel blockers.
• Amlodipine - tablet to take by mouth. It is
  usually taken once a day
• Amlodipine may cause side effects.
• swelling of the hands, feet, ankles, or lower
  legs
• headache
• upset stomach
• stomach pain
• dizziness or lightheadedness
• drowsiness
• excessive tiredness
• flushing (feeling of warmth)

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Amlodipine ( Norvasc )

• Dose 0.05 0.1 mg/kg/day once daily increase to
  effect
• Usual target dose is 0.2-0.25 mg/kg/day
• Younger children may require 0.3-0.4 mg/kg/day
• Titrate over 1-2 week period

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Diuretics

• No longer 1st line recommendation of chronic
  pediatric hypertension
• Furosemide
• Spirinolactone

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When to refer to specialist

• Blood pressure values greater than 95 for gender
  , age, height on three different occasions.
• One or more risks factors of cardiovascular
  disease
• Obesity
• Diabetes
• High blood lipids
• Family hx. of stroke, cardiovascular disease
• Failed pharmacological management

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General concepts

• Suggested initial medications are lisinopril
  (ACE inhibitor), amlodipine (calcium channel
  blocker) and hydrochlorothiazide (thiazide
  diuretic).
• Know the side effects that may cause health
  issues or lack of compliance.
• Generally avoid beta-blockers in patients where
  physical activity is important (athletes and/or
  overweight).

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So which drugs should I use?

• Labetalol for initial bolus, it alone may control
  BP, may require rebolusing
• Nicardipine if placing on a drip. Use on neonates
  is not recommended due to immature function of
  sarcoplasmic reticulum.
• If using PO Norvasc or Labetalol

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•  Classification of Hypertension in Children and
  Adolescents With Measurement Frequency and
  Therapy Recommendations

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The End !