Download Hypertensive Emergencies in Children

Management of
Hypertension in Children
Carlos A. Delgado, M.D.FAAP
Div. Pediatric Emergency Medicine
Emory University School of Medicine
CHOA
Enregistrement de la pression artérielle à l'aide d'un capteur
introduit dans l'aorte: première méthode historique de mesure
de la pression artérielle (1732, Stephen Hales).
The Sphygmomanometer - Riva Rocci's instrument
Marey's wrist sphygmograph, c.
1857.
Dudgeon's wrist sphygmograph, c. 1890
The Korotkoff sounds
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
Hypertension basics
•
•
•
Primary hypertension:
Significant health problem, with overweight/obesity
being a major contributor to much of the prehypertension 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.
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
Prevalence of Elevated
Blood Pressure
•
•
•
•
Hispanics 25%
African American 19.5%
White 9.5%
Asian 4.5%
Prevalence of Hypertension
Compared to BMI
Pediatrics 113;3;475-482;March 2004
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.
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.
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.
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 physician’s office or clinic, who is
normotensive outside the clinical setting.
* 1987/2004 Task Force on Blood Pressure Control in Children
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
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.
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.
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 < 25% over 1st 8 hours
and normalizing the BP over 26 to 48hrs.
Hypertensive Urgencies
• Less serious symptoms such as:
– headache,
– vomiting
• Can be treated by either intravenous or
oral antihypertensives
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
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
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
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
Management
• Persistent mild to moderate BP elevation:
– Close follow up with outpatient evaluation
and management.
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.
Drugs
•
•
•
•
•
•
•
•
•
•
Sodium Nitroprusside
Labetalol
Metoprolol
Nicardipine
Esmolol
Hydralazine
Fenoldopam
Nifedipine
Lisinopril
Amlodipine
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
Sodium Nitroprusside
• It’s rapid vasodilatory effects cause reflex
stimulation of sympathetic nervous
system resulting in tachycardia
• Long term therapy( > 24hrs) may lead to
accumulation of cyanide and thiocyanate.
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.
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
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
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%
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
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
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
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
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
Nifedipine
• Sublingual or orally best absorption is to
bite and swallow
• Recommended oral administration to be
limited to hypertensive urgencies
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
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
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.
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)
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
Diuretics
• No longer 1st line recommendation of
chronic pediatric hypertension
• Furosemide
• Spirinolactone
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
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
•
Classification of Hypertension in Children and Adolescents With Measurement
Frequency and Therapy Recommendations
•