Child with hypertension
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Transcript of Child with hypertension
OBJECTIVES
Identify children and adolescents for whom
hypertension screening is appropriate
Implement an initial workup for pediatric
hypertension
Develop treatment plans for children with
essential or secondary hypertension
Hypertensive children
Usually asymptomatic
HOWEVER already manifest evidence of target organ damage
Left ventricular hypertrophy ( up to 40%)
Increased carotid intima-media thickness
Children with BP > 90th percentile have a 2.4-fold greater risk having hypertension as adults
BACKGROUND
Systemic hypertension is uncommon (<1%)
If present often indicative of an underlying disease process
SEVERE and SYMPTOMATIC HYPERTENSION in children is usually due to SECONDARY HYPERTENSION
Prevalence of primary essential hypertension has increased, mostly in older school age and adolescents
PREVALENCE OF HYPERTENSION IN CHILDREN
Hypertension is defined as average SBP and/or
diastolic BP that is 95th percentile for gender , age and height on 3 or more occasions.
DEFINITION
Normal Blood Pressure : < 90th percentile for age,
gender and height.
Pre-hypertension : SBP and/or DBP >90th percentile but less than 95th percentile for age, gender and height.
For age >12years, BP >120/80 regardless of 90th percentile considered pre-hypertension
Hypertension : SBP and/or DBP >95th percentile for age, gender and height
Stage 1: 95th – 99th percentile + 5 mmHg Stage 2: > 99th percentile + 5 mmHg
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CLASSIFICATION OF HYPERTENSION
Hypertensive urgency:
Significant elevation in BP without accompanying end-organ damage; more common in children.
(180 or higher for your systolic pressure or 110 or higher for your diastolic pressure)
Symptoms include headache, blurred vision, and nausea
Hypertensive emergency: Elevation of both systolic and diastolic BP
(exceeding 180 systolic or 120 diastolic)
with acute end-organ damage (e.g., cerebral infarction or hemorrhage, pulmonary edema, renal failure, hypertensive encephalopathy, or seizures)
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HYPERTENSIVE CRISIS
Short term mechanisms
Baroreceptors (low pressure & high pressure)
Hormonal
Noradrenaline-adrenaline system
Renin-angiotensin-aldosterone system
Vasopressin system
Long term mechanisms
Renal body fluid pressure control system
BLOOD PRESSURE REGULATIONS
BARORECEPTOR REFLEX CONTROL
How should blood pressure be
measured in children?
The child should be calm and free of anxiety The child should have been sitting quietly for 5 minutes.
The child should be sitting with back supported, both feet on the floor and right cubital fossa supported at heart level.
Choose the appropriate cuff size: The cuff width should cover ~70% of the distance
between the acromion and the olecranon . The cuff bladder length should be 80 to 100% of the arm
circumference, and the cuff bladder width should be at least 40% of the arm circumference at the midpoint of the acromion-olecranon distance.
Choose the appropriate size cuff
Recommended Dimensions for Blood Pressure Cuff Bladders
Maximum Arm
Age Range Width (cm) Length (cm) Circumference (cm)*
Newborn 4 8 10
Infant 6 12 15
Child 9 18 22
Small adult 10 24 26
Adult 13 30 34
Large adult 16 38 44
Thigh 20 42 52
*Calculated so that the largest arm would still allow the bladder to encircle the arm by at least 80 percent.
METHODSPalpatory Method BP recording is 10 mm Hg less
than that obtained by auscultatory method .
Auscultatory Method Preferred method. BP tables are based on it.
Doppler Study Non invasive procedure
Oscillometric Method Better to record mean BP. Useful in infants and young children. BP > 90th percentile should be rechecked by auscultatory method.
Flush Method Used in newborns. Only SBP can be recorded.
Ambulatory Blood Pressure Monitoring
White-coat hypertension Target-organ injury risk
BP should be recorded in all 4 limbs.
Cuff should not be applied too tight (low BP recording) or too loose (high BP recording).
BP monitoring subsequently should be taken in the same limb and position.
Normally the BP is 10-20mm Hg higher in lower limbs compared to the upper limbs.
POINTS TO BE REMEMBERED
COMMONEST CAUSES
Newborn Umbilical artery catheterization and
Renal artery thrombosis.
Childhood Renal disease, COA, endocrine
disorders or medications.
Adolescents. Essential hypertension becomes
increasingly common.
ETIOLOGY
DEVELOPING A DIFFERENTIAL . . . “M.O.N.S.T.E.R.”: A simple pneumonic to start the thinking process
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Renal Causes Renal Parenchymal diseases (78%)
Renal vascular diseases (12%)
Cardiovascular CoA(2%)
Condition with large stroke volume (PDA, AV fistula)
Endocrine Hyperthyroidism
Excessive Catecholamine levels (Pheochromocytoma)
Adrenal dysfunction (CAH 11b, 17 a hydroxylase deficiency)
Hyperaldosteronism (Conn's Syndrome, Renin Producing Tumors)
Hyperparathyroidism
Neurogenic Raised ICT, Poliomyelitis,GBS, encephalitis
Drugs and Chemical Sympathomimetic drugs , Amphetamines, Steroids, OCP, Heavy matal poising (Hg, Lead), Cocaine, Cyclosporine
Miscellaneous Hypercalcemia, After Coarctation repair, fractures of long bone,Pre eclampsia etc.
CAUSES OF HYPERTENSION IN PEDIATRIC POPULATION
Obesity-- for each one unit increase in BMIz-score, children 8 to 17 years of age have been shown tohave twice the risk of having a BP greater than the 95thpercentile.1
Usually asymptomatic
Mild to moderate obesity
Clinical manifestation of the underlying disease
Headache, dizziness, epistaxis, anorexia, visual changes, seizures
Hypertensive encephalopathy : vomiting, temperature elevation, ataxia, stupor, seizures
CLINICAL MANIFESTATIONS
Acute Gromerulonephritis Oliguria, haematuria, mild proteinuria, oedema
Pyelonephritis Urinary tract infection, fever
Haemolytic UraemicSyndrome
AGE (bloody stool), weakness, irritability, oliguria, oedema
Henoch-Schonlein purpura Palpable purpuric rash, abdominal pain, haematochezia, periarticular swelling, scalp & scrotal oedema, haematuria
SLE Arthritis, arthralgia, weight loss, fever, malaise, malar rash, alopecia, oral ulcers, haematuria
Renal vein thrombosis Abdominal pain, history of umbilical catheterization
Familial nephritis Frequent haematuria
Wilms tumour Abdominal mass, abd pain, fever, microscopic/gross haematuria
Neuroblastoma Abdominal mass, fever, weight loss, limp, back pain
Neufibromatosis Skin nodules, family history
Hyperthyroidism Tremor, anxiety, sweating, heat intolerance, inability to concentrate, weight loss, hyperactivity, neck mass
Pheochromocytoma Anxiety, tremor, sweating, headache, flushing, nausea, vomiting, weight loss, constipation/diarrhoea, Raynaud’s, chest pain, polyuria/nocturia
Cushing syndrome Obesity, failure of long. growth, hirsutism, weakness, acne, hyperpigmentation, history of taking steroid
Congenital adrenal hyperplasia
Ambiguous genitalia, virilization, precociouspuberty
Complete blood count : anaemia(chronic renal disease)
BUSE, Creatinine: Renal disease, hyperaldosteronism (hyperkalemia)
Urinalysis : proteinuria, haematuria
24 hr urinary protein or spot albumin to creatinine ratio
Urine culture& sensitivity: chronic pyelonephritis
Chest radiograph : CoA
Electrocardiogram : cardiac cause of HPT
Ultrasonography for kidneys , adrenals : hydroneprosis, PKD, Wilm’s tumour
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SCREENING INVESTIGATION
Aims;Assessment for target organ damageAssessment for aetiologyAssessment for other cardiovascular risk factors
Retinal fundus examination
Urine spot protein to creatinine ratio
Echocardiography : LVH, LV function
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SCREENING FOR TARGET ORGAN
DAMAGE
Renin level : plasma renin (high-renovascular; low-
hyperaldosteronism)
Toxicology screen
Thyroid and adrenal testing :T3 T4, plasma aldosterone, plasma catecholamines (pheochoromocytoma, neuroblastoma)
Urine catecholamines
Abdominal ultrasound : : Structure anomalies of kidney, renal vasculature and tumours; renal scarring, renal asymmetry(r. dysplasia, r. artery stenosis), extrarenal masses (neuroblastoma, Wilms tumour)
Renal Doppler ultrasound
Brain CT scan
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CONSIDER
NON PHARMACOLOGICAL Recommended in all children with prehypertension and
hypertension Weight management: reduction in obese children and
maintenance in normal weight Lifestyle modifications Diet modification (reduce salt intake, low fat diet).
Note that those with severe HTN should avoid very strenuous exercises including weight lifting and high intensity sports, until evaluations clears an individual for participation Some exercises can result in a brisk increase in BP that may
result in significant adverse consequences
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Management
Reduction of BP to < 95th percentile without any
concurrent conditions .
Reduction of BP to <90th percentile with concurrent conditions (eg.Hyperlipidemia ,End organ damage, Obesity, CKD Complications etc)
GOALS OF ANTIHYPERTENSIVE
THERAPY
Pharmacologic1. Hypertension but asymptomatic :
Bed rest. Re-check BP ½ hour later. Monitor BP hourly x 4 hours then 4 hourly until stable. Oral nifedipine 0.25-0.5mg/kg if necessary 4 hourly basis. Consider regular oral nifedipine (6-8 hourly) if BP
persistently high. Add frusemide 1mg/kg/dose if BP still not well controlled. Other anti-hypertensive if BP still not well controlled : Captopril 0.1-0.5 mg/kg 8 hourly. Metoprolol 1-4 mg/kg 12 hourly
2.Long standing/poorly controlled hypertension:
Combination of antihypertensives.
Different sites or mechanism of action.
Compliance.
COMBINATION THERAPY
SYNERGISTIC COMBINATIONS.
Drugs increasing renin
activity+ Drugs decreasing
renin activity
ACE inhibitors , Diuretics
+
b blockers
Sympathic inhibitors and
vasodilators cause fluid
retention. Add diuretics
b blockers + Thiazide,
Lasix ( furosemide)
ACE inhibitors + Diuretics Enalapril (Envas) +
Thiazide, Lasix
a Blocker + b blocker Prazosin + Propranolol
a or b blocker + clonidine (antagonism)
b blocker + CCB (marked bradycardia/ AV block).
Any 2 drugs of same class.
COMBINATIONS TO BE AVOIDED
Severe symptomatic hypertension with BP well above
99th percentile .
Hypertensive emergencies(encepalopathy,chf)
controlled reduction in BP
25% in first 8hrs
then gradually normalising BP 75% within 48 hours. .
Hypertensive crisis
Nifedipine0.25-0.5 mg/kg/dose oral.May be repeated twice if no response.
Sodium nitroprussideNeed to be given in ICU setting.0.5-1.0 mcg/kg/min IV infusion.May be increased to 8.0 mcg/kg/min maximum.Caution in renal and liver failure.
Labetolol0.2-1.0 mg/kg/dose repeated IV boluses0.25-2.0 mg/kg/hour IV infusion
Hydralazine0.2-0.4 mg/kg/dose IV bolus.May be repeated twice if no response.
EMERGENCIES
SECONDARY HYPERTENSION
Treatment should be aimed at removing the cause of hypertension whenever possible.
Curable forms of Hypertension
Renal Unilateral kidney disease (Nephritis,
Pyelonephritis, hydronephrosis)
Cardiovascular CoA, Renal artery stenosis, thrombosis.
Adrenal Pheochromocytoma, Neuroblastoma,
hyperaldosteronism
Miscellaneous Drugs/ OCP etc.
Management Algorithm of Systemic Hypertension