2. Background
●Neonatal hypertension may occur in up to 3% of
babies admitted to intensive care units.
●Incidence increases with low gestational age and
birth weight, and is higher in babies with BPD,
PDA, IVH or indwelling UAC
3. Definition
Hypertension is defined as:
Persistent systolic and/or diastolic blood pressure values
that exceed the 95th percentile for postmenstrual age.
Persistent hypertension should be treated because it can
cause hypertensive cardiomyopathy, nephropathy,
encephalopathy, and retinopathy
4. Measurement of BL.P
●Invasive method:
An indwelling arterial line is the most accurate method of monitoring blood
pressure.
●Non invasive:
An automated oscillometric device is the next most commonly available method
(This technique relies on detection of the pressure oscillations in the artery, from
which is determined the mean arterial pressure (MAP) when the oscillations are
maximal.)
○ oscillometric measurements are generally 3–8 mm Hg higher than intra-
arterial measures for MAP
○ Measure by oscillometric device, and do 3 successive BP readings at 2-minute
intervals.
○ Make sure the infant is asleep or in a quiet state, lying prone or supine (BP is 5
mm Hg lower in sleeping infants than in infants who are awake)
5. Measurement of BL.P
●Place an appropriate-sized cuff on the right upper arm and let the
infant rest undisturbed after cuff placement for 15 minutes.
●Do not place the cuff on the extremity where an intravenous (IV) or
intra-arterial line is placed or where there is injured skin.
●The American Heart Association recommends a 4 × 8 cm cuff size for
newborns and infants.
●Measure blood pressure 1.5 hours after feeding or a medical
intervention
(BP rises when the infant is feeding , crying, has pain, agitated,
sucking on a pacifier, or has the head in an upright position).
7. A) UAC – associated thromboembolism
●Thromboembolism affecting the aorta, the renal arteries,
probably is a common cause of hypertension observed in the
NICU.
●Thrombus formation at the time of line placement, which is
probably related to disruption of the vascular endothelium of the
umbilical artery, may then embolize into the kidneys, causing areas
of infarction and increased renin release.
●Potential predisposing factors, such as duration of line placement
and line position (low versus high), have been studied, these
studies have not been conclusive
8. C) Renal parenchymal
disease
B) renovascular causes
◆Polycystic kidney
disease (PKD)
◆Severe acute
tubular necrosis.
◆Interstitial
nephritis.
◆Cortical necrosis.
◆Hemolytic uremic
syndrome, although
rare in the newborn,
it is usually
accompanied by
hypertension that
can be quite
difficult to control.
◆Renal venous
thrombosis (RVT)
◆Renal artery
stenosis
◆Mechanical
compression of one
or both renal
arteries by tumors,
hydronephrotic
kidneys, or other
abdominal masses.
9. D) Bronchopulmonary dysplasia
(BPD)/Chronic lung disease (CLD)
●The most important nonrenal cause of neonatal
hypertension is BPD.
●The clear cause is unknown
●It is probably multifactorial as a result of increased
renin activity and catecholamine secretion and
chronic hypoxemia which may be associated with CLD.
●The majority of these infants develop hypertension
after being discharged from the hospital at 4 to 5
months of age.
10. E) Additional causes of
hypertension
❖Coarctation of the thoracic aorta
❖Endocrine disorders as * congenital adrenal hyperplasia
(CAH),
❖Hyperaldosteronism ,hyperthyroidism.
❖Iatrogenic as
◇Dexamethasone
◇High doses of adrenergic agents
◇Prolonged use of pancuronium,
◇Phenylephrine ophthalmic drops.
◇Prolonged total parenteral nutrition (TPN): hypertension
may result from salt and water overload or from
hypercalcemia.
11. E) Additional causes cont.
❖Tumors
as neuroblastoma, Wilms tumor, and mesoblastic nephroma, may present
in the neonatal period, and the tumors may produce hypertension either
because of compression of the renal vessels or ureters or because of
production of vasoactive substances, such as catecholamines.
❖Neurologic problems
such as:
seizures, intracranial hypertension, and pain, constitute fairly common
causes of episodic hypertension.
❖Maternal causes
as receiving cocaine and heroin during pregnancy, may lead to
significant problems with hypertension in the newborn either by direct
effects on the developing kidney or because of drug withdrawal.
12. Diagnosis
Symptoms:
●Neonatal hypertension is often asymptomatic and noted during
routine monitoring in ICU.
●Some neonates may show symptoms such as poor feeding,
tachypnoea and lethargy, and in severe cases seizures and
congestive cardiac failure .
Full examination:
●All four limb blood pressure,
●Palpation for abdominal masses,
●Femoral pulses,
●Genitalia and any dysmorphic features.
●Renal artery stenosis may produce a bruit.
13. Laboratory studies:
1. Assess renal function : 2. Other useful tests:
A.Serum creatinine and
blood urea nitrogen.
B.Urinalysis. May show
gross or microscopic
hematuria or
proteinuria.
C.Urine culture.
D.Serum electrolytes.
E.Urine protein/creatinine
ratio, urine
albumin/creatinine
ratio.
This is in selected infants
A.Plasma renin levels
B.Thyroid function test
C.Serum cortisol.
D.Serum aldosterone.
E.Urine vanillylmandelic
acid/homovanillic acid.
F.Urinary 17-
hydroxysteroid and 17-
ketosteroid levels
G.Urine toxicology screen.
H.Coagulation panel.
14. Imaging studies
1. Renal ultrasound with Doppler
●It is the preferred screening test in neonates and should
be done in all hypertensive infants.
●It will identify:
○ congenital anomalies ,
○ tumors,
○ assess adrenals;
○ and check for renal vein thrombosis
15. Imaging studies cont…
2. Renal scans – Radionuclide imaging
●Sometimes recommended when sonography is
nondiagnostic.
●It evaluate differential renal blood flow and glomerular
filtration
●It may be best to defer radionuclide imaging until the
infant reach at least 44 weeks postconceptional age , as
useful diagnostic images are difficult to obtain in the
neonatal period due to the immaturity of kidney
function.
16. Imaging studies cont…
3. Angiography
● In infants with severe hypertension and no etiology detected by
sonography, angiography should be considered.
● Although this test is invasive, it is the gold standard for the diagnosis of
renovascular hypertension.
● In many instances, it will be appropriate to control the hypertension
medically until the baby reaches a size at which angiography can be
performed safely
4. Chest radiograph. Evaluate heart size.
5. Echocardiography.
● To assess structural lesions
● To evaluate end-organ damage and dysfunction caused by hypertension
(eg, left ventricular hypertrophy/dysfunction, hypertensive
cardiomyopathy.
17. Treatment / Management
Medical treatment should be considered for hypertensive neonates
based upon the severity and the cause of hypertension
●Treat or remove the underlying cause if iatrogenic
●Consultations with pediatric cardiology and nephrology to help
manage hypertension are recommended.
●Other consults may be required depending on the underlying
cause of hypertension.
●If treatment is required, try to use a single agent and only move to a
second agent if the first is ineffective or if side effects
develop.(wean the 1st gradually).
●Continuous IV infusion should be used in neonates with BP > 99th
centile or who are demonstrating systemic symptoms
●Surgical treatment / thrombolysis may be indicated depending on
the underlying cause.
18. Antihypertensives
A)Intravenous treatment:
●Reserved for management of hypertensive crisis BP > 99th
centile or symptomatic.
●All patients on continuous intravenous infusions of
antihypertensive agents require continuous invasive blood
pressure monitoring and must have adequate intravenous
access to allow bolus of fluids in event of sudden hypotension.
●Aim to reduce systolic BP by 5 mmHg every 4 hours until
systolic BP is less than or equal to 95th centile for corrected
gestational age
1st line IV treatment
Nicardipine (calcium channel blockers)
2nd line IV treatment
Labetalol (alpha and B blockers)
19. Antihypertensives
B) Oral treatment
● If less severe but chronic hypertension
● Aim for gradual reduction in systolic BP to less than or equal to 95th
centile
● over 12 -48hrs.
● Monitor BP every 30 minutes for 2hrs after first dose and any increase in
dose.
● Monitor BP 4-6 hourly whilst on regular antihypertensives as an inpatient.
1st line oral treatment
Hydralazine (vasodilator)
Hydralazine can be given as slow intravenous injection if NPO
2nd line oral treatment
Amlodipine (calcium channel blockers)
3rd line oral treatment
Propranolol (Beta blocker)
4th line oral treatment:
Captopril (ACE inhibitors)
20. Contraindications and
cautions
●Do not use an ACE inhibitor < 44 weeks corrected
gestational age (as may interfere with renal
development). Monitor U&Es regularly following
commencement of an ACE inhibitor, beware
concomitant use of other nephrotoxic drugs (eg
aminoglycosides, furosemide, NSAIDs) and potassium
sparing diuretics.
●Ensure patients are volume replete particularly before
use of vasodilators and ACE inhibitors.
●Do not use beta blockers in severe BPD/chronic lung
disease as this may cause bronchospasm.
21. Prognosis and follow up
●Prognosis is dependent on the underlying cause and
treatment required.
●Hypertension secondary to umbilical artery
catheterisation tends to resolve over time
●If hypertension is due to polycystic kidney disease or
renal vein thrombosis it is more likely to persist.
●Long term follow up may be necessary for neonates
found to have renal disease.
