Neonatal Hypertension - Management of

Publication: 20/10/2016  --
Last review: 12/07/2019  
Next review: 12/07/2022  
Clinical Guideline
CURRENT 
ID: 4758 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2019  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Management of Neonatal Hypertension

Summary of Guideline

This guideline offers guidance on the recognition, diagnosis, treatment and investigation of hypertension in newborn infants on the neonatal unit. It outlines the treatment thresholds and first, second and third line drug treatment.  

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Aims

To improve the diagnosis and management of high blood pressure (hypertension) in newborn infants.

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Background

Neonatal hypertension may occur in up to 3% of babies admitted to intensive care units.  It is defined as a systolic blood pressure >95th centile when compared to infants of similar weight, gestational and postnatal age . The most common cause of neonatal hypertension is renal artery thrombosis secondary to umbilical arterial catheterisation, particularly in catheters with the tip lying above the diaphragm, and there is close correlation with duration of catheterisation.

Causes of neonatal hypertension

Renal

Iatrogenic

Neurological

Other

  • Renal artery thrombosis or stenosis
  • Renal vein thrombosis
  • Polycytic kidney disease
  • Congenital nephropathy
  • Acute tubular/cortical necrosis
  • Nephrocalcinosis
  • Obstructive uropathy/PUJ obstruction
  • Haemolytic uraemic syndrome
  • UAC vascular occlusion
  • Steroids
  • ECMO
  • Inotropes
  • Abdominal wall closure (exomphalos etc)
  • TPN
  • Fluid overload
  • Intraventricular Haemorrhage (IVH)
  • Seizures
  • Raised intracranial pressure
  • Pain
  • Bronchopulmonary dysplasia (BPD)
  • Neonatal abstinence syndrome (NAS)
  • Neuroblastoma
  • Endocrine causes:
  • Congenital adrenal hyperplasia
  • Hyperaldosteronism
  • Hyperthyroidism
  • Coarctation of aorta/left ventricular outflow tract obstruction

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Diagnosis

Neonatal hypertension is often asymptomatic and noted during routine monitoring on ICU.  Some neonates may show symptoms such as poor feeding, tachypnoea and lethargy, and in severe cases seizures and congestive cardiac failure . An arterial line is the optimum method of measurement of BP (invasive BP) but oscillated devices may be used, ensuring that the cuff size is appropriate (non-invasive BP). The width of the cuff should be at least 60% of the length of the upper arm. An abnormal BP should be repeated within 15 minutes. If non-invasive BP is used it should be measured in a different limb. The table below shows BP centiles for babies of 2 weeks of age.  Mean or Systolic BP > 95th centile should lead to consideration of treatment.

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Investigation

Any neonate found to be significantly hypertensive (see table above) should be investigated to establish the underlying cause. First line investigations should include:

  • Full examination - in particular all four limb blood pressure, palpation for abdominal masses, femoral pulses, genitalia and any dysmorphic features. Renal artery stenosis may produce a bruit.
  • Urinalysis - for protein and blood
  • U&E
  • Calcium
  • Arterial blood gas
  • Renal ultrasound with dopplers of artery and vein
  • Consider echocardiogram

Further investigations may be warranted following these preliminary tests. All neonates found to be persistently hypertensive should be discussed with the paediatric nephrology team.

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Treatment / Management

Medical treatment should be considered for hypertensive neonates based upon the severity of hypertension and underlying cause

  • Treat or remove the underlying cause if iatrogenic (e.g. remove UAC immediately if thrombosis present or reno-vascular disease suspected)
  • 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. The first agent should then be stopped as soon as possible. For example, once second agent is infusing, start to wean the first agent every hour until stopped.
  • Continuous IV infusion should be used in neonates with BP  >99th centile for mean or systolic BP (see table above)  or who are demonstrating systemic symptoms .
  • Surgical treatment / thrombolysis may be indicated depending on the underlying vascular cause .

Antihypertensives
Intravenous treatment: reserved for management of hypertensive crisis BP >99th centile (see table above) 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 5mmHg every 4 hours until systolic BP is less than or equal to 95th centile for corrected gestational age (a worked example is given in appendix 1).

1st line IV treatment
Hydralazine  i.v. - initial rate: 12.5microgram/kg/hour; increase in steps of 12.5micrograms/kg/hour every 4 hours if required, up to 50 micrograms/kg/hour.

2nd line IV treatment
Labetalol i.v. 500microgram/kg/hour adjusted at intervals of at least 15 minutes according to response; maximum 3mg/kg/hr

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  p.o. 250-500 microgram/kg every 8-12hrs increased as necessary to max of 2-3mg/kg every 8 hrs.

NB: Hydralazine can be given as slow intravenous injection if NBM: hydralazine 100-500microgram/kg every 4-6hrs, max 3mg/kg daily

2nd line oral treatment
Amlodipine: 50-300 micrograms/kg once daily

3rd line oral treatment
Propranolol (Beta blocker) 250-500 micrograms/kg TDS.

4th line oral treatment:
Captopril (ACE inhibitor)  10-50 micrograms/kg TDS (under direction of cardiology/nephrology team).

Contraindications and cautions:

  • Do not use an ACE inhibitor <37 weeks as may interfere with renal development. Always give a test dose (10 micrograms/kg) initially. 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 as may cause bronchospasm.

Prognosis and follow up
Once treatment has commenced blood pressure and renal function should be assessed regularly. Discussion should take place with a paediatric nephrologist. Prognosis is dependent on the underlying cause and treatment required. Hypertension secondary to umbilical artery catheterisation tends to resolve over time, however 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.

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Appendix 1

Worked Example

Corrected gestational age - 30 weeks
Weight - 1.2kg
Systolic BP - 120mmHg
95th centile systolic BP for 30 week infant - 80mmHg

Commence IV hydralazine at 12.5micrograms/kg/hr = 12.5 x 1.2 = 15micrograms/hr

Aim to bring systolic BP down by 5mmHg every 4 hours until less than or equal to 80mmHg.

Increase dose of hydralazine by 12.5micrograms/kg/hr every 4 hours if no change or ongoing rise in blood pressure.

Once at 50micrograms/kg/hr hydralazine and if BP not falling, consider switching to labetolol.

Commence IV labetolol at 500micrograms/kg/hr = 500 x 1.2 = 600micrograms/kg/hr

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Provenance

Record: 4758
Objective:

To provide evidence-based recommendations for appropriate diagnosis, investigation and management of neonatal hypertension

Clinical condition:

Hypertension (high blood pressure)

Target patient group: Neonatal patients/newborns
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

References

  1. Pediatric Nephrology. 2000 Apr;14(4):332-41. Neonatal hypertension: diagnosis and management. Flynn JT1.
  2. Pediatric Nephrology. 2007 Dec;22(12):2081-7. Epub 2007 Sep 14. Antenatal and postnatal risk factors for neonatal hypertension and infant follow-up. Seliem WA1, Falk MC, Shadbolt B, Kent AL.
  3. Pediatric Nephrology. 2012 Jan;27(1):17-32. doi: 10.1007/s00467-010-1755-z. Epub 2011 Jan 22. Hypertension in infancy: diagnosis, management and outcome. Dionne JM1, Abitbol CL, Flynn JT.
  4. Fanaroff& Martin’s  Neonatal-perinatal medicine. 2015 .Martin RJ, Fanaroff AA, Walsh MC. Elsevier Saunders.
  5. Seminars Fetal Neonatal Medicine. 2006 Jun;11(3):174-81. Epub 2006 Mar 3. Blood pressure disorders in the neonate: hypotension and hypertension. Fanaroff JM1, Fanaroff AA.
  6. Etiology, clinical features, and diagnosis of neonatal hypertension:  ‘Up to date’  accessed online 1/12/15.

Evidence levels:
C. Expert consensus.

Approved By

Trust Clinical Guidelines Group

Document history

LHP version 1.0

Related information

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