HYPERTENSION

This is defined as elevation of systemic blood pressure beyond the 95th blood pressure centile for age (or above the upper limit of normal).

The blood pressure varies with age and gender and stature and these are found in normograms for blood pressure for children. In order to record blood pressure accurately, a correct size cuff for the child is needed; such a cuff is expected to cover about
two-thirds of the arm.

Upper limits of normal blood pressure values for both sexes at different ages (in mmHg)

Average age 12 hours 8 years 9 years 10 years 12 years 14 years
Systolic blood pressure 80 120 125 130 135 140
Diastolic blood pressure 50 82 84 86 88 90

The following are the common causes of hypertension at different ages:

  • For neonates and infants: Renal artery thrombosis or stenosis and coarctation of the aorta.
  • From 1 year to 10 years: Renal parenchyma disease and coarctation of the aorta.
  • From 11 years to 18 years: Renal parenchyma disease, essential hypertension.

Clinical Features

  • Essential hypertension may initially be asymptomatic.
  • Coarctation of the aorta in a neonate may present with sudden collapse or features suggesting sepsis.
  • Others will present with clinical features of the underlying disease or target organ system
    • Hypertensive encephalopathy
    • Pulmonary oedema.

Investigation

  • Urinalysis
  • Urea and creatinine
  • Chest x-ray
  • Special investigations as indicated for the suspected cause

Management – General

  • Maintain blood pressure at or slightly below the 95th centile for age (blood pressure should not be reduced by more than 25% in the acute phase).
  • Determine and treat any underlying cause of hypertension.
  • Advise aerobic exercise, salt restriction, weight reduction.

Management – Pharmacological

This is summarized in the table below

Summary of plan for care in hypertension

Severity of hypertension Drugs to be used
Mild: HCTZ* OR propranolol/atenolol OR HCTZ* + propranolol/atenolol
Moderate: HCTZ* + propranolol/atenolol + hydralazine OR HCTZ* + methyldopa OR
HCTZ* + nifedipine/captopril
Severe: HCTZ* + propranolol/atenolol + hydralazine/captopril OR HCTZ* +
propranolol/atenolol + nifedipine/captopril OR HCTZ* + propranolol/atenolol +
methyldopa

Note:

*HCTZ = Hydrochlorothiazide; bendroflumethiazide, frusemide, or other appropriate diuretics
may be substituted
Beta-blockers: Propranolol oral 1–8mg/kg/24 hours on 3 divided doses OR Atenolol oral 0.1–
0.5mg/kg/24 hours in 2 divided doses, maximum 20mg per day
Calcium channel blockers: Nifedipine oral 0.2–1mg/kg/24 hrs in 3–4 divided doses (6–8 hourly)

Hypertensive Crisis

  • Defined as systolic or diastolic pressure above the 95th percentile by 50% or when signs of hypertensive encephalopathy or pulmonary oedema occur.
  • Congestive heart failure

Management

  • Admit urgently.
  • Monitor closely: This is mandatory – may require ICU care.
  • Aim to lower BP by 20% over 1 hour, by one-third over 6 hrs, and return to baseline levels within 24–48 hrs.
  • Administer nifedipine sublingual 0.2–0.5mg/kg dose 4 every 4–6 hours (max 10mg/dose). Watch: precipitous fall in BP may occur. OR
  • Hydralazine IM/IV 0.1–0.8mg/kg/dose every 4–6 hours (max. 20mg/dose). Be careful not to cause uncontrollable hypotension. OR
  • Sodium nitroprusside IV continuous infusion 0.5–8ìg/kg/minute. Requires ICU setting.
  • Monitor blood pressure during infusion, titrate dose according to response.