Paediatrics: Hypertension: definition

Hypertension: definition

Defined by reference to sex, height centile charts (see Fig. 11.1).

• Normal: systolic and diastolic <90th centile.
•  High normal: systolic or diastolic between 90th and 95th centile.
• Hypertension: systolic or diastolic >95th centile.
• Severe hypertension: systolic or diastolic >99th centile.

 BP measurement should be part of a routine examination.

Measurement technique

• Cuff size.
• bladder width—70% of acromion olecranon distance or 40%

o mid-arm circumference;

o bladder length—should completely encircle arm.

o Note: small cuff area is a common cause of false-positive high BP!

• After 5min rest (ideally!).
• A sitting position with the arm at the level of the heart (children).
• Supine position in infants.
• On auscultation: 1st and 5th (disappearance) Korotkoff sounds used for systolic and diastolic values, respectively.

Measurement devices

• Manual oscillometric sphygmomanometer (mercury is now withdrawn).
• Doppler: infants (for systolic pressure).
• Automatic oscillometry: not all devices suitable.
• Ambulatory blood pressure monitoring (ABPM) for 24-hr profiles:

o little normative data in paediatrics;

o significant hypertension ≥30% readings above 95th centile.

• Intra-arterial (in intensive therapy unit (ITU) setting).