[Blood pressure in children and adolescents. Influence of methods of measurement -- Distribution of frequent values].

The effects of the following conditions on blood pressure were studied: cuff size (9 x 22 cm and 12 x 26 cm), period of rest (0,5 and 10 min) position (lying, sitting, standing), left or right arm, venepuncture, observer error. The measurements were made by a single observer in two groups of 205 and 50 children and adolescents. Systolic blood pressure was influenced, in order to decreasing importance, by cuff size (difference of 8,8 mm Hg), position (4,5 mm Hg), venepuncture (4,2 mm Hg), period of rest (3,2 mm Hg). Diastolic blood pressure was only influenced by cuff size (7,5 mm Hg) and venepuncture (2 mm Hg). The side on which the readings were taken and the use of a sphygmomanometer with an adjustable zero had no significant effects on the measurements. The distribution of blood pressure readings measured using an easily reproducible protocol was studied in 17067 children and adolescents of both sexes aged between 4 and 18 years old. The graphs of the principal quantiles of blood pressure with respect to age are presented, and the necessity of taking the children's height into consideration is also emphasised. These graphs may contribute to improved detection and follow-up of children at risk from border line or elevated blood pressure.