Assessment of techniques for measurement of blood pressure in infants and children.

Assessment of techniques for measurement of blood pressure in infants and children. Indirect techniques for blood pressure (BP) measurement in infants and children include palpation, auscultation, flush, and the Doppler shift technique. In a double-blind controlled trial these indirect methods were compared to direct intra-arterial measurements. 22 children, aged 1 to 11 years, had their BP measured by a nurse and a doctor each using the four indirect techniques in a randomized order while a third observer recorded intra-arterial pressures. Nurses and doctors obtained similar readings. There was no significant difference between direct measurements and pressures obtained by the Doppler shift technique, but other techniques underestimated systolic pressure: auscultation 3 * 6 ±7 * 6 mmHg (mean systolic difference±SD) P <0 05; palpation 10-9±7-9, P <0*001; flush 40*1±11 6, P <0*001. The Doppler technique was also assessed in situations where it was impossible to record lower limb systolic pressures by other indirect methods. Lower limb BP was successfully recorded in 10 of 12 patients with coarctation of the aorta and in 4 obese infants with absent pedal pulses. Measurement of svstemic blood pressure in infants and young children may be difficult. Intra-arterial recording is accurate but is not suitable for routine use. Attempts have been made to compare blood pressure recordings obtained by the various indirect methods with intra-arterial measurements (Van Bergen et al. 1971), but few of these studies were carried out in a controlled, double-blind manner, and in none were all the techniques evaluated in a randomized order. Not only may knowledge of the intra-arterial pressure prejudice an observer using an indirect technique, but there is a tendency to regard the first of a series of repeated measurements as correct (Armitage, 1971). In paediatric practice there are situations where it is particularly difficult to record the blood pressure. A relatively common example is measurement of lower limb blood pressure in infants with coarctation of the aorta, but similar difficulties are experienced in obese infants, after arteriotomy, and in the arm after a Blalock-Taussig shunt. Here the most accurate noninvasive technique has yet to be established. The dual purpose of this study was to assess the accuracy of palpation, flush, auscultation, and Doppler techniques when compared to intra-arterial measurements and to establish which methods can be used in the different situations mentioned.