Both body and arm position significantly influence blood pressure measurement

Abstract

The position of both the body and the arm during indirect blood pressure (BP) measurement is often neglected. The aim of the present study was to test the influence of the position of the patient on BP readings: (1) sitting with the arms supported precisely at the right atrium level and (2) supine: (a) with the arms precisely at the right atrium level and (b) with the arms on the examination bed. In a first group of 57 hypertensive patients, two sessions of BP and heart rate (HR) measurements were performed in two positions: sitting and supine with the arms supported precisely at right atrium level in both positions. BP was measured simultaneously at both arms, with a Hawksley Random Zero sphygmomanometer at the right arm, and with an automated oscillometric device (Bosomat) at the left arm. BP and HR readings obtained in the two positions were then compared. In a second group of 25 normoand hypertensive persons, two sessions of BP and HR readings were performed in supine with the arms in two different arm positions: (a) the arm placed precisely at right atrium level and (b) the other arm on the examination bed. The measurements were performed at both arms with two automated devices (Bosomat). The readings taken in the two positions were compared. Both systolic BP (SBP; by 9.5 7 9.0 (standard deviation, s.d.); right arm) and diastolic BP (DBP; by 4.8 7 6.0 mmHg; right arm) were significantly higher in the supine than in the sitting position. When the two different arm positions (body continously supine) were compared in the second part of the study, significantly higher SBP (by 4.6 7 6.1 mmHg) and DBP (by 3.9 7 2.8 mmHg) were obtained when the arm of the patient was placed on the bed (below the right atrium level), than when the arm was placed at the level of the right atrium. BP readings in sitting and supine positions are not the same. When according to guidelines the arm of the patient is meticulously placed at the right atrium level in both positions, the difference is even greater than when the arm rests on the desk or on the arm support of the chair. Moreover, in the supine position small but significant differences in BP are measured between arm on a 5 cm-high pillow and arm on the bed. In every study reporting BP values, the position of both the body and especially the arm should be precisely mentioned.

Effect of fractionized vs continuous, single-session exercise on blood pressure in adults

“…The effect of posture on BP, however, is relatively modest, with B0-6 mm Hg higher SBP and diastolic BP being reported for the supine position as compared with sitting upright. 13 These differences are smaller than the afternoon SBP reductions observed in our fractionized exercise group (B6-8 mm Hg; Figure 1). Our results need to be extended to natural settings with ambulatory BP monitoring.…”

Physical Activity, Obesity Status, and Blood Pressure in Preschool Children

“…After 15 minutes of supine rest in a quiet, temperature-controlled room, BP measurements were taken with the subjects seated in an upright position with back supported, feet on the floor, and the right arm comfortably placed at heart level. 18,19 Two measures were completed; the second BP measurement was taken 5 minutes after the initial assessment. The average of 2 measures for SBP and diastolic BP (DBP) were recorded.…”

Principles and techniques of blood pressure measurement

“…49 Body position-Blood pressure measurements are also influenced by the position of the arm. 45,47,48,94 As shown in Fig. 3, there is a progressive increase in the pressure of about 5 to 6 mm Hg as the arm is moved down from the horizontal to vertical position.…”