Volume 6 Supplement 1
The effect of pre–measurement rest time on systolic ankle pressure measurements
© Chuter and Casey; licensee BioMed Central Ltd. 2013
Published: 31 May 2013
Systolic ankle pressures are measured as part of an ankle-brachial index (ABI) to screen for the presence of peripheral arterial disease (PAD). Despite widespread use of the ABI, there is currently no research evidence investigating the amount of pre-measurement rest required for the systolic ankle pressure to stabilise.
One hundred and forty participants meeting current guidelines for screening for PAD volunteered for this study. Following 5 minutes of rest in the supine horizontal position, ankle systolic pressures of the left or right lower extremity were taken using hand-held Doppler. Measurements were repeated at 10 and 15 minutes. Testing was repeated 7-10 days later.
A significant drop in ankle pressure of 5.02 mmHg occurred between 5 and 10 minutes (p<0.05) however no significant change occurred between 10 and 15 minutes (mean change 0.15 mmHg, p=0.99). Presence of diabetes was associated with a smaller drop between 5 and 15 minutes (mean change 1.85 mmHg) and predicted 14% of the variance in change in ankle pressure (beta=-3.72, p>0.05). Test-retest reliability after 5 minutes was excellent (intraclass correlation co-efficient (ICC): 0.84) however increased for measurements taken at 10 and 15 minutes (ICC: 0.89 and 0.89 respectively).
Results suggest ankle systolic pressures stabilise after 10 minutes of rest. Longer periods of pre-measurement rest did not improve reliability of the measurement significantly. Presence of diabetes affects ankle pressure changes in response to rest, however further investigation is required to identify the cause.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.