The effect of different body positions on the assessment of dynamic cerebral autoregulation (1184.4)

Abstract

The Effect of Different Body Positions on the Assessment of Dynamic Cerebral AutoregulationJL Jara1, Max Chacón1: 1Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Avda. Ecuador 3659, 9170124, Santiago, Chile.Dynamic Cerebral Autoregulation (dCA) has been assessed for changes in arterial blood pressure induced by a change in the position of the subject, as in the sit‐to‐stand technique (Sorond et al. 2009). However, the most common method to evaluate dCA has been the thigh‐cuff maneuver proposed by Tiecks et al. (1995). But this technique has been performed with the subject lying in supine or in Fowler's position, and there are no studies of its use with other body positions.In this work, the classic index of autoregulation (ARI) and a recently‐proposed index, named model‐free ARI (mfARI), are utilized to assess dCA in 18 healthy subjects when they are laying supine, seated and standing. Three thigh‐cuff maneuvers are performed in each position. Subject means by position were compared with one‐way repeated‐measures ANOVA. Separated analysis were conducted for each index and cerebral hemisphere.Significant differences were only observed with the classic ARI on the left hemisphere (p<0.01), which might be attributed to the great variability that this index exhibits in different conditions rather than to a real physiological hemispheric difference.