Skin Hemodynamics During Change from Supine to Lateral Position.

Abstract: The purpose of this study was to identify the skin hemodynamics during the position change from supine to lateral in patients with neurodegenerative diseases. The participants were 19 patients with neurodegenerative diseases and 12 healthy volunteers. The alteration in the total concentration

of oxyhemoglobin and deoxyhemoglobin, indicative of change in blood volume, was measured in the skin of the left flank by using a portable noninvasive tissue oxygen monitor by near-infrared spectroscopy. The positions were changed from the left and right lateral with a return to the supine between each procedure.

In healthy volunteers, total hemoglobin concentration (skin blood volume) increased when the position changed from supine to left lateral and decreased when changed from supine to right lateral. The decreased skin blood volume gradually recovered after a change from the supine to the right lateral position in healthy volunteers. However, it did not recover in three sporadic olivopontocerebellar atrophy (OPCA) patients with marked autonomic dysfunction and one Parkinsonian patient with severe orthostatic hypotension. Our study identified that the intracutaneous blood was changing dynamically during the position change from supine to lateral and was regulated by autonomic nerve function.

Introduction

Bedridden patients must often be changed from the supine to the lateral position or vice versa to prevent decubiti. It is important to clarify the skin hemodynamics during such a position change. There are several reports on skin microcirculation over various body parts during the position change from the supine to the lateral position.[10,13,14] The measured body parts were bony prominences such as the trochanter, sacrum, and ischium. Blood flow was studied by using laser doppler flowmetry while the body parts were pressed or after the release of the pressure due to a position change. All the studies investigated the skin hemodynamics during the position change from supine to lateral or vice versa and evaluated the influence of pressure on skin microcirculation in the pressured areas. But the skin hemodynamics during such a position change itself, without the effect of pressure, are quite unclear.

Patients with neurodegenerative diseases usually become bedridden as the disease progress to an advanced stage. The diseases are often associated with autonomic dysfunction, which are thought to have some influence on their skin hemodynamics. Thus, it is important to understand the skin hemodynamics during position changes in these patients and compare them with those of healthy controls.