- Poster presentation
- Open Access
Perfusion index as a predictor for central hypovolemia in humans
© Lima et al. 2011
- Published: 1 March 2011
- Supine Position
- Pulse Oximetry
- Hemodynamic Response
- Peripheral Circulation
- Pressure Monitor
In low flow shock, almost 30% of the circulating volume may be lost before hypotension occurs. Thus, shock should be early recognized prior to the development of hypotension. An earlier sign to look for is vasoconstriction in peripheral tissues due to neurohumoral response to the low circulating volume. The perfusion index (PI) derived from the pulse oximetry signal permits a quantitative analysis of variations of peripheral circulation. However, its ability to detect peripheral vasoconstriction due to neurohumoral response in central hypovolemia induced by lower body negative pressure (LBNP) has never been studied.
The PI was measured in 24 healthy volunteers during the LBNP test using the pulse oximetry Masimo SET Perfusion Index. The LBNP protocol consisted of 5-minute baseline measurements in the supine position followed by stepwise increases of negative pressure from 0 to -20, -40, -60, -80 and 0 mmHg. HR, BP, and cardiac output were recorded during all of the procedure using a Finometer Blood Pressure Monitor.
PI is a sensitive indicator of acute hemodynamic responses to the LBNP-induced central hypovolemia. In addition, it could detect hypovolemia earlier than the 20% decrease in stroke volume.
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.