This article is part of the supplement: Tissue oxygenation (StO2) in healthy volunteers and critically-ill patients

Research

Simultaneous multi-depth assessment of tissue oxygen saturation in thenar and forearm using near-infrared spectroscopy during a simple cardiovascular challenge

Rick Bezemer^1,2*, John M Karemaker^3,4, Eva Klijn², Daniel Martin⁵, Kay Mitchell⁵, Mike Grocott⁵, Michal Heger⁶ and Can Ince^1,2

• * Corresponding author: Rick Bezemer r.bezemer@amc.uva.nl

Author Affiliations

¹ Department of Translational Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands

² Department of Intensive Care, Erasmus MC, University Medical Center Rotterdam, 's-Gravendijkwal 230, 3015 CE Rotterdam, the Netherlands

³ Department of Systems Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands

⁴ Heart Failure Research Center, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands

⁵ Centre for Altitude, Space, and Extreme Environment Medicine, University College London Institute of Human Health and Performance, Archway Campus, Highgate Hill, London N19 5LW, UK

⁶ Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands

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Critical Care 2009, 13(Suppl 5):S5 doi:10.1186/cc8003

Published: 30 November 2009

Abstract

Introduction

Hypovolemia and hypovolemic shock are life-threatening conditions that occur in numerous clinical scenarios. Near-infrared spectroscopy (NIRS) has been widely explored, successfully and unsuccessfully, in an attempt to use it as an early detector of hypovolemia by measuring tissue oxygen saturation (StO₂). In order to investigate the measurement site dependence and probe dependence of NIRS in response to hemodynamic changes, such as hypovolemia, we applied a simple cardiovascular challenge: a posture change from supine to upright, causing a decrease in stroke volume (as in hypovolemia) and a heart rate increase in combination with peripheral vasoconstriction to maintain adequate blood pressure.

Methods

Multi-depth NIRS was used in nine healthy volunteers to assess changes in StO₂ in the thenar and forearm in response to the hemodynamic changes associated with a posture change from supine to upright.

Results

A posture change from supine to upright resulted in a significant increase (P < 0.001) in heart rate. Thenar StO₂ did not respond to the hemodynamic changes following the posture change, whereas forearm StO₂ did. Forearm StO₂ was significantly lower (P < 0.001) in the upright position compared to supine for all probing depths.

Conclusions

The primary findings in this study were that forearm StO₂ is a more sensitive parameter to hemodynamic changes than thenar StO₂ and that the depth at which StO₂ is measured is of minor influence. Our data support the use of forearm StO₂ as a sensitive parameter for the detection of central hypovolemia and hypovolemic shock in (trauma) patients.