Tissue Oxygenation Change on Upper Extremities After Ultrasound-Guided Axillary Brachial Plexus Blockade; Prospective Observational Study

Sto2 in the assessment of Axillary block success

Abstract

ABSTRACT

Introduction

The aim of the study was to investigate whether tissue oxygen saturation (St02), is a reliable and objective method for assessing the adequacy of axillary blockade and to describe the time course of StO2 changes.

Materials and Methods

The study was approved by the Ethical Committee and met the Declaration of Helsinki criteria. In this prospective observational study, St02 was measured in 30 patients scheduled for elective hand surgery under axillary nerve block. Non-invasive StO2 -monitoring (In Spectra™ StO2, Hutchinson Technology Inc., Hutchinson, Minnesota, USA) was used in patients before ultrasound guided axillary brachial plexus blockade and during the first 30 minute of the blockade. To measure tissue oxygen saturation near-infrared light is emitted into the thenar tissue. In the light that is reflected from the tissue, the percentage of oxygenated haemoglobin is calculated by using the different absorption spectra of oxygenated and deoxygenated haemoglobin. Repeated measure ANOVA test for repeated measurement and paired sample t test were used for comparison of two hands StO2 levels.

Results

StO2 measurements were statistically increased in 1st,5th, 10th, 15th,20th,25th,30th minutes compared to baseline levels (p< 0.05 for all comparisons). Mean StO2 levels of the hand with axillary brachial plexus blockade were statistically increased compared the levels of the hand StO2 without blockade in 15th,20th, 25th, 30th. minutes (p< 0.05 for all comparisons).

Conclusion

There has been found a significant correlation between tissue StO2 values of two limbs using NIRS in axillary blockage operations of upper extremity.