Tissue oxygen saturation change on upper extremities after ultrasound guided infraclavicular brachial plexus blockade.

Several methods were studied for objective assessment of the peripheral nerve block. The aim of the study will investigate whether tissue oxygen saturation (StO2), a measure of the proportion of oxygenated haemoglobin relative to total haemoglobin level in the tissue, is a reliable and objective method for assessing the adequacy of infraclavicular blockade and to describe the time course of StO2 changes once peripheral nerve block has been achieved during surgery. The InSpectraTM tissue spectrometer (Hutchinson technology, Hutchinson, MN, USA) is a novel non-invasive haemodynamic monitor. It utilises near infra-red spectroscopy (NIRS) technology to measure the proportion of oxygenated haemoglobin relative to total haemoglobin level in the tissue StO 2 was measured in 40 patients schedule for elective hand surgery under infraclavicular nerve block. Non-invasive StO 2-monitoring (InSpectraTM StO 2, Hutchinson Technology Inc., Hutchinson, Minnesota, USA) will use in patients before ultrasound guided infraclavicular plexus blockade and during the first 30 minute of the blockade in both hands. The StO 2 sensor will be place on the thenar muscle of the right hand in a position, which ensured an adequate total haemoglobin index (THI) of more than 5.0 according to the manufacturer recommendation. To measure tissue oxygen saturation near-infrared light (680–800 nm) is emitted into the thenar tissue with a depth of about 15 mm. 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. infraclavicular blocks will perform using a 22-gauge stimulating needle under US guidance (Esaote My Lab 30 US gold machine, Florence, Italy) using in-plane approach. The blocked and non-blocked arms will compare at precisely timed intervals. However, the duration of sensory block, the duration of motor block, side effects and complications Bromage scale for motor block and Pinprick test in the sensory block will be recorded.