Comparison of Change of Tissue Oxygenation During a Vascular Occlusion Test Using Two Different Near-infrared Spectroscopy (O3TM vs. INVOS®)
Comparison of Change of Tissue Oxygenation During a Vascular Occlusion Test Using Two Different Near-infrared Spectroscopy (O3TM vs. INVOS®)
This study evaluates the change of tissue oxygenation during a vascular occlusion test using two NIRS ( O3TM and INVOS®). NIRS probe will be attached on volunteer's forearm during vascular occlusion test and tissue oxygenation change will be recorded
Near-infrared spectroscopy (NIRS) has been used to measure regional hemoglobin oxygen saturation of tissue. Recently, it also has been used to monitor peripheral tissue oxygen saturation, and micro-vascular reactivity using vascular occlusion test (VOT).
O3 TM is recently developed NIRS and there are only two clinical trials using this device, until now. In one study, this device could adequately predict cerebral regional oxygen saturation. And in the other study, peripheral tissue oxygenation was measured during ischemic pre-conditioning in heart surgery and it showed correlation between O3 TM and other NIRS ( EQUANOX) which has been used to monitor peripheral tissue oxygenation. But in this study, study group was patient with heart disease and the deoxygenation and reoxygenation rate during VOT was not not measured, which reflects tissue oxygen extraction and micro-vascular reactivity.
In NIRS devices, there are assumed cerebral arterial-venous ratio upon which oximetry values are calculated. In INVOS®, assumed arterial-venous ratio is 25/75. In other NIRS, assumed arterial-venous ratio is 30/70. But unlike other NIRS, O3 TM can change its preset arterial-venous ratio between 25/75 and 30/70, and there are no studies compare oximetry values between these two different settings.
In this study, the investigators try to compare INVOS®, which has been used widely for monitor tissue oxygenation, and two different settings of O3 TM ( arterial-venous ratio; 30/70 and 25/75). Three probes will be attached at same site simultaneously and the investigators will measure change of tissue oxygenation, deoxygenation rate and reoxygenation rate during vascular occlusion test
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