Changes in Tissue Microcirculation During Ischemic Conditioning: Pilot Study

Overview

Changes in tissue microcirculation during ischemic conditioning (4 cycles of 5-min ischemia and 5-min reperfusion) has not been well documented. In previous studies, there was difference in changes in microcirculation, such as recovery slope and occlusion slope, between healthy subjects and cardiac surgery patients. Moreover, the occlusion slope, which reflects local tissue oxygen consumption during ischemic period, is anticipated to decrease during repeated ischemia-reperfusion cycle by its protecting effect, however there has not been well-conducted study. The purpose of the study is to evaluate the changes in microcirculation measured by tissue oxygen saturation during ischemic conditioning between healthy volunteers and cardiac surgery patients.

Subjects who are male healthy volunteers (aged 20-45) or who are scheduled to receive cardiac surgery (aged 20-80) will undergo ischemic conditioning, consisting of 4 cycles of 5-min ischemia with pressure of 200 mmHg on upper extremity followed by 5-min reperfusion with no pressure. During ischemic conditioning, changes in tissue microcirculation (baseline tissue saturation, occlusion slope during ischemia, and recovery slope during reperfusion) will be observed using tissue oxygen saturation sensor attached to the thenar muscle of the hand. For cardiac surgery patients, the study will be conducted before anesthesia induction on the surgery day to exclude any potential effect of anesthetics.

Conditions