Changes in Tissue Microcirculation During Ischemic Conditioning: Pilot Study

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.

Study Overview

• Status: Completed
• Conditions: Microcirculation
• Intervention / Treatment: Procedure: ischemic conditioning

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 03080
    • Seoul National University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

<Healthy volunteers>

Inclusion Criteria:

• Age 20-45
• No underlying chronic disease
• Male volunteer

Exclusion Criteria:

• Under taking prescription drugs
• Taking herbal medicines within 2 weeks
• Baseline systolic blood pressure > 150 mmHg or diastolic pressure > 100 mmHg
• Body mass index < 18 kg/m^2 or > 30 kg/m^2
• Vigorous exercise, excessive alcohol, smoking or caffeine within 24 hours
• Any abnormalities on upper extremities
• Do not consent to participate

<Cardiac surgery patients>

Inclusion Criteria:

• Age 20-80
• Scheduled for cardiac surgery

Exclusion Criteria:

• Baseline systolic blood pressure > 150 mmHg or diastolic pressure > 100 mmHg
• Body mass index < 18 kg/m^2 or > 30 kg/m^2
• Uncontrolled diabetes
• Under taking beta-blockers
• Severe renal dysfunction, chronic kidney disease, on hemodialysis
• Any abnormalities on upper extremities (i.e, AV fistula on arms)
• Peripheral vascular disease, peripheral neuropathy, coagulopathy
• Vigorous exercise, excessive alcohol, smoking or caffeine within 24 hours
• Pregnant
• Emergency surgery
• Do not consent to participate

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Healthy volunteers; Healthy male volunteers will receive ischemic conditioning (4 cycles of 5-min ischemia followed by 5-min reperfusion on upper extremity) while measuring changes in tissue microcirculation at the thenar muscle.	Procedure: ischemic conditioning; Four cycles of 5-min inflation of pneumatic cuff on upper extremity up to 200 mmHg, followed by 5-min deflation with no pressure.
Active Comparator: Cardiac surgery patients; Patients scheduled for cardiac surgery will receive ischemic conditioning (4 cycles of 5-min ischemia followed by 5-min reperfusion on upper extremity) while measuring changes in tissue microcirculation at the thenar muscle.	Procedure: ischemic conditioning; Four cycles of 5-min inflation of pneumatic cuff on upper extremity up to 200 mmHg, followed by 5-min deflation with no pressure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in microcirculation during ischemic conditioning	Changes in occlusion slope during ischemia and recovery slope during reperfusion	During 4-cycles of 5-min ischemia followed by 5-min reperfusion

Collaborators and Investigators

• Sponsor: Seoul National University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 23, 2017
• Primary Completion (Actual): July 10, 2017
• Study Completion (Actual): July 10, 2017

Study Registration Dates

• First Submitted: March 14, 2017
• First Submitted That Met QC Criteria: March 20, 2017
• First Posted (Actual): March 24, 2017

Study Record Updates

• Last Update Posted (Actual): February 28, 2018
• Last Update Submitted That Met QC Criteria: February 26, 2018
• Last Verified: February 1, 2018

More Information

Terms related to this study

• Keywords: tissue oxygen saturation, ischemic conditioning
• Additional Relevant MeSH Terms: Pathologic Processes; Ischemia
• Other Study ID Numbers: RIPC-VOT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No